U.S. patent application number 10/880028 was filed with the patent office on 2005-07-28 for modified binding molecules comprising connecting peptides.
This patent application is currently assigned to Biogen Idec MA Inc.. Invention is credited to Chinn, Paul, Glaser, Scott, Reff, Mitchell, Wu, Xiufeng, Yang, Tzung-Horng.
Application Number | 20050163782 10/880028 |
Document ID | / |
Family ID | 33556653 |
Filed Date | 2005-07-28 |
United States Patent
Application |
20050163782 |
Kind Code |
A1 |
Glaser, Scott ; et
al. |
July 28, 2005 |
Modified binding molecules comprising connecting peptides
Abstract
The instant invention describes methods of separating or
preferentially synthesizing dimers which are linked via at least
one interchain disulfide linkage from dimers which are not linked
via at least one interchain disulfide linkage from a mixture
comprising the two types of polypeptide dimers. These forms can be
separated from each other using hydrophobic interaction
chromatography. In addition, the invention pertains to connecting
peptides that result in the preferential biosynthesis of dimers
that are linked via at least one interchain disulfide linkage or
that are not linked via at least one interchain disulfide linkage.
The invention also pertains to compositions in which a majority of
the dimers are linked via at least one interchain disulfide linkage
or are not linked via at least one interchain disulfide linkage.
The invention still further pertains to novel binding molecules,
e.g., comprising connecting peptides of the invention.
Inventors: |
Glaser, Scott; (San Diego,
CA) ; Reff, Mitchell; (San Diego, CA) ; Yang,
Tzung-Horng; (San Diego, CA) ; Wu, Xiufeng;
(San Diego, CA) ; Chinn, Paul; (Carlsbad,
CA) |
Correspondence
Address: |
LAHIVE & COCKFIELD, LLP.
28 STATE STREET
BOSTON
MA
02109
US
|
Assignee: |
Biogen Idec MA Inc.
Cambridge
MA
|
Family ID: |
33556653 |
Appl. No.: |
10/880028 |
Filed: |
June 28, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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60483877 |
Jun 27, 2003 |
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60508810 |
Oct 3, 2003 |
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60515351 |
Oct 28, 2003 |
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60516030 |
Oct 30, 2003 |
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Current U.S.
Class: |
424/155.1 ;
435/320.1; 435/344; 435/69.1; 530/388.8; 536/23.53 |
Current CPC
Class: |
A61P 3/10 20180101; A61P
7/06 20180101; C07K 2319/00 20130101; A61P 7/02 20180101; A61P 9/10
20180101; A61P 9/14 20180101; A61P 15/08 20180101; C07K 2317/24
20130101; A61P 1/04 20180101; A61P 17/00 20180101; A61P 37/00
20180101; C07K 16/00 20130101; A61P 13/02 20180101; A61P 25/08
20180101; A61P 17/04 20180101; A61P 31/04 20180101; A61P 35/02
20180101; A61P 21/04 20180101; A61P 11/02 20180101; C07K 2317/53
20130101; A61P 3/00 20180101; A61P 35/00 20180101; A61P 1/16
20180101; A61P 31/12 20180101; A61P 7/04 20180101; C07K 16/2896
20130101; A61P 21/00 20180101; C07K 2317/622 20130101; A61P 37/02
20180101; C07K 2317/624 20130101; A61P 27/02 20180101; A61P 11/00
20180101; A61K 2039/505 20130101; A61P 19/02 20180101; A61P 25/00
20180101; A61P 29/00 20180101; A61P 5/14 20180101; A61P 17/02
20180101; A61P 17/06 20180101; A61P 17/14 20180101; C07K 16/30
20130101; A61P 37/06 20180101; A61P 43/00 20180101; C07K 16/2851
20130101; A61P 31/10 20180101; C07K 16/18 20130101; A61P 11/06
20180101; A61P 35/04 20180101; A61P 13/12 20180101; A61P 3/04
20180101; A61P 9/00 20180101; A61P 7/00 20180101; A61P 5/00
20180101; C07K 2317/52 20130101; A61P 15/00 20180101; A61P 37/08
20180101 |
Class at
Publication: |
424/155.1 ;
435/069.1; 435/320.1; 435/344; 530/388.8; 536/023.53 |
International
Class: |
A61K 039/395; C07H
021/04; C07K 016/30; C12N 005/06 |
Claims
What is claimed is:
1. A composition comprising polypeptide dimers comprising at least
four binding sites and at least two polypeptide chains, wherein
said at least two polypeptide chains comprise at least one heavy
chain portion and a synthetic connecting peptide, and wherein
greater than about 50% of the dimers comprise polypeptide chains
that are linked via at least one interchain disulfide linkage.
2. The composition of claim 1 wherein greater than about 90% of the
dimers are linked via at least one interchain disulfide
linkage.
3. The composition of claim 1 wherein at least one of the
polypeptide chains comprises a CH3 domain linked to a VL, VH or CH1
domain via the connecting peptide.
4. The composition of claim 1, wherein the polypeptide chains lack
all or part of a CH2 domain.
5. The composition of claim 1, wherein the dimers are linked via
two or more interchain disulfide linkages.
6. The composition of claim 1, wherein the heavy chain portion is
derived from an antibody of an isotype selected from the group
consisting of: IgG1, IgG2, IgG3, and IgG4.
7. The composition of claim 6, wherein the heavy chain portion
comprises an amino acid sequence derived from a hinge region
selected from the group consisting of: a .gamma.1 hinge, a .gamma.2
hinge a .gamma.3 hinge, and a .gamma.4 hinge.
8. The composition of claim 1, wherein the molecules are
bispecific.
9. The composition of claim 1, wherein the molecules comprise at
least one binding site specific for a soluble ligand.
10. The composition of claim 1, wherein the molecules comprise at
least one binding site specific for a cell surface molecule.
11. The composition of claim 1, wherein the molecules comprise two
binding sites specific for a tumor cell antigen and two binding
sites specific for a prodrug.
12. The composition of claim 11, wherein the binding sites specific
for the prodrug are catalytic.
13. The composition of claim 1, wherein the synthetic connecting
peptide comprises a proline residue at position 243, Kabat
numbering system.
14. The composition of claim 13, wherein the synthetic connecting
peptide further comprises an alanine residue at position 244 and a
proline residue at position 245, Kabat numbering system.
15. The composition of claim 1, wherein the heavy chain portion
comprises a chimeric hinge.
16. The composition of claim 1, wherein the synthetic connecting
peptide comprises at least a portion of an IgG1 hinge domain, at
least a portion of an IgG3 hinge domain.
17. The composition of claim 1, wherein the connecting peptide
comprises an amino acid sequence selected from the group consisting
of: SEQ ID NOs: 8-15 and 48.
18. A method of treating a subject that would benefit from
treatment with an antigen binding molecule comprising administering
a composition of claim 1 to the subject such that treatment
occurs.
19. The method of claim 18, wherein the subject is suffering from
cancer.
20. The method of claim 18, wherein the subject is suffering from
lymphoma.
21. The method of claim 18, wherein the subject is suffering from
an autoimmune disease or disorder.
22. The method of claim 18, wherein the subject is suffering from
an inflammatory disease or disorder.
23. A nucleic acid molecule comprising a nucleotide sequence
encoding a polypeptide chain of claim 1.
24. The composition of claim 1, wherein the polypeptide dimers
comprise four polypeptide chains and wherein two of the polypeptide
chains comprise at least one heavy chain portion and a synthetic
connecting peptide.
25. A nucleic acid molecule comprising a nucleotide sequence shown
in FIG. 8B (SEQ ID NO: 17)
26. A nucleic acid molecule comprising a nucleotide sequence shown
in FIG. 8C (SEQ ID NO: 18)
27. A nucleic acid molecule comprising a nucleotide sequence shown
in FIG. 10B (SEQ ID NO: 23)
28. A nucleic acid molecule comprising a nucleotide sequence shown
in FIG. 12A (SEQ ID NO:26).
29. A nucleic acid molecule comprising a nucleotide sequence shown
in FIG. 12B (SEQ ID NO:27).
30. A nucleic acid molecule comprising a nucleotide sequence shown
in FIG. 14 (SEQ ID NO:30).
31. A nucleic acid molecule comprising a nucleotide sequence shown
in FIG. 15 (SEQ ID NO:31).
32. The nucleic acid molecule of any one of claims 24-30 which is
in a vector.
33. A host cell comprising the vector of claim 32.
34. A binding molecule comprising the amino acid sequence of FIG.
9B (SEQ ID NO: 20).
35. A binding molecule comprising the amino acid sequence of FIG.
9C (SEQ ID NO: 21).
36. A binding molecule comprising the amino acid sequence of FIG.
11B (SEQ ID NO: 25).
37. A binding molecule comprising the amino acid sequence of FIG.
13A (SEQ ID NO: 28).
38. A binding molecule comprising the amino acid sequence of FIG.
13B (SEQ ID NO: 29).
39. An binding molecule comprising the amino acid sequence of FIG.
16 (SEQ ID NO: 32).
40. A binding molecule comprising the amino acid sequence of FIG.
17 (SEQ ID NO: 33).
41. The composition of claim 1, wherein said binding sites are
individually selected from the group consisting of: an antigen
binding site, a ligand binding portion of a receptor, and a
receptor binding portion of a ligand.
42. The method of claim 41, wherein the polypeptide chains have at
least one binding site derived from an antibody selected from the
group consisting of: 2B8, Lym 1, Lym 2, LL2, Her2, B1, MB1, BH3,
B4, B72.3, CC49, 5E8, B3F6, and 5E10.
43. The composition of claim 1, wherein the polypeptide dimers are
tetravalent minibody molecules.
44. The composition of claim 1, wherein the polypeptide dimers are
tetravalent domain deleted antibody molecules.
45. The composition of claim 1, wherein the polypeptide dimers are
diabodies.
46. A composition comprising minibody molecules comprising two
polypeptide chains, wherein the polypeptide chains comprise a heavy
chain portion and a synthetic connecting peptide, wherein the
polypeptide chains lack all or part of a CH2 domain, and wherein
greater than about 50% of the molecules are present in a form in
which one of the polypeptide chains are linked via at least one
interchain disulfide linkage.
47. The composition of claim 46, wherein greater than about 90% of
the dimers are linked via at least one interchain disulfide
linkage.
48. The composition of claim 46 wherein at least one of the
polypeptide chains comprises a CH3 domain genetically fused to a
VL, VH or CH1 domain via the connecting peptide.
49. The composition of claim 46, wherein the polypeptide chains
lack the entire CH2 domain.
50. The composition of claim 46, wherein the dimers are linked via
two or more interchain disulfide linkages.
51. The composition of claim 46, wherein a heavy chain portion is
derived from an antibody of an isotype selected from the group
consisting of: IgG1, IgG2, IgG3, and IgG4.
52. The composition of claim 46, wherein the heavy chain portion
comprises an amino acid sequence is derived from a hinge region
selected from the group consisting of: a .gamma.1 hinge, a .gamma.2
hinge a .gamma.3 hinge, and a .gamma.4 hinge.
53. The composition of claim 46, wherein said binding sites are
individually selected from the group consisting of: an antigen
binding site, a ligand binding portion of a receptor, and a
receptor binding portion of a ligand.
54. The composition of claim 46, wherein the molecules are
bispecific.
55. The composition of claim 46, wherein the connecting peptide
comprises a proline residue at position 243, Kabat numbering
system.
56. The composition of claim 46, wherein the synthetic connecting
peptide comprises a chimeric hinge.
57. The composition of claim 46, wherein the synthetic connecting
peptide comprises at least a portion of an IgG1 hinge domain, at
least a portion of an IgG3 hinge domain.
58. A method of treating a subject that would benefit from
treatment with an antigen binding molecule comprising administering
a composition of claim 45 to the subject such that treatment
occurs.
59. A nucleic acid molecule comprising a nucleotide sequence
encoding a polypeptide chain of claim 46.
60. A composition comprising polypeptide dimers having at least
four binding sites and at least two polypeptide chains, wherein
said at least two polypeptide chains comprise at least one heavy
chain portion and lack all or part of a CH2 domain, wherein greater
than 50% of the polypeptide dimers comprise polypeptide chains that
are linked via at least one interchain disulfide linkage.
Description
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Ser. No. 60/483877,
titled "Purification and Preferential Synthesis of Polypeptides,"
filed on Jun. 27, 2003 and to U.S. Ser. No. 60/508,810, titled
"Purification and Preferential Synthesis of Antigen Binding
Polypeptides," filed Oct. 3, 2003. This application also claims
priority to U.S. Ser. No. 60/515,351, titled "Modified Antibody
Molecules Comprising Connecting Peptides," Oct. 28, 2003 and to
U.S. Ser. No. 60/516,030, titled "Modified Antibody Molecules
Comprising Connecting Peptides," filed Oct. 30, 2003. This
application is also related to U.S. Ser. No. XX/XXXXXX, titled
"Purification and preferential synthesis of Binding Polypeptides"
filed on Jun. 28, 2004. The contents of these applications are
incorporated in their entirety by this reference.
BACKGROUND OF THE INVENTION
[0002] Antibodies are dimeric molecules; each monomer making up the
dimer comprises one light and one heavy chain. Solutions of
antibody molecules exist in two forms associated with hinge
heterogeneity. Using SDS-PAGE analysis of purified Mab MAb,
typically the two forms are observed as two protein bands, a major
band (MW approximately 150-160 kDa) and a minor band (MW
approximately 75-80 kDa). This latter form is typically observed
after SDS-PAGE analysis of purified IgG4 preparations, but can be
identified at much lower frequencies in all IgG isotypes, including
purified, recombinant MAbs (Angal et al. 1993. Mol. Immunol.
30:105; Norderhaug et al. 1990. Eur. J Immunol. 21:2370). The
larger molecular weight isoform, referred to as Form A, contains
covalent interchain disulfide bonds at positions corresponding to
239 and 242, Kabat numbering system (positions 226 and 229, EU
numbering system) (Kabat, E, Wu, T T, Perry, H M, Gottesman, K S,
Foeller, C: Sequences of Proteins of Immunological Interest.
Bethesda, US Department of Health and Human Services, NIH, 1991).
The second isoform, Form B, is thought to contain no covalent
linkages between the two heavy chains and an intrachain disulfide
bond between the two neighboring cysteine residues as evidenced by
the 75-80 kDa seen in non-reducing SDS-PAGE electrophoresis. The
two heavy chains of Form B are presumably held together by strong
non-covalent (e.g., ionic) interactions associated with the CH3
domain region of the molecule. These mixtures of A and B forms are
not present in solutions of MAb fragments that contain an intact
hinge, but lack a CH3 domain, such as, for example, F(ab).sub.2
fragments. Typically, genetically engineered or enzymatically
digested F(ab).sub.2 MAb preparations lack the B-form, since the
molecule lacks the necessary domains for maintaining non-covalent
interactions (e.g., hydrogen bonding). However, they are present in
MAb preparations that do contain a CH3 domain, such as IgG4, CH2
domain deleted MAb fragments (e.g., as described in 02/060955 A2)
and minibodies (see, e.g., Hu et al. 1996. Cancer Research
56:3055).
[0003] The application of protein engineering techniques to
therapeutic antibody design has also produced a number of antibody
formats that have been shown to have altered, and in some cases,
improved pharmacodynamic, biodistribution, and activity profiles.
Some altered antibody molecules have been made in which the number
of cysteine residues in the hinge region is reduced to one to
facilitate assembly of antibody molecules as it is only necessary
to form a single disulfide bond. This also provides a specific
target for attaching the hinge region either to another hinge
region or to an effector or reporter molecule (U.S. Pat. No.
5,677,425). The number of cysteine residues in the antibody hinge
has also been increased (U.S. Pat. No. 5,677,425). Other mutated
antibodies have been constructed in which the IgGl hinge region and
the CH2 domain have been replaced with the human IgG3 hinge region.
(WO 97/11370). These molecules contain 11 sulfhydryl groups for
substitution of multiple haptens via thiol groups.
[0004] CH2 domain deleted antibodies have a molecular mass of
approximately 120 kDa and have been shown to penetrate tumors
significantly better than full length IgG. Minibodies, which also
have deletion of the CH2 domain, have similar characteristics.
These domain deleted molecules accumulate at tumor sites more
efficiently than other MAb fragments, such as F(ab)'.sub.2s, but
without the unfavorable pharmacodynamic profiles seen with intact
IgG antibody. CH2 domain deleted antibodies consist of a VLCL light
chain and a VH1 heavy chain domain and a portion of the hinge
region (e.g., the upper and middle hinge) genetically fused (either
directly or through a modified peptide spacer) to a CH3 domain. As
an example, the biosynthesis of recombinant CH2 domain deleted
ddCC49, a domain deleted antibody that recognizes the tumor
associated TAG72 antigen expressed on a variety of human
carcinomas, produces the A and B isoforms in approximately 50:50
distribution in cell cultures. Cells engineered to express
alternative forms of CH2 domain deleted antibodies, for example,
tetravalent CH2 domain deleted antibodies, minibodies, or
tetravalent minibodies also express a mixture consisting of A and B
isoforms and/or monomeric half-mer molecules.
[0005] Form A and Form B are extremely difficult to separate even
after MAb purification, since they are composed of identical amino
acids and, therefore, have identical molecular weight and similar
physical and chemical properties. They cannot be separated by
standard gel filtration, affinity chromatography, or ion exchange
chromatography typically used to purify antibody molecules,
including recombinant MAb proteins. Current manufacturing processes
discard at least 50% of the total antibody produced, having a
negative impact on overall yield. Moreover, the presence of the two
isoforms increases efforts required for downstream processing.
Thus, a method of separating forms A and B or of increasing
biosynthesis of one or the other form of antibody would be of great
benefit.
SUMMARY OF THE INVENTION
[0006] The invention is based, at least in part, on the finding
that in a composition comprising a mixture of dimeric polypeptide
molecules comprising different isoforms (molecules comprising two
heavy chain portions in which a fraction of the molecules comprise
two heavy chain portions that are linked via at least one
interchain disulfide linkage (Form A) and a portion of the
molecules comprise two heavy chain portions that are not linked via
at least one interchain disulfide linkage (Form B)) one form or the
other can be preferentially obtained, e.g., by separation using
hydrophobic interaction chromatography or by inclusion of synthetic
connecting peptides which result in the preferential biosynthesis
of either Form A or Form B.
[0007] In one embodiment, the binding molecules of the invention
are tetravalent. The connecting peptides of the invention can be
included in any dimeric molecule that tends to form both Form A and
Form B, e.g., antibody molecules, domain deleted antibody molecules
(e.g., lacking all or part of a CH2 domain), minibodies, diabodies,
fusion proteins, etc. In a preferred embodiment, the formation of
Form A is enhanced.
[0008] In another embodiment, the invention pertains to a
composition comprising polypeptide dimers comprising at least four
binding sites and at least two polypeptide chains, wherein said at
least two polypeptide chains comprise at least one heavy chain
portion and a synthetic connecting peptide, and wherein greater
than about 50% of the dimers are linked via at least one interchain
disulfide linkage.
[0009] In another embodiment, greater than about 90% of the dimers
are linked via at least one interchain disulfide linkage.
[0010] In another embodiment, at least one of the polypeptide
chains comprises a CH3 domain linked to a VL, VH or CH1 domain via
the connecting peptide.
[0011] In another embodiment, the polypeptide chains lack all or
part of a CH2 domain.
[0012] In another embodiment, the dimers are linked via two or more
interchain disulfide linkages.
[0013] In another embodiment, the heavy chain portion is derived
from an antibody of an isotype selected from the group consisting
of: IgG1, IgG2, IgG3, and IgG4.
[0014] In another embodiment, the heavy chain portion comprises an
amino acid sequence derived from a hinge region selected from the
group consisting of: a .gamma.1 hinge, a .gamma.2 hinge, a .gamma.3
hinge, and a .gamma.4 hinge.
[0015] In another embodiment, the molecules are bispecific.
[0016] In another embodiment, the molecules comprise at least one
binding site specific for a soluble ligand.
[0017] In another embodiment, the molecules comprise at least one
binding site specific for a cell surface molecule.
[0018] In another embodiment, the molecules comprise two binding
sites specific for a tumor cell antigen and two binding sites
specific for a prodrug.
[0019] In another embodiment, the binding sites specific for the
prodrug are catalytic.
[0020] In another embodiment, the synthetic connecting peptide
comprises a proline residue at position 243, Kabat numbering
system.
[0021] In another embodiment, the synthetic connecting peptide
further comprises an alanine residue at position 244 and a proline
residue at position 245, Kabat numbering system.
[0022] In another embodiment, the heavy chain portion comprises a
chimeric hinge.
[0023] In another embodiment, the synthetic connecting peptide
comprises at least a portion of an IgG1 hinge domain, at least a
portion of an IgG3 hinge domain.
[0024] In another embodiment, the connecting peptide comprises an
amino acid sequence selected from the group consisting of: SEQ ID
NOs: 8-15 and 48.
[0025] In a second aspect, the invention provides a method of
treating a subject that would benefit from treatment with an
antigen binding molecule comprising administering to the subject a
composition comprising a mixture of dimeric polypeptide molecules
comprising different isoforms, wherein one isoform or the other is
preferentially obtained, such that treatment occurs.
[0026] In one embodiment, the subject is suffering from cancer.
[0027] In another embodiment, the subject is suffering from
lymphoma.
[0028] In another embodiment, the subject is suffering from an
autoimmune disease or disorder.
[0029] In another embodiment, the subject is suffering from an
inflammatory disease or disorder.
[0030] In a third aspect, the invention provides a nucleic acid
molecule comprising a nucleotide sequence encoding a polypeptide
molecule comprising different isoforms (molecules comprising two
heavy chain portions in which a fraction of the molecules comprise
two heavy chain portions that are linked via at least one
interchain disulfide linkage (Form A) and a portion of the
molecules comprise two heavy chain portions that are not linked via
at least one interchain disulfide linkage (Form B)) such that one
form or the other can be preferentially obtained.
[0031] In one embodiment, the polypeptide dimers comprise four
polypeptide chains and wherein two of the polypeptide chains
comprise at least one heavy chain portion and a synthetic
connecting peptide.
[0032] In another embodiment, the nucleic acid molecule comprises a
nucleotide sequence shown in FIG. 8B (SEQ ID NO: 17).
[0033] In another embodiment, the nucleic acid molecule comprises a
nucleotide sequence shown in FIG. 8C (SEQ ID NO: 18).
[0034] In another embodiment, the nucleic acid molecule comprises a
nucleotide sequence shown in FIG. 10B (SEQ ID NO: 23).
[0035] In another embodiment, the nucleic acid molecule comprises a
nucleotide sequence shown in FIG. 12A (SEQ ID NO:26).
[0036] In another embodiment, the nucleic acid molecule comprises a
nucleotide sequence shown in FIG. 12B (SEQ ID NO:27).
[0037] In another embodiment, the nucleic acid molecule comprises a
nucleotide sequence shown in FIG. 14 (SEQ ID NO:30).
[0038] In another embodiment, the nucleic acid molecule comprises a
nucleotide sequence shown in FIG. 15 (SEQ ID NO:31).
[0039] In another embodiment, the nucleic acid molecule is in a
vector. In still another embodiment, the vector is in a host
cell.
[0040] In a fourth aspect, the invention provides binding molecules
comprising an amino acid sequence encoding a polypeptide molecule
comprising different isoforms (molecules comprising two heavy chain
portions in which a fraction of the molecules comprise two heavy
chain portions that are linked via at least one interchain
disulfide linkage (Form A) and a portion of the molecules comprise
two heavy chain portions that are not linked via at least one
interchain disulfide linkage (Form B)) such that one form or the
other can be preferentially obtained.
[0041] In one embodiment, the binding molecule comprises the amino
acid sequence of FIG. 9B (SEQ ID NO: 20).
[0042] In another embodiment, the binding molecule comprises the
amino acid sequence of FIG. 9C (SEQ ID NO: 21).
[0043] In another embodiment, the binding molecule comprises the
amino acid sequence of FIG. 11B (SEQ ID NO: 25).
[0044] In another embodiment, the binding molecule comprises the
amino acid sequence of FIG. 13A (SEQ ID NO: 28).
[0045] In another embodiment, the binding molecule comprises the
amino acid sequence of FIG. 13B (SEQ ID NO: 29).
[0046] In another embodiment, the binding molecule comprises the
amino acid sequence of FIG. 16 (SEQ ID NO: 32).
[0047] In another embodiment, the binding molecule comprises the
amino acid sequence of FIG. 17 (SEQ ID NO: 33).
[0048] In a fifth aspect, the invention provides a composition
comprising a mixture of dimeric polypeptide molecules comprising
different isoforms (molecules comprising two heavy chain portions
in which a fraction of the molecules comprise two heavy chain
portions that are linked via at least one interchain disulfide
linkage (Form A) and a portion of the molecules comprise two heavy
chain portions that are not linked via at least one interchain
disulfide linkage (Form B)) one form or the other can be
preferentially obtained, and wherein said binding sites are
individually selected from the group consisting of: an antigen
binding site, a ligand binding portion of a receptor, and a
receptor binding portion of a ligand.
[0049] In one embodiment, the polypeptide chains have at least one
binding site derived from an antibody selected from the group
consisting of: 2B8, Lym 1, Lym 2, LL2, Her2, B1, MB1 BH3, B4,
B72.3, CC49, 5E8, B3F6, and 5E10.
[0050] In another embodiment, the polypeptide dimers are
tetravalent minibody molecules.
[0051] In another embodiment, the polypeptide dimers are
tetravalent domain deleted antibody molecules.
[0052] In another embodiment, the polypeptide dimers are
diabodies.
[0053] In a sixth aspect, the invention provides a composition
comprising minibody molecules comprising two polypeptide chains,
wherein the polypeptide chains comprise a heavy chain portion and a
synthetic connecting peptide, wherein the polypeptide chains lack
all or part of a CH2 domain, and wherein greater than about 50% of
the molecules are present in a form in which one of the polypeptide
chains are linked via at least one interchain disulfide
linkage.
[0054] In one embodiment, greater than about 90% of the dimers are
linked via at least one interchain disulfide linkage.
[0055] In another embodiment, at least one of the polypeptide
chains comprises a CH3 domain genetically fused to a VL, VH or CH1
domain via the connecting peptide.
[0056] In another embodiment, the polypeptide chains lack the
entire CH2 domain.
[0057] In another embodiment, the dimers are linked via two or more
interchain disulfide linkages.
[0058] In another embodiment, the heavy chain portion is derived
from an antibody of an isotype selected from the group consisting
of: IgG1, IgG2, IgG3, and IgG4.
[0059] In another embodiment, the heavy chain portion comprises an
amino acid sequence is derived from a hinge region selected from
the group consisting of: a .gamma.1 hinge, a .gamma.2 hinge a
.gamma.3 hinge, and a .gamma.4 hinge.
[0060] In another embodiment, the binding sites are individually
selected from the group consisting of: an antigen binding site, a
ligand binding portion of a receptor, and a receptor binding
portion of a ligand.
[0061] In another embodiment, the molecules are bispecific.
[0062] In another embodiment, the connecting peptide comprises a
proline residue at position 243, Kabat numbering system.
[0063] In another embodiment, the synthetic connecting peptide
comprises a chimeric hinge.
[0064] In another embodiment, the synthetic connecting peptide
comprises at least a portion of an IgG1 hinge domain, at least a
portion of an IgG3 hinge domain.
[0065] In a seventh aspect, the invention provides a method of
treating a subject that would benefit from treatment with an
antigen binding molecule comprising administering to the subject a
composition comprising minibody molecules comprising two
polypeptide chains, wherein the polypeptide chains comprise a heavy
chain portion and a synthetic connecting peptide, wherein the
polypeptide chains lack all or part of a CH2 domain, and wherein
greater than about 50% of the molecules are present in a form in
which one of the polypeptide chains are linked via at least one
interchain disulfide linkage, such that treatment occurs.
[0066] In another aspect, the invention provides a nucleic acid
molecule comprising a nucleotide sequence encoding a polypeptide
chain comprising a heavy chain portion and a synthetic connecting
peptide, wherein the polypeptide chains lack all or part of a CH2
domain, and wherein greater than about 50% of the molecules are
present in a form in which one of the polypeptide chains are linked
via at least one interchain disulfide linkage.
[0067] In still another aspect, the invention provides a
composition comprising polypeptide dimers having at least four
binding sites and at least two polypeptide chains, wherein said at
least two polypeptide chains comprise at least one heavy chain
portion and lacks all or part of a CH2 domain, wherein greater than
50% of the polypeptide dimers are linked via at least one
interchain disulfide linkage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0068] FIG. 1 shows Form A which appears as a 120 kDa dimer and
Form B which appears as a 60 kDa monomer in domain deleted
antibodies.
[0069] FIG. 2 shows a schematic diagram of an exemplary two chain
dimeric minibody and an exemplary two chain dimeric tetravalent
minibody each comprising a hinge connecting peptide (HCP). Other
configurations are also possible, for example, the two chain
dimeric tetravalent minibody comprising a connecting peptide (HCP)
can also be constructed to be bispecific. In another embodiment,
the orientation of the VH and VL domains in the scFv may be
changed.
[0070] FIG. 3 shows a schematic diagram of a four chain dimeric
diabody comprising a hinge connecting peptide (HCP). The four chain
dimeric diabody comprising a hinge connecting peptide (HCP) can
also be constructed to be bispecific. The orientation of the VH and
VL domains may be changed.
[0071] FIG. 4 shows a schematic diagram of a four chain dimeric
tetravalent scFv antibody (C-scFv tetravalent antibody) and a four
chain tetravalent scFv CH2 domain deleted antibody (C-scFv
tetravalent CH2 domain deleted antibody) each comprising a scFv
appended to the carboxyl terminus of CH3 and a hinge connecting
peptide. The orientation of the VH and VL domains in the scFv may
be changed.
[0072] FIG. 5 shows a schematic diagram of a four chain dimeric CH2
domain deleted tetravalent (N.sub.L-scFv CH2 domain deleted
tetravalent) antibody comprising a hinge connecting peptide (HCP).
The four chain dimeric CH2 domain deleted tetravalent antibody
comprising a connecting peptide (HCP) can also be constructed to be
bispecific. The orientation of the VH and VL domains in the scFv
appended to the light chain may be changed.
[0073] FIG. 6 shows a schematic diagram of a four chain dimeric CH2
domain deleted tetravalent (N.sub.H-scFv CH2 domain deleted
tetravalent) antibody comprising a hinge connecting peptide (HCP).
The four chain dimeric CH2 domain deleted tetravalent antibody
comprising a connecting peptide (HCP) can also be constructed to be
bispecific. The orientation of the VH and VL domains in the scFv
appended to the heavy chain may be changed.
[0074] FIG. 7 shows a schematic diagram of a two chain dimeric
tetravalent minibody (C-scFv tetravalent minibody) comprising a
hinge connecting peptide (HCP). The two chain dimeric tetravalent
minibody comprising a connecting peptide (HCP) can also be
constructed to be bispecific. The orientation of the VH and VL
domains in both scFvs may be changed.
[0075] FIG. 8A (SEQ ID NO: 16) shows the single-stranded DNA
sequence of heavy chain CH2 domain-deleted sc(Fv)2 tetravalent
(C-scFv tetravalent CH2 domain deleted) huCC49 gene. FIG. 8B (SEQ
ID NO:17) shows the single-stranded DNA sequence of heavy chain
tetravalent CH2 domain-deleted sc(Fv)2 tetravalent (C-scFv
tetravalent CH2 domain deleted) huCC49 gene containing the
synthetic G1/G3:/Pro243Ala244Pro245+[- Gly/Ser] hinge connecting
peptide. FIG. 8C (SEQ ID NO: 18) shows the single-stranded DNA
sequence of light chain CH2 domain-deleted sc(Fv)2 tetravalent
(C-scFv tetravalent CH2 domain deleted) huCC49.
[0076] FIG. 9A (SEQ ID NO:19) shows the amino acid sequence of
heavy chainCH2 domain-deleted sc(Fv)2 tetravalent (C-scFv
tetravalent CH2 domain deleted) huCC49. FIG. 9B (SEQ ID NO:20)
shows the amino acid sequence of heavy chain CH2 domain-deleted
sc(Fv)2 tetravalent (C-scFv tetravalent CH2 domain deleted) huCC49
containing the synthetic G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge
connecting peptide. FIG. 9C (SEQ ID NO:21) shows the amino acid
sequence of light chain CH2 domain-deleted sc(Fv)2 tetravalent
(C-scFv tetravalent CH2 domain deleted) huCC49
[0077] FIG. 10A (SEQ ID NO:22) shows the single-stranded DNA
sequence of CH2 domain-deleted huCC49 tetravalent (N-scFv
tetravalent) minibody gene. FIG. 10B (SEQ ID NO:23) shows the
single-stranded DNA sequence of tetravalent CH2 domain-deleted
(N-scFv tetravalent) huCC49 tetravalent minibody gene containing
the synthetic G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting
peptide.
[0078] FIG. 11A (SEQ ID NO:24) shows the amino acid sequence of
tetravalent CH2 domain-deleted (N-scFv tetravalent) huCC49
minibody. FIG. 11B (SEQ ID NO:25) shows the amino acid sequence of
tetravalent CH2 domain-deleted (N-scFv tetravalent) huCC49 minibody
containing the synthetic G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge
connecting peptide.
[0079] FIG. 12A (SEQ ID NO:26) shows the single-stranded DNA
sequence of heavy chain tetravalent CH2 domain-deleted
PRIMATIZED.RTM. p5E8 sc(Fv)2 (C-scFv tetravalent CH2 domain
deleted) antibody gene containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting peptide.
[0080] FIG. 12B (SEQ ID NO:27) shows the single-stranded DNA
sequence of light chain tetravalent CH2 domain-deleted (C-scFv
tetravalent CH2 domain deleted) PRIMATIZED.RTM. p5E8 sc(Fv)2
gene.
[0081] FIG. 13A (SEQ ID NO:28) shows the amino acid sequence of
heavy chain tetravalent CH2 domain-deleted (C-scFv tetravalent CH2
domain deleted) PRIMATIZED.RTM. p5E8 sc(Fv)2 antibody containing
the G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting
peptide.
[0082] FIG. 13B (SEQ ID NO:29) shows the amino acid sequence of
light chain tetravalent CH2 domain-deleted (C-scFv tetravalent CH2
domain deleted) PRIMATIZED.RTM. p5E8 sc(Fv)2 antibody.
[0083] FIG. 14 (SEQ ID NO:30) shows the single-stranded DNA
sequence of CH2 domain-deleted PRIMATIZED.RTM. p5E8 VL/VH minibody
gene containing the G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge
connecting peptide.
[0084] FIG. 15 (SEQ ID NO:31) shows the single-stranded DNA
sequence of CH2 domain-deleted PRIMATIZED.RTM. p5E8 VH/VL minibody
gene containing the G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge
connecting peptide.
[0085] FIG. 16 (SEQ ID NO:32) shows the amino acid sequence of CH2
domain-deleted PRIMATIZED.RTM. p5E8 VL/VH minibody containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting peptide.
[0086] FIG. 17 (SEQ ID NO:33) shows the amino acid sequence of CH2
domain-deleted PRIMATIZED.RTM. p5E8 VH/VL minibody containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting peptide.
[0087] FIG. 18 shows a Western Blot of supernatants from five
independent clones producing huCC49 domain-deleted sc(Fv)2
tetravalent (C-scFv tetravalent CH2 domain deleted) antibody. Each
supernatant was electrophoresed under both reducing and
non-reducing conditions.
[0088] FIG. 19 shows a Coomassie Blue stained gel of purified Forms
A and B huCC49 domain-deleted sc(Fv)2 tetravalent (C-scFv
tetravalent CH2 domain deleted) antibodies. Each antibody was
electrophoresed under reducing and non-reducing conditions.
[0089] FIG. 20 shows that purified Form A huCC49 domain-deleted
sc(Fv)2 tetravalent (C-scFv tetravalent CH2 domain deleted)
antibody predominantly elutes as a single peak by HPLC
size-exclusion chromatography.
[0090] FIG. 21 shows the results of a competitive binding assay of
Form A huCC49 domain-deleted sc(Fv)2 tetravalent (C-scFv
tetravalent CH2 domain deleted) antibody to bovine submaxillary
mucine, a source of the TAG-72 antigen, by time-resolved
fluorometic immunoassay using a Delphia fluorimeter (Wallac Inc,
Gaithersburg, Md.).
[0091] FIG. 22 shows a Western Blot of supernatant from a
representative clone producing huCC49 CH2 domain-deleted sc(Fv)2
tetravalent (C-scFv tetravalent CH2 domain deleted) antibody
containing the G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting
peptide.
[0092] FIG. 23 shows a Coomassie Blue stained gel of purified Form
A huCC49 CH2 domain-deleted sc(Fv)2 tetravalent G1/G3/PAP (C-scFv
tetravalent CH2 domain deleted) antibody containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting peptide.
[0093] FIG. 24 shows that purified Form A huCC49 CH2 domain-deleted
sc(Fv)2 tetravalent G1/G3/PAP (C-scFv tetravalent CH2 domain
deleted) antibody containing the G1/G3/Pro243Ala244Pro245+[Gly/Ser]
hinge connecting peptide predominantly elutes as a single peak by
HPLC size-exclusion chromatography.
[0094] FIG. 25 shows the results of a competitive binding assay of
Form A huCC49 CH2 domain-deleted sc(Fv)2 tetravalent G1/G3/PAP
(C-scFv tetravalent CH2 domain deleted) antibody containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting peptide to
bovine submaxillary mucine, a source of the TAG-72 antigen, by
time-resolved fluorometic immunoassay using a Delphia fluorimeter
(Wallac Inc, Gaithersburg, Md.).
[0095] FIG. 26 shows Western Blots of supernatants from
representative clones producing huCC49 minibody, huCC49 2 sc(Fv)2
tetravalent antibody (N-scFv tetravalent huCC49 minibody), and
huCC49 CH2 domain deleted antibody. A Western Blot was performed on
supernatants that were electrophoresed under reducing and
non-reducing conditions.
[0096] FIG. 27 shows a Western Blot of supernatants from
representative clones producing huCC49 2 sc(Fv)2 tetravalent
antibody (N-scFv tetravalent huCC49 minibody) and huCC49 2 sc(Fv)2
tetravalent antibody (N-scFv tetravalent huCC49 minibody)
containing the G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting
peptide.
[0097] FIG. 28 shows a Coomassie Blue stained gel of purified Form
A huCC49 domain-deleted sc(Fv)2 tetravalent antibody (N-scFv
tetravalent minibody) containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting peptide.
[0098] FIG. 29 shows purified Form A huCC49 domain-deleted sc(Fv)2
tetravalent antibody (N-scFv tetravalent minibody) containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting peptide
predominantly elutes as a single peak by HPLC size-exclusion
chromatography.
[0099] FIG. 30 shows the results of a competitive binding assay of
huCC49 domain-deleted sc(Fv)2 tetravalent antibody (N-scFv
tetravalent minibody) containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting peptide, huCC49
minibody, huCC49 CH2 domain-deleted sc(Fv)2 tetravalent antibody
(C-scFv tetravalent antibody) containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting peptide, and
control parent CH2 domain-deleted huCC49 (referred to as HuCC49 or
IDEC 159) to bovine submaxillary mucine, a source of the TAG-72
antigen, by time-resolved fluorometic immunoassay using a Delphia
fluorimeter (Wallac Inc, Gaithersburg, Md.).
[0100] FIG. 31 shows a Western Blot of supernatant from a cell line
producing tetravalent CH2 domain-deleted (C-scFv tetravalent CH2
domain deleted) PRIMATIZED.RTM. p5E8 sc(Fv)2 antibody containing
the G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting
peptide.
[0101] FIG. 32 shows a Western Blot of supernatants from five
independent cell lines producing CH2 domain-deleted huCC49 VL/VH
minibody. Minibody samples were analyzed under non-reducing,
denaturing conditions revealing the presence of Form A and Form B
isoforms.
[0102] FIG. 33 show the results of an ELISA binding assay of
PRIMATIZED.RTM. p5E8 VH/VL and VL/VH minibodies containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide binding to
the CD23 antigen. p5E8G1 is intact full length PRIMATIZED.RTM.
IgG1.
[0103] FIG. 34 shows a Western Blot of supernatant from cell lines
producing PRIMATIZED.RTM. p5E8 VH/VL and VL/VH minibodies
containing the G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting
peptide.
[0104] FIG. 35A shows tumor retention for control parent huCC49 and
huCC49 CH2 domain-deleted sc(Fv)2 tetravalent antibody as measured
by % ID/gm. FIG. 35B shows the same tumor retention data normalized
to peak antibody accumulation.
DETAILED DESCRIPTION OF THE INVENTION
[0105] Human immunoglobulins (Igs), including monoclonal antibodies
(MAbs), can exist in two forms that are associated with hinge
heterogeneity. In native solutions, both of these forms are present
as dimeric proteins (each monomer comprising one heavy chain and
one light chain). One immunoglobulin molecule comprises a stable
four chain construct of approximately 150-160 kDa in which the
dimers are held together by an interchain heavy chain disulfide
bond (Form A) and one comprises form in which the dimers are not
linked via interchain disulfide bonds (Form B). Form B also forms a
stable dimer under native conditions, but can be identified under
denaturing, non-reducing conditions, in which the heavy chains
dissociate yielding a 75-80 kDa molecule. These forms have been
extremely difficult to separate, even after MAb affinity
purification.
[0106] The frequency of appearance of the B form in various intact
IgG isotypes is due to, but not limited to, structural differences
associated with the hinge region isotype of the MAb molecule. In
fact, a single amino acid substitution in the hinge region of the
human IgG4 hinge can significantly reduce the appearance of the B
form (Angal et al. 1993. Molecular Immunology 30:105) to levels
typically observed using a human IgG1 hinge. However, applying this
same amino acid substitution to MAb fragments in which the CH3
domain was retained did not eliminate Form B from preparations.
Typically, all recombinant CH2 domain deleted antibodies produced
in cell cultures often result in hinge heterogeneity which is not
corrected via similar molecular mutations in the hinge.
[0107] The instant invention advances the state of the art by
providing methods of, e.g., separating a first dimeric polypeptide
from a second dimeric polypeptide wherein the first and second
polypeptides comprise at least two polypeptide chains and at least
two of the polypeptide chains comprise at least one heavy chain
portion. In one embodiment, the polypeptides of the invention lack
all or part of a CH2 domain. The monomers are linked via at least
one interchain disulfide linkage (referred to herein as "Form A")
and the monomers of the second polypeptide are not linked via at
least one interchain disulfide linkage (referred to herein as "Form
B"). These forms can be separated from each other using hydrophobic
interaction chromatography. In addition, the invention pertains to
polypeptides that comprise connecting peptides. The inclusion of
certain connecting peptides results in the preferential
biosynthesis of polypeptide dimers comprising polypeptide chains
that are linked via at least one interchain disulfide linkage or
that are not linked via at least one interchain disulfide
linkage.
[0108] Before further description of the invention, for
convenience, certain terms are described below:
[0109] I. Definitions
[0110] The polypeptides of the invention are binding molecules,
i.e., polypeptide molecules or the nucleic acid molecules that
encode them, that comprise at least one binding domain which
comprises a binding site that specifically binds to a target
molecule (such as an antigen or binding partner). For example, in
one embodiment, a binding molecule of the invention comprises an
immunoglobulin antigen binding site or the portion of a receptor
molecule responsible for ligand binding or the portion of a ligand
molecule that is responsible for receptor binding. The binding
molecules of the invention are polypeptides or the nucleic acid
molecules which encode them.
[0111] In one embodiment, the binding molecules comprise at least
two binding sites. In one embodiment, the binding molecules
comprise two binding sites. In one embodiment, the binding
molecules comprise three binding sites. In another embodiment, the
binding molecules comprise four binding sites.
[0112] The polypeptides of the invention are multimers. For
example, in one embodiment, the polypeptides of the invention are
dimers. In one embodiment, the dimers of the invention are
homodimers, comprising two identical monomeric subunits. In another
embodiment, the dimers of the invention are heterodimers,
comprising two non-identical monomeric subunits. The subunits of
the dimer may comprise one or more polypeptide chains. For example,
in one embodiment, the dimers comprise at least two polypeptide
chains. In one embodiment, the dimers comprise two polypeptide
chains. In another embodiment, the dimers comprise four polypeptide
chains (e.g., as in the case of antibody molecules).
[0113] The polypeptides of the invention comprise at least one
amino acid sequence derived from an immunoglobulin domain. A
polypeptide or amino acid sequence "derived from" a designated
protein refers to the origin of the polypeptide. Preferably, the
polypeptide or amino acid sequence which is derived from a
particular starting polypeptide or amino acid sequence has an amino
acid sequence that is essentially identical to that of the starting
sequence, or a portion thereof wherein the portion consists of at
least 10-20 amino acids, preferably at least 20-30 amino acids,
more preferably at least 30-50 amino acids, or which is otherwise
identifiable to one of ordinary skill in the art as having its
origin in the starting sequence.
[0114] Preferred binding polypeptides comprise an amino acid
sequence derived from a human amino acid sequence. However, binding
polypeptides may comprise one or more amino acids from another
mammalian species. For example, a primate heavy chain portion,
hinge portion, or binding site may be included in the subject
binding polypeptides and/or connecting polypeptides. Alternatively,
one or more murine amino acids may be present in a binding
polypeptide, e.g., in an antigen binding site of a binding
molecule. Preferred binding molecules of the invention are not
immunogenic.
[0115] It will also be understood by one of ordinary skill in the
art that the binding molecules of the invention (e.g., the heavy
chain or light chain portions or binding portions of the subject
polypeptides) may be modified such that they vary in amino acid
sequence from the naturally occurring immunoglobulin molecule from
which they were derived. For example, nucleotide or amino acid
substitutions leading to conservative substitutions or changes at
"non-essential" amino acid residues may be made.
[0116] An isolated nucleic acid molecule encoding a non-natural
variant of a polypeptide derived from an immunoglobulin (e.g., an
immunoglobulin heavy chain portion or light chain portion) can be
created by introducing one or more nucleotide substitutions,
additions or deletions into the nucleotide sequence of the
immunoglobulin such that one or more amino acid substitutions,
additions or deletions are introduced into the encoded protein.
Mutations may be introduced by standard techniques, such as
site-directed mutagenesis and PCR-mediated mutagenesis. Preferably,
conservative amino acid substitutions are made at one or more
non-essential amino acid residues. A "conservative amino acid
substitution" is one in which the amino acid residue is replaced
with an amino acid residue having a similar side chain. Families of
amino acid residues having similar side chains have been defined in
the art, including basic side chains (e.g., lysine, arginine,
histidine), acidic side chains (e.g., aspartic acid, glutamic
acid), uncharged polar side chains (e.g., glycine, asparagine,
glutamine, serine, threonine, tyrosine, cysteine), nonpolar side
chains (e.g., alanine, valine, leucine, isoleucine, proline,
phenylalanine, methionine, tryptophan), beta-branched side chains
(e.g., threonine, valine, isoleucine) and aromatic side chains
(e.g., tyrosine, phenylalanine, tryptophan, histidine). Thus, a
nonessential amino acid residue in an immunoglobulin polypeptide is
preferably replaced with another amino acid residue from the same
side chain family. In another embodiment, a string of amino acids
can be replaced with a structurally similar string that differs in
order and/or composition of side chain family members.
[0117] Alternatively, in another embodiment, mutations may be
introduced randomly along all or part of the immunoglobulin coding
sequence, such as by saturation mutagenesis, and the resultant
mutants can be incorporated into polypeptides of the invention and
screened for their ability to bind to the desired antigen.
[0118] As used herein, the term "heavy chain portion" includes
amino acid sequences derived from an immunoglobulin heavy chain. A
polypeptide comprising a heavy chain portion comprises at least one
of: a CH1 domain, a hinge (e.g., upper, middle, and/or lower hinge
region) domain, a CH2 domain, a CH3 domain, or a variant or
fragment thereof. In one embodiment, a polypeptide of the invention
comprises a polypeptide chain comprising a CH1 domain, at least a
portion of a hinge domain, and a CH2 domain. In another embodiment,
a polypeptide of the invention comprises a polypeptide chain
comprising a CH1 domain and a CH3 domain. In another embodiment, a
polypeptide of the invention comprises a polypeptide chain
comprising a CH1 domain, at least a portion of a hinge domain, and
a CH3 domain. In another embodiment, a polypeptide of the invention
comprises a polypeptide chain comprising a CH3 domain. In one
embodiment, a polypeptide of the invention lacks at least a portion
of a CH2 domain (e.g., all or part of a CH2 domain). In another
embodiment, a polypeptide of the invention comprises a complete Ig
heavy chain. As set forth above, it will be understood by one of
ordinary skill in the art that these domains (e.g., the heavy chain
portions) may be modified such that they vary in amino acid
sequence from the naturally occurring immunoglobulin molecule.
[0119] In one embodiment, at least two of the polypeptide chains of
a binding molecule of the invention comprise at least one heavy
chain portion derived from an antibody or immunoglobulin molecule.
In one embodiment, at least two heavy chain portions of a
polypeptide of the invention are present on different polypeptide
chains and interact, e.g., via at least one disulfide linkage (Form
A) or via non-covalent interactions (Form B) to form a dimeric
polypeptide, each monomer of the dimer comprising at least one
heavy chain portion.
[0120] In one embodiment, the heavy chain portions of one
polypeptide chain of a dimer are identical to those on a second
polypeptide chain of the dimer. In one embodiment, the monomers (or
half-mers) of a dimer of the invention are identical to each other.
In another embodiment, they are not identical. For example, each
monomer may comprise a different target binding site.
[0121] In one embodiment, a dimer of the invention is held together
by covalent interactions, e.g., disulfide bonds. In one embodiment,
a dimer of the invention is held together by one or more disulfide
bonds. In another embodiment, a dimer of the invention is held
together by one or more, preferably two disulfide bonds. In another
embodiment, a dimer of the invention is held together by one or
more, preferably three disulfide bonds. In another embodiment, a
dimer of the invention is held together by one or more, preferably
four disulfide bonds. In another embodiment, a dimer of the
invention is held together by one or more, preferably five
disulfide bonds. In another embodiment a dimer of the invention is
held together by one or more, preferably six disulfide bonds. In
another embodiment, a dimer of the invention is held together by
one or more, preferably seven disulfide bonds. In another
embodiment, a dimer of the invention is held together by one or
more, preferably eight disulfide bonds. In another embodiment, a
dimer of the invention is held together by one or more, preferably
nine disulfide bonds. In another embodiment, a dimer of the
invention is held together by one or more, preferably ten disulfide
bonds. In a further embodiment, a dimer of the invention is not
held together by disulfide bonds, but is held together, e.g., by
non-covalent interactions.
[0122] The heavy chain portions of a polypeptide may be derived
from different immunoglobulin molecules. For example, a heavy chain
portion of a polypeptide may comprise a CH1 domain derived from an
IgG1 molecule and a hinge region derived from an IgG3 molecule. In
another example, a heavy chain portion can comprise a hinge region
derived, in part, from an IgG1 molecule and, in part, from an IgG3
molecule. In another example, a heavy chain portion can comprise a
chimeric hinge derived, in part, from an IgG1 molecule and, in
part, from an IgG4 molecule. As used herein, the term "light chain
portion" includes amino acid sequences derived from an
immunoglobulin light chain. Preferably, the light chain portion
comprises at least one of a VL or CL domain.
[0123] In one embodiment a polypeptide of the invention comprises
an amino acid sequence or one or more moieties not derived from an
Ig molecule. Exemplary modifications are described in more detail
below. For example, in one embodiment, a polypeptide of the
invention may comprise a flexible linker sequence. In another
embodiment, a polypeptide may be modified to add a functional
moiety (e.g., PEG, a drug, or a label).
[0124] In one embodiment, a binding polypeptide of the invention is
a fusion protein. Fusion proteins are chimeric molecules which
comprise a binding domain comprising at least one target binding
site and at least one heavy chain portion. In one embodiment, a
fusion protein further comprises a synthetic connecting
peptide.
[0125] A "chimeric" protein comprises a first amino acid sequence
linked to a second amino acid sequence with which it is not
naturally linked in nature. The amino acid sequences may normally
exist in separate proteins that are brought together in the fusion
polypeptide or they may normally exist in the same protein but are
placed in a new arrangement in the fusion polypeptide. A chimeric
protein may be created, for example, by chemical synthesis, or by
creating and translating a polynucleotide in which the peptide
regions are encoded in the desired relationship. Exemplary chimeric
polypeptides include fusion proteins and the chimeric hinge
connecting peptides of the invention.
[0126] The term "heterologous" as applied to a polynucleotide or a
polypeptide, means that the polynucleotide or polypeptide is
derived from a genotypically distinct entity from that of the rest
of the entity to which it is being compared. For instance, a
heterologous polynucleotide or antigen may be derived from a
different species origin, different cell type, or the same type of
cell of distinct individuals.
[0127] The term "ligand binding domain" or "ligand binding portion
of a receptor" as used herein refers to any native receptor (e.g.,
cell surface receptor) or any region or derivative thereof
retaining at least a qualitative ligand binding ability, and
preferably the biological activity of a corresponding native
receptor.
[0128] The term "receptor binding domain" or "receptor binding
portion of a ligand" as used herein refers to any native ligand or
any region or derivative thereof retaining at least a qualitative
receptor binding ability, and preferably the biological activity of
a corresponding native ligand.
[0129] In one embodiment, a binding molecule of the invention is a
fusion protein. A fusion protein of the invention is a chimeric
molecule that comprises a binding domain (which comprises at least
one binding site) and a dimerization domain (which comprises at
least one heavy chain portion). The heavy chain portion may be from
any immunoglobulin, such as IgG1, IgG2, IgG3, or IgG4 subtypes,
IgA, IgE, IgD or IgM.
[0130] In another embodiment of the invention, a binding molecule
is an "antibody-fusion protein chimera." Such molecules comprise a
molecule which combines at least one binding domain of an antibody
with at least one fusion protein. Preferably, the interface between
the two polypeptides is a CH3 domain of an immunoglobulin
molecule.
[0131] In one embodiment, the binding molecules of the invention
are "antibody" or "immunoglobulin" molecules, e.g., naturally
occurring antibody or immunoglobulin molecules or genetically
engineered antibody molecules that bind antigen in a manner similar
to antibody molecules. As used herein, the term "immunoglobulin"
includes a polypeptide having a combination of two heavy and two
light chains whether or not it possesses any relevant specific
immunoreactivity. "Antibodies" refers to such assemblies which have
significant known specific immunoreactive activity to an antigen of
interest (e.g. a tumor associated antigen). Antibodies and
immunoglobulins comprise light and heavy chains, with or without an
interchain covalent linkage between them. Basic immunoglobulin
structures in vertebrate systems are relatively well
understood.
[0132] As will be discussed in more detail below, the generic term
"immunoglobulin" comprises five distinct classes of antibody that
can be distinguished biochemically. All five classes of antibodies
are clearly within the scope of the present invention, the
following discussion will generally be directed to the IgG class of
immunoglobulin molecules. With regard to IgG, immunoglobulins
comprise two identical light polypeptide chains of molecular weight
approximately 23,000 Daltons, and two identical heavy chains of
molecular weight 53,000-70,000. The four chains are joined by
disulfide bonds in a "Y" configuration wherein the light chains
bracket the heavy chains starting at the mouth of the "Y" and
continuing through the variable region.
[0133] Both the light and heavy chains are divided into regions of
structural and functional homology. The terms "constant" and
"variable" are used functionally. In this regard, it will be
appreciated that the variable domains of both the light (VL) and
heavy (VH) chain portions determine antigen recognition and
specificity. Conversely, the constant domains of the light chain
(CL) and the heavy chain (CH1, CH2 or CH3) confer important
biological properties such as secretion, transplacental mobility,
Fc receptor binding, complement binding, and the like. By
convention the numbering of the constant region domains increases
as they become more distal from the antigen binding site or
amino-terminus of the antibody. The N-terminus is a variable region
and at the C-terminus is a constant region; the CH3 and CL domains
actually comprise the carboxy-terminus of the heavy and light
chain, respectively.
[0134] Light chains are classified as either kappa or lambda
(.kappa., .lambda.). Each heavy chain class may be bound with
either a kappa or lambda light chain. In general, the light and
heavy chains are covalently bonded to each other, and the "tail"
portions of the two heavy chains are bonded to each other by
covalent disulfide linkages or non-covalent linkages when the
immunoglobulins are generated either by hybridomas, B cells or
genetically engineered host cells. In the heavy chain, the amino
acid sequences run from an N-terminus at the forked ends of the Y
configuration to the C-terminus at the bottom of each chain. Those
skilled in the art will appreciate that heavy chains are classified
as gamma, mu, alpha, delta, or epsilon, (.gamma., .mu., .alpha.,
.delta., .epsilon.) with some subclasses among them (e.g.,
.gamma.1-.gamma.4). It is the nature of this chain that determines
the "class" of the antibody as IgG, IgM, IgA IgG, or IgE,
respectively. The immunoglobulin subclasses (isotypes) e.g.,
IgG.sub.1, IgG.sub.2, IgG.sub.3, IgG.sub.4, IgA.sub.1, etc. are
well characterized and are known to confer functional
specialization. Modified versions of each of these classes and
isotypes are readily discemable to the skilled artisan in view of
the instant disclosure and, accordingly, are within the scope of
the instant invention.
[0135] As indicated above, the variable region allows the antibody
to selectively recognize and specifically bind epitopes on
antigens. That is, the V.sub.L domain and V.sub.H domain of an
antibody combine to form the variable region that defines a three
dimensional antigen binding site. This quaternary antibody
structure forms the antigen binding site present at the end of each
arm of the Y. More specifically, the antigen binding site is
defined by three complementary determining regions (CDRs) on each
of the V.sub.H and V.sub.L chains.
[0136] As used herein, the term "binding site" or "binding domain"
comprises a region of a polypeptide which is responsible for
selectively binding to a target molecule of interest (e.g. an
antigen, ligand, receptor, substrate or inhibitor). Exemplary
binding domains include an antibody variable domain, a receptor
binding domain of a ligand, a ligand binding domain of a receptor
or an enzymatic domain.
[0137] In one embodiment, the binding molecules have at least one
binding site specific for a molecule targeted for reduction or
elimination, e.g., a cell surface antigen or a soluble antigen.
[0138] In preferred embodiments, the binding domain is an antigen
binding site. An antigen binding site is formed by variable regions
that vary from one polypeptide to another. The polypeptides of the
invention comprise at least two antigen binding sites. As used
herein, the term "antigen binding site" includes a site that
specifically binds (immunoreacts with) an antigen (e.g., a cell
surface or soluble antigen). The antigen binding site includes an
immunoglobulin heavy chain and light chain variable region and the
binding site formed by these variable regions determines the
specificity of the antibody. In one embodiment, an antigen binding
molecule of the invention comprises at least one heavy or light
chain CDR of an antibody molecule (e.g., the sequence of which is
known in the art or described herein). In another embodiment, an
antigen binding molecule of the invention comprises at least two
CDRs from one or more antibody molecules. In another embodiment, an
antigen binding molecule of the invention comprises at least three
CDRs from one or more antibody molecules. In another embodiment, an
antigen binding molecule of the invention comprises at least four
CDRs from one or more antibody molecules. In another embodiment, an
antigen binding molecule of the invention comprises at least five
CDRs from one or more antibody molecules. In another embodiment, an
antigen binding molecule of the invention comprises at least six
CDRs from one or more antibody molecules. Exemplary antibody
molecules comprising at least one CDR that can be included in the
subject antigen binding molecules are known in the art and
exemplary molecules are described herein.
[0139] The polypeptides comprising two heavy chain portions
disclosed herein may be linked to form two associated Ys so there
will be four binding sites forming a "tetravalent" molecule (see
e.g., WO02/096948A2)). In another embodiment, tetravalent
minibodies or domain deleted antibodies can be made.
[0140] The term "specificity" includes the number of potential
binding sites which specifically bind (e.g., immunoreact with) a
given target. A polypeptide may be monospecific and contain one or
more binding sites which specifically bind a target or a
polypeptide may be multispecific and contain two or more binding
sites which specifically bind the same or different targets.
[0141] In one embodiment, a binding molecule of the invention is a
bispecific molecule (e.g., antibody, minibody, domain deleted
antibody, or fusion protein having binding specificity for more
than one molecule, e.g., more than one antigen or more than one
epitope on the same antigen. In one embodiment, the bispecific
molecules have at least one target binding site specific for a
molecule targeted for reduction or elimination and a targeting
molecule on a cell. In another embodiment, the bispecific molecules
have at least one target binding site specific for a molecule
targeted for reduction or elimination and at least one target
binding site specific for a drug. In yet another embodiment, the
bispecific molecules have at least one target binding site specific
for a molecule targeted for reduction or elimination and at least
one target binding site specific for a prodrug. In a preferred
embodiment, the bispecific molecules are tetravalent antibodies
that have two target binding sites specific for one target and two
target binding sites specific for the second target. A tetravalent
bispecific molecule may be bivalent for each specificity. Further
description of bispecific molecules is provided below.
[0142] As used herein the term "valency" refers to the number of
potential target binding sites in a polypeptide. Each target
binding site specifically binds one target molecule or specific
site on a target molecule. When a polypeptide comprises more than
one target binding site, each target binding site may specifically
bind the same or different molecules (e.g., may bind to different
ligands or different antigens, or different epitopes on the same
antigen).
[0143] In naturally occurring antibodies, the six CDRs present on
each monomeric antibody are short, non-contiguous sequences of
amino acids that are specifically positioned to form the antigen
binding site as the antibody assumes its three dimensional
configuration in an aqueous environment. The remainder of the heavy
and light variable domains show less inter-molecular variability in
amino acid sequence and are termed the framework regions. The
framework regions largely adopt a .beta.-sheet conformation and the
CDRs form loops which connect, and in some cases form part of, the
.beta.-sheet structure. Thus, these framework regions act to form a
scaffold that provides for positioning the six CDRs in correct
orientation by inter-chain, non-covalent interactions. The antigen
binding site formed by the positioned CDRs defines a surface
complementary to the epitope on the immunoreactive antigen. This
complementary surface promotes the non-covalent binding of the
antibody to the immunoreactive antigen epitope. The position of
CDRs can be readily identified by one of ordinary skill in the
art.
[0144] As previously indicated, the subunit structures and three
dimensional configuration of the constant regions of the various
immunoglobulin classes are well known. As used herein, the term "VH
domain" includes the amino terminal variable domain of an
immunoglobulin heavy chain and the term "CH1 domain" includes the
first (most amino terminal) constant region domain of an
immunoglobulin heavy chain. The CH1 domain is adjacent to the VH
domain and is amino terminal to the hinge region of an
immunoglobulin heavy chain molecule.
[0145] As used herein the term "CH2 domain" includes the portion of
a heavy chain molecule that extends, e.g., from about residue 244
to residue 360 of an antibody using conventional numbering schemes
(residues 244 to 360, Kabat numbering system; and residues 231-340,
EU numbering system,; and Kabat E A et al. Sequences of Proteins of
Immunological Interest. Bethesda, US Department of Health and Human
Services, NIH. 1991). The CH2 domain is unique in that it is not
closely paired with another domain. Rather, two N-linked branched
carbohydrate chains are interposed between the two CH2 domains of
an intact native IgG molecule. It is also well documented that the
CH3 domain extends from the CH2 domain to the C-terminal of the IgG
molecule and comprises approximately 108 residues.
[0146] As used herein, the term "hinge region" includes the portion
of a heavy chain molecule that joins the CH1 domain to the CH2
domain. This hinge region comprises approximately 25 residues and
is flexible, thus allowing the two N-terminal antigen binding
regions to move independently. Hinge regions can be subdivided into
three distinct domains: upper, middle, and lower hinge domains
(Roux et al. J. Immunol. 1998 161:4083).
[0147] In one embodiment, a binding molecule of the invention
comprises a connecting peptide. The connecting peptides of the
invention are synthetic. As used herein the term "synthetic" with
respect to polypeptides includes polypeptides which comprise an
amino acid sequence that is not naturally occurring. For example,
non-naturally occurring polypeptides which are modified forms of
naturally occurring polypeptides (e.g., comprising a mutation such
as an addition, substitution or deletion) or which comprise a first
amino acid sequence (which may or may not be naturally occurring)
that is linked in a linear sequence of amino acids to a second
amino acid sequence (which may or may not be naturally occurring)
to which it is not naturally linked in nature.
[0148] Connecting peptides of the invention connect two domains
(e.g., a binding domain and a dimerization domain) of a binding
molecule of the invention. For example, connecting peptides connect
a heavy chain portion to a binding domain comprising a binding
site. In one embodiment, a connecting peptide connects two heavy
chain constant region domains, such as CH1 and CH2 domains; CH1 and
CH3 domains; hinge and CH1 domains; hinge and CH3 domains; VH and
hinge domains, or a CH3 domain and a non-immunoglobulin
polypeptide) in a linear amino acid sequence of a polypeptide
chain. Preferably, such connecting peptides provide flexibility to
the polypeptide molecule and facilitate dimerization via disulfide
bonding. In one embodiment, the connecting peptides of the
invention are used to replace one or more heavy chain domains
(e.g., at least a portion of a constant region domain (e.g., at
least a portion of a CH2 domain) and/or at least a portion of the
hinge region (e.g., at least a portion of the lower hinge region
domain) in a domain deleted construct). For example, in one
embodiment, a VH domain is fused to a CH3 domain via a connecting
peptide (the C-terminus of the connecting peptide is attached to
the N-terminus of the CH3 domain and the N-terminus of the
connecting peptide is attached to the C-terminus of the VH domain).
In another embodiment, a VL domain is fused to a CH3 domain via a
connecting peptide (the C-terminus of the connecting peptide is
attached to the N-terminus of the CH3 domain and the N-terminus of
the connecting peptide is attached to the C-terminus of the VL
domain. In another embodiment, a CH1 domain is fused to a CH3
domain via a connecting peptide (the C-terminus of the connecting
peptide is attached to the N-terminus of the CH3 domain and the
N-terminus of the connecting peptide is attached to the C-terminus
of the CH1 domain).
[0149] In one embodiment, a synthetic connecting peptide comprises
a portion of a constant region domain. For example, in one
embodiment, a connecting peptide that replaces a CH2 domain can
comprise a portion of the CH2 domain.
[0150] In one embodiment, a connecting peptide comprises or
consists of a gly-ser linker. As used herein, the term "gly-ser
linker" refers to a peptide that consists of glycine and serine
residues An exemplary gly/ser linker comprises the amino acid
sequence GGGSSGGGSG (SEQ ID NO:1). In one embodiment, a connecting
peptide of the invention comprises at least a portion of an upper
hinge region (e.g., derived from an IgG1, IgG3, or IgG4 molecule),
at least a portion of a middle hinge region (e.g., derived from an
IgG1, IgG3, or IgG4 molecule) and a series of gly/ser amino acid
residues (e.g., a gly/ser linker such as GGGSSGGGSG (SEQ ID NO:1)).
In one embodiment, the connecting peptide comprises a substitution
of one or more amino acids as compared to naturally occurring IgG1
or IgG3 hinge regions. In another embodiment, a connecting peptide
comprises an amino acid sequence such as described in WO 02/060955.
Connecting peptides are described in more detail below.
[0151] As used herein the term "disulfide bond" includes the
covalent bond formed between two sulfur atoms. The amino acid
cysteine comprises a thiol group that can form a disulfide bond or
bridge with a second thiol group. In most naturally occurring IgG
molecules, the CH1 and CL regions are linked by a disulfide bond
and the two heavy chains are linked by two disulfide bonds at
positions corresponding to 239 and 242 using the Kabat numbering
system (position 226 or 229, EU numbering system).
[0152] It is known in the art that the constant region mediates
several effector functions. For example, binding of the C1
component of complement to antibodies activates the complement
system. Activation of complement is important in the opsonisation
and lysis of cell pathogens. The activation of complement also
stimulates the inflammatory response and may also be involved in
autoimmune hypersensitivity. Further, antibodies bind to cells via
the Fc region, with a Fc receptor site on the antibody Fc region
binding to a Fc receptor (FcR) on a cell. There are a number of Fc
receptors which are specific for different classes of antibody,
including IgG (gamma receptors), IgE (epsilon receptors), IgA
(alpha receptors) and IgM (mu receptors). Binding of antibody to Fc
receptors on cell surfaces triggers a number of important and
diverse biological responses including engulfment and destruction
of antibody-coated particles, clearance of immune complexes, lysis
of antibody-coated target cells by killer cells (called
antibody-dependent cell-mediated cytotoxicity, or ADCC), release of
inflammatory mediators, placental transfer and control of
immunoglobulin production.
[0153] In one embodiment, the Fc portion may be mutated to decrease
effector function using techniques known in the art. For example,
the deletion or inactivation (through point mutations or other
means) of a constant region domain may reduce Fc receptor binding
of the circulating modified antibody thereby increasing tumor
localization. In other cases it may be that constant region
modifications consistent with the instant invention moderate
compliment binding and thus reduce the serum half life and
nonspecific association of a conjugated cytotoxin. Yet other
modifications of the constant region may be used to modify
disulfide linkages or oligosaccharide moieties that allow for
enhanced localization due to increased antigen specificity or
antibody flexibility. More generally, those skilled in the art will
realize that antibodies modified as described herein may exert a
number of subtle effects that may or may not be readily
appreciated. However the resulting physiological profile,
bioavailability and other biochemical effects of the modifications,
such as tumor localization, biodistribution and serum half-life,
may easily be measured and quantified using well know immunological
techniques without undue experimentation.
[0154] In one embodiment, modified forms of antibodies can be made
from a whole precursor or parent antibody using techniques known in
the art. Exemplary techniques are discussed in more detail below.
In particularly preferred embodiments both the variable and
constant regions of polypeptides of the invention are human. In one
embodiment, fully human antibodies can be made using techniques
that are known in the art. For example, fully human antibodies
against a specific antigen can be prepared by administering the
antigen to a transgenic animal which has been modified to produce
such antibodies in response to antigenic challenge, but whose
endogenous loci have been disabled. Exemplary techniques that can
be used to make antibodies are described in U.S. Pat. Nos.
6,150,584; 6,458,592; 6,420,140. Other techniques are known in the
art.
[0155] A polypeptide comprising a heavy chain portion may or may
not comprise other amino acid sequences or moieties not derived
from an immunoglobulin molecule. Such modifications are described
in more detail below. For example, in one embodiment, a polypeptide
of the invention may comprise a flexible linker sequence. In
another embodiment, a polypeptide may be modified to add a
functional moiety such as PEG.
[0156] The polypeptides of the instant invention comprise at least
two binding sites that provide for the association of the
polypeptide with the selected target molecule.
[0157] In one embodiment, a binding molecule of the invention
comprises an antibody molecule, e.g., an intact antibody molecule,
or a fragment of an antibody molecule. In another embodiment,
binding molecule of the invention is a modified or synthetic
antibody molecule. In one embodiment, a binding molecule of the
invention comprises all or a portion of (e.g., at least one antigen
binding site from, at least one CDR from, or at least one heavy
chain portion from) a monoclonal antibody, a humanized antibody, a
chimeric antibody, or a recombinantly produced antibody.
[0158] In embodiments where the binding molecule is an antibody or
modified antibody, the antigen binding site and the heavy chain
portions need not be derived from the same immunoglobulin molecule.
In this regard, the variable region may or be derived from any type
of animal that can be induced to mount a humoral response and
generate immunoglobulins against the desired antigen. As such, the
variable region of the polypeptides may be, for example, of
mammalian origin e.g., may be human, murine, non-human primate
(such as cynomolgus monkeys, macaques, etc.), lupine, camelid
(e.g., from camels, llamas and related species). In another
embodiment, the variable region may be condricthoid in origin
(e.g., from sharks).
[0159] Polypeptides of the invention can be made using techniques
that are known in the art. In one embodiment, the polypeptides of
the invention are antibody molecules that have been "recombinantly
produced," i.e., are produced using recombinant DNA technology.
Exemplary techniques for making antibody molecules are discussed in
more detail below.
[0160] In one embodiment, the polypeptides of the invention are
modified antibodies. As used herein, the term "modified antibody"
includes synthetic forms of antibodies which are altered such that
they are not naturally occurring, e.g., antibodies that comprise at
least two heavy chain portions but not two complete heavy chains
(such as, domain deleted antibodies or minibodies); multispecific
forms of antibodies (e.g., bispecific, trispecific, etc.) altered
to bind to two or more different antigens or to different epitopes
on a single antigen); heavy chain molecules joined to scFv
molecules and the like. ScFv molecules are known in the art and are
described, e.g., in U.S. Pat. No. 5,892,019. In addition, the term
"modified antibody" includes multivalent forms of antibodies (e.g.,
trivalent, tetravalent, etc., antibodies that bind to three or more
copies of the same antigen). In another embodiment, a binding
molecule of the invention is a fusion protein comprising at least
one heavy chain portion lacking a CH2 domain and comprising a
binding domain of a polypeptide comprising the binding portion of
one member of a ligand and its receptor.
[0161] In one embodiment, the term, "modified antibody" according
to the present invention includes immunoglobulins, antibodies, or
immunoreactive fragments or recombinants thereof, in which at least
a fraction of one or more of the constant region domains has been
deleted or otherwise altered so as to provide desired biochemical
characteristics such as the ability to non-covalently dimerize,
increased ability to localize at the site of a tumor, or reduced
serum half-life when compared with a whole, unaltered antibody of
approximately the same immunogenicity. In a preferred embodiment,
the polypeptides of the present invention are domain deleted
antibodies which comprise a polypeptide chain similar to an
immunoglobulin heavy chain, but which lack at least a portion of
one or more heavy chain domains. More preferably, one entire domain
of the constant region of the modified antibody will be deleted and
even more preferably all or part of the CH2 domain will be
deleted.
[0162] In preferred embodiments, a polypeptide of the invention
will not elicit a deleterious immune response in a human.
Modifications to the constant region compatible with the instant
invention comprise additions, deletions or substitutions of one or
more amino acids in one or more domains. That is, the polypeptides
of the invention disclosed herein may comprise alterations or
modifications to one or more of the three heavy chain constant
domains (CH1, CH2 or CH3) and/or to the light chain constant region
domain (CL).
[0163] In one embodiment, the invention pertains to a modified
antibody molecule comprising at least one CC49 binding site
(specific for Tag72). For example, FIG. 8A (SEQ ID NO: 16) shows
the single-stranded DNA sequence of sc(Fv)2 heavy chain tetravalent
CH.sub.2 domain-deleted huCC49 gene. FIG. 8B (SEQ ID NO: 17) shows
the single-stranded DNA sequence of sc(Fv)2 heavy chain tetravalent
CH2 domain-deleted huCC49 gene containing the synthetic
G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting peptide. FIG.
8C (SEQ ID NO: 18) shows the single-stranded DNA sequence of
sc(Fv)2 light chain CH.sub.2 domain-deleted huCC49. FIG. 9A (SEQ ID
NO: 19) shows the amino acid sequence of heavy chain sc(Fv)2
tetravalent CH.sub.2 domain-deleted huCC49. FIG. 9B (SEQ ID NO:20)
shows the amino acid sequence of heavy chain tetravalent CH.sub.2
domain-deleted sc(Fv)2 huCC49 containing the synthetic
G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting peptide. FIG.
9C (SEQ ID NO:21) shows the amino acid sequence of light chain
CH.sub.2 domain-deleted sc(Fv)2 huCC49. FIG. 10A (SEQ ID NO:22)
shows the single-stranded DNA sequence of tetravalent CH.sub.2
domain-deleted 2sc(Fv)2 huCC49 minibody gene. FIG. 10B (SEQ ID
NO:23) shows the single-stranded DNA sequence of tetravalent
CH.sub.2 domain-deleted sc(Fv)2 huCC49 minibody gene containing the
synthetic G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting
peptide. FIG. 11A (SEQ ID NO:24) shows the amino acid sequence of
tetravalent CH.sub.2 domain-deleted sc(Fv)2 huCC49 minibody. FIG.
11B (SEQ ID NO:25) shows the amino acid sequence of tetravalent
CH.sub.2 domain-deleted sc(Fv)2 huCC49 minibody containing the
synthetic G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting
peptide.
[0164] In another embodiment, the invention pertains to a modified
antibody molecule comprising at least one p5E8 binding site
(specific for CD23). FIG. 12A (SEQ ID NO:26) shows the
single-stranded DNA sequence of heavy chain tetravalent CH2
domain-deleted PRIMATIZED.RTM. p5E8 sc(Fv)2 antibody gene
containing the G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting
peptide. FIG. 12B (SEQ ID NO:27) shows the single-stranded DNA
sequence of light chain tetravalent CH2 domain-deleted
PRIMATIZED.RTM. p5E8 sc(Fv)2 gene. FIG. 13A (SEQ ID NO:28) shows
the amino acid sequence of heavy chain tetravalent CH2
domain-deleted PRIMATIZED.RTM. p5E8 sc(Fv)2 antibody containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting peptide. FIG.
13B (SEQ ID NO:29) shows the amino acid sequence of light chain
tetravalent CH2 domain-deleted PRIMATIZED.RTM. p5E8 sc(Fv)2
antibody. FIG. 14 (SEQ ID NO:30) shows the single-stranded DNA
sequence of CH2 domain-deleted PRIMATIZED.RTM. p5E8 VL/VH minibody
gene containing the G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge
connecting peptide. FIG. 15 (SEQ ID NO:31) shows the
single-stranded DNA sequence of CH2 domain-deleted PRIMATIZED.RTM.
p5E8 VH/VL minibody gene containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting peptide. FIG.
16 (SEQ ID NO:32) shows the amino acid sequence of CH2
domain-deleted PRIMATIZED.RTM. p5E8 VL/VH minibody containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting peptide. FIG.
17 (SEQ ID NO:33) shows the amino acid sequence of CH2
domain-deleted PRIMATIZED.RTM. p5E8 VH/VL minibody containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge connecting peptide.
[0165] In one embodiment, the polypeptides of the invention may be
modified to reduce their immunogenicity using art-recognized
techniques. For example, antibodies or polypeptides of the
invention can be humanized, deimmunized, or chimeric antibodies can
be made. These types of antibodies are derived from a non-human
antibody, typically a murine antibody, that retains or
substantially retains the antigen-binding properties of the parent
antibody, but which is less immunogenic in humans. This may be
achieved by various methods, including (a) grafting the entire
non-human variable domains onto human constant regions to generate
chimeric antibodies; (b) grafting at least a part of one or more of
the non-human complementarity determining regions (CDRs) into a
human framework and constant regions with or without retention of
critical framework residues; or (c) transplanting the entire
non-human variable domains, but "cloaking" them with a human-like
section by replacement of surface residues. Such methods are
disclosed in Morrison et al., Proc. Natl. Acad. Sci. 81: 6851-5
(1984); Morrison et al., Adv. Immunol. 44: 65-92 (1988); Verhoeyen
et al., Science 239: 1534-1536 (1988); Padlan, Molec. Immun. 28:
489-498 (1991); Padlan, Molec. Immun. 31: 169-217 (1994), and U.S.
Pat. Nos. 5,585,089, 5,693,761 and 5,693,762 all of which are
hereby incorporated by reference in their entirety.
[0166] De-immunization can also be used to decrease the
immunogenicity of an antibody. As used herein, the term
"de-immunization" includes alteration of an antibody to modify T
cell epitopes (see, e.g., WO9852976A1, WO0034317A2). For example,
VH and VL sequences from the starting antibody are analyzed and a
human T cell epitope "map" from each V region showing the location
of epitopes in relation to complementarity-determining regions
(CDRs) and other key residues within the sequence. Individual T
cell epitopes from the T cell epitope map are analyzed in order to
identify alternative amino acid substitutions with a low risk of
altering activity of the final antibody. A range of alternative VH
and VL sequences are designed comprising combinations of amino acid
substitutions and these sequences are subsequently incorporated
into a range of polypeptides of the invention that are tested for
function. Typically, between 12 and 24 variant antibodies are
generated and tested. Complete heavy and light chain genes
comprising modified V and human C regions are then cloned into
expression vectors and the subsequent plasmids introduced into cell
lines for the production of whole antibody. The antibodies are then
compared in appropriate biochemical and biological assays, and the
optimal variant is identified.
[0167] In one embodiment, the binding molecule comprises a chimeric
antibody. In the context of the present application the term
"chimeric antibodies" will be held to mean any antibody wherein the
immunoreactive region or site is obtained or derived from a first
species and the constant region (which may be intact, partial or
modified in accordance with the instant invention) is obtained from
a second species. In preferred embodiments the target binding
region or site will be from a non-human source (e.g. mouse) and the
constant region is human. Preferably, the variable domains in both
the heavy and light chains are altered by at least partial
replacement of one or more CDRs and, if necessary, by partial
framework region replacement and sequence changing. Although the
CDRs may be derived from an antibody of the same class or even
subclass as the antibody from which the framework regions are
derived, it is envisaged that the CDRs will be derived from an
antibody of different class and preferably from an antibody from a
different species. It may not be necessary to replace all of the
CDRs with the complete CDRs from the donor variable region to
transfer the antigen binding capacity of one variable domain to
another. Rather, it may only be necessary to transfer those
residues that are necessary to maintain the activity of the target
binding site. Given the explanations set forth in U.S. Pat. Nos.
5,585,089, 5,693,761 and 5,693,762, it will be well within the
competence of those skilled in the art, either by carrying out
routine experimentation or by trial and error testing to obtain a
functional antibody with reduced inmunogenicity.
[0168] As used herein the term "properly folded polypeptide"
includes polypeptides (e.g., antigen binding molecules such as
antibodies) in which all of the functional domains comprising the
polypeptide are distinctly active. As used herein, the term
"improperly folded polypeptide" includes polypeptides in which at
least one of the functional domains of the polypeptide is not
active. In one embodiment, a properly folded polypeptide comprises
polypeptide chains linked by at least one disulfide bond and,
conversely, an improperly folded polypeptide comprises polypeptide
chains not linked by at least one disulfide bond.
[0169] As used herein, the term "malignancy" refers to a non-benign
tumor or a cancer. As used herein, the term "cancer" includes a
malignancy characterized by deregulated or uncontrolled cell
growth. Exemplary cancers include: carcinomas, sarcomas, leukemias,
and lymphomas. The term "cancer" includes primary malignant tumors
(e.g., those whose cells have not migrated to sites in the
subject's body other than the site of the original tumor) and
secondary malignant tumors (e.g., those arising from metastasis,
the migration of tumor cells to secondary sites that are different
from the site of the original tumor).
[0170] In one embodiment, a binding molecule of the invention binds
to a tumor cell. Exemplary antibodies which comprise antigen
binding sites that bind to antigens expressed on tumor cells are
known in the art and one or more CDRs from such antibodies can be
included in a binding molecule of the invention. Exemplary
antibodies include: 2B8, Lym 1, Lym 2, LL2, Her2, B1, MB1, BH3, B4,
B72.3, 5E8, B3F6 and 5E10. In a preferred embodiment, a polypeptide
of the invention is a C2B8 antibody which binds to CD20. In another
preferred embodiment, a polypeptide of the invention is a CC49
antibody which recognizes TAG72.
[0171] In one embodiment, a binding molecule of the invention binds
to a molecule which is useful in treating an autoimmune or
inflammatory disease or disorder.
[0172] As used herein, the term "autoimmune disease or disorder"
refers to disorders or conditions in a subject wherein the immune
system attacks the body's own cells, causing tissue destruction.
Autoimmune diseases include general autoimmune diseases, i.e., in
which the autoimmune reaction takes place simultaneously in a
number of tissues, or organ specific autoimmune diseases, ie., in
which the autoimmune reaction targets a single organ. Examples of
autoimmune diseases that can be diagnosed, prevented or treated by
the methods and compositions of the present invention include, but
are not limited to, Crohn's disease; Inflammatory bowel disease
(IBD); systemic lupus erythematosus; ulcerative colitis; rheumatoid
arthritis; goodpasture's syndrome; Grave's disease; Hashimoto's
thyroiditis; pemphigus vulgaris; myasthenia gravis; scleroderma;
autoimmune hemolytic anemia; autoimmune thrombocytopenic purpura;
polymyositis and dermatomyositis; pernicious anemia; Sjogren's
syndrome; ankylosing spondylitis; vasculitis; type I diabetes
mellitus; neurological disorders, multiple sclerosis, and secondary
diseases caused as a result of autoimmune diseases.
[0173] As used herein the term "inflammatory disease or disorder"
includes diseases or disorders which are caused, at least in part,
or exacerbated by inflammation, e.g., increased blood flow, edema,
activation of immune cells (e.g., proliferation, cytokine
production, or enhanced phagocytosis). Exemplary disorders include
those in which inflammation or inflammatory factors (e.g., matrix
metalloproteinases (MMPs), nitric oxide (NO), TNF, interleukins,
plasma proteins, cellular defense systems, cytokines, lipid
metabolites, proteases, toxic radicals, mitochondria, apoptosis,
adhesion molecules, etc.) are involved or are present in an area in
aberrant amounts, e.g., in amounts which may be advantageous to
alter, e.g., to benefit the subject. The inflammatory process is
the response of living tissue to damage. The cause of inflammation
may be due to physical damage, chemical substances,
micro-organisms, tissue necrosis, cancer or other agents. Acute
inflammation is short-lasting, lasting only a few days. If it is
longer lasting however, then it may be referred to as chronic
inflammation.
[0174] Inflammatory disorders include acute inflammatory disorders,
chronic inflammatory disorders, and recurrent inflammatory
disorders. Acute inflammatory disorders are generally of relatively
short duration, and last for from about a few minutes to about one
to two days, although they may last several weeks. The main
characteristics of acute inflammatory disorders include increased
blood flow, exudation of fluid and plasma proteins (edema) and
emigration of leukocytes, such as neutrophils. Chronic inflammatory
disorders, generally, are of longer duration, e.g., weeks to months
to years or even longer, and are associated histologically with the
presence of lymphocytes and macrophages and with proliferation of
blood vessels and connective tissue. Recurrent inflammatory
disorders include disorders which recur after a period of time or
which have periodic episodes. Examples of recurrent inflammatory
disorders include asthma and multiple sclerosis. Some disorders may
fall within one or more categories.
[0175] Inflammatory disorders are generally characterized by heat,
redness, swelling, pain and loss of function. Examples of causes of
inflammatory disorders include, but are not limited to, microbial
infections (e.g., bacterial, viral and fungal infections), physical
agents (e.g., burns, radiation, and trauma), chemical agents (e.g.,
toxins and caustic substances), tissue necrosis and various types
of immunologic reactions. Examples of inflammatory disorders
include, but are not limited to, osteoarthritis, rheumatoid
arthritis, acute and chronic infections (bacterial, viral and
fungal); acute and chronic bronchitis, sinusitis, and other
respiratory infections, including the common cold; acute and
chronic gastroenteritis and colitis; acute and chronic cystitis and
urethritis; acute respiratory distress syndrome; cystic fibrosis;
acute and chronic dermatitis; acute and chronic conjunctivitis;
acute and chronic serositis (pericarditis, peritonitis, synovitis,
pleuritis and tendinitis); uremic pericarditis; acute and chronic
cholecystis; acute and chronic vaginitis; acute and chronic
uveitis; drug reactions; and burns (thermal, chemical, and
electrical).
[0176] As used herein the term "medium that separates polypeptides
based on hydrophobic interaction" includes a medium comprising
hydrophobic ligands (e.g., alkyl or aryl groups) covalently
attached to a matrix. Such a medium can be used to separate
polypeptides based on interaction between a solvent and accessible
non-polar groups on the surface of the polypeptides and the
hydrophobic ligands of the medium. An exemplary medium is Phenyl
5PW-HR available from Tosoh Bioscience.
[0177] As used herein, the term "conductivity" includes electrical
conductivity of a solution as measured in microSiemens/cm (formerly
micromhos/cm). The greater the ion content of a solution, the
greater the conductivity of the solution. Conductivity can be
readily measured using techniques that are well known in the art
(e.g., by measuring the current passing between two
electrodes).
[0178] The separation methods of the invention can be used with
solutions having a pH ranging from acid to neutral, e.g., from
about pH 3.5 to approximately neutral. As used herein, the term
"approximately neutral pH" includes pH values of approximately 7.
For example, in one embodiment, a separation method of the
invention can be performed using a solution (e.g., a buffer) having
a pH of about 3, about 4, about 5, about 6, about 7, or about 8.
Preferably, the pH of the solution is about 6 or about 7. In one
embodiment, the pH of the solution is about 4.0, about 4.1, about
4.2, about 4.3, about 4.4, about 4.5, about 4.6, about 4.7, about
4.8, about 4.9, about 5.0, about 5.1, about 5.2, about 5.3, about
5.4, about 5.5, about 5.6, about 5.7, about 5.8, about 5.9, about
6.0, about 6.1, about 6.2, about 6.3, about 6.4, about 6.5, about
6.6, about 6.7, about 6.8, about 6.9, about 7.0, about 7.1, about
7.2, about 7.3, about 7.4, about 7.5, about 7.6, about 7.7, about
7.8, about 7.9, or about 8.0.
[0179] As used herein the term "affinity matrix" includes a matrix,
such as agarose, controlled pore glass, or
poly(styrenedivinyl)benzene to which an affinity ligand is
attached. The affinity ligand binds to the desired polypeptide and
the contaminating polypeptides are not bound to the affinity
ligand. The desired polypeptide can be eluted from the affinity
matrix using known protocols.
[0180] As used herein the term "engineered" includes manipulation
of nucleic acid or polypeptide molecules by synthetic means (e.g.
by recombinant techniques, in vitro peptide synthesis, by enzymatic
or chemical coupling of peptides or some combination of these
techniques). Preferably, the binding molecules of the invention are
engineered, e.g., to express a connecting peptide of the
invention.
[0181] As used herein, the terms "linked," "fused" or "fusion" are
used interchangeably. These terms refer to the joining together of
two more elements or components, by whatever means including
chemical conjugation or recombinant means. An "in-frame fusion"
refers to the joining of two or more open reading frames (ORFs) to
form a continuous longer ORF, in a manner that maintains the
correct reading frame of the original ORFs. Thus, the resulting
recombinant fusion protein is a single protein containing two ore
more segments that correspond to polypeptides encoded by the
original ORFs (which segments are not normally so joined in
nature.) Although the reading frame is thus made continuous
throughout the fused segments, the segments may be physically or
spatially separated by, for example, in-frame linker sequence.
[0182] In the context of polypeptides, a "linear sequence" or a
"sequence" is an order of amino acids in a polypeptide in an amino
to carboxyl terminal direction in which residues that neighbor each
other in the sequence are contiguous in the primary structure of
the polypeptide.
[0183] As used herein, the phrase "subject that would benefit from
administration of a binding molecule" includes subjects, such as
mammalian subjects, that would benefit from administration of a
binding molecule used, e.g., for detection of an antigen recognized
by a binding molecule (e.g., for a diagnostic procedure) and/or
from treatment with a binding molecule to reduce or eliminate the
target recognized by the binding molecule. For example, in one
embodiment, the subject may benefit from reduction or elimination
of a soluble or particulate molecule from the circulation or serum
(e.g., a toxin or pathogen) or from reduction or elimination of a
population of cells expressing the target (e.g., tumor cells). As
described in more detail herein, the binding molecule can be used
in unconjugated form or can be conjugated, e.g., to a drug,
prodrug, or an isotope.
[0184] II. Synthetic Connecting Peptides
[0185] At least one polypeptide chain of a dimer of the invention
can comprise a synthetic connecting peptide of the invention. In
one embodiment, at least two chains of a dimer of the invention
comprise a connecting peptide. In a preferred embodiment, two
chains of a dimer of the invention comprise a connecting
peptide.
[0186] In one embodiment, connecting peptides can be used to join
two heavy chain portions in frame in a single polypeptide chain.
For example, in one embodiment, a connecting peptide of the
invention can be used to fuse a CH3 domain (or synthetic CH3
domain) to a hinge region (or synthetic hinge region). In another
embodiment, a connecting peptide of the invention can be used to
fuse a CH3 domain (or synthetic CH3 domain) to a CH1 domain (or
synthetic CH1 domain). In still another embodiment, a connecting
peptide can act as a peptide spacer between the hinge region (or
synthetic hinge region) and a CH2 domain (or a synthetic CH2
domain).
[0187] In another embodiment, a CH3 domain can be fused to an
extracellular protein domain (e.g., a VL domain (or synthetic
domain), a VH domain (or synthetic domain), a CH1 domain (or
synthetic domain), a hinge domain (or synthetic hinge), or to the
ligand binding portion of a receptor or the receptor binding
portion of a ligand). For example, in one embodiment, a VH or VL
domain is fused to a CH3 domain via a connecting peptide (the
C-terminus of the connecting peptide is attached to the N-terminus
of the CH3 domain and the N-terminus of the connecting peptide is
attached to the C-terminus of the VH or VL domain). In another
embodiment, a CH1 domain is fused to a CH3 domain via a connecting
peptide (the C-terminus of the connecting peptide is attached to
the N-terminus of the CH3 domain and the N-terminus of the
connecting peptide is attached to the C-terminus of the CH1
domain). In another embodiment, a connecting peptide of the
invention can be used to fuse a CH3 domain (or synthetic CH3
domain) to a hinge region (or synthetic hinge region) or portion
thereof. In still another embodiment, a connecting peptide can act
as a peptide spacer between the hinge region (or synthetic hinge
region) and a CH2 domain (or a synthetic CH2 domain).
[0188] In one embodiment, a connecting peptide can comprise or
consist of a gly/ser spacer. For example, a domain deleted CC49
construct having a short amino acid spacer GGSSGGGGSG (SEQ. ID No.
1) substituted for the CH2 domain and the lower hinge region
(CC49.66 CH2 [gly/ser]) can be used. In another embodiment, a
connecting peptide comprises the amino acid sequence IGKTISKKAK
(SEQ ID NO:36).
[0189] In another embodiment, connecting peptide can comprise at
least a portion of an immunoglobulin hinge region. For example,
chimeric hinge domains can be constructed which combine hinge
elements derived from different antibody isotypes. In one
embodiment, a connecting peptide comprises at least a portion of an
IgG1 hinge region. In another embodiment, a connecting peptide can
comprise at least a portion of an IgG3 hinge region. In another
embodiment, a connecting peptide can comprise at least a portion of
an IgG1 hinge region and at least a portion of an IgG3 hinge
region. In one embodiment, a connecting peptide can comprise an
IgG1 upper and middle hinge and a single IgG3 middle hinge repeat
motif.
[0190] Because the numbering of individual amino acids in such
connecting peptides comprising an amino acid sequence derived from
an immunoglobulin hinge region may vary depending upon the length
of the connecting peptide, the numbering of amino acid positions in
these molecules is given using Kabat numbering see, e.g., Table 2).
Table 1 shows naturally occurring hinge sequence for IgG1, IgG3,
and IgG4 molecules. Table 2 shows Kabat numbering for portions of
these hinge molecules and also shows Kabat numbering for connecting
peptide amino acid residues presented in that table.
[0191] In one embodiment, a connecting peptide of the invention
comprises a non-naturally occurring immunoglobulin hinge region
domain, e.g., a hinge region domain that is not naturally found in
the polypeptide comprising the hinge region domain and/or a hinge
region domain that has been altered so that it differs in amino
acid sequence from a naturally occurring immunoglobulin hinge
region domain. In one embodiment, mutations can be made to hinge
region domains to make a connecting peptide of the invention. In
one embodiment, a connecting peptide of the invention comprises a
hinge domain which does not comprise a naturally occurring number
of cysteines, i.e., the connecting peptide comprises either fewer
cysteines or a greater number of cysteines than a naturally
occurring hinge molecule. In a preferred embodiment, incorporation
of a connecting peptide (e.g., comprising a non-naturally occurring
number of cysteines) into a polypeptide results in a composition in
which greater than 50%, 60%, 70%, 80% or 90% of the dimeric
molecules present in a form in which the two heavy chain portions
are linked via at least one interchain disulfide linkage.
[0192] In one embodiment of the invention, a connecting peptide
comprises hinge region domain comprising a proline residue at an
amino acid position corresponding to amino acid position 243 in the
Kabat numbering system (position 230, EU numbering system). In one
embodiment, a connecting peptide comprises an alanine residue at an
amino acid position corresponding to position 244, Kabat numbering
system (position 246, EU numbering system). In another embodiment,
a connecting peptide of the invention comprises a proline residue
at an amino acid position corresponding to position 245 (Kabat
numbering system; position 247, EU numbering system)). In one
embodiment, a connecting peptide comprises a cysteine residue at an
amino acid position corresponding to position 239, Kabat numbering
system (position 226, EU numbering system). In one embodiment, a
connecting peptide comprises a serine residue at an amino acid
position corresponding to position 239, Kabat numbering system
(position 226, EU numbering system). In one embodiment, a
connecting peptide comprises a cysteine residue at an amino acid
position corresponding to position 242, Kabat numbering system
(position 229, EU numbering system). In one embodiment, a
connecting peptide comprises a serine residue at an amino acid
position corresponding to position 242, Kabat numbering system
(position 229, EU numbering system).
[0193] In one embodiment, the connecting peptide can be chosen to
result in the preferential synthesis of a particular isoform of
polypeptide, e.g., in which the two heavy chain portions are linked
via disulfide bonds or are not linked via disulfide bonds. For
example, as described in the instant examples, the
G1/G3/Pro243+[gly/ser] linker (SEQ ID NO: 8),
G1/G3/Pro243Ala244Pro245+[gly/ser] linker (SEQ ID NO: 9),
Pro243+[gly/ser] linker (SEQ ID NO: 15), and
Pro243Ala244Pro245+[gly/ser] linker (SEQ ID NO: 14), connecting
peptides resulted in the production of only Form A CH2
domain-deleted antibody with no detectable Form B. In contrast, CH2
domain-deleted Cys242Ser:Pro243 (SEQ ID NO: 12), and CH2
domain-deleted Cys242Ser:Pro243Ala244Pro245 (SEQ ID NO: 13), both
resulted in a preference for the Form B isoform. These synthetic
hinge region connecting peptides would thus be useful for favoring
synthesis of Form A or B isoform. This is true for any isotype of
antibody, (e.g., IgG1, IgG2, IgG3, or IgG4) based on the high
degree of homology among the CH3 domains for all four human
isotypes. (Including identical and conserved amino acid residues,
IgG1 CH3 domain is 98.13% homologous to IgG2 CH3, 97.20% homologous
to IgG3 CH3, and 96.26% homologous to IgG4 CH3). The parentheticals
referring to connecting peptides and various binding molecules of
the invention represent equivalent terminology unless otherwise
indicated.
[0194] In one embodiment, a connecting peptide of the invention
comprises a hinge region domain followed by a flexible gly/ser
linker. Exemplary connecting peptides are shown in Table 2 and in
SEQ ID NOs: 8-15, 48, and 49. It will be understood that variant
forms of these exemplary connecting peptides can be created by
introducing one or more nucleotide substitutions, additions or
deletions into the nucleotide sequence encoding a connecting
peptide such that one or more amino acid substitutions, additions
or deletions are introduced into the connecting peptide. For
example, mutations may be introduced by standard techniques, such
as site-directed mutagenesis and PCR-mediated mutagenesis.
Preferably, conservative amino acid substitutions are made at one
or more non-essential amino acid residues such that the ability of
the connecting peptide to preferentially enhance synthesis of Form
A or Form B is not altered. A "conservative amino acid
substitution" is one in which the amino acid residue is replaced
with an amino acid residue having a similar side chain. Families of
amino acid residues having similar side chains have been defined in
the art, including basic side chains (e.g., lysine, arginine,
histidine), acidic side chains (e.g., aspartic acid, glutamic
acid), uncharged polar side chains (e.g., glycine, asparagine,
glutamine, serine, threonine, tyrosine, cysteine), nonpolar side
chains (e.g., alanine, valine, leucine, isoleucine, proline,
phenylalanine, methionine, tryptophan), beta-branched side chains
(e.g., threonine, valine, isoleucine) and aromatic side chains
(e.g., tyrosine, phenylalanine, tryptophan, histidine). Thus, a
nonessential amino acid residue in an immunoglobulin polypeptide is
preferably replaced with another amino acid residue from the same
side chain family. In another embodiment, a string of amino acids
can be replaced with a structurally similar string that differs in
order and/or composition of side chain family members.
[0195] Connecting peptides of the invention can be of varying
lengths. In one embodiment, a connecting peptide of the invention
is from about 15 to about 50 amino acids in length. In another
embodiment, a connecting peptide of the invention is from about 20
to about 45 amino acids in length. In another embodiment, a
connecting peptide of the invention is from about 25 to about 40
amino acids in length. In another embodiment, a connecting peptide
of the invention is from about 30 to about 35 amino acids in
length. In another embodiment, a connecting peptide of the
invention is from about 24 to about 27amino acids in length. In
another embodiment, a connecting peptide of the invention is from
about 40 to about 42 amino acids in length.
[0196] Connecting peptides can be introduced into polypeptide
sequences using techniques known in the art. For example, in one
embodiment, the Splicing by Overlap Extension (SOE) method (Horton,
R. M. 1993 Methods in Molecular Biology, Vol 15: PCR Protocols:
Current Methods and applications. Ed. B. A. White) can be used.
Modifications can be confirmed by DNA sequence analysis. Plasmid
DNA can be used to transform host cells for stable production of
the polypeptides produced.
[0197] In one embodiment, incorporation of one of the subject
connecting peptides into a polypeptide yields a composition
comprising polypeptide molecules having at least two binding sites
and at least two polypeptide chains, wherein at least two of the
polypeptide chains comprise a synthetic connecting peptide and
wherein greater than 50% of the molecules are present in a form in
which the two heavy chain portions are linked via at least one
interchain disulfide linkage. In another embodiment, greater than
60% of the molecules are present in a form in which the two heavy
chain portions are linked via at least one interchain disulfide
linkage. In another embodiment, greater than 70% of the molecules
are present in a form in which the two heavy chain portions are
linked via at least one interchain disulfide linkage. In another
embodiment, greater than 80% of the molecules are present in a form
in which the two heavy chain portions are linked via at least one
interchain disulfide linkage. In another embodiment, greater than
90% of the molecules are present in a form in which the two heavy
chain portions are linked via at least one interchain disulfide
linkage.
[0198] In one embodiment, incorporation of one of the subject
connecting peptides into an IgG4 molecule yields a composition in
which greater than 95% of the molecules are present in a form in
which the two heavy chain portions are linked via at least one
interchain disulfide linkage.
[0199] III. Binding Molecules
[0200] The polypeptides of the invention comprise at least two
binding sites which bind to a target molecule of interest.
Exemplary binding sites include, e.g., sites which bind to an
antigen (antigen binding sites), sites which bind to a receptor
(receptor binding sites), or sites which bind to a ligand (ligand
binding sites). In one embodiment, the binding molecules comprise
at least two binding sites. In one embodiment, the binding
molecules comprise two binding sites. In one embodiment, the
binding molecules comprise three binding sites. In another
embodiment, the binding molecules comprise four binding sites.
[0201] In one embodiment, the binding molecules have at least one
target binding site specific for a molecule which mediates a
biological effect (e.g., which modulates cellular activation (e.g.,
by binding to a cell surface receptor and resulting in transmission
or inhibition of an activating or inhibitory signal), which results
in death of the cell (e.g., by complement fixation or exposure to a
payload present on the binding molecule), or which modulates a
disease or disorder in a subject (e.g., by promoting lysis of a
fibrin clot or promoting clot formation, or by modulating the
amount of a substance which is bioavailable (e.g., by enhancing or
reducing the amount of a ligand such as TNF.alpha. in the
subject)).
[0202] In one embodiment, the binding molecules have at least one
target binding site specific for an molecule targeted for reduction
or elimination, e.g., a cell surface antigen or a soluble antigen.
In one embodiment, binding of the binding molecule to the target
results in reduction or elimination of the target, e.g., from a
tissue or from the circulation. In another embodiment, the binding
molecules have at least one binding site specific for a molecule
that can be used to detect the presence of a target molecule (e.g.,
to detect a contaminant or diagnose a condition or disorder). In
yet another embodiment, a binding molecule of the invention
comprises at least one binding site that targets the binding
molecule to a specific site in a subject (e.g., to a tumor cell or
blood clot).
[0203] Exemplary binding sites that can be included in the binding
domain of a binding molecule of the invention include: the receptor
binding portion of a ligand, the ligand binding portion of a
receptor, the substrate binding portion of an enzyme, the enzyme
binding portion of a substrate, or one or more antigen binding
portions of an antibody.
[0204] In one embodiment, at least one target binding site of a
binding molecule (e.g., an antibody molecule, a bispecific
antibody, or a modified antibody) is catalytic (Shokat and Schultz.
1990. Annu. Rev. Immunol. 8:335).
[0205] In one embodiment, a heavy chain variable portion and a
light chain variable portion of a binding molecule are present in
the same polypeptide, e.g., as in a single chain antibody or a
minibody (see e.g., U.S. Pat. No. 5,837,821 or WO 94/09817A1). In
another embodiment, the heavy chain portion and the light chain
portion of a polypeptide are present in different polypeptide
chains, e.g., as in antibody molecules.
[0206] The target binding polypeptides of the invention are
multimeric molecules. In one embodiment, the target binding
polypeptides are dimers. In one embodiment, the dimers of the
invention are homodimers, comprising two identical monomeric
subunits. In another embodiment, the dimers of the invention are
heterodimers, comprising two non-identical monomeric subunits. The
dimers comprise at least two polypeptide chains. In one embodiment,
the binding molecules comprise two polypeptide chains. In another
embodiment, the binding molecules comprise three polypeptide
chains. In another embodiment, the binding molecules comprise four
polypeptide chains.
[0207] In a preferred embodiment, a binding molecule of the
invention comprises at least one CDR of an antibody, e.g., an
antibody known in the art to bind to a target of interest. In
another embodiment, a binding molecule of the invention comprises
at least two CDRs. In another embodiment, a binding molecule of the
invention comprises at least three CDRs. In another embodiment, a
binding molecule of the invention comprises at least four CDRs. In
another embodiment, a binding molecule of the invention comprises
at least five CDRs. In another embodiment, a binding molecule of
the invention comprises at least six CDRs. In a preferred
embodiment, a binding molecule of the invention comprises at least
one VH domain of an antibody, e.g., an antibody known in the art to
bind to a target of interest. In a preferred embodiment, a binding
molecule of the invention comprises at least one VL domain. In
another preferred embodiment, a binding molecule of the invention
comprises at least one VH domain and one VL domain of an
antibody.
[0208] In one embodiment, an antigen binding site consists of a VH
domain, e.g., derived from camelids, which is stable in the absence
of a VL chain (Hamers-Casterman et al. 1993. Nature 363:446;
Desmyter et al. 1996. Nat. Struct. Biol. 3:803; Desmyter, A., 1996.
Nat. Struct. Biol. 3:803; Decanniere, K., et al. 1999. Structure
7:361; Davies et al. 1996. Protein Eng. 9:531; Kortt et al. 1995.
J. Protein Chem. 14:167).
[0209] A. Fusion Proteins
[0210] The invention also pertains to binding molecules which
comprise one or more immunoglobulin domains. The fusion proteins of
the invention comprise a binding domain (which comprises at least
one binding site) and a dimerization domain (which comprises at
least one heavy chain portion). The subject fusion proteins may be
bispecific (with one binding site for a first target and a second
binding site for a second target) or may be multivalent (with two
binding sites for the same target).
[0211] Exemplary fusion proteins reported in the literature include
fusions of the T cell receptor (Gascoigne et al., Proc. Natl. Acad.
Sci. USA 84:2936-2940 (1987)); CD4 (Capon et al., Nature
337:525-531 (1989); Traunecker et al., Nature 339:68-70 (1989);
Zettmeissl et al., DNA Cell Biol. USA 9:347-353 (1990); and Byrn et
al., Nature 344:667-670 (1990)); L-selectin (homing receptor)
(Watson et al., J. Cell. Biol. 110:2221-2229 (1990); and Watson et
al., Nature 349:164-167 (1991)); CD44 (Aruffo et al., Cell
61:1303-1313 (1990)); CD28 and B7 (Linsley et al., J. Exp. Med.
173:721-730 (1991)); CTLA-4 (Lisley et al., J. Exp. Med.
174:561-569 (1991)); CD22 (Stamenkovic et al., Cell 66:1133-1144
(1991)); TNF receptor (Ashkenazi et al., Proc. Natl. Acad. Sci. USA
88:10535-10539 (1991); Lesslauer et al., Eur. J. Immunol.
27:2883-2886 (1991); and Peppel et al., J. Exp. Med. 174:1483-1489
(1991)); and IgE receptor a (Ridgway and Gorman, J. Cell. Biol.
Vol. 115, Abstract No. 1448 (1991)).
[0212] In one embodiment a fusion protein combines the binding
domain(s) of the ligand or receptor (e.g. the extracellular domain
(ECD) of a receptor) with at least one heavy chain domain and a
synthetic connecting peptide. In one embodiment, when preparing the
fusion proteins of the present invention, nucleic acid encoding the
binding domain of the ligand or receptor will be fused C-terminally
to nucleic acid encoding the N-terminus of an immunoglobulin
constant domain sequence. N-terminal fusions are also possible. In
one embodiment, a fusion protein includes a CH2 and a CH3 domain.
Fusions may also be made to the C-terminus of the Fc portion of a
constant domain, or immediately N-terminal to the CH1 of the heavy
chain or the corresponding region of the light chain.
[0213] In one embodiment, the sequence of the ligand or receptor
domain is fused to the N-terminus of the Fc domain of an
immunoglobulin molecule. It is also possible to fuse the entire
heavy chain constant region to the sequence of the ligand or
receptor domain. In one embodiment, a sequence beginning in the
hinge region just upstream of the papain cleavage site which
defines IgG Fc chemically (i.e. residue 216, taking the first
residue of heavy chain constant region to be 114), or analogous
sites of other immunoglobulins is used in the fusion. The precise
site at which the fusion is made is not critical; particular sites
are well known and may be selected in order to optimize the
biological activity, secretion, or binding characteristics of the
molecule. Methods for making fusion proteins are known in the
art.
[0214] For bispecific fusion proteins, the fusion proteins are
assembled as multimers, and particularly as heterodimers or
heterotetramers. Generally, these assembled immunoglobulins will
have known unit structures. A basic four chain structural unit is
the form in which IgG, IgD, and IgE exist. A four chain unit is
repeated in the higher molecular weight immunoglobulins; IgM
generally exists as a pentamer of four basic units held together by
disulfide bonds. IgA globulin, and occasionally IgG globulin, may
also exist in multimeric form in serum. In the case of multimer,
each of the four units may be the same or different.
[0215] Additional exemplary ligands and their receptors that may be
included in the subject fusion proteins include the following:
[0216] Cytokines and Cytokine Receptors
[0217] Cytokines have pleiotropic effects on the proliferation,
differentiation, and functional activation of lymphocytes. Various
cytokines, or receptor binding portions thereof, can be utilized in
the fusion proteins of the invention. Exemplary cytokines include
the interleukins (e.g. IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7,
IL-8, IL-10, IL-11, IL-12, IL-13, and IL-18), the colony
stimulating factors (CSFs) (e.g. granulocyte CSF (G-CSF),
granulocyte-macrophage CSF (GM-CSF), and monocyte macrophage CSF
(M-CSF)), tumor necrosis factor (TNF) alpha and beta, and
interferons such as interferon-.alpha., .beta., or .gamma. (U.S.
Pat. Nos. 4,925,793 and 4,929,554).
[0218] Cytokine receptors typically consist of a ligand-specific
alpha chain and a common beta chain. Exemplary cytokine receptors
include those for GM-CSF, IL-3 (U.S. Pat. No. 5,639,605), IL-4
(U.S. Pat. No. 5,599,905), IL-5 (U.S. Pat. No. 5,453,491),
IFN.gamma. (EP0240975), and the TNF family of receptors (e.g.,
TNF.alpha. (e.g. TNFR-1 (EP 417,563), TNFR-2 (EP 417,014)
lymphotoxin beta receptor).
[0219] Adhesion Proteins
[0220] Adhesion molecules are membrane-bound proteins that allow
cells to interact with one another. Various adhesion proteins,
including leukocyte homing receptors and cellular adhesion
molecules, of receptor binding portions thereof, can be
incorporated in a fusion protein of the invention. Leucocyte homing
receptors are expressed on leucocyte cell surfaces during
inflammation and include the .beta.-1 integrins (e.g. VLA-1, 2, 3,
4, 5, and 6) which mediate binding to extracellular matrix
components, and the .beta.2-integrins (e.g. LFA-1, LPAM-1, CR3, and
CR4) which bind cellular adhesion molecules (CAMs) on vascular
endothelium. Exemplary CAMs include ICAM-1, ICAM-2, VCAM-1, and
MAdCAM-1. Other CAMs include those of the selectin family including
E-selectin, L-selectin, and P-selectin.
[0221] Chemokines
[0222] Chemokines, chemotactic proteins which stimulate the
migration of leucocytes towards a site of infection, can also be
incorporated into a fusion protein of the invention. Exemplary
chemokines include Macrophage inflammatory proteins (MIP-1-.alpha.
and MIP-1-.beta.), neutrophil chemotactic factor, and RANTES
(regulated on activation normally T-cell expressed and
secreted).
[0223] Growth Factors and Growth Factor Receptors
[0224] Growth factors or their receptors (or receptor binding or
ligand binding portions thereof) may be incorporated in the fusion
proteins of the invention. Exemplary growth factors include
Vascular Endothelial Growth Factor (VEGF) and its isoforms (U.S.
Pat. No. 5,194,596); Fibroblastic Growth Factors (FGF), including
aFGF and bFGF; atrial natriuretic factor (ANF); hepatic growth
factors (HGFs; U.S. Pat. Nos. 5,227,158 and 6,099,841),
neurotrophic factors such as bone-derived neurotrophic factor
(BDNF), neurotrophin-3, -4, -5, or -6 (NT-3, NT-4, NT-5, or NT-6),
or a nerve growth factor such as NGF-.beta. platelet-derived growth
factor (PDGF) (U.S. Pat. Nos. 4,889,919, 4,845,075, 5,910,574, and
5,877,016); transforming growth factors (TGF) such as TGF-alpha and
TGF-beta (WO 90/14359), osteoinductive factors including bone
morphogenetic protein (BMP); insulin-like growth factors-I and -II
(IGF-I and IGF-II; U.S. Pat. Nos. 6,403,764 and 6,506,874);
Erythropoietin (EPO); stem-cell factor (SCF), thrombopoietin (c-Mpl
ligand), and the Wnt polypeptides (U.S. Pat. No. 6,159,462).
Exemplary growth factor receptors which may be used as targeting
receptor domains of the invention include EGF receptors; VEGF
receptors (e.g. Flt1 or Flk1/KDR), PDGF receptors (WO 90/14425);
HGF receptors (U.S. Pat. Nos. 5,648,273, and 5,686,292), and
neurotrophic receptors including the low affinity receptor (LNGFR),
also termed as p75.sup.NTR or p75, which binds NGF, BDNF, and NT-3,
and high affinity receptors that are members of the trk family of
the receptor tyrosine kinases (e.g. trkA, trkb (EP 455,460), trkC
(EP 522,530)).
[0225] Hormones
[0226] Exemplary growth hormones for use as targeting agents in the
fusion proteins of the invention include renin, human growth
hormone (HGH; U.S. Pat. No. 5,834,598), N-methionyl human growth
hormone; bovine growth hormone; growth hormone releasing factor;
parathyroid hormone (PTH); thyroid stimulating hormone (TSH);
thyroxine; proinsulin and insulin (U.S. Pat. Nos. 5,157,021 and
6,576,608); follicle stimulating hormone (FSH), calcitonin,
luteinizing hormone (LH), leptin, glucagons; bombesin; somatropin;
mullerian-inhibiting substance; relaxin and prorelaxin;
gonadotropin-associated peptide; prolactin; placental lactogen; OB
protein; or mullerian-inhibiting substance.
[0227] Clotting Factors
[0228] Exemplary blood coagulation factors for use as targeting
agents in the fusion proteins of the invention include the clotting
factors (e.g., factors V, VII, VIII, X, IX, XI, XII and XIII, von
Willebrand factor); tissue factor (U.S. Pat. Nos. 5,346,991,
5,349,991, 5,726,147, and 6,596,84); thrombin and prothrombin;
fibrin and fibrinogen; plasmin and plasminogen; plasminogen
activators, such as urokinase or human urine or tissue-type
plasminogen activator (t-PA).
[0229] Other exemplary fusion proteins are taught, e.g., in
WO0069913A1 and WO0040615A2. Another exemplary molecule that may be
included in a fusion protein of the invention is IGSF9.
[0230] Fusion proteins can be prepared using methods that are well
known in the art (see for example U.S. Pat. Nos. 5,116,964 and
5,225,538). Ordinarily, the ligand or receptor domain is fused
C-terminally to the N-terminus of the constant region of the heavy
chain (or heavy chain portion) and in place of the variable region.
Any transmembrane regions or lipid or phospholipids anchor
recognition sequences of ligand binding receptor are preferably
inactivated or deleted prior to fusion. DNA encoding the ligand or
receptor domain is cleaved by a restriction enzyme at or proximal
to the 5' and 3' ends of the DNA encoding the desired ORF segment.
The resultant DNA fragment is then readily inserted into DNA
encoding a heavy chain constant region. The precise site at which
the fusion is made may be selected empirically to optimize the
secretion or binding characteristics of the soluble fusion protein.
DNA encoding the fusion protein is then transfected into a host
cell for expression.
[0231] B. Antibodies or Portions Thereof
[0232] In one embodiment, a binding molecule, e.g., antigen binding
molecule, of the invention is an antibody molecule. Using art
recognized protocols, for example, antibodies are preferably raised
in mammals by multiple subcutaneous or intraperitoneal injections
of the relevant antigen (e.g., purified tumor associated antigens
or cells or cellular extracts comprising such antigens) and an
adjuvant. This immunization typically elicits an immune response
that comprises production of antigen-reactive antibodies from
activated splenocytes or lymphocytes. While the resulting
antibodies may be harvested from the serum of the animal to provide
polyclonal preparations, it is often desirable to isolate
individual lymphocytes from the spleen, lymph nodes or peripheral
blood to provide homogenous preparations of monoclonal antibodies
(MAbs). Preferably, the lymphocytes are obtained from the
spleen.
[0233] In this well known process (Kohler et al., Nature, 256:495
(1975)) the relatively short-lived, or mortal, lymphocytes from a
mammal which has been injected with antigen are fused with an
immortal tumor cell line (e.g. a myeloma cell line), thus,
producing hybrid cells or "hybridomas" which are both immortal and
capable of producing the genetically coded antibody of the B cell.
The resulting hybrids are segregated into single genetic strains by
selection, dilution, and regrowth with each individual strain
comprising specific genes for the formation of a single antibody.
They produce antibodies which are homogeneous against a desired
antigen and, in reference to their pure genetic parentage, are
termed "monoclonal."
[0234] Hybridoma cells thus prepared are seeded and grown in a
suitable culture medium that preferably contains one or more
substances that inhibit the growth or survival of the unfused,
parental myeloma cells. Those skilled in the art will appreciate
that reagents, cell lines and media for the formation, selection
and growth of hybridomas are commercially available from a number
of sources and standardized protocols are well established.
Generally, culture medium in which the hybridoma cells are growing
is assayed for production of monoclonal antibodies against the
desired antigen. Preferably, the binding specificity of the
monoclonal antibodies produced by hybridoma cells is determined by
immunoprecipitation or by an in vitro assay, such as a
radioimmunoassay (RIA) or enzyme-linked immunoabsorbent assay
(ELISA). After hybridoma cells are identified that produce
antibodies of the desired specificity, affinity and/or activity,
the clones may be subcloned by limiting dilution procedures and
grown by standard methods (Goding, Monoclonal Antibodies:
Principles and Practice, pp 59-103 (Academic Press, 1986)). It will
further be appreciated that the monoclonal antibodies secreted by
the subclones may be separated from culture medium, ascites fluid
or serum by conventional purification procedures such as, for
example, protein-A, hydroxylapatite chromatography, gel
electrophoresis, dialysis or affinity chromatography.
[0235] In another embodiment, DNA encoding a desired monoclonal
antibodies may be readily isolated and sequenced using conventional
procedures (e.g., by using oligonucleotide probes that are capable
of binding specifically to genes encoding the heavy and light
chains of murine antibodies). The isolated and subcloned hybridoma
cells serve as a preferred source of such DNA. Once isolated, the
DNA may be placed into expression vectors, which are then
transfected into prokaryotic or eukaryotic host cells such as E.
coli cells, simian COS cells, Chinese Hamster Ovary (CHO) cells or
myeloma cells that do not otherwise produce immunoglobulins. More
particularly, the isolated DNA (which may be modified as described
herein) may be used to clone constant and variable region sequences
for the manufacture antibodies as described in Newman et al., U.S.
Pat. No. 5,658,570, filed Jan. 25, 1995, which is incorporated by
reference herein. Essentially, this entails extraction of RNA from
the selected cells, conversion to cDNA, and amplification by PCR
using Ig specific primers. Suitable primers for this purpose are
also described in U.S. Pat. No. 5,658,570. As will be discussed in
more detail below, transformed cells expressing the desired
antibody may be grown up in relatively large quantities to provide
clinical and commercial supplies of the immunoglobulin.
[0236] Those skilled in the art will also appreciate that DNA
encoding antibodies or antibody fragments may also be derived from
antibody phage libraries, e.g., using pd phage or Fd phagemid
technology. Exemplary methods are set forth, for example, in EP 368
684 B1; U.S. Pat. No. 5,969,108, Hoogenboom, H. R. and Chames.
2000. Immunol. Today 21:371; Nagy et al. 2002. Nat. Med. 8:801;
Huie et al. 2001. Proc. Natl. Acad. Sci. USA 98:2682; Lui et al.
2002. J. Mol. Biol. 315:1063, each of which is incorporated herein
by reference. Several publications (e.g., Marks et al.
Bio/Technology 10:779-783 (1992)) have described the production of
high affinity human antibodies by chain shuffling, as well as
combinatorial infection and in vivo recombination as a strategy for
constructing large phage libraries. In another embodiment,
Ribosomal display can be used to replace bacteriophage as the
display platform (see, e.g., Hanes et al. 2000. Nat. Biotechnol.
18:1287; Wilson et al. 2001. Proc. Natl. Acad. Sci. USA 98:3750; or
Irving et al. 2001 J. Immunol. Methods 248:31. In yet another
embodiment, cell surface libraries can be screened for antibodies
(Boder et al. 2000. Proc. Natl. Acad. Sci. USA 97:10701; Daugherty
et al. 2000 J. Immunol. Methods 243:211. Such procedures provide
alternatives to traditional hybridoma techniques for the isolation
and subsequent cloning of monoclonal antibodies.
[0237] Yet other embodiments of the present invention comprise the
generation of human or substantially human antibodies in transgenic
animals (e.g., mice) that are incapable of endogenous
immunoglobulin production (see e.g., U.S. Pat. Nos. 6,075,181,
5,939,598, 5,591,669 and 5,589,369 each of which is incorporated
herein by reference). For example, it has been described that the
homozygous deletion of the antibody heavy-chain joining region in
chimeric and germ-line mutant mice results in complete inhibition
of endogenous antibody production. Transfer of a human
immunoglobulin gene array to such germ line mutant mice will result
in the production of human antibodies upon antigen challenge.
Another preferred means of generating human antibodies using SCID
mice is disclosed in U.S. Pat. No. 5,811,524 which is incorporated
herein by reference. It will be appreciated that the genetic
material associated with these human antibodies may also be
isolated and manipulated as described herein.
[0238] Yet another highly efficient means for generating
recombinant antibodies is disclosed by Newman, Biotechnology, 10:
1455-1460 (1992). Specifically, this technique results in the
generation of primatized antibodies that contain monkey variable
domains and human constant sequences. This reference is
incorporated by reference in its entirety herein. Moreover, this
technique is also described in commonly assigned U.S. Pat. Nos.
5,658,570, 5,693,780 and 5,756,096 each of which is incorporated
herein by reference.
[0239] In another embodiment, lymphocytes can be selected by
micromanipulation and the variable genes isolated. For example,
peripheral blood mononuclear cells can be isolated from an
immunized mammal and cultured for about 7 days in vitro. The
cultures can be screened for specific IgGs that meet the screening
criteria. Cells from positive wells can be isolated. Individual
Ig-producing B cells can be isolated by FACS or by identifying them
in a complement-mediated hemolytic plaque assay. Ig-producing B
cells can be micromanipulated into a tube and the Vh and Vl genes
can be amplified using, e.g., RT-PCR. The VH and VL genes can be
cloned into an antibody expression vector and transfected into
cells (e.g., eukaryotic or prokaryotic cells) for expression.
[0240] Moreover, genetic sequences useful for producing the
polypeptides of the present invention may be obtained from a number
of different sources. For example, as discussed extensively above,
a variety of human antibody genes are available in the form of
publicly accessible deposits. Many sequences of antibodies and
antibody-encoding genes have been published and suitable antibody
genes can be chemically synthesized from these sequences using art
recognized techniques. Oligonucleotide synthesis techniques
compatible with this aspect of the invention are well known to the
skilled artisan and may be carried out using any of several
commercially available automated synthesizers. In addition, DNA
sequences encoding several types of heavy and light chains set
forth herein can be obtained through the services of commercial DNA
synthesis vendors. The genetic material obtained using any of the
foregoing methods may then be altered or modified to provide obtain
polypeptides of the present invention.
[0241] Alternatively, antibody-producing cell lines may be selected
and cultured using techniques well known to the skilled artisan.
Such techniques are described in a variety of laboratory manuals
and primary publications. In this respect, techniques suitable for
use in the invention as described below are described in Current
Protocols in Immunology, Coligan et al., Eds., Green Publishing
Associates and Wiley-Interscience, John Wiley and Sons, New York
(1991) which is herein incorporated by reference in its entirety,
including supplements.
[0242] It will fturther be appreciated that the scope of this
invention further encompasses all alleles, variants and mutations
of antigen binding DNA sequences.
[0243] As is well known, RNA may be isolated from the original
hybridoma cells or from other transformed cells by standard
techniques, such as guanidinium isothiocyanate extraction and
precipitation followed by centrifugation or chromatography. Where
desirable, mRNA may be isolated from total RNA by standard
techniques such as chromatography on oligo dT cellulose. Suitable
techniques are familiar in the art.
[0244] Variable and constant region domains can be obtained from
any source and be incorporated into a modified antibody of the
invention. To clone antibodies, mRNA can be isolated from
hybridoma, spleen, or lymph cells, reverse transcribed into DNA,
and antibody genes amplified by PCR. PCR may be initiated by
consensus constant region primers or by more specific primers based
on the published heavy and light chain DNA and amino acid
sequences. As discussed above, PCR also may be used to isolate DNA
clones encoding the antibody light and heavy chains. In this case
the libraries may be screened by consensus primers or larger
homologous probes, such as mouse constant region probes. Numerous
primer sets suitable for amplification of antibody genes are known
in the art (e.g., 5' primers based on the N-terminal sequence of
purified antibodies (Benhar and Pastan. 1994. Protein Engineering
7:1509); rapid amplification of cDNA ends (Ruberti, F. et al. 1994.
J. Immunol. Methods 173:33); antibody leader sequences (Larrick et
al. 1989 Biochem. Biophys. Res. Commun. 160:1250); or based on
known variable region framework amino acid sequences from the Kabat
(Kabat et al. 1991. Sequences of Proteins of Immunological
Interest. Bethesda, Md: JS Dep. Health Hum. Serv. 5.sup.th ed.) or
the V-base databases (e.g., Orlandi et al. 1989. Proc. Natl. Acad.
Sci. USA 86:3833; Sblattero et al. 1998. Immunotechnology 3:271; or
Krebber et al. 1997. J. Immunol. Methods 201:35). Constant region
domains can be selected having a particular effector function (or
lacking a particular effector function) or with a particular
modification to reduce immunogenicity. Variable and constant
domains can be cloned, e.g., using the polymerase chain reaction
and primers which are selected to amplify the domain of interest.
PCR amplification methods are described in detail in U.S. Pat. Nos.
4,683,195; 4,683,202; 4,800,159; 4,965,188; and in, e.g., "PCR
Protocols: A Guide to Methods and Applications" Innis et al. eds.,
Academic Press, San Diego, Calif. (1990); Ho et al. 1989. Gene
77:51; Horton et al. 1993. Methods Enzymol. 217:270).
[0245] Alternatively, V domains can be obtained from libraries of V
gene sequences from an animal of choice. Libraries expressing
random combinations of domains, e.g., VH and VL domains, can be
screened with a desired antigen to identify elements which have
desired binding characteristics. Methods of such screening are well
known in the art. For example, antibody gene repertoires can be
cloned into a .lambda. bacteriophage expression vector (Huse, W D
et al. 1989. Science 2476:1275). In addition, cells (Boder and
Wittrup. 1997. Nat. Biotechnol. 15:553; Daugtherty, P. et al. 2000.
J. Immunol. Methods. 243:211; Francisco et al. 1994. Proc. Natl.
Acad. Sci. USA 90:10444; Georgiou et al. 1997. Nature Biotechnology
15:29) or viruses (e.g., Hoogenboom, H R. 1998 Immunotechnology 4:1
Winter et al. 1994. Annu. Rev. Immunol. 12:433; Griffiths, A D.
1998. Curr. Opin. Biotechnol. 9:102) expressing antibodies on their
surface can be screened. Ribosomal display can also be used to
screen antibody libraries (Hanes J., et al. 1998. Proc. Natl. Acad.
Sci. USA 95:14130; Hanes, J. and Pluckthun. 1999. Curr. Top.
Microbiol. Immunol. 243:107; He, M. and Taussig. 1997. Nucleic
Acids Research 25:5132).
[0246] Preferred libraries for screening are human V gene
libraries. VL and VH domains from a non-human source may also be
used. In one embodiment, such non-human V domains can be altered to
reduce their immunogenicity using art recognized techniques.
[0247] Libraries can be nave, from immunized subjects, or
semi-synthetic (Hoogenboom, H. R. and Winter. 1992. J. Mol. Biol.
227:381; Griffiths, A D, et al. EMBO J. 13:3245; de Kruif, J. et
al. 1995. J. Mol. Biol. 248:97; Barbas, C. F., et al. 1992. Proc.
Natl. Acad. Sci. USA 89:4457).
[0248] In addition, the sequences of many antibody V and C domains
are known and such domains can be synthesized using methods well
known in the art.
[0249] In one embodiment, mutations can be made to immunoglobulin
domains to create a library of nucleic acid molecules having
greater heterogeneity (Thompson, J., et al. 1996. J. Mol. Biol.
256:77; Lamminmaki, U. et al. 1999. J. Mol. Biol. 291:589;
Caldwell, R. C. and Joyce G F. 1992. PCR Methods Appl. 2:28;
Caldwell R C and Joyce G F. 1994. PCR Methods Appl. 3:S136.
Standard screening procedures can be used to select high affinity
variants. In another embodiment, changes to VH and VL sequences can
be made to increase antibody avidity, e.g., using information
obtained from crystal structures using techniques known in the
art.
[0250] C. Modified Antibodies
[0251] Exemplary constructs include, e.g., minibodies, diabodies,
diabodies fused to CH3 molecules, tetravalent antibodies,
intradiabodies (e.g., Jendreyko et al. 2003. J. Biol. Chem.
278:47813), bispecific antibodies, fusion proteins (e.g., antibody
cytokine fusion proteins, proteins fused to at least a portion of
an Fc receptor), bispecific antibodies. Other immunoglobulins (Ig)
and certain variants thereof are described, for example in U.S.
Pat. No. 4,745,055; EP 256,654; Faulkner et al., Nature 298:286
(1982); EP 120,694; EP 125,023; Morrison, J. Immun. 123:793 (1979);
Kohler et al., Proc. Natl. Acad. Sci. USA 77:2197 (1980); Raso et
al., Cancer Res. 41:2073 (1981); Morrison et al., Ann. Rev.
Immunol. 2:239 (1984); Morrison, Science 229:1202 (1985); Morrison
et al., Proc. Natl. Acad. Sci. USA 81:6851 (1984); EP 255,694; EP
266,663; and WO 88/03559. Reassorted immunoglobulin chains also are
known. See, for example, U.S. Pat. No. 4,444,878; WO 88/03565; and
EP 68,763 and references cited therein.
[0252] In one embodiment, a polypeptide of the invention comprises
an immunoglobulin heavy chain having deletion or substitution of at
least one amino acid. For example, the mutation of one or more
single amino acid in selected areas of the CH2 domain may be enough
to substantially reduce Fc binding and thereby increase tumor
localization. Similarly, it may be desirable to simply delete that
part of one or more constant region domains that control the
effector function (e.g. complement binding) to be modulated. Such
partial deletions of the constant regions may improve selected
characteristics of the antibody (serum half-life) while leaving
other desirable functions associated with the subject constant
region domain intact. Accordingly, in one embodiment, a binding
molecule of the invention lacks all or part of a CH2 domain.
Moreover, as alluded to above, the constant regions of the
disclosed antibodies may be modified through the mutation or
substitution of one or more amino acids that enhances the profile
of the resulting construct. In this respect it may be possible to
disrupt the activity provided by a conserved binding site (e.g. Fc
binding) while substantially maintaining the configuration and
immunogenic profile of the modified antibody. Yet other preferred
embodiments may comprise the addition of one or more amino acids to
the constant region to enhance desirable characteristics such as
effector function or provide for more cytotoxin or carbohydrate
attachment. In such embodiments it may be desirable to insert or
replicate specific sequences derived from selected constant region
domains.
[0253] In another embodiment, mutations to naturally occurring
hinge regions can be made. Such modifications to the constant
region in accordance with the instant invention may easily be made
using well known biochemical or molecular engineering techniques
well within the skill of the art.
[0254] In one embodiment, polypeptides of the invention comprise
modified constant regions wherein one or more domains are partially
or entirely deleted ("domain deleted antibodies"). In especially
preferred embodiments compatible modified antibodies will comprise
domain deleted constructs or variants wherein the entire CH2 domain
has been removed. A variety of modified antibody constructs are
described in more detail below.
[0255] i. Minibodies
[0256] In one embodiment, the modified antibodies of the invention
are minibodies. Minibodies are dimeric molecules made up of two
polypeptide chains each comprising an ScFv molecule (a single
polypeptide comprising one or more antigen binding sites, e.g., a
VL domain linked by a flexible linker to a VH domain fused to a CH3
domain via a connecting peptide. An exemplary minibody construct is
shown in FIG. 2. In FIG. 2 a CH3 domain is fused at its N-terminus
to a connecting peptide which is fused at its N-terminus to a VH
domain which is fused via its N-terminus to a flexible linker which
is fused at its N-terminus to a VL domain.
[0257] ScFv molecules can be constructed in a VH-linker-VL
orientation or VL-linker-VH orientation.
[0258] The flexible hinge that links the VL and VH domains that
make up the antigen binding site preferably comprises from about 10
to about 50 amino acid residues. An exemplary connecting peptide
for this purpose is (Gly4Ser)3 (SEQ ID NO:35) (Huston et al. 1988.
Proc. Natl. Acad. Sci. USA 85:5879). Other connecting peptides are
known in the art.
[0259] Methods of making single chain antibodies are well known in
the art, e.g., Ho et al. 1989. Gene 77:51; Bird et al. 1988 Science
242:423; Pantoliano et al. 1991. Biochemistry 30:10117; Milenic et
al. 1991. Cancer Research 51:6363; Takkinen et al. 1991. Protein
Engineering 4:837.
[0260] Minibodies can be made by constructing an ScFv component and
connecting peptide-CH3 component using methods described in the art
(see, e.g., U.S. Pat. No. 5,837,821 or WO 94/09817A1). These
components can be isolated from separate plasmids as restriction
fragments and then ligated and recloned into an appropriate vector.
Appropriate assembly can be verified by restriction digestion and
DNA sequence analysis.
[0261] In one embodiment, a minibody of the invention comprises a
connecting peptide. In one embodiment, the connecting peptide
comprises a gly/ser linker, e.g., GGGSSGGGSGG (SEQ ID NO: 1).
[0262] In another embodiment, a tetravalent minibody can be
constructed. Tetravalent minibodies can be constructed in the same
manner as minibodies, except that two ScFv molecules are linked
using a flexible linker, e.g., having an amino acid sequence
(G4S).sub.4G3AS (SEQ ID NO: 36). An exemplary tetravalent minibody
is illustrated in FIG. 2.
[0263] ii. Domain Deleted Antibodies
[0264] In another embodiment, the modified antibodies of the
invention are CH2 domain deleted antibodies. Domain deleted
constructs can be derived from a vector (e.g., from IDEC
Pharmaceuticals, San Diego) encoding an IgG.sub.1 human constant
domain (see, e.g., WO 02/060955A2 and WO02/096948A2). Essentially,
the vector was engineered to delete the CH2 domain and provide a
modified vector expressing a domain deleted IgG.sub.1 constant
region. Genes encoding the murine variable region of the C2B8
antibody, 5E8 antibody, B3F6 antibody, or the variable region of
the humanized CC49 antibody were then inserted in the modified
vector and cloned. When expressed in transformed cells, these
vectors provided C2B8..DELTA.CH2, 5E8..DELTA.CH2, B3F6..DELTA.CH2
or huCC49..DELTA.CH2 or respectively. These constructs exhibit a
number of properties that make them particularly attractive
candidates for monomeric subunits.
[0265] Besides the deletion of whole constant region domains, it
will be appreciated that the antibodies of the present invention
can be engineered to partially delete or substitute of a few amino
acids or even a single amino acid. For example, the mutation of a
single amino acid in selected areas of the C.sub.H2 domain may be
enough to substantially reduce Fc binding and thereby increase
tumor localization. Similarly, it may be desirable to simply delete
that part of one or more constant region domains that control the
effector function (e.g. complement C1Q binding). Such partial
deletions of the constant regions may improve selected
characteristics of the antibody (serum half-life) while leaving
other desirable functions associated with the subject constant
region domain intact. Creation of a C.sub.H2 domain deleted version
can be accomplished by way of overlapping PCR mutagenesis. The
gamma 1 constant domain begins with a plasmid encoded NheI site
with is in translational reading frame with the immunoglobulin
sequence. A 5' PCR primer was constructed encoding the NheI site as
well as sequence immediately downstream. A 3' PCR primer mate was
constructed such that it anneals with the 3' end to the
immunoglobulin hinge region and encodes in frame the first several
amino acids of the gamma 1 CH3 domain. A second PCR primer pair
consisted of the reverse complement of the 3' PCR primer from the
first pair (above) as the 5' primer and a 3' primer that anneals at
a loci spanning the BsrGI restriction site within the C.sub.H3
domain. Following each PCR amplification, the resultant products
were utilized as template with the NheI and BsrGI 5' and 3',
respectively primers. The amplified product was then cloned back
into N5KG1 to create the plasmid N5KG1.DELTA.C.sub.H2. This
construction places the intact CH3 domain immediately downstream
and in frame with the intact hinge region. A similar procedure can
be used to create a domain deleted construct in which the CH3
domain is immediately downstream of a connecting peptide. For
example, a domain deleted version of the C2B8 antibody was created
in this manner as described in U.S. Pat. Nos. 5,648,267 and
5,736,137 each of which is incorporated herein by reference.
[0266] In one embodiment, tetravalent domain-deleted antibodies can
be produced by combining a DNA sequence encoding a domain deleted
antibody with a ScFv molecule. For example, in one embodiment,
these sequences are combined such that the ScFv molecule is linked
at its N-terminus to the CH3 domain of the domain deleted antibody
via a flexible linker (e.g., a gly/ser linker such as
(Gly4Ser).sub.3 (SEQ ID NO: 35).
[0267] In another embodiment a tetravalent antibody can be made by
fusing an ScFv molecule to a connecting peptide, which is fused to
a CH1 domain to construct an ScFv-Fab tetravalent molecule. (Coloma
and Morrison. 1997. Nature Biotechnology. 15:159; WO 95/09917).
[0268] iii. Diabodies
[0269] Diabodies are similar to scFv molecules, but usually have a
short (less than 10 and preferably 1-5) amino acid residue linker
connecting both V-domains, such that the VL and VH domains on the
same polypeptide chain can not interact. Instead, the VL and VH
domain of one polypeptide chain interact with the VH and VL domain
(respectively) on a second polypeptide chain (WO 02/02781). In one
embodiment, a binding molecule of the invention is a diabody fused
to at least one heavy chain portion. In a preferred embodiment, a
binding molecule of the invention is a diabody fused to a CH3
domain.
[0270] In one embodiment a modified antibody of the invention a
binding molecule comprises a tetravalent or bispecific tetravalent
CH2 domain-deleted antibody with a scFv appended to the N-terminus
of the light chain. In another embodiment of the invention, a
binding molecule comprises a a tetravalent or bispecific
tetravalent CH2 domain-deleted antibody with a scFv appended to the
N-terminus of the heavy chain. In one embodiment, the attachment of
the scFv to the N-terminus results in reduced aggregation of the
molecules as compared to molecules in which the scFv is attached at
the carboxy-terminus. In one embodiment, less than about 30%
aggregates are present in a composition of binding molecules
produced by cells expressing a N-terminal fusion construct. In one
embodiment, less than about 20% aggregates are present in a
composition of binding molecules produced by cells expressing a
N-terminal fusion construct. In one embodiment, less than about 10%
aggregates are present in a composition of binding molecules
produced by cells expressing a N-terminal fusion construct. In one
embodiment, less than about 5% aggregates are present in a
composition of binding molecules produced by cells expressing a
N-terminal fusion construct.
[0271] Other forms of modified antibodies are also within the scope
of the instant invention (e.g., WO 02/02781 A1; U.S. Pat. Nos.
5,959,083; 6,476,198 B1; US 2002/0103345 A1; WO 00/06605; Byrn et
al. 1990. Nature. 344:667-70; Chamow and Ashkenazi. 1996. Trends
Biotechnol. 14:52).
[0272] D. Catalytic Antibodies
[0273] In one embodiment, at least one binding specificity of a
modified antibody molecule of the invention is catalytic. Catalytic
binding specificities can be made using art recognized techniques
(see, e.g., U.S. Pat. No. 6,590,080, U.S. Pat. No. 5,658,753).
Catalytic binding specificities can work by a number of basic
mechanisms similar to those identified for enzymes to stabilize the
transition state, thereby reducing the free energy of activation.
For example, general acid and base residues can be optimally
positioned for participation in catalysis within catalytic active
sites; covalent enzyme-substrate intermediates can be formed;
catalytic antibodies can also be in proper orientation for reaction
and increase the effective concentration of reactants by at least
seven orders of magnitude (Fersht, A. R., et al., Am. Chem. Soc. 90
(1968):5833) and thereby greatly reduce the entropy of a chemical
reaction. Finally, catalytic antibodies can convert the energy
obtained upon substrate binding to distort the reaction towards a
structure resembling the transition state.
[0274] In one embodiment, acid or base residues can be brought into
the binding site by using a complementary charged molecule as an
immunogen. This technique proved successful for elicitation of
antibodies with a hapten containing a positively-charged ammonium
ion (Shokat, et al., Chem. Int. Ed. Engl. 27 (1988):269-271).
[0275] In another approach, antibodies can be elicited to stable
compounds that resemble the size, shape, and charge of the
transition state of a desired reaction (i.e., transition state
analogs). See U.S. Pat. No. 4,792,446 and U.S. Pat. No. 4,963,355
which describe the use of transition state analogues to immunize
animals and the production of catalytic antibodies. Both of these
patents are hereby incorporated by reference. In one embodiment,
such molecules can be administered as part of an immunoconjugate,
e.g., with an immunogenic carrier molecule, such as KLH.
[0276] Exemplary catalytic binding specificities can have, e.g.,
esterase activity (involving a charged transition state whose
electrostatic and shape characteristics can be mimicked by a
phosphonate structure; Jacobs, et al., J. Am. Chem. Soc. 109
(1987):2174-2176; Durfor, et al., J. Am. Chem. Soc. 110
(1988):8713-8714; Tramontano, et al., J. Am. Chem. Soc. 110
(1988):2282; Pollack, et al., J. Am. Chem. Soc. 111
(1989):5961-5962); peptidase or amidase activity (Janda, et al.,
Science 241 (1988):1188-1191; Iverson, et al., Science 243
(1989):1184-1188; Paul, et al., Science 244 (1989):1158-1162);
Claisen rearrangement (Jackson, et al., J. Am. Chem. Soc. 110
(1988):4841-4842; Hilvert, et al., Proc. Natl. Acad. Sci. USA 85
(1988):4953-4955; Hilvert, et al., J. Am. Chem. Soc. 110
(1988):5593-5594); redox reactions (Shokat, et al., Angew. Chem.
Int. Ed. Engl. 27 (1989):269-271); photochemical cleavage of a
thymine dimer (Cochran, et al., J. Am. Chem. Soc. 110
(1988):7888-7890); stereospecific transesterification
rearrangements (Napper, et al., Science 237 (1987):1041-1043); or a
bimolecular amide synthesis (Benkovic, et al., Proc. Natl. Acad.
Sci. USA 85 (1988):5355-5358; Janda, et al., Science 241
(1988):1188-1191).
[0277] In another approach, conventional binding specificities can
be mutated to render them catalytic.
[0278] Methods of screening for catalytic antibody activity are
well known in the art (e.g., Reymond, J. L. 2002. Journal of
Immunological Methods 269:125; Mouratou et al. 2002. J. of
Immunological Methods. 269:147. In yet another embodiment,
catalytic B cells can be selected, e.g., as described in U.S. Pat.
No. 6,590,080 using a molecule can be constructed which facilitates
selection of catalytic B cells.
[0279] In another embodiment, catalytic binding specificities can
be developed as part of a two step process. Catalytic antibodies
can be selected only if displaying the following binding features:
binding both the substrate and a reactive group in such a way that
the two groups are in a reactive position towards each other.
Second, the selected antibodies can be chemically engineered by
covalently binding a reactive group into the binding pocket of the
antibody. J Immunol Methods. 2002. 269:81-98.
[0280] In one embodiment, a catalytic binding specificity is
specific for a prodrug. Such a binding specificity can be used to
catalyze the conversion of a prodrug into a drug which is effective
in vivo. Preferably, the reaction catalyzed is one that cannot be
accomplished by natural enzymes in vivo. Examples of prodrug
activation by antibodies are known in the art (see, e.g., Miyashita
et al. 1993. Proc. Natl. Acad. Sci. USA 90:5337).
[0281] In one embodiment, a modified antibody molecule of the
invention comprises at least one binding specificity for a target
cell and at least one binding specificity for a prodrug. For
example, in a preferred embodiment, an modified antibody molecule
of the invention comprises at least one binding specificity for a
tumor cell and at least one binding specificity for a prodrug which
can be converted to cytotoxic drug. In one example, a modified
antibody of the invention comprises a binding specificity for a
carbamate prodrug 4-[N,N,-bis(2-chloroethyl)]aminopheny-
l-N-[(1S-(1,3-dicarboxy)propyl]carbamate and generates the
corresponding cytotoxic nitrogen mustard (Wentworth et al. 1996.
Proc Natl. Acad. Sci. USA. 93:799).
[0282] In one embodiment, the modified antibody is administered
prior to administration of the prodrug to allow accumulation at the
site of the target cell. Exemplary prodrugs are known in the art.
Prodrugs can also be synthesized by incorporating a portion
designed to be released by catalytic action, e.g., by sequential
retro-aldol/retro-Michael reactions catalyzed by an antibody with
aldolase activity. (Shabat et al. 2001. Proc. Natl. Acad. Sci. USA
98:7428). Such drug masking portions can be made, e.g., by
modification of hydroxyl or thiol groups of drugs.
[0283] E. Multispecific Binding Molecules
[0284] In one embodiment, a binding molecule of the invention is
multispecific, i.e., has at least one binding site that binds to a
first molecule or epitope of a molecule and at least one second
binding site that binds to a second molecule of epitope of a
molecule.
[0285] In one embodiment, a binding molecule of the invention is
bispecific. Bispecific molecules can bind to two different target
sites, e.g., on the same target molecule or on different target
molecules. For example, in the case of antibodies, bispecific
molecules can bind to two different epitopes, e.g., on the same
antigen or on two different antigens. Bispecific molecules can be
used, e.g., in diagnostic and therapeutic applications. For
example, they can be used to immobilize enzymes for use in
immunoassays. They can also be used in diagnosis and treatment of
cancer, e.g., by binding both to a tumor associated molecule and a
detectable marker (e.g., a chelator which tightly binds a
radionuclide. Bispecific molecules can also be used for human
therapy, e.g., by directing cytotoxicity to a specific target (for
example by binding to a pathogen or tumor cell and to a cytotoxic
trigger molecule, such as the T cell receptor or the Fc.gamma.
receptor. Bispecific antibodies can also be used, e.g., as
fibrinolytic agents or vaccine adjuvants.
[0286] Examples of bispecific binding molecules include those with
at least two arms directed against tumor cell antigens; bispecific
binding molecules with at least one arm directed against a tumor
cell antigen and the at least one arm directed against a cytotoxic
trigger molecule (such as anti-Fc.gamma.RI/anti-CD15,
anti-p185.sup.HER2/Fc.gamma.RIII (CD16), anti-CD3/anti-malignant
B-cell (1D10), anti-CD3/anti-p185.sup.HER2, anti-CD3/anti-p97,
anti-CD3/anti-renal cell carcinoma, anti-CD3/anti-OVCAR-3,
anti-CD3/L-D1 (anti-colon carcinoma), anti-CD3/anti-melanocyte
stimulating hormone analog, anti-EGF receptor/anti-CD3,
anti-CD3/anti-CAMA1, anti-CD3/anti-CD19, anti-CD3/MoV18,
anti-neural cell adhesion molecule (NCAM)/anti-CD3, anti-folate
binding protein (FBP)/anti-CD3, anti-pan carcinoma associated
antigen (AMOC-31)/anti-CD3); bispecific binding molecules with at
least one which binds specifically to a tumor antigen and at least
one which binds to a toxin (such as anti-saporin/anti-Id-1,
anti-CD22/anti-saporin, anti-CD7/anti-saporin,
anti-CD38/anti-saporin, anti-CEA/anti-ricin A chain,
anti-interferon-.alpha.(IFN-.alpha.)/anti-hybridoma idiotype,
anti-CEA/anti-vinca alkaloid); bispecific binding molecules for
converting enzyme activated prodrugs (such as
anti-CD30/anti-alkaline phosphatase (which catalyzes conversion of
mitomycin phosphate prodrug to mitomycin alcohol)); bispecific
binding molecules which can be used as fibrinolytic agents (such as
anti-fibrin/anti-tissue plasminogen activator (tPA),
anti-fibrin/anti-urokinase-type plasminogen activator (uPA));
bispecific binding molecules for targeting immune complexes to cell
surface receptors (such as anti-low density lipoprotein
(LDL)/anti-Fc receptor (e.g. Fc.gamma.RI, Fc.gamma.RII or
Fc.gamma.RIII)); bispecific binding molecules for use in therapy of
infectious diseases (such as anti-CD3/anti-herpes simplex virus
(HSV), anti-T-cell receptor: CD3 complex/anti-influenza,
anti-Fc.gamma.R/anti-HI- V; bispecific binding molecules for tumor
detection in vitro or in vivo such as anti-CEA/anti-EOTUBE,
anti-CEA/anti-DPTA, anti-p185HER2/anti-hapt- en); bispecific
binding molecules as vaccine adjuvants (see Fanger et al., supra);
and bispecific binding molecules as diagnostic tools (such as
anti-rabbit IgG/anti-ferritin, anti-horse radish peroxidase
(HRP)/anti-hormone, anti-somatostatin/anti-substance P,
anti-HRP/anti-FITC, anti-CEA/anti-.beta.-galactosidase (see Nolan
et al., supra)). Examples of trispecific antibodies include
anti-CD3/anti-CD4/anti-CD37, anti-CD3/anti-CD5/anti-CD37 and
anti-CD3/anti-CD8/anti-CD37.
[0287] In a preferred embodiment, a bispecific molecule of the
invention binds to CRIPTO-I.
[0288] Bispecific molecules may be monovalent for each specificity
or be multivalent for each specificity. For example, an antibody
molecule or fusion protein may comprise one binding site that
reacts with a first target molecule and one binding site that
reacts with a second target molecule or it may comprise two binding
sites that react with a first target molecule and two binding sites
that react with a second target molecule. Methods of producing
bispecific molecules are well known in the art. For example,
recombinant technology can be used to produce bispecific molecules,
e.g., diabodies, single-chain diabodies, tandem scFvs, etc.
Exemplary techniques for producing bispecific molecules are known
in the art (e.g., Kontermann et al. Methods in Molecular Biology
Vol. 248: Antibody Engineering: Methods and Protocols. Pp 227-242
US 2003/0207346 A1 and the references cited therein;). In one
embodiment, a multimeric bispecific molecules are prepared using
methods such as those described e.g., in US 2003/0207346 A1 or U.S.
Pat. No. 5,821,333, or US2004/0058400.
[0289] As used herein the phrase "multispecific fusion protein"
designates fusion proteins (as hereinabove defined) having at least
two binding specificities (i.e. combining two or more binding
domains of a ligand or receptor). Multispecific fusion proteins can
be assembled as heterodimers, heterotrimers or heterotetramers,
essentially as disclosed in WO 89/02922 (published Apr. 6, 1989),
in EP 314,317 (published May 3, 1989), and in U.S. Pat. No.
5,116,964 issued May 2, 1992. Preferred multispecific fusion
proteins are bispecific. Examples of bispecific fusion proteins
include CD4-IgG/TNFreceptor-IgG and CD4-IgG/L-selectin-IgG. The
last mentioned molecule combines the lymph node binding function of
the lymphocyte homing receptor (LHR, L-selectin), and the HIV
binding function of CD4, and finds potential application in the
prevention or treatment of HIV infection, related conditions, or as
a diagnostic.
[0290] Target binding sites for the multispecific binding molecules
of the invention can readily be selected by one of ordinary skill
in the art. While not limiting in any way, exemplary binding sites
include one or more epitopes of a tumor antigen. Other exemplary
target molecules include one or more epitopes of, e.g., heparin
sulfate, growth factors or their receptors (e.g., epidermal growth
factor receptor, insulin-like growth factor receptor, hepatocyte
growth factor (HGF/SF) receptor, MORE (See, e.g., Cao et al. Proc.
Natl. Acad. Sci 2001. 98:7443; Lu et al. 2004. J. Biol. Chem.
279:2856).
[0291] In another embodiment, the invention pertains to bispecific
molecules, e.g., antibodies, which incorporate at least one binding
site that binds to a known target and at least one binding site
which recognizes an unknown target (for example, in one embodiment,
the bispecific molecule incorporates binding sites selected from a
semi-synthetic antibody phage display library).
[0292] In one embodiment of the invention, one of ordinary skill in
the art could start with a single chain antibody of known
specificity and build a Fab library using techniques known in the
art or, alternatively, the skilled artisan could start with an Fab
fragment of known specificity and build a single chain library
using techniques known in the art. It is known in the art that
libraries from nonimmunized sources and prepared by synthetic
recombination of V-gene sequences (preferably recombination of VH
with, DH and JH, and VL with JL sequences) can be used to isolate
antibodies to any antigen. For example, patent application
WO92/01047 teaches that antibody fragments can be displayed on the
surface of bacteriophage and that they will bind antigen. Antibody
fragments (e.g., Fab, Fv, ScFv and VH) can be directly selected
using this characteristic. Other methods known in the art include
those taught, e.g., in U.S. Pat. No. 5,698,426; 6,291,159;
5,658,727; 5,667,988; and 5,969,108.
[0293] In another embodiment, scFv which recognize a known target
can be dimerized with scFv isolated from a semi-synthetic human
phage antibody display library. (see, e.g., Kruif and Logtenberg
1996. J. Biol. Chem. 271:7630).
[0294] In one embodiment, the subject bispecific molecule is
expressed in any expression system used to express antibody
molecules, for example mammalian cells, yeast such as Picchia, E.
coli, Bacculovirus, etc. In one embodiment, the subject bispecific
molecule is expressed in the NEOSPLA vector system (see, e.g., U.S.
Pat. No. 6,159,730). This vector contains the cytomegalovirus
promoter/enhancer, the mouse beta globin major promoter, the SV40
origin of replication, the bovine growth hormone polyadenylation
sequence, neomycin phosphotransferase exon 1 and exon 2, the
dihydrofolate reductase gene and leader sequence.
[0295] In one embodiment, the subject bispecific molecules comprise
a synthetic connecting peptide.
[0296] These bispecific molecules have one or more binding sites
for a known target and express a library at one or more binding
sites. Such bispecific molecules can be used, e.g., to identify
molecules in close proximity to or associated with the known
target. For example, the skilled artisan could use the subject
bispecific molecules in an assay to select for those that induce a
particular response, e.g., apoptosis or cellular activation, using
screening methods well known in the art. The bispecific molecule
identified as producing the response screened for can then be
identified and its specificity determined. Using such methods it is
possible to identify molecules in close association with particular
targets of interest, e.g., T cell markers or other signaling
molecules (such as CRIPTO-I, death domain molecules, or molecules
involved in apoptosis). The proximity of the known target and the
molecule newly identified as a "nearest neighbor" can be confirmed
using immunoprecipitation or other techniques known to those of
skill in the art. Using these methods it is possible to identify
molecules as targets for modulating a particular cellular
response.
[0297] In one embodiment, a polypeptide molecule of the invention
comprises an amino acid sequence encoded by a nucleic acid molecule
comprising a nucleic acid sequence shown in FIG. 8A (SEQ ID NO:16),
FIG. 8B (SEQ ID NO:17), FIG. 8C (SEQ ID NO:18), FIG. 10A (SEQ ID
NO:22), FIG. 10B (SEQ ID NO:23). In another embodiment, a nucleic
acid molecule of the invention comprises a nucleotide sequence
shown in FIG. 8A (SEQ ID NO:16), FIG. 8B (SEQ ID NO:17), FIG. 8C
(SEQ ID NO:18), FIG. 10A (SEQ ID NO:22), FIG. 10B (SEQ ID
NO:23).
[0298] In another embodiment, a polypeptide of the invention
comprises an amino acid sequence shown in FIG. 9A (SEQ ID NO:19),
FIG. 9B (SEQ ID NO:20), FIG. 9C (SEQ ID NO:21), FIG. 11A (SEQ ID
NO:24), or FIG. 11B (SEQ ID NO:25).
[0299] In another embodiment, a polypeptide of the invention is
encoded by a nucleic acid molecule comprising the nucleotide
sequence shown in FIG. 12A (SEQ ID NO:26), FIG. 12B (SEQ ID NO:27),
FIG. 14 (SEQ ID NO:30), or FIG. 15 (SEQ ID NO:31). In another
embodiment, a nucleic acid molecule of the invention comprises a
nucleotide sequence shown in FIG. 12A (SEQ ID NO:26), FIG. 12B (SEQ
ID NO:27), FIG. 14 (SEQ ID NO:30), or FIG. 15 (SEQ ID NO:31).
[0300] In one embodiment, a polypeptide molecule of the invention
comprises an amino acid sequence shown in FIG. 13A (SEQ ID NO:28),
FIG. 13B (SEQ ID NO:29), FIG. 16 (SEQ ID NO:32), or FIG. 17 (SEQ ID
NO:33).
[0301] The other nucleic acid and amino acid sequences disclosed
herein in the sequence listing and Figures are also embraced by the
invention.
[0302] B. Expression of Polypeptides
[0303] Following manipulation of the isolated genetic material to
provide polypeptides of the invention as set forth above, the genes
are typically inserted in an expression vector for introduction
into host cells that may be used to produce the desired quantity of
modified antibody that, in turn, provides the claimed
polypeptides.
[0304] The term "vector" or "expression vector" is used herein for
the purposes of the specification and claims, to mean vectors used
in accordance with the present invention as a vehicle for
introducing into and expressing a desired gene in a cell. As known
to those skilled in the art, such vectors may easily be selected
from the group consisting of plasmids, phages, viruses and
retroviruses. In general, vectors compatible with the instant
invention will comprise a selection marker, appropriate restriction
sites to facilitate cloning of the desired gene and the ability to
enter and/or replicate in eukaryotic or prokaryotic cells.
[0305] For the purposes of this invention, numerous expression
vector systems may be employed. For example, one class of vector
utilizes DNA elements which are derived from animal viruses such as
bovine papilloma virus, polyoma virus, adenovirus, vaccinia virus,
baculovirus, retroviruses (RSV, MMTV or MOMLV) or SV40 virus.
Others involve the use of polycistronic systems with internal
ribosome binding sites. Exemplary vectors include those taught in
U.S. Pat. Nos. 6,159,730 or 6,413,777 or US 2003 0157641 A1).
Additionally, cells which have integrated the DNA into their
chromosomes may be selected by introducing one or more markers
which allow selection of transfected host cells. The marker may
provide for prototrophy to an auxotrophic host, biocide resistance
(e.g., antibiotics) or resistance to heavy metals such as copper.
The selectable marker gene can either be directly linked to the DNA
sequences to be expressed, or introduced into the same cell by
cotransformation.
[0306] In one embodiment, an inducible expression system can be
employed.
[0307] Additional elements may also be needed for optimal synthesis
of mRNA. These elements may include signal sequences, splice
signals, as well as transcriptional promoters, enhancers, and
termination signals.
[0308] In one embodiment, a secretion signal, e.g., any one of
several well characterized bacterial leader peptides (e.g., pelB,
phoA, or ompA), can be fused in-frame to the N terminus of a
polypeptide of the invention to obtain optimal secretion of the
polypeptide. (Lei et al. 1988 Nature 331:543; Better et al. Science
1988. 240:1041; Mullinax et al., 1990. Proc. Natl. Acad. Sci. USA
87:8095).
[0309] In one embodiment, a vector can be used which comprises a
nucleic acid sequence encoding a peptide linker. In another
embodiment, it might be desirable to first assemble the desired
coding sequences (e.g., secretion signal, VL, linker peptide, VH,
etc.) into a single sequence, for example, by PCR amplification
using overlapping primers, followed by ligation into a plasmid or
other vector.
[0310] In particularly preferred embodiments the cloned variable
region genes are inserted into an expression vector along with the
heavy and light chain constant region genes (preferably human)
modified as discussed above. Preferably, this is effected using a
proprietary expression vector of IDEC, Inc., referred to as NEOSPLA
see U.S. Pat. No. 6,159,730. This vector contains the
cytomegalovirus promoter/enhancer, the mouse beta globin major
promoter, the SV40 origin of replication, the bovine growth hormone
polyadenylation sequence, neomycin phosphotransferase exon 1 and
exon 2, the dihydrofolate reductase gene and leader sequence. As
seen in the examples below, this vector has been found to result in
very high level expression of antibodies upon incorporation of
variable and constant region genes, transfection in CHO cells,
followed by selection in G418 containing medium and methotrexate
amplification. Vector systems are also taught in U.S. Pat. Nos.
5,736,137 and 5,658,570, each of which is incorporated by reference
in its entirety herein. This system provides for high expression
levels, e.g., >30 pg/cell/day. Other exemplary vector systems
are disclosed e.g., in U.S. Pat. No. 6,413,777.
[0311] In other preferred embodiments the polypeptides of the
invention of the instant invention may be expressed using
polycistronic constructs such as those disclosed in United States
provisional application No. 60/331,481 filed Nov. 16, 2001 and
incorporated herein in its entirety. In these novel expression
systems, multiple gene products of interest such as heavy and light
chains of antibodies may be produced from a single polycistronic
construct. These systems advantageously use an internal ribosome
entry site (IRES) to provide relatively high levels of polypeptides
of the invention in eukaryotic host cells. Compatible IRES
sequences are disclosed in U.S. Pat. No. 6,193,980 which is also
incorporated herein. Those skilled in the art will appreciate that
such expression systems may be used to effectively produce the full
range of polypeptides disclosed in the instant application.
[0312] More generally, once the vector or DNA sequence encoding a
monomeric subunit of the polypeptide (e.g. a modified antibody) has
been prepared, the expression vector may be introduced into an
appropriate host cell. That is, the host cells may be transformed.
Introduction of the plasmid into the host cell can be accomplished
by various techniques well known to those of skill in the art.
These include, but are not limited to, transfection (including
electrophoresis and electroporation), protoplast fusion, calcium
phosphate precipitation, cell fusion with enveloped DNA,
microinjection, and infection with intact virus. See, Ridgway, A.
A. G. "Mammalian Expression Vectors" Chapter 24.2, pp. 470-472
Vectors, Rodriguez and Denhardt, Eds. (Butterworths, Boston, Mass.
1988). Most preferably, plasmid introduction into the host is via
electroporation. The transformed cells are grown under conditions
appropriate to the production of the light chains and heavy chains,
and assayed for heavy and/or light chain protein synthesis.
Exemplary assay techniques include enzyme-linked immunosorbent
assay (ELISA), radioimmunoassay (RIA), or flourescence-activated
cell sorter analysis (FACS), immunohistochemistry and the like.
[0313] As used herein, the term "transformation" shall be used in a
broad sense to refer to any introduction of DNA into a recipient
host cell that changes the genotype and consequently results in a
change in the recipient cell.
[0314] Along those same lines, "host cells" refers to cells that
have been transformed with vectors constructed using recombinant
DNA techniques and encoding at least one heterologous gene. In
descriptions of processes for isolation of antibodies from
recombinant hosts, the terms "cell" and "cell culture" are used
interchangeably to denote the source of antibody unless it is
clearly specified otherwise. In other words, recovery of
polypeptide from the "cells" may mean either from spun down whole
cells, or from the cell culture containing both the medium and the
suspended cells.
[0315] The host cell line used for protein expression is most
preferably of mammalian origin; those skilled in the art are
credited with ability to preferentially determine particular host
cell lines which are best suited for the desired gene product to be
expressed therein. Exemplary host cell lines include, but are not
limited to, DG44 and DUXB11 (Chinese Hamster Ovary lines, DHFR
minus), HELA (human cervical carcinoma), CVI (monkey kidney line),
COS (a derivative of CVI with SV40 T antigen), R1610 (Chinese
hamster fibroblast) BALBC/3T3 (mouse fibroblast), HAK (hamster
kidney line), SP2/O (mouse myeloma), P3.times.63-Ag3.653 (mouse
myeloma), BFA-1c1BPT (bovine endothelial cells), RAJI (human
lymphocyte) and 293 (human kidney). CHO cells are particularly
preferred. Host cell lines are typically available from commercial
services, the American Tissue Culture Collection or from published
literature.
[0316] In another embodiment, a host cell is a prokaryotic cell,
e.g., a strain which allows the formation of disulfide bonds
(Derman, A I, et al. 1993. Science. 262:1744; Bessette, P H. Et al.
1999. Proc. Natl. Acad. Sci. USA 96:13703).
[0317] In vitro production allows scale-up to give large amounts of
the desired polypeptides. Techniques for mammalian cell cultivation
under tissue culture conditions are known in the art and include
homogeneous suspension culture, e.g. in an airlift reactor or in a
continuous stirrer reactor, or immobilized or entrapped cell
culture, e.g. in hollow fibers, microcapsules, on agarose
microbeads or ceramic cartridges. If necessary and/or desired, the
solutions of polypeptides can be purified by the customary
chromatography methods, for example gel filtration, ion-exchange
chromatography, chromatography over DEAE-cellulose or
(immuno-)affinity chromatography, e.g., after preferential
biosynthesis of a modified hinge region polypeptide or prior to or
subsequent to the HIC chromatography step described herein.
[0318] Genes encoding the polypeptide of the invention can also be
expressed non-mammalian cells such as bacteria or yeast or plant
cells. In this regard it will be appreciated that various
unicellular non-mammalian microorganisms such as bacteria can also
be transformed; i.e. those capable of being grown in cultures or
fermentation. Bacteria, which are susceptible to transformation,
include members of the enterobacteriaceae, such as strains of
Escherichia coli or Salmonella; Bacillaceae, such as Bacillus
subtilis; Pneumococcus; Streptococcus, and Haemophilus influenzae.
It will further be appreciated that, when expressed in bacteria,
the polypeptides typically become part of inclusion bodies. The
polypeptides must be isolated, purified and then assembled into
functional molecules. Where tetravalent forms of antibodies are
desired, the subunits will then self-assemble into tetravalent
antibodies (WO02/096948A2).
[0319] In addition to prokaryates, eukaryotic microbes may also be
used. Saccharomyces cerevisiae, or common baker's yeast, is the
most commonly used among eukaryotic microorganisms although a
number of other strains are commonly available. For expression in
Saccharomyces, the plasmid YRp7, for example, (Stinchcomb et al.,
Nature, 282:39 (1979); Kingsman et al., Gene, 7:141 (1979);
Tschemper et al., Gene, 10:157 (1980)) is commonly used. This
plasmid already contains the TRP1 gene which provides a selection
marker for a mutant strain of yeast lacking the ability to grow in
tryptophan, for example ATCC No. 44076 or PEP4-1 (Jones, Genetics,
85:12 (1977)). The presence of the trpl lesion as a characteristic
of the yeast host cell genome then provides an effective
environment for detecting transformation by growth in the absence
of tryptophan.
[0320] IV. Separation of Polypeptides Comprising at Least One
Interchain Disulfide Linkage from those Lacking Interchain
Disulfide Linkages
[0321] In one aspect, the invention pertains to separation of
molecules having two heavy chain portions from a mixture, where a
fraction of the molecules are present in a form in which the two
heavy chain portions are linked via at least one interchain
disulfide linkage and a fraction of the molecules comprise heavy
chain portions that are not linked via at least one disulfide
linkage by hydrophobic interaction chromatography.
[0322] Hydrophobic interaction chromatography was first developed
following the observation that proteins could be retained on
affinity gels which comprised hydrocarbon spacer arms but lacked
the affinity ligand. Elution from HIC supports can be effected by
alterations in solvent, pH, ionic strength, or by the addition of
chaotropic agents or organic modifiers, such as ethylene or
propylene glycol. A description of the general principles of
hydrophobic interaction chromatography can be found e.g., in U.S.
Pat. No. 3,917,527 and in U.S. Pat. No. 4,000,098. HIC in the
context of high performance liquid chromatography (HPLC) has been
used to separate antibody fragments lacking heavy chain portions
(e.g., F(ab').sub.2) from intact antibody molecules in a single
step protocol. (Morimoto, K. et al., L Biochem. Biophys. Meth. 24:
107 (1992)).
[0323] The separation method of the invention can be performed on
an unpurified population of polypeptides (e.g., culture
supernatants or preparations or preparations of polypeptides
isolated from prokaryotic inclusion bodies). Alternatively, the
instant separation methods can be used on polypeptide mixtures
obtained after one or more initial purification steps, e.g., after
a preparation comprising forms A and B has been eluted from an
affinity matrix.
[0324] In one embodiment, the binding molecules subjected to HIC
chromatography comprise a connecting peptide of the invention.
[0325] In a preferred embodiment, HIC can be applied to mixtures
that have been partially purified by other protein purification
procedures. The term "partially purified" as used herein includes a
protein preparation in which the protein of interest is present in
at least 5% by weight, more preferably at least 10% and most
preferably at least 45%. Initial or subsequent purification steps
can be used to remove, e.g., immunoglobulin aggregates, misfolded
species, host cell protein, residue material from preceding
chromatographic steps (such as Protein A when employed). In one
embodiment, HIC can be performed on polypeptides comprising a
connecting peptide of the invention. Accordingly, the application
of HIC can also be appreciated in the context of an overall
purification protocol. Exemplary purification steps that can be
used prior to or subsequent to HIC include: affinity chromatography
(for example, PROSEP-A.RTM. (BioProcessing Ltd., U.K.) which
consists of Protein A covalently coupled to controlled pore glass
or Protein A SEPHAROSE.RTM. Fast Flow (Pharmacia) or TOYOPEARL 650M
Protein A (TosoHaas)). Protein A is preferred for human .gamma.1,
.gamma.2, or .gamma.4 heavy chains and protein G for mouse
isotypes. Bakerbond ABXtm resin can be used if the molecule
comprises a CH3 domain. In addition or alternatively, ion exchange
chromatography may be employed. In this regard various anionic or
cationic substituents may be attached to matrices in order to form
anionic or cationic supports for chromatography. Anionic exchange
substituents include diethylaminoethyl (DEAE), quaternary
aminoethyl (QAE) and quaternary amine (Q) groups. Cationic exchange
substituents. include carboxymethyl (CM), sulfoethyl (SE),
sulfopropyl (SP), phosphate (P) and sulfonate (S). Cellulose ion
exchange resins such as DE23, DE32, DE52, CM-23, CM-32 and CM-52
are available from Whatman Ltd. Maidstone, Kent, U.K.
SEPHADEX.RTM.-based and -locross-linked ion exchangers are also
known. For example, DEAE-, QAE-, CM-, and SP-SEPHADEX.RTM. and
DEAE-, Q-, CM-and S-SEPHAROSE.RTM. and SEPHAROSE.RTM. Fast Flow are
all available from Pharmacia AB. Further, both DEAE and CM
derivitized ethylene glycol-methacrylate copolymer such as
TOYOPEARL DEAE-650S or M and TOYOPEARL CM-650S or M are available
from Toso Haas Co., Philadelphia, Pa. Because elution from ion
exchange supports usually involves addition of salt and because HIC
is enhanced under increased salt concentrations, the introduction
of a HIC step following an ionic exchange chromatographic step or
other salt mediated purification step is preferred. Additional
purification protocols may be added including but not necessarily
limited to: further ionic exchange chromatography, size exclusion
chromatography, viral inactivation, concentration and freeze
drying, hydroxylapatite chromatography, gel electrophoresis,
dialysis, ethanol precipitation, reverse phase HPLC, chromatography
on silica, chromatography on heparin SEQHAROSE.TM.,
chromatofocusing, or ammonium sulfate precipitation.
[0326] Prior to purification using the subject methods, the
composition comprising the mixture of polypeptides to be separated
will preferably be placed in a buffer of acidic or approximately
neutral pH. This can be done, for example, by adding concentrated
buffer, resuspending the sample in the buffer, exchanging the
buffer (e.g., using dialysis or ultrafiltration). Alternatively,
the pH of the sample buffer can simply be adjusted to be within the
desired range.
[0327] Hydrophobic interactions are strongest at high ionic
strength, therefore, this form of separation is conveniently
performed following salt precipitations or ion exchange procedures.
Adsorption of the proteins to a HIC column is favored by high salt
concentrations, but the actual concentrations can vary over a wide
range depending on the nature of the protein and the particular HIC
ligand chosen. Various ions can be arranged in a so-called
soluphobic series depending on whether they promote hydrophobic
interactions (salting-out effects) or disrupt the structure of
water (chaotropic effect) and lead to the weakening of the
hydrophobic interaction. Cations are ranked in terms of increasing
salting out effect as Ba.sup.++<; Ca.sup.++<; Mg.sup.++<;
Li.sup.+<; Cs.sup.+<; Na.sup.+<; K.sup.+<;
Rb.sup.+<; NH.sub.4.sup.+, while anions may be ranked in terms
of increasing chaotropic effect as PO.sup.---<;
SO.sub.4.sup.--<; CH.sub.3COOO.sup.-<; Cl.sup.-<;
Br.sup.-<; NO.sub.3.sup.-<; ClO.sub.4.sup.-<; I.sup.-<;
SCN.sup.-
[0328] In general, Na, K or NH.sub.4 sulfates effectively promote
ligand-protein interaction in HIC. Salts may be formulated that
influence the strength of the interaction as given by the following
relationship: (NH.sub.4).sub.2SO.sub.4>; Na.sub.2SO.sub.4>;
NaCl>; NH.sub.4Cl>; NaBr>; NaSCN. In general, salt
concentrations of between about 0.75 and about 2M ammonium sulfate
or between about 1 and 4M NaCl are useful.
[0329] A number of chromatographic supports may be employed in the
preparation of HIC columns, the most extensively used are agarose,
silica and organic polymer or co-polymer resins. The hydrophobic
interaction material is generally a base matrix (e.g., a
hydrophilic carbohydrate (such as cross-linked agarose) or
synthetic copolymer material) to which hydrophobic ligands (e.g.,
alkyl or aryl groups) are coupled. The preferred HIC material
comprises an agarose resin substituted with phenyl groups.
Exemplary HIC material includes: phenyl SEPHAROSE.TM., FAST FLOW
with low or high substitution (Pharmacia LKB Biotechnology, AB,
Sweden); phenyl SEPHAROSE.TM. High Performance column; phenyl or
butyl-SEPHAROSE.RTM. CL-4B, butyl-SEPHAROSE.RTM. FF,
octyl-SEPHAROSE.RTM. FF and phenyl-SEPHAROSE.RTM. FF (Pharmacia LKB
Biotechnology AB, Sweden); Fractogel.TM. EMD Propyl or
FRACTOGEL.TM. EMC Phenyl columns (E. Merck, Germany); MACROPREP.TM.
Methyl or MACRO-PREP.TM. t-Butyl Supports (Bio-Rad, California); WP
HI-Propyl (C3).TM. column (J.T. Baker, New Jersey). Exemplary HIC
materials are also available from Tosoh Corporation, Tokyo, Japan
under the product names TOYOPEARL ether 650, phenyl 650, butyl 650
(Fractogel), ether-5PW-HR, or phenyl-5PW-HR; Miles-Yeda, Rehovot,
Israel under the product name alkyl-agarose, wherein the alkyl
group contains from 2-10 carbon atoms, and J.T. Baker,
Phillipsburg, N.J. under the product name Bakerbond WP-HI-propyl.
It is also possible to prepare the desired HIC column using
conventional chemistry. (Sa: for example, Er-el. Z. gl all,
Biochem. Biophys. Res. Comm. 49:383 (1972) or Ulbrich, V. rd gL
Coll. Czech. Chem. Commum. 9:1466 (1964)).
[0330] The choice of a particular gel can be determined by the
skilled artisan. In general the strength of the interaction of the
protein and the HIC ligand increases with the chain length of the
alkyl ligands but ligands having from about 4 to about 8 carbon
atoms are suitable for most separations. A phenyl group has about
the same hydrophobicity as a pentyl group, although the selectivity
can be different owing to the possibility of pi-pi orbital
interaction with aromatic groups on the protein. Selectively may
also be affected by the chemistry of the supporting resin.
[0331] Ligand density is an important parameter in that it
influences not only the strength of the interaction but the
capacity of the column as well. The ligand density of the
commercially available phenyl or octyl phenyl gels is on the order
of 40 pmoles/ml gel bed. Gel capacity is a function of the
particular protein in question as well as pH, temperature and salt
type and concentration but generally can be expected to fall in the
range of 3-20 mg/ml of gel.
[0332] In general, a decrease in temperature decreases the
interaction with HIC material. However, any benefit that would
accrue by increasing the temperature must also be weighed against
adverse effects such an increase may have on the stability of the
protein.
[0333] In one embodiment, the polypeptides of the invention can be
eluted isocratically. In isocratic elution, all compounds begin
migration through the column at onset. However, each migrates at a
different rate, resulting in faster or slower elution rate. For
example, as described in the instant examples, form A can be eluted
with the flow through of the column.
[0334] In another embodiment, one or more polypeptides of the
invention can be bound to the column and eluted, e.g., using
stepwise elution or gradient elution. Elution, whether stepwise or
in the form of a gradient, can be accomplished in a variety of
ways: (a) by changing the salt concentration, (b) by changing the
polarity of the solvent or (c) by adding detergents. By decreasing
salt concentration adsorbed proteins are eluted in order of
increasing hydrophobicity. Changes in polarity may be affected by
additions of solvents such as ethylene or propylene glycol or
(iso)propanol, thereby decreasing the strength of the hydrophobic
interactions. Detergents function as displacers of proteins and
have been used primarily in connection with the purification of
membrane proteins
[0335] In performing the separation, the polypeptide mixture can be
contacted with the HIC material e.g., using a batch purification
technique or using a column. Prior to HIC purification it may be
desirable to remove any chaotropic agents or very hydrophobic
substances, e.g., by passing the mixture through a precolumn.
[0336] For example, for batch purification, HIC material is
prepared in or equilibrated to the desired starting buffer. A
slurry of the HIC material is obtained. The polypeptide solution is
contacted with the slurry to adsorb at least one of the
polypeptides to be separated to the HIC material. The solution
containing the polypeptides that do not bind to the HIC material is
separated from the slurry, e.g., by allowing the slurry to settle
and removing the supernatant. The slurry can be subjected to one or
more washing steps. If desired, the slurry can be contacted with a
solution of lower conductivity to desorb polypeptides that have
bound to the HIC material. In order to elute bound polypeptides,
the salt concentration can be decreased.
[0337] In one embodiment, the HIC material can be packed in a
column. A mixture comprising the polypeptides to be separated can
be applied to the column allowing at least one of the polypeptides
to be separated to adsorb to the column. The polypeptides that do
not adsorb to the column pass through and can be collected. In
order to elute bound polypeptides, the salt concentration can be
decreased, e.g., in a step-wise fashion or using a salt
gradient.
[0338] Since form B is more hydrophobic than form A, it adsorbs
irreversibly to the stationary phase using approximately 0.7 M
(e.g., 0.73M)Ammonium Sulfate/20 mM Sodium Phosphate, pH 4.0 to pH
8.0 as the mobile phase. Form A binds to a lesser extent to the
stationary phase under these conditions and is therefore eluted
isocratically, i.e. it leaves the column with the flowthrough
fraction. Subsequent to the isocratic elution of form A, omitting
Ammonium sulfate from the mobile phase desorbs form B.
[0339] In an exemplary purification scheme, the HIC material is
equilibrated in a buffer comprising a salt concentration yielding a
conductivity of from between about 160 to about 110, preferably
from between about 140 to about 115, even more preferably from
between about 130 or about 120 to about 117 mS/cm. For example, an
exemplary starting solution comprises a salt concentration of
approximately 1M to 0.7M, e.g., 1M to 0.7M ammonium sulfate. In a
preferred embodiment, the solution comprising the mixture of
polypeptides to be separated is also brought to the same, or
approximately the same conductivity (e.g., using a concentrated
stock solution of salt). Under these conditions, Form A is eluted
from the column at a conductivity of about 120 mS/cm. In order to
elute Form B, a stepwise or linear gradient of reducing ammonium
sulfate content can be applied to the column. Form B elutes at a
conductivity of approximately 115 to approximately 100 mS/cm.
[0340] In one embodiment, the subject purification method yields a
composition comprising polypeptide molecules having at least two
target binding sites and two heavy chain portions, wherein the
heavy chain portions lack CH2 domains and wherein greater than
about 50% of the molecules are present in a form in which the two
heavy chain portions are linked via at least one interchain
disulfide linkage. In another embodiment, greater than about 60% of
the molecules are present in a form in which the two heavy chain
portions are linked via at least one interchain disulfide linkage.
In another embodiment, greater than about 70% of the molecules are
present in a form in which the two heavy chain portions are linked
via at least one interchain disulfide linkage. In another
embodiment, greater than about 80% of the molecules are present in
a form in which the two heavy chain portions are linked via at
least one interchain disulfide linkage. In another embodiment,
greater than about 90% of the molecules are present in a form in
which the two heavy chain portions are linked via at least one
interchain disulfide linkage.
[0341] In one embodiment, the subject purification method yields a
composition comprising recombinant polypeptide molecules having at
least two target binding sites and two heavy chain portions,
wherein greater than about 99% of the molecules are present in a
form in which the two heavy chain portions are linked via at least
one interchain disulfide linkage.
[0342] In one embodiment, the subject purification method yields a
composition comprising polypeptide molecules having at least two
target binding sites and two heavy chain portions, wherein greater
than about 95% of the molecules are present in a form in which the
two heavy chain portions are linked via at least one interchain
disulfide linkage, and wherein the heavy chain portions of the
polypeptides are derived from an antibody of the IgG4 isotype.
[0343] In one embodiment, the subject purification method yields a
composition comprising polypeptide molecules having two light chain
portions and two heavy chain portions, wherein the heavy chain
portions lack CH2 domains and wherein greater than about 80% of the
molecules are present in a form in which the two heavy chain
portions are not linked via at least one interchain disulfide
linkage.
[0344] In another aspect, the instant invention also provides
methods for monitoring the results of purification and/or
preferential biosynthesis comprising measuring the relative amounts
of Form A and Form B in a composition. Form A and Form B can be
measured, e.g., as described herein using non-reducing SDS
polyacrylamide gel electrophoresis or mass spectrometry.
[0345] V. Labeling or Conjugation of Polypeptides
[0346] The polypeptide molecules of the present invention may be
used in non-conjugated form or may conjugated to at least one of a
variety of molecules, e.g., to facilitate antigen detection or for
imaging or therapy of the patient. The polypeptides of the
invention can be labeled or conjugated either before or after
purification, when purification is performed. In particular, the
polypeptides of the present invention may be conjugated to
cytotoxins (such as radioisotopes, cytotoxic drugs, or toxins)
therapeutic agents, cytostatic agents, biological toxins, prodrugs,
peptides, proteins, enzymes, viruses, lipids, biological response
modifiers, pharmaceutical agents, immunologically active ligands
(e.g., lymphokines or antibodies wherein the resulting molecule
binds to both the neoplastic cell and an effector cell such as a T
cell), or PEG. In another embodiment, a polypeptide of the
invention can be conjugated to a molecule that decreases
vascularization of tumors. In other embodiments, the disclosed
compositions may comprise polypeptides of the invention coupled to
drugs or prodrugs. Still other embodiments of the present invention
comprise the use of polypeptides of the invention conjugated to
specific biotoxins or their cytotoxic fragments such as ricin,
gelonin, pseudomonas exotoxin or diphtheria toxin. The selection of
which conjugated or unconjugated polypeptide to use will depend on
the type and stage of cancer, use of adjunct treatment (e.g.,
chemotherapy or external radiation) and patient condition. It will
be appreciated that one skilled in the art could readily make such
a selection in view of the teachings herein.
[0347] It will be appreciated that, in previous studies, anti-tumor
antibodies labeled with isotopes have been used successfully to
destroy cells in solid tumors as well as lymphomas/leukemias in
animal models, and in some cases in humans. Exemplary radioisotopes
include: .sup.90Y, .sup.125I, .sup.131I, .sup.123I, .sup.111In,
.sup.105Rh, .sup.153Sm, .sup.67Cu, .sup.67Ga, .sup.166Ho,
.sup.177Lu, .sup.186Re and .sup.188Re. The radionuclides act by
producing ionizing radiation which causes multiple strand breaks in
nuclear DNA, leading to cell death. The isotopes used to produce
therapeutic conjugates typically produce high energy .alpha.- or
.beta.-particles which have a short path length. Such radionuclides
kill cells to which they are in close proximity, for example
neoplastic cells to which the conjugate has attached or has
entered. They have little or no effect on non-localized cells.
Radionuclides are essentially non-immunogenic.
[0348] With respect to the use of radiolabeled conjugates in
conjunction with the present invention, polypeptides of the
invention may be directly labeled (such as through iodination) or
may be labeled indirectly through the use of a chelating agent. As
used herein, the phrases "indirect labeling" and "indirect labeling
approach" both mean that a chelating agent is covalently attached
to a molecule and at least one radionuclide is associated with the
chelating agent. Such chelating agents are typically referred to as
bifinctional chelating agents as they bind both the polypeptide and
the radioisotope. Particularly preferred chelating agents comprise
1-isothiocycmatobenzyl-3-methyldiothelene triaminepentaacetic acid
("MX-DTPA") and cyclohexyl diethylenetriamine pentaacetic acid
("CHX-DTPA") derivatives. Other chelating agents comprise P-DOTA
and EDTA derivatives. Particularly preferred radionuclides for
indirect labeling include .sup.111In and .sup.90Y.
[0349] As used herein, the phrases "direct labeling" and "direct
labeling approach" both mean that a radionuclide is covalently
attached directly to a polypeptide (typically via an amino acid
residue). More specifically, these linking technologies include
random labeling and site-directed labeling. In the latter case, the
labeling is directed at specific sites on the polypeptide, such as
the N-linked sugar residues present only on the Fc portion of the
conjugates. Further, various direct labeling techniques and
protocols are compatible with the instant invention. For example,
Technetium-99m labeled polypeptides may be prepared by ligand
exchange processes, by reducing pertechnate (TcO.sub.4.sup.-) with
stannous ion solution, chelating the reduced technetium onto a
Sephadex column and applying the polypeptides to this column, or by
batch labeling techniques, e.g. by incubating pertechnate, a
reducing agent such as SnCl.sub.2, a buffer solution such as a
sodium-potassium phthalate-solution, and the molecules. In any
event, preferred radionuclides for directly labeling polypeptides
are well known in the art and a particularly preferred radionuclide
for direct labeling is .sup.131I covalently attached via tyrosine
residues. Polypeptides according to the invention may be derived,
for example, with radioactive sodium or potassium iodide and a
chemical oxidizing agent, such as sodium hypochlorite, chloramine T
or the like, or an enzymatic oxidizing agent, such as
lactoperoxidase, glucose oxidase and glucose. However, for the
purposes of the present invention, the indirect labeling approach
is particularly preferred. Patents relating to chelators and
chelator conjugates are known in the art. For instance, U.S. Pat.
No. 4,831,175 of Gansow is directed to polysubstituted
diethylenetriaminepentaacetic acid chelates and protein conjugates
containing the same, and methods for their preparation. U.S. Pat.
Nos. 5,099,069, 5,246,692, 5,286,850, 5,434,287 and 5,124,471 of
Gansow also relate to polysubstituted DTPA chelates. These patents
are incorporated herein in their entirety. Other examples of
compatible metal chelators are ethylenediaminetetraacetic acid
(EDTA), diethylenetriaminepentaacetic acid (DPTA),
1,4,8,11-tetraazatetradecane,
1,4,8,11-tetraazatetradecane-1,4,8,11-tetra- acetic acid,
1-oxa-4,7,12,15-tetraazaheptadecane-4,7,12,15-tetraacetic acid, or
the like. Cyclohexyl-DTPA or CHX-DTPA is particularly preferred.
Still other compatible chelators, including those yet to be
discovered, may easily be discerned by a skilled artisan and are
clearly within the scope of the present invention.
[0350] Compatible chelators, including the specific bifunctional
chelator used to facilitate chelation in co-pending application
Ser. Nos. 08/475,813, 08/475,815 and 08/478,967, are preferably
selected to provide high affinity for trivalent metals, exhibit
increased tumor-to-non-tumor ratios and decreased bone uptake as
well as greater in vivo retention of radionuclide at target sites,
i.e., B-cell lymphoma tumor sites. However, other bifunctional
chelators that may or may not possess all of these characteristics
are known in the art and may also be beneficial in tumor therapy.
It will also be appreciated that, in accordance with the teachings
herein, polypeptides may be conjugated to different radiolabels for
diagnostic and therapeutic purposes. To this end the aforementioned
co-pending applications, herein incorporated by reference in their
entirety, disclose radiolabeled therapeutic conjugates for
diagnostic "imaging" of tumors before administration of therapeutic
molecule. "In2B8" conjugate comprises a murine monoclonal antibody,
2B8, specific to human CD20 antigen, that is attached to .sup.111In
via a bifunctional chelator, i.e., MX-DTPA
(diethylenetriaminepentaacetic acid), which comprises a 1:1 mixture
of 1-isothiocyanatobenzyl-3-methyl-DTPA and
1-methyl-3-isothiocyanatobenzyl-DTPA. .sup.111In is particularly
preferred as a diagnostic radionuclide because between about 1 to
about 10 mCi can be safely administered without detectable
toxicity; and the imaging data is generally predictive of
subsequent .sup.90Y-labeled antibody distribution. Most imaging
studies utilize 5 mCi .sup.111In-labeled antibody, because this
dose is both safe and has increased imaging efficiency compared
with lower doses, with optimal imaging occurring at three to six
days after antibody administration. See, for example, Murray, J.
Nuc. Med. 26: 3328 (1985) and Carraguillo et al., J. Nuc. Med. 26:
67 (1985).
[0351] As indicated above, a variety of radionuclides are
applicable to the present invention and those skilled in the can
readily determine which radionuclide is most appropriate under
various circumstances. For example, .sup.131I is a well known
radionuclide used for targeted immunotherapy. However, the clinical
usefulness of .sup.131I can be limited by several factors
including: eight-day physical half-life; dehalogenation of
iodinated antibody both in the blood and at tumor sites; and
emission characteristics (e.g., large gamma component) which can be
suboptimal for localized dose deposition in tumor. With the advent
of superior chelating agents, the opportunity for attaching metal
chelating groups to proteins has increased the opportunities to
utilize other radionuclides such as .sup.111In and .sup.90Y.
.sup.90Y provides several benefits for utilization in
radioimmunotherapeutic applications: the 64 hour half-life of
.sup.90Y is long enough to allow accumulation by tumor and, unlike
e.g., .sup.131I, .sup.90Y is a pure beta emitter of high energy
with no accompanying gamma irradiation in its decay, with a range
in tissue of 100 to 1,000 cell diameters. Furthermore, the minimal
amount of penetrating radiation allows for outpatient
administration of .sup.90Y-labeled molecules. Additionally,
internalization of labeled polypeptides is not required for cell
killing, and the local emission of ionizing radiation should be
lethal for adjacent tumor cells lacking the target antigen.
[0352] Those skilled in the art will appreciate that these
non-radioactive conjugates may also be assembled using a variety of
techniques depending on the selected agent to be conjugated. For
example, conjugates with biotin are prepared e.g. by reacting the
polypeptides with an activated ester of biotin such as the biotin
N-hydroxysuccinimide ester. Similarly, conjugates with a
fluorescent marker may be prepared in the presence of a coupling
agent, e.g. those listed above, or by reaction with an
isothiocyanate, preferably fluorescein-isothiocyanate. Conjugates
of the polypeptides of the invention with cytostatic/cytotoxic
substances and metal chelates are prepared in an analogous
manner.
[0353] Preferred agents for use in the present invention are
cytotoxic drugs, particularly those which are used for cancer
therapy. As used herein, "a cytotoxin or cytotoxic agent" means any
agent that is detrimental to the growth and proliferation of cells
and may act to reduce, inhibit or destroy a cell or malignancy.
Exemplary cytotoxins include, but are not limited to,
radionuclides, biotoxins, enzymatically active toxins, cytostatic
or cytotoxic therapeutic agents, prodrugs, immunologically active
ligands and biological response modifiers such as cytokines. Any
cytotoxin that acts to retard or slow the growth of immunoreactive
cells or malignant cells is within the scope of the present
invention.
[0354] Exemplary cytotoxins include, in general, cytostatic agents,
alkylating agents, antimetabolites, anti-proliferative agents,
tubulin binding agents, hormones and hormone antagonists, and the
like. Exemplary cytostatics that are compatible with the present
invention include alkylating substances, such as mechlorethamine,
triethylenephosphoramide, cyclophosphamide, ifosfamide,
chlorambucil, busulfan, melphalan or triaziquone, also nitrosourea
compounds, such as carmustine, lomustine, or semustine. Other
preferred classes of cytotoxic agents include, for example, the
maytansinoid family of drugs. Other preferred classes of cytotoxic
agents include, for example, the anthracycline family of drugs, the
vinca drugs, the mitomycins, the bleomycins, the cytotoxic
nucleosides, the pteridine family of drugs, diynenes, and the
podophyllotoxins. Particularly useful members of those classes
include, for example, adriamycin, carminomycin, daunorubicin
(daunomycin), doxorubicin, aminopterin, methotrexate, methopterin,
mithramycin, streptonigrin, dichloromethotrexate, mitomycin C,
actinomycin-D, porfiromycin, 5-fluorouracil, floxuridine, ftorafur,
6-mercaptopurine, cytarabine, cytosine arabinoside,
podophyllotoxin, or podophyllotoxin derivatives such as etoposide
or etoposide phosphate, melphalan, vinblastine, vincristine,
leurosidine, vindesine, leurosine and the like. Still other
cytotoxins that are compatible with the teachings herein include
taxol, taxane, cytochalasin B, gramicidin D, ethidium bromide,
emetine, tenoposide, colchicin, dihydroxy anthracin dione,
mitoxantrone, procaine, tetracaine, lidocaine, propranolol, and
puromycin and analogs or homologs thereof. Hormones and hormone
antagonists, such as corticosteroids, e.g. prednisone, progestins,
e.g. hydroxyprogesterone or medroprogesterone, estrogens, e.g.
diethylstilbestrol, antiestrogens, e.g. tamoxifen, androgens, e.g.
testosterone, and aromatase inhibitors, e.g. aminogluthetimide are
also compatible with the teachings herein. As noted previously, one
skilled in the art may make chemical modifications to the desired
compound in order to make reactions of that compound more
convenient for purposes of preparing conjugates of the
invention.
[0355] One example of particularly preferred cytotoxins comprise
members or derivatives of the enediyne family of anti-tumor
antibiotics, including calicheamicin, esperamicins or dynemicins.
These toxins are extremely potent and act by cleaving nuclear DNA,
leading to cell death. Unlike protein toxins which can be cleaved
in vivo to give many inactive but immunogenic polypeptide
fragments, toxins such as calicheamicin, esperamicins and other
enediynes are small molecules which are essentially
non-immunogenic. These non-peptide toxins are chemically-linked to
the dimers or tetramers by techniques which have been previously
used to label monoclonal antibodies and other molecules. These
linking technologies include site-specific linkage via the N-linked
sugar residues present only on the Fc portion of the constructs.
Such site-directed linking methods have the advantage of reducing
the possible effects of linkage on the binding properties of the
constructs.
[0356] As previously alluded to, compatible cytotoxins may comprise
a prodrug. As used herein, the term "prodrug" refers to a precursor
or derivative form of a pharmaceutically active substance that is
less cytotoxic to tumor cells compared to the parent drug and is
capable of being enzymatically activated or converted into the more
active parent form. Prodrugs compatible with the invention include,
but are not limited to, phosphate-containing prodrugs,
thiophosphate-containing prodrugs, sulfate containing prodrugs,
peptide containing prodrugs, .beta.-lactam-containing prodrugs,
optionally substituted phenoxyacetamide-containing prodrugs or
optionally substituted phenylacetamide-containing prodrugs,
5-fluorocytosine and other 5-fluorouridine prodrugs that can be
converted to the more active cytotoxic free drug. Further examples
of cytotoxic drugs that can be derivatized into a prodrug form for
use in the present invention comprise those chemotherapeutic agents
described above.
[0357] Among other cytotoxins, it will be appreciated that
polypeptides can also be associated with a biotoxin such as ricin
subunit A, abrin, diptheria toxin, botulinum, cyanginosins,
saxitoxin, shigatoxin, tetanus, tetrodotoxin, trichothecene,
verrucologen or a toxic enzyme. Preferably, such constructs will be
made using genetic engineering techniques that allow for direct
expression of the binding molecule-toxin construct. Other
biological response modifiers that may be associated with the
polypeptides of the invention of the present invention comprise
cytokines such as lymphokines and interferons. In view of the
instant disclosure it is submitted that one skilled in the art
could readily form such constructs using conventional
techniques.
[0358] Another class of compatible cytotoxins that may be used in
conjunction with the disclosed polypeptides are radiosensitizing
drugs that may be effectively directed to tumor or immunoreactive
cells. Such drugs enhance the sensitivity to ionizing radiation,
thereby increasing the efficacy of radiotherapy. An conjugate
internalized by the tumor cell would deliver the radiosensitizer
nearer the nucleus where radiosensitization would be maximal. The
unbound radiosensitizer linked polypeptides of the invention would
be cleared quickly from the blood, localizing the remaining
radiosensitization agent in the target tumor and providing minimal
uptake in normal tissues. After rapid clearance from the blood,
adjunct radiotherapy would be administered in one of three ways:
1.) external beam radiation directed specifically to the tumor, 2.)
radioactivity directly implanted in the tumor or 3.) systemic
radioimmunotherapy with the same targeting molecule. A potentially
attractive variation of this approach would be the attachment of a
therapeutic radioisotope to the radiosensitized immunoconjugate,
thereby providing the convenience of administering to the patient a
single drug.
[0359] In one embodiment, a moiety that enhances the stability or
efficacy of the polypeptide can be conjugated. For example, in one
embodiment, PEG can be conjugated to the polypeptides of the
invention to increase their half-life in vivo. Leong, S. R., et al.
2001. Cytokine 16:106; 2002; Adv. in Drug Deliv. Rev. 54:531; or
Weir et al. 2002. Biochem. Soc. Transactions 30:512.
[0360] VI. Administration of Polypeptides
[0361] Methods of preparing and administering polypeptides of the
invention to a subject are well known to or are readily determined
by those skilled in the art. The route of administration of the
polypeptide of the invention may be oral, parenteral, by inhalation
or topical. The term parenteral as used herein includes
intravenous, intraarterial, intraperitoneal, intramuscular,
subcutaneous, rectal or vaginal administration. The intravenous,
intraarterial, subcutaneous and intramuscular forms of parenteral
administration are generally preferred. While all these forms of
administration are clearly contemplated as being within the scope
of the invention, a form for administration would be a solution for
injection, in particular for intravenous or intraarterial injection
or drip. Usually, a suitable pharmaceutical composition for
injection may comprise a buffer (e.g. acetate, phosphate or citrate
buffer), a surfactant (e.g. polysorbate), optionally a stabilizer
agent (e.g. human albumin), etc. However, in other methods
compatible with the teachings herein, the polypeptides can be
delivered directly to the site of the adverse cellular population
thereby increasing the exposure of the diseased tissue to the
therapeutic agent.
[0362] Preparations for parenteral administration includes sterile
aqueous or non-aqueous solutions, suspensions, and emulsions.
Examples of non-aqueous solvents are propylene glycol, polyethylene
glycol, vegetable oils such as olive oil, and injectable organic
esters such as ethyl oleate. Aqueous carriers include water,
alcoholic/aqueous solutions, emulsions or suspensions, including
saline and buffered media. In the subject invention,
pharmaceutically acceptable carriers include, but are not limited
to, 0.01-0.1M and preferably 0.05M phosphate buffer or 0.8% saline.
Other common parenteral vehicles include sodium phosphate
solutions, Ringer's dextrose, dextrose and sodium chloride,
lactated Ringer's, or fixed oils. Intravenous vehicles include
fluid and nutrient replenishers, electrolyte replenishers, such as
those based on Ringer's dextrose, and the like. Preservatives and
other additives may also be present such as for example,
antimicrobials, antioxidants, chelating agents, and inert gases and
the like.
[0363] More particularly, pharmaceutical compositions suitable for
injectable use include sterile aqueous solutions (where water
soluble) or dispersions and sterile powders for the extemporaneous
preparation of sterile injectable solutions or dispersions. In such
cases, the composition must be sterile and should be fluid to the
extent that easy syringability exists. It should be stable under
the conditions of manufacture and storage and will preferably be
preserved against the contaminating action of microorganisms, such
as bacteria and fungi. The carrier can be a solvent or dispersion
medium containing, for example, water, ethanol, polyol (e.g.,
glycerol, propylene glycol, and liquid polyethylene glycol, and the
like), and suitable mixtures thereof. The proper fluidity can be
maintained, for example, by the use of a coating such as lecithin,
by the maintenance of the required particle size in the case of
dispersion and by the use of surfactants. Prevention of the action
of microorganisms can be achieved by various antibacterial and
antifungal agents, for example, parabens, chlorobutanol, phenol,
ascorbic acid, thimerosal and the like. In many cases, it will be
preferable to include isotonic agents, for example, sugars,
polyalcohols, such as mannitol, sorbitol, or sodium chloride in the
composition. Prolonged absorption of the injectable compositions
can be brought about by including in the composition an agent which
delays absorption, for example, aluminum monostearate and
gelatin.
[0364] In any case, sterile injectable solutions can be prepared by
incorporating an active compound (e.g., a polypeptide by itself or
in combination with other active agents) in the required amount in
an appropriate solvent with one or a combination of ingredients
enumerated herein, as required, followed by filtered sterilization.
Generally, dispersions are prepared by incorporating the active
compound into a sterile vehicle, which contains a basic dispersion
medium and the required other ingredients from those enumerated
above. In the case of sterile powders for the preparation of
sterile injectable solutions, the preferred methods of preparation
are vacuum drying and freeze-drying, which yields a powder of an
active ingredient plus any additional desired ingredient from a
previously sterile-filtered solution thereof. The preparations for
injections are processed, filled into containers such as ampoules,
bags, bottles, syringes or vials, and sealed under aseptic
conditions according to methods known in the art. Further, the
preparations may be packaged and sold in the form of a kit such as
those described in co-pending U.S. Ser. No. 09/259,337 and U.S.
Ser. No. 09/259,338 each of which is incorporated herein by
reference. Such articles of manufacture will preferably have labels
or package inserts indicating that the associated compositions are
useful for treating a subject suffering from, or predisposed to
autoimmune or neoplastic disorders.
[0365] Effective doses of the compositions of the present
invention, for the treatment of the above described conditions vary
depending upon many different factors, including means of
administration, target site, physiological state of the patient,
whether the patient is human or an animal, other medications
administered, and whether treatment is prophylactic or therapeutic.
Usually, the patient is a human but non-human mammals including
transgenic mammals can also be treated. Treatment dosages may be
titrated using routine methods known to those of skill in the art
to optimize safety and efficacy. For passive immunization with an
antibody, the dosage can range, e.g., from about 0.0001 to 100
mg/kg, and more usually 0.01 to 5 mg/kg (e.g., 0.02 mg/kg, 0.25
mg/kg, 0.5 mg/kg, 0.75 mg/kg, 1 mg/kg, 2 mg/kg, etc.), of the host
body weight. For example dosages can be 1 mg/kg body weight or 10
mg/kg body weight or within the range of 1-10 mg/kg, preferably at
least 1 mg/kg. Doses intermediate in the above ranges are also
intended to be within the scope of the invention. Subjects can be
administered such doses daily, on alternative days, weekly or
according to any other schedule determined by empirical analysis.
An exemplary treatment entails administration in multiple dosages
over a prolonged period, for example, of at least six months.
Additional exemplary treatment regimes entail administration once
per every two weeks or once a month or once every 3 to 6 months.
Exemplary dosage schedules include 1-10 mg/kg or 15 mg/kg on
consecutive days, 30 mg/kg on alternate days or 60 mg/kg weekly. In
some methods, two or more monoclonal antibodies with different
binding specificities are administered simultaneously, in which
case the dosage of each antibody administered falls within the
ranges indicated.
[0366] Polypeptides of the invention can be administered on
multiple occasions. Intervals between single dosages can be weekly,
monthly or yearly. Intervals can also be irregular as indicated by
measuring blood levels of polypeptide or antigen in the patient. In
some methods, dosage is adjusted to achieve a plasma polypeptide
concentration of 1-1000 .mu.g/ml and in some methods 25-300
.mu.g/ml. Alternatively, binding molecules can be administered as a
sustained release formulation, in which case less frequent
administration is required. Dosage and frequency vary depending on
the half-life of the molecule in the patient. In general, humanized
antibodies show the longest half-life, followed by chimeric
antibodies and nonhuman antibodies. In one embodiment, the binding
molecules of the invention can be administered in unconjugated
form, In another embodiment, the polypeptides of the invention can
be administered multiple times in conjugated form. In still another
embodiment, the binding molecules of the invention can be
administered in unconjugated form, then in conjugated form, or vise
versa.
[0367] The dosage and frequency of administration can vary
depending on whether the treatment is prophylactic or therapeutic.
In prophylactic applications, compositions containing the present
polypeptides or a cocktail thereof are administered to a patient
not already in the disease state to enhance the patient's
resistance. Such an amount is defined to be a "prophylactic
effective dose." In this use, the precise amounts again depend upon
the patient's state of health and general immunity, but generally
range from 0.1 to 25 mg per dose, especially 0.5 to 2.5 mg per
dose. A relatively low dosage is administered at relatively
infrequent intervals over a long period of time. Some patients
continue to receive treatment for the rest of their lives.
[0368] In therapeutic applications, a relatively high dosage (e.g.,
from about 1 to 400 mg/kg of antibody per dose, with dosages of
from 5 to 25 mg being more commonly used for radioimmunoconjugates
and higher doses for cytotoxin-drug conjugated molecules) at
relatively short intervals is sometimes required until progression
of the disease is reduced or terminated, and preferably until the
patient shows partial or complete amelioration of symptoms of
disease. Thereafter, the patent can be administered a prophylactic
regime.
[0369] In one embodiment, a subject can be treated with a nucleic
acid molecule encoding a polypeptide of the invention (e.g., in a
vector). Doses for nucleic acids encoding polypeptides range from
about 10 ng to 1 g, 100 ng to 100 mg, 1 .mu.g to 10 mg, or 30-300
.mu.g DNA per patient. Doses for infectious viral vectors vary from
10-100, or more, virions per dose.
[0370] Therapeutic agents can be administered by parenteral,
topical, intravenous, oral, subcutaneous, intraarterial,
intracranial, intraperitoneal, intranasal or intramuscular means
for prophylactic and/or therapeutic treatment. The most typical
route of administration of an immunogenic agent is subcutaneous
although other routes can be equally effective. The next most
common route is intramuscular injection. This type of injection is
most typically performed in the arm or leg muscles. In some
methods, agents are injected directly into a particular tissue
where deposits have accumulated, for example intracranial
injection. Intramuscular injection or intravenous infusion are
preferred for administration of molecules. In some methods,
particular therapeutic molecules are injected directly into the
cranium. In some methods, molecules are administered as a sustained
release composition or device, such as a Medipad.TM. device.
[0371] Agents of the invention can optionally be administered in
combination with other agents that are effective in treating the
disorder or condition in need of treatment (e.g., prophylactic or
therapeutic).
[0372] Effective single treatment dosages (i.e., therapeutically
effective amounts) of .sup.90Y-labeled polypeptides of the
invention range from between about 5 and about 75 mCi, more
preferably between about 10 and about 40 mCi. Effective single
treatment non-marrow ablative dosages of .sup.131I-labeled
antibodies range from between about 5 and about 70 mCi, more
preferably between about 5 and about 40 mCi.
[0373] Effective single treatment ablative dosages (i.e., may
require autologous bone marrow transplantation) of
.sup.131I-labeled antibodies range from between about 30 and about
600 mCi, more preferably between about 50 and less than about 500
mCi. In conjunction with a chimeric antibody, owing to the longer
circulating half life vis--vis murine antibodies, an effective
single treatment non-marrow ablative dosages of iodine-131 labeled
chimeric antibodies range from between about 5 and about 40 mCi,
more preferably less than about 30 mCi. Imaging criteria for, e.g.,
the .sup.111In label, are typically less than about 5 mCi.
[0374] While a great deal of clinical experience has been gained
with .sup.131I and .sup.90Y, other radiolabels are known in the art
and have been used for similar purposes. Still other radioisotopes
are used for imaging. For example, additional radioisotopes which
are compatible with the scope of the instant invention include, but
are not limited to, .sup.123I, .sup.125I, .sup.32P, .sup.57Co,
.sup.64Cu, .sup.67Cu, .sup.77Br, .sup.81Rb, .sup.81Kr, .sup.87Sr,
.sup.113In, .sup.127Cs, .sup.129Cs, .sup.132I, .sup.197Hg,
.sup.203Pb, .sup.206Bi, .sup.177Lu, .sup.186Re, .sup.212Pb,
.sup.212Bi, .sup.47Sc, .sup.105Rh, .sup.109Pd, .sup.153Sm,
.sup.188Re, .sup.199Au, .sup.225Ac, .sup.211At, and .sup.213Bi. In
this respect alpha, gamma and beta emitters are all compatible with
in the instant invention. Further, in view of the instant
disclosure it is submitted that one skilled in the art could
readily determine which radionuclides are compatible with a
selected course of treatment without undue experimentation. To this
end, additional radionuclides which have already been used in
clinical diagnosis include .sup.125I, .sup.123I, .sup.99Tc,
.sup.43K, .sup.52Fe, .sup.67Ga, .sup.68Ga, as well as .sup.111In.
Antibodies have also been labeled with a variety of radionuclides
for potential use in targeted immunotherapy (Peirersz et al.
Immunol. Cell Biol. 65: 111-125 (1987)). These radionuclides
include .sup.188Re and .sup.186Re as well as .sup.199Au and
.sup.67Cu to a lesser extent. U.S. Pat. No. 5,460,785 provides
additional data regarding such radioisotopes and is incorporated
herein by reference.
[0375] Whether or not the polypeptides of the invention are used in
a conjugated or unconjugated form, it will be appreciated that a
major advantage of the present invention is the ability to use
these polypeptides in myelosuppressed patients, especially those
who are undergoing, or have undergone, adjunct therapies such as
radiotherapy or chemotherapy. That is, the beneficial delivery
profile (i.e. relatively short serum dwell time, high binding
affinity and enhanced localization) of the polypeptides makes them
particularly useful for treating patients that have reduced red
marrow reserves and are sensitive to myelotoxicity. In this regard,
the unique delivery profile of the polypeptides make them very
effective for the administration of radiolabeled conjugates to
myelosuppressed cancer patients. As such, the polypeptides of the
invention are useful in a conjugated or unconjugated form in
patients that have previously undergone adjunct therapies such as
external beam radiation or chemotherapy. In other preferred
embodiments, the polypeptides (again in a conjugated or
unconjugated form) may be used in a combined therapeutic regimen
with chemotherapeutic agents. Those skilled in the art will
appreciate that such therapeutic regimens may comprise the
sequential, simultaneous, concurrent or coextensive administration
of the disclosed molecules and one or more chemotherapeutic agents.
Particularly preferred embodiments of this aspect of the invention
will comprise the administration of a radiolabeled polypeptide.
[0376] While the polypeptides may be administered as described
immediately above, it must be emphasized that in other embodiments
conjugated and unconjugated polypeptides may be administered to
otherwise healthy patients as a first line therapeutic agent. In
such embodiments the polypeptides may be administered to patients
having normal or average red marrow reserves and/or to patients
that have not, and are not, undergoing adjunct therapies such as
external beam radiation or chemotherapy.
[0377] However, as discussed above, selected embodiments of the
invention comprise the administration of polypeptides to
myelosuppressed patients or in combination or conjunction with one
or more adjunct therapies such as radiotherapy or chemotherapy
(i.e. a combined therapeutic regimen). As used herein, the
administration of polypeptides in conjunction or combination with
an adjunct therapy means the sequential, simultaneous, coextensive,
concurrent, concomitant or contemporaneous administration or
application of the therapy and the disclosed molecules. Those
skilled in the art will appreciate that the administration or
application of the various components of the combined therapeutic
regimen may be timed to enhance the overall effectiveness of the
treatment. For example, chemotherapeutic agents could be
administered in standard, well known courses of treatment followed
within a few weeks by radioimmunoconjugates of the present
invention. Conversely, cytotoxin associated polypeptides could be
administered intravenously followed by tumor localized external
beam radiation. In yet other embodiments, the polypeptide may be
administered concurrently with one or more selected
chemotherapeutic agents in a single office visit. A skilled artisan
(e.g. an experienced oncologist) would be readily be able to
discern effective combined therapeutic regimens without undue
experimentation based on the selected adjunct therapy and the
teachings of the instant specification.
[0378] In this regard it will be appreciated that the combination
of the polypeptide (with or without cytotoxin) and the
chemotherapeutic agent may be administered in any order and within
any time frame that provides a therapeutic benefit to the patient.
That is, the chemotherapeutic agent and polypeptide may be
administered in any order or concurrently. In selected embodiments
the polypeptides of the present invention will be administered to
patients that have previously undergone chemotherapy. In yet other
embodiments, the polypeptides and the chemotherapeutic treatment
will be administered substantially simultaneously or concurrently.
For example, the patient may be given the binding molecule while
undergoing a course of chemotherapy. In preferred embodiments the
binding molecule will be administered within 1 year of any
chemotherapeutic agent or treatment. In other preferred embodiments
the polypeptide will be administered within 10, 8, 6, 4, or 2
months of any chemotherapeutic agent or treatment. In still other
preferred embodiments the polypeptide will be administered within
4, 3, 2 or 1 week of any chemotherapeutic agent or treatment. In
yet other embodiments the polypeptide will be administered within
5, 4, 3, 2 or 1 days of the selected chemotherapeutic agent or
treatment. It will further be appreciated that the two agents or
treatments may be administered to the patient within a matter of
hours or minutes (i.e. substantially simultaneously).
[0379] Moreover, in accordance with the present invention a
myelosuppressed patient shall be held to mean any patient
exhibiting lowered blood counts. Those skilled in the art will
appreciate that there are several blood count parameters
conventionally used as clinical indicators of myelosuppresion and
one can easily measure the extent to which myelosuppresion is
occurring in a patient. Examples of art accepted myelosuppression
measurements are the Absolute Neutrophil Count (ANC) or platelet
count. Such myelosuppression or partial myeloablation may be a
result of various biochemical disorders or diseases or, more
likely, as the result of prior chemotherapy or radiotherapy. In
this respect, those skilled in the art will appreciate that
patients who have undergone traditional chemotherapy typically
exhibit reduced red marrow reserves. As discussed above, such
subjects often cannot be treated using optimal levels of cytotoxin
(i.e. radionuclides) due to unacceptable side effects such as
anemia or immunosuppression that result in increased mortality or
morbidity.
[0380] More specifically conjugated or unconjugated polypeptides of
the present invention may be used to effectively treat patients
having ANCs lower than about 2000/mm.sup.3 or platelet counts lower
than about 150,000/mm.sup.3. More preferably the polypeptides of
the present invention may be used to treat patients having ANCs of
less than about 1500/mm.sup.3, less than about 1000/mm.sup.3 or
even more preferably less than about 500/mm.sup.3. Similarly, the
polypeptides of the present invention may be used to treat patients
having a platelet count of less than about 75,000/mm.sup.3, less
than about 50,000/mm.sup.3 or even less than about 10,000/mm.sup.3.
In a more general sense, those skilled in the art will easily be
able to determine when a patient is myelosuppressed using
government implemented guidelines and procedures.
[0381] As indicated above, many myelosuppressed patients have
undergone courses of treatment including chemotherapy, implant
radiotherapy or external beam radiotherapy. In the case of the
latter, an external radiation source is for local irradiation of a
malignancy. For radiotherapy implantation methods, radioactive
reagents are surgically located within the malignancy, thereby
selectively irradiating the site of the disease. In any event, the
disclosed polypeptides may be used to treat disorders in patients
exhibiting myelosuppression regardless of the cause.
[0382] In this regard it will further be appreciated that the
polypeptides of the instant invention may be used in conjunction or
combination with any chemotherapeutic agent or agents (e.g. to
provide a combined therapeutic regimen) that eliminates, reduces,
inhibits or controls the growth of neoplastic cells in vivo. As
discussed, such agents often result in the reduction of red marrow
reserves. This reduction may be offset, in whole or in part, by the
diminished myelotoxicity of the compounds of the present invention
that advantageously allow for the aggressive treatment of
neoplasias in such patients. In other preferred embodiments the
radiolabeled immunoconjugates disclosed herein may be effectively
used with radiosensitizers that increase the susceptibility of the
neoplastic cells to radionuclides. For example, radiosensitizing
compounds may be administered after the radiolabeled binding
molecule has been largely cleared from the bloodstream but still
remains at therapeutically effective levels at the site of the
tumor or tumors.
[0383] With respect to these aspects of the invention, exemplary
chemotherapeutic agents that are compatible with the instant
invention include alkylating agents, vinca alkaloids (e.g.,
vincristine and vinblastine), procarbazine, methotrexate and
prednisone. The four-drug combination MOPP (mechlethamine (nitrogen
mustard), vincristine (Oncovin), procarbazine and prednisone) is
very effective in treating various types of lymphoma and comprises
a preferred embodiment of the present invention. In MOPP-resistant
patients, ABVD (e.g., adriamycin, bleomycin, vinblastine and
dacarbazine), ChlVPP (chlorambucil, vinblastine, procarbazine and
prednisone), CABS (lomustine, doxorubicin, bleomycin and
streptozotocin), MOPP plus ABVD, MOPP plus ABV (doxorubicin,
bleomycin and vinblastine) or BCVPP (carmustine, cyclophosphamide,
vinblastine, procarbazine and prednisone) combinations can be used.
Arnold S. Freedman and Lee M. Nadler, Malignant Lymphomas, in
HARRISON'S PRINCIPLES OF INTERNAL MEDICINE 1774-1788 (Kurt J.
Isselbacher et al., eds., 13.sup.th ed. 1994) and V. T. DeVita et
al., (1997) and the references cited therein for standard dosing
and scheduling. These therapies can be used unchanged, or altered
as needed for a particular patient, in combination with one or more
polypeptides of the invention as described herein.
[0384] Additional regimens that are useful in the context of the
present invention include use of single alkylating agents such as
cyclophosphamide or chlorambucil, or combinations such as CVP
(cyclophosphamide, vincristine and prednisone), CHOP (CVP and
doxorubicin), C-MOPP (cyclophosphamide, vincristine, prednisone and
procarbazine), CAP-BOP (CHOP plus procarbazine and bleomycin),
m-BACOD (CHOP plus methotrexate, bleomycin and leucovorin),
ProMACE-MOPP (prednisone, methotrexate, doxorubicin,
cyclophosphamide, etoposide and leucovorin plus standard MOPP),
ProMACE-CytaBOM (prednisone, doxorubicin, cyclophosphamide,
etoposide, cytarabine, bleomycin, vincristine, methotrexate and
leucovorin) and MACOP-B (methotrexate, doxorubicin,
cyclophosphamide, vincristine, fixed dose prednisone, bleomycin and
leucovorin). Those skilled in the art will readily be able to
determine standard dosages and scheduling for each of these
regimens. CHOP has also been combined with bleomycin, methotrexate,
procarbazine, nitrogen mustard, cytosine arabinoside and etoposide.
Other compatible chemotherapeutic agents include, but are not
limited to, 2-chlorodeoxyadenosine (2-CDA), 2' -deoxycoformycin and
fludarabine.
[0385] For patients with intermediate- and high-grade NHL, who fail
to achieve remission or relapse, salvage therapy is used. Salvage
therapies employ drugs such as cytosine arabinoside, cisplatin,
etoposide and ifosfamide given alone or in combination. In relapsed
or aggressive forms of certain neoplastic disorders the following
protocols are often used: IMVP-16 (ifosfamide, methotrexate and
etoposide), MIME (methyl-gag, ifosfamide, methotrexate and
etoposide), DHAP (dexamethasone, high dose cytarabine and
cisplatin), ESHAP (etoposide, methylpredisolone, HD cytarabine,
cisplatin), CEPP(B) (cyclophosphamide, etoposide, procarbazine,
prednisone and bleomycin) and CAMP (lomustine, mitoxantrone,
cytarabine and prednisone) each with well known dosing rates and
schedules.
[0386] The amount of chemotherapeutic agent to be used in
combination with the polypeptides of the instant invention may vary
by subject or may be administered according to what is known in the
art. See for example, Bruce A Chabner et al., Antineoplastic
Agents, in GOODMAN & GILMAN'S THE PHARMACOLOGICAL BASIS OF
THERAPEUTICS 1233-1287 ((Joel G. Hardman et al., eds., 9.sup.th ed.
1996).
[0387] As previously discussed, the polypeptides of the present
invention, immunoreactive fragments or recombinants thereof may be
administered in a pharmaceutically effective amount for the in vivo
treatment of mammalian disorders. In this regard, it will be
appreciated that the disclosed binding molecules will be formulated
so as to facilitate administration and promote stability of the
active agent. Preferably, pharmaceutical compositions in accordance
with the present invention comprise a pharmaceutically acceptable,
non-toxic, sterile carrier such as physiological saline, non-toxic
buffers, preservatives and the like. For the purposes of the
instant application, a pharmaceutically effective amount of the
polypeptide, immunoreactive fragment or recombinant thereof,
conjugated or unconjugated to a therapeutic agent, shall be held to
mean an amount sufficient to achieve effective binding to an
antigen and to achieve a benefit, e.g., to ameliorate symptoms of a
disease or disorder or to detect a substance or a cell. In the case
of tumor cells, the polypeptide will be preferably be capable of
interacting with selected immunoreactive antigens on neoplastic or
immunoreactive cells and provide for an increase in the death of
those cells. Of course, the pharmaceutical compositions of the
present invention may be administered in single or multiple doses
to provide for a pharmaceutically effective amount of the
polypeptide.
[0388] In keeping with the scope of the present disclosure, the
polypeptides of the invention may be administered to a human or
other animal in accordance with the aforementioned methods of
treatment in an amount sufficient to produce a therapeutic or
prophylactic effect. The binding molecules of the invention can be
administered to such human or other animal in a conventional dosage
form prepared by combining the binding molecule of the invention
with a conventional pharmaceutically acceptable carrier or diluent
according to known techniques. It will be recognized by one of
skill in the art that the form and character of the
pharmaceutically acceptable carrier or diluent is dictated by the
amount of active ingredient with which it is to be combined, the
route of administration and other well-known variables. Those
skilled in the art will further appreciate that a cocktail
comprising one or more species of polypeptides according to the
present invention may prove to be particularly effective.
[0389] VII. Methods of Use
[0390] The polypeptides of the invention can be used for diagnostic
or therapeutic purposes. Preferred embodiments of the present
invention provide compounds, compositions, kits and methods for the
diagnosis and/or treatment of disorders, e.g., neoplastic disorders
in a mammalian subject in need of such treatment. Preferably, the
subject is a human.
[0391] The polypeptides of the instant invention will be useful in
a number of different applications. For example, in one embodiment,
the subject binding molecules should be useful for reducing or
eliminating cells bearing an epitope recognized by a binding
molecule of the invention. In another embodiment, the subject
binding molecules are effective in reducing the concentration of or
eliminating soluble antigen in the circulation
[0392] In one embodiment, tumor size, inhibiting tumor growth
and/or prolonging the survival time of tumor-bearing animals.
Accordingly, this invention also relates to a method of treating
tumors in a human or other animal by administering to such human or
animal an effective, non-toxic amount of polypeptide. One skilled
in the art would be able, by routine experimentation, to determine
what an effective, non-toxic amount of polypeptide would be for the
purpose of treating malignancies. For example, a therapeutically
active amount of a polypeptide may vary according to factors such
as the disease stage (e.g., stage I versus stage IV), age, sex,
medical complications (e.g., immunosuppressed conditions or
diseases) and weight of the subject, and the ability of the
molecule to elicit a desired response in the subject. The dosage
regimen may be adjusted to provide the optimum therapeutic
response. For example, several divided doses may be administered
daily, or the dose may be proportionally reduced as indicated by
the exigencies of the therapeutic situation. Generally, however, an
effective dosage is expected to be in the range of about 0.05 to
100 milligrams per kilogram body weight per day and more preferably
from about 0.5 to 10, milligrams per kilogram body weight per
day.
[0393] For purposes of clarification "mammal" refers to any animal
classified as a mammal, including humans, domestic and farm
animals, and zoo, sports, or pet animals, such as dogs, horses,
cats, cows, etc. Preferably, the mammal is human.
[0394] "Treatment" refers to both therapeutic treatment and
prophylactic or preventative measures. Those in need of treatment
include those already with the disease or disorder as well as those
in which the disease or disorder is to be prevented. Hence, the
mammal may have been diagnosed as having the disease or disorder or
may be predisposed or susceptible to the disease.
[0395] As discussed above, the polypeptides of the present
invention may be immunoreactive with one or more tumor antigens or
antigens associated with immune disorders. For example, for
neoplastic disorders, the antigen binding site (i.e. the variable
region or immunoreactive fragment or recombinant thereof) of the
disclosed polypeptides binds to a selected tumor associated antigen
at the site of the malignancy. Similarly, in immune (including
autoimmune) disorders the disclosed polypeptides will bind to
selected markers on the offending cells. Given the number of
reported antigens associated with neoplasias and immune disorders,
and the number of related antibodies, those skilled in the art will
appreciate that the presently disclosed polypeptides may therefore
be derived from any one of a number of whole antibodies. More
generally, polypeptides useful in the present invention may be
obtained or derived from any antibody (including those previously
reported in the literature) that reacts with a molecule or marker
associated with the selected condition. Further, the parent or
precursor antibody, or fragment thereof, used to generate the
disclosed polypeptides may be murine, human, chimeric, humanized,
non-human primate or primatized. In other preferred embodiments the
polypeptides of the present invention may comprise single chain
antibody constructs (such as that disclosed in U.S. Pat. No.
5,892,019 which is incorporated herein by reference) having altered
constant domains as described herein. Consequently, any of these
types of antibodies modified in accordance with the teachings
herein is compatible with the instant invention.
[0396] As used herein, "tumor associated antigens" means any
antigen which is generally associated with tumor cells, i.e.,
occurring at the same or to a greater extent as compared with
normal cells. More generally, tumor associated antigens comprise
any antigen that provides for the localization of immunoreactive
antibodies at a neoplastic cell irrespective of its expression on
non-malignant cells. Such antigens may be relatively tumor specific
and limited in their expression to the surface of malignant cells.
Alternatively, such antigens may be found on both malignant and
non-malignant cells. For example, CD20 is a pan B antigen that is
found on the surface of both malignant and non-malignant B cells
that has proved to be an extremely effective target for
immunotherapeutic antibodies for the treatment of non-Hodgkin's
lymphoma. In this respect, pan T cell antigens such as CD2, CD3,
CD5, CD6 and CD7 also comprise tumor associated antigens within the
meaning of the present invention. Still other exemplary tumor
associated antigens comprise but not limited to MAGE-1, MAGE-3,
MUC-1, HPV 16, HPV E6 & E7, TAG-72, CEA, L6-Antigen, CD19,
CD22, CD37, CD52, HLA-DR, EGF Receptor and HER2 Receptor. In many
cases immunoreative antibodies for each of these antigens have been
reported in the literature. Those skilled in the art will
appreciate that each of these antibodies may serve as a precursor
for polypeptides of the invention in accordance with the present
invention.
[0397] The polypeptides of the present invention preferably
associate with, and bind to, tumor or immune associated antigens as
described above. Accordingly, as will be discussed in some detail
below the polypeptides of the present invention may be derived,
generated or fabricated from any one of a number of antibodies that
react with tumor associated antigens. In preferred embodiments the
polypeptides are modified or domain deleted antibodies that are
derived using common genetic engineering techniques whereby at
least a portion of one or more constant region domains are deleted
or altered so as to provide the desired biochemical characteristics
such as reduced serum half-life. More particularly, one skilled in
the art may readily isolate the genetic sequence corresponding to
the variable and/or constant regions of the subject antibody and
delete or alter the appropriate nucleotides to provide polypeptides
of the invention for use as monomeric subunits in accordance with
the instant invention. It will further be appreciated that
compatible polypeptides of the invention may be expressed and
produced on a clinical or commercial scale using well-established
protocols.
[0398] Previously reported antibodies that react with tumor
associated antigens may be altered as described herein to provide
the polypeptides of the present invention. Exemplary antibodies
that may be used to provide antigen binding regions for, generate
or derive the disclosed polypeptides include, but are not limited
to 2B8 and C2B8 (Zevalin.RTM. and Rituxan.RTM., IDEC
Pharmaceuticals Corp., San Diego), Lym 1 and Lym 2 (Techniclone),
LL2 (Immunomedics Corp., New Jersey), HER2 (Herceptin.RTM.,
Genentech Inc., South San Francisco), B1 (Bexxar.RTM., Coulter
Pharm., San Francisco), Campath.RTM. (Millennium Pharmaceuticals,
Cambridge) MB1, BH3, B4, B72.3 (Cytogen Corp.), CC49 (National
Cancer Institute) and 5E10 (University of Iowa). Other antibody
binding sites that can be incorporated into the subject binding
molecules include: Orthoclone OKT3 (CD3), ReoPro (GpIIb/gIIa),
Zenapax (C25), Remicade (TNF-a), Simulect (CD25), Synagis (RSV),
Mylotarg (CD33), and Campath (CD52). In preferred embodiments, the
polypeptides of the present invention will bind to the same tumor
associated antigens as the antibodies enumerated immediately above.
In particularly preferred embodiments, the polypeptides will be
derived from or bind the same antigens as 2B8, C2B8, CC49 and C5E10
and, even more preferably, will lack all or part of a CH2
domain.
[0399] In one embodiment, a binding molecule of the invention binds
to the CD23 (U.S. Pat. No. 6,011,138). In a preferred embodiment, a
binding molecule of the invention binds to the same epitope as the
5E8 antibody. In another embodiment, a binding molecule of the
invention comprises at least one CDR from an anti-CD23 antibody,
e.g., the 5E8 antibody.
[0400] In one embodiment, a binding molecule of the invention binds
to the CRIPTO-I antigen (WO02/088170A2 or WO03/083041A2). In a
preferred embodiment, a binding molecule of the invention binds to
the same epitope as the B3F6 antibody. In another embodiment, a
binding molecule of the invention comprises at least one CDR from
an anti-CRIPTO-I antibody, e.g., the B3F6 antibody.
[0401] In a first preferred embodiment, the polypeptide will bind
to the same tumor associated antigen as Rituxan.RTM.. Rituxan.RTM.
(also known as, rituximab, IDEC-C2B8 and C2B8) was the first
FDA-approved monoclonal antibody for treatment of human B-cell
lymphoma (see U.S. Pat. Nos. 5,843,439; 5,776,456 and 5,736,137
each of which is incorporated herein by reference). Y2B8 (90Y
labeled 2B8; Zevalin.RTM.; ibritumomab tiuxetan) is the murine
parent of C2B8. Rituxan.RTM. is a chimeric, anti-CD20 monoclonal
antibody which is growth inhibitory and reportedly sensitizes
certain lymphoma cell lines for apoptosis by chemotherapeutic
agents in vitro. The antibody efficiently binds human complement,
has strong FcR binding, and can effectively kill human lymphocytes
in vitro via both complement dependent (CDC) and antibody-dependent
(ADCC) mechanisms (Reffet al., Blood 83: 435-445 (1994)). Those
skilled in the art will appreciate that dimeric variants
(homodimers or heterodimers) of C2B8 or 2B8, modified according to
the instant disclosure, may be used in conjugated or unconjugated
forms to effectively treat patients presenting with CD20+
malignancies. More generally, it must be reiterated that the
polypeptides disclosed herein may be used in either a "naked" or
unconjugated state or conjugated to a cytotoxic agent to
effectively treat any one of a number of disorders.
[0402] In other preferred embodiments of the present invention, the
polypeptide of the invention will be derived from, or bind to, the
same tumor associated antigen as CC49. As previously alluded to,
CC49 binds human tumor associated antigen TAG-72 which is
associated with the surface of certain tumor cells of human origin,
specifically the LS174T tumor cell line. LS174T [American Type
Culture Collection (herein ATCC) No. CL 188] is a variant of the
LS180 (ATCC No. CL 187) colon adenocarcinoma line.
[0403] It will further be appreciated that numerous murine
monoclonal antibodies have been developed which have binding
specificity for TAG-72. One of these monoclonal antibodies,
designated B72.3, is a murine IgG1 produced by hybridoma B72.3
(ATCC No. HB-8108). B72.3 is a first generation monoclonal antibody
developed using a human breast carcinoma extract as the immunogen
(see Colcher et al., Proc. Natl. Acad. Sci. (USA), 78:3199-3203
(1981); and U.S. Pat. Nos. 4,522,918 and 4,612,282 each of which is
incorporated herein by reference). Other monoclonal antibodies
directed against TAG-72 are designated "CC" (for colon cancer). As
described by Schlom et al. (U.S. Pat. No. 5,512,443 which is
incorporated herein by reference) CC monoclonal antibodies are a
family of second generation murine monoclonal antibodies that were
prepared using TAG-72 purified with B72.3. Because of their
relatively good binding affinities to TAG-72, the following CC
antibodies have been deposited at the ATCC, with restricted access
having been requested: CC49 (ATCC No. HB 9459); CC 83 (ATCC No. HB
9453); CC46 (ATCC No. HB 9458); CC92 (ATTCC No. HB 9454); CC30
(ATCC No. HB 9457); CC11 (ATCC No. 9455); and CC15 (ATCC No. HB
9460). U.S. Pat. No. 5,512,443 further teaches that the disclosed
antibodies may be altered into their chimeric form by substituting,
e.g., human constant regions (Fc) domains for mouse constant
regions by recombinant DNA techniques known in the art. Besides
disclosing murine and chimeric anti-TAG-72 antibodies, Schlom et
al. have also produced variants of a humanized CC49 antibody as
disclosed in PCT/US99/25552 and single chain constructs as
disclosed in U.S. Pat. No. 5,892,019 each of which is also
incorporated herein by reference. Those skilled in the art will
appreciate that each of the foregoing antibodies, constructs or
recombinants, and variations thereof, may be modified and used to
provide polypeptides in accordance with the present invention.
[0404] In addition to the anti-TAG-72 antibodies discussed above,
various groups have also reported the construction and partial
characterization of domain-deleted CC49 and B72.3 antibodies (e.g.,
Calvo et al. Cancer Biotherapy, 8(1):95-109 (1993), Slavin-Chiorini
et al. Int. J. Cancer 53:97-103 (1993) and Slavin-Chiorini et al.
Cancer. Res. 55:5957-5967 (1995
[0405] Still other preferred embodiments of the present invention
comprise modified antibodies that are derived from or bind to the
same tumor associated antigen as C5E10. As set forth in co-pending
application Ser. No. 09/104,717, C5E10 is an antibody that
recognizes a glycoprotein determinant of approximately 115 kDa that
appears to be specific to prostate tumor cell lines (e.g. DU145,
PC3, or ND1). Thus, in conjunction with the present invention,
polypeptides (e.g. CH2 domain-deleted antibodies) that specifically
bind to the same tumor associated antigen recognized by C5E10
antibodies could be produced and used in a conjugated or
unconjugated form for the treatment of neoplastic disorders. In
particularly preferred embodiments, the modified antibody will be
derived or comprise all or part of the antigen binding region of
the C5E10 antibody as secreted from the hybridoma cell line having
ATCC accession No. PTA-865. The resulting modified antibody could
then be conjugated to a radionuclide as described below and
administered to a patient suffering from prostate cancer in
accordance with the methods herein.
[0406] In general, the disclosed invention may be used to
prophylactically or therapeutically treat any neoplasm comprising
an antigenic marker that allows for the targeting of the cancerous
cells by the binding molecule. Exemplary cancers that may be
treated include, but are not limited to, prostate, gastric
carcinomas, such as colon, skin, breast, ovarian, lung and
pancreatic. More particularly, the binding molecules of the instant
invention may be used to treat Kaposi's sarcoma, CNS neoplasias
(capillary hemangioblastomas, meningiomas and cerebral metastases),
melanoma, gastrointestinal and renal sarcomas, rhabdomyosarcoma,
glioblastoma (preferably glioblastoma multiforme), leiomyosarcoma,
retinoblastoma, papillary cystadenocarcinoma of the ovary, Wilm's
tumor or small cell lung carcinoma. It will be appreciated that
appropriate polypeptides may be derived for tumor associated
antigens related to each of the forgoing neoplasias without undue
experimentation in view of the instant disclosure. Exemplary
hematologic malignancies that are amenable to treatment with the
disclosed invention include Hodgkins and non-Hodgkins lymphoma as
well as leukemias, including ALL-L3 (Burkitt's type leukemia),
chronic lymphocytic leukemia (CLL) and monocytic cell leukemias. It
will be appreciated that the compounds and methods of the present
invention are particularly effective in treating a variety of
B-cell lymphomas, including low grade/follicular non-Hodgkin's
lymphoma (NHL), cell lymphoma (FCC), mantle cell lymphoma (MCL),
diffuse large cell lymphoma (DLCL), small lymphocytic (SL) NHL,
intermediate grade/follicular NHL, intermediate grade diffuse NHL,
high grade immunoblastic NHL, high grade lymphoblastic NHL, high
grade small non-cleaved cell NHL, bulky disease NHL and
Waldenstrom's Macroglobulinemia. It should be clear to those of
skill in the art that these lymphomas will often have different
names due to changing systems of classification, and that patients
having lymphomas classified under different names may also benefit
from the combined therapeutic regimens of the present invention. In
addition to the aforementioned neoplastic disorders, it will be
appreciated that the disclosed invention may advantageously be used
to treat additional malignancies bearing compatible tumor
associated antigens.
[0407] Besides neoplastic disorders, the polypeptides of the
instant invention are particularly effective in the treatment of
autoimmune disorders or abnormal immune responses. In this regard,
it will be appreciated that the polypeptide of the present
invention may be used to control, suppress, modulate or eliminate
unwanted immune responses to both external and autoantigens. For
example, in one embodiment, the antigen is an autoantigen. In
another embodiment, the antigen is an allergen. In yet other
embodiments, the antigen is an alloantigen or xenoantigen. Use of
the disclosed polypeptides to reduce an immune response to
alloantigens and xenoantigens is of particular use in
transplantation, for example to inhibit rejection by a transplant
recipient of a donor graft, e.g. a tissue or organ graft or bone
marrow transplant. Additionally, suppression or elimination of
donor T cells within a bone marrow graft is useful for inhibiting
graft versus host disease.
[0408] In yet other embodiments the polypeptides of the present
invention may be used to treat immune disorders that include, but
are not limited to, allergic bronchopulmonary aspergillosis;
Allergic rhinitis Autoimmune hemolytic anemia; Acanthosis
nigricans; Allergic contact dermatitis; Addison's disease; Atopic
dermatitis; Alopecia areata; Alopecia universalis; Amyloidosis;
Anaphylactoid purpura; Anaphylactoid reaction; Aplastic anemia;
Angioedema, hereditary; Angioedema, idiopathic; Ankylosing
spondylitis; Arteritis, cranial; Arteritis, giant cell; Arteritis,
Takayasu's; Arteritis, temporal; Asthma; Ataxia-telangiectasia;
Autoimmune oophoritis; Autoimmune orchitis; Autoimmune
polyendocrine failure; Behcet's disease; Berger's disease;
Buerger's disease; bronchitis; Bullous pemphigus; Candidiasis,
chronic mucocutaneous; Caplan's syndrome; Post-myocardial
infarction syndrome; Post-pericardiotomy syndrome; Carditis; Celiac
sprue; Chagas's disease; Chediak-Higashi syndrome; Churg-Strauss
disease; Cogan's syndrome; Cold agglutinin disease; CREST syndrome;
Crohn's disease; Cryoglobulinemia; Cryptogenic fibrosing
alveolitis; Dermatitis herpetifomis; Dermatomyositis; Diabetes
mellitus; Diamond-Blackfan syndrome; DiGeorge syndrome; Discoid
lupus erythematosus; Eosinophilic fasciitis; Episcleritis; Drythema
elevatum diutinum; Erythema marginatum; Erythema multiforme;
Erythema nodosum; Familial Mediterranean fever; Felty's syndrome;
Fibrosis pulmonary; Glomerulonephritis, anaphylactoid;
Glomerulonephritis, autoimmune; Glomerulonephritis,
post-streptococcal; Glomerulonephritis, post-transplantation;
Glomerulopathy, membranous; Goodpasture's syndrome;
Granulocytopenia, immune-mediated; Granuloma annulare;
Granulomatosis, allergic; Granulomatous myositis; Grave's disease;
Hashimoto's thyroiditis; Hemolytic disease of the newborn;
Hemochromatosis, idiopathic; Henoch-Schoenlein purpura; Hepatitis,
chronic active and chronic progressive; Histiocytosis X;
Hypereosinophilic syndrome; Idiopathic thrombocytopenic purpura;
Job's syndrome; Juvenile dermatomyositis; Juvenile rheumatoid
arthritis (Juvenile chronic arthritis); Kawasaki's disease;
Keratitis; Keratoconjunctivitis sicca; Landry-Guillain-Barre-Strohl
syndrome; Leprosy, lepromatous; Loeffler's syndrome; lupus; Lyell's
syndrome; Lyme disease; Lymphomatoid granulomatosis; Mastocytosis,
systemic; Mixed connective tissue disease; Mononeuritis multiplex;
Muckle-Wells syndrome; Mucocutaneous lymph node syndrome;
Mucocutaneous lymph node syndrome; Multicentric
reticulohistiocytosis; Multiple sclerosis; Myasthenia gravis;
Mycosis fingoides; Necrotizing vasculitis, systemic; Nephrotic
syndrome; Overlap syndrome; Panniculitis; Paroxysmal cold
hemoglobinuria; Paroxysmal nocturnal hemoglobinuria; Pemphigoid;
Pemphigus; Pemphigus erythematosus; Pemphigus foliaceus; Pemphigus
vulgaris; Pigeon breeder's disease; Pneumonitis, hypersensitivity;
Polyarteritis nodosa; Polymyalgia rheumatic; Polymyositis;
Polyneuritis, idiopathic; Portuguese familial polyneuropathies;
Pre-eclampsia/eclampsia; Primary biliary cirrhosis; Progressive
systemic sclerosis (Scleroderma); Psoriasis; Psoriatic arthritis;
Pulmonary alveolar proteinosis; Pulmonary fibrosis, Raynaud's
phenomenon/syndrome; Reidel's thyroiditis; Reiter's syndrome,
Relapsing polychrondritis; Rheumatic fever; Rheumatoid arthritis;
Sarcoidosis; Scleritis; Sclerosing cholangitis; Serum sickness;
Sezary syndrome; Sjogren's syndrome; Stevens-Johnson syndrome;
Still's disease; Subacute sclerosing panencephalitis; Sympathetic
ophthalmia; Systemic lupus erythematosus; Transplant rejection;
Ulcerative colitis; Undifferentiated connective tissue disease;
Urticaria, chronic; Urticaria, cold; Uveitis; Vitiligo;
Weber-Christian disease; Wegener's granulomatosis and
Wiskott-Aldrich syndrome.
[0409] In another embodiment, the binding molecules of the
invention can be used for pretargeting applications. For example,
the same advantages will be apparent in pretargeting applications
for chemotherapeutic drug delivery.
[0410] For example, in pretargeting a tumor is pretargeted with a
binding construct that has affinity for the tumor-associated
antigen on the one hand and for, e.g., a radiolabeled hapten on the
other. The radiolabeled hapten is administered later, preferably
after the binding molecule has cleared (see, e.g., Boerman et al.
2003. J. Nuclear Med. 44:400). In another example, an antibody
which is non-toxic, but has been derivitized to react with a drug
or prodrug that is toxic only when bound by the binding molecule.
Given the biodistribution data in the instant examples, the binding
molecules of the invention are well suited to use in pretargeting
applications. In one embodiment, a clearing agent could be
eliminated from the pretargeting methodology by using the instant
binding molecules.
[0411] This invention is further illustrated by the following
examples which should not be construed as limiting. The contents of
all references, patents and published patent applications cited
throughout this application are incorporated herein by
reference.
EXAMPLES
Example 1
Identification of A and B Isoforms
[0412] Solutions of antibody molecules comprise two different
isoforms. One form, Form A comprises heavy chain molecules that are
linked via at least one disulfide linkage. The other form, Form B,
comprises heavy chain molecules that are not linked via at least
one disulfide linkage. Form B does not appear or appears at a very
low frequency in with intact gamma 1 MAbs, such as Rituxan.RTM..
However with domain deleted (dd) constructs having a similar hinge,
the frequency of Form B is much higher. These forms can be
distinguished using denaturing, non-reducing SDS page. In domain
deleted antibody preparations, Form A appears as a 120 kDa dimer
while form B appears as a 60 kDa monomer (FIG. 1).
Example 2
Identification of Hinge Region Heterogeneity in CH2 Domain Deleted
MAb Fragments
[0413] Hinge domains can be subdivided into three distinct regions:
upper, middle, and lower hinge regions (Roux et al. J. Immunol.
1998 161:4083). Polypeptide sequences encompassing these regions
for IgG1 and IgG3 hinges are shown in Table 1. The IgG3 hinge
middle region contains, in addition to the two conserved cysteine
residues, a 15 amino acid motif that repeats three times. Amino
acid sequences from these regions were used to design synthetic
IgG1/IgG3 connecting peptides. These consisted of IgG1 upper hinge
residues corresponding to positions 226 through 238, an IgG1 middle
hinge corresponding to positions 239 through 241, and a single IgG3
middle hinge repeat motif corresponding to positions 241 EE through
242 combined with either an added proline at position 243 or an
added proline, alanine, proline at positions 243, 244, and 245,
respectively (Kabat numbering system), followed by a flexible
Gly/Ser spacer (Table 2). In addition, novel connecting peptides
were designed consisting of a serine amino acid residue substituted
for the cysteine at positions 239 or 242 combined with either an
added proline at position 243 or an added proline, alanine, proline
at positions 243, 244, and 245, respectively (Kabat numbering
system). Pro243Ala244Pro245 and Pro 243 connecting peptides were
also made. The amino acid sequence of the parent CH2 domain deleted
humanized CC49 connecting peptide beginning at the first residue of
the IgG1 hinge (position 226, Kabat numbering system) to the last
residue of the hinge/GlySer connecting peptide is shown in Table 2.
Also shown are the various connecting peptide designs by alignment
to CC49 with positions of the cysteine residues indicated in Kabat
numbering system.
1TABLE 1 IgG1, IgG3 and IgG4 Hinge Regions IgG Upper Hinge Middle
Hinge Lower Hinge IgG1 EPKSCDKTHT CPPCP APELLGGP (SEQ ID NO:2) (SEQ
ID NO:3) (SEQ ID NO:4) IgG3 ELKTPLGDTTHT CPRCP
(EPKSCDTPPPCPRCP).sub.3 APELLGGP (SEQ ID NO:5) (SEQ ID NO:6) (SEQ
ID NO:4) IgG4 ESKYGPP CPSCP APEFLGGP (SEQ ID NO:45) (SEQ ID NO:46)
(SEQ ID NO:47)
[0414]
2TABLE 2 Hinge Region Connecting Peptide Sequences Kabat hinge
position: 226 227 228 229 230 232 235 236 237 238 239 240 241 241EE
241FF 241GG 241HH 241II 241JJ lgG1 hinge E P K S C D K T H T C P P
sequence lgG4 hinge E S K Y G P P C P S sequence lgG3 middle C P E
P K S hinge sequence Connecting peptide: Connecting peptide
sequences G1 E P K S C D K T H T C P P (Seq. ID NO:7) G1/G3/Pro243
E P K S C D K T H T C P P C P E P K S (Seq. ID NO:8) G1/G3/ E P K S
C D K T H T C P P C P E P K S Pro243Ala244Pro245 (Seq. ID NO:9)
G1/Cys239Ser: E P K S C D K T H T S P P Pro243 (Seq. ID NO:10)
G1/Cys239Ser: E P K S C D K T H T S P P Pro243Ala24 (Seq. ID NO:11)
4Pro245 G1/Cys242Ser: E P K S C D K T H T C P P Pro243 (Seq. ID
NO:12) G1/Cys242Ser: E P K S C D K T H T C P P Pro243Ala24 (Seq. ID
NO:13) 4Pro245 G1/ E P K S C D K T H T C P P Pro243Ala244Pro245
(Seq. ID NO:14) G1/Pro243 E P K S C D K T H T C P P (Seq. ID NO:15)
G4/G3/ E S K Y G P P C P S C P E P K S Pro243Ala244Pro245 (Seq. ID
NO:48) Kabat hinge position: 241KK 241LL 241MM 241NN 241OO 241PP
241OO 241RR 241SS 242 243 244 245 lgG1 hinge C P A P sequence lgG4
hinge C P A P sequence lgG3 middle C D T P P P C P R hinge sequence
Connecting peptide: Connecting peptide sequences G1 C GGGSSGGGSG
G1/G3/Pro243 C D T P P P C P R C P GGGSSGGGSG G1/G3/ C D T P P P C
P R C P A P GGGSSGGGSG Pro243Ala244Pro245 G1/Cys239Ser: C P
GGGSSGGGSG Pro243 G1/Cys239Ser: C P A P GGGSSGGGSG Pro243Ala24
4Pro245 G1/Cys242Ser: S P GGGSSGGGSG Pro243 G1/Cys242Ser: S P A P
GGGSSGGGSG Pro243Ala24 4Pro245 G1/ C P A P GGGSSGGGSG
Pro243Ala244Pro245 G1/Pro243 C P GGGSSGGGSG G4/G3/ C D T P P P C P
R C P A P Pro243Ala244Pro245
Example 3
Construction of Connecting Polypeptides and Preferential Synthesis
of Isoforms
[0415] Nucleic acid sequences encoding the hinge region connecting
peptides shown in Table 2 were introduced into CH2 domain deleted
huCC49 gene sequences using the Splicing by Overlap Extension (SOE)
method (Horton, R. M. 1993 Methods in Molecular Biology, Vol 15:
PCR Protocols: Current Methods and applications. Ed. B. A. White).
Correct modifications to the hinge region were confirmed by DNA
sequence analysis. Plasmid DNA was used to transform CHO DG44 cells
for stable production of antibody protein.
[0416] CH2 domain deleted huCC49 antibodies containing the eight
designed synthetic connecting peptides indicated in Table 2 were
constructed and antibody produced in CHO DG44 cells. Supernatants
were collected from isolated cell lines and concentration of
antibody in the culture supernatants determined by immunoassay.
Supernatants containing antibody ranging from 0 to 30 ng of total
antibody protein from each cell line was analyzed by non-reducing
SDS-PAGE electrophoresis followed by Western Blot with anti-human
kappa HRP conjugated antibody to detect CH2 domain deleted huCC49
Form A and Form B isoforms. Under these conditions, Form A migrates
as a single 120 kDa homodimer and Form B as a 60 kDa doublet. Also
visible are kappa chain monomer and dimers. Connecting peptides
shown in SEQ ID NOs: 8,. 9, 14, and 15 were all found to increase
the proportion of Form A produced.
3TABLE 3 The percentage of Form A antibody after affinity
chromatography (Protein G) and after HIC purification CH2 domain
deleted % Form A Antibody After HIC Antibody After Protein G
purification HuCC49 60 98 (connecting peptide SEQ ID NO: 7) HuCC49
PAP 83 98 (connecting peptide SEQ ID NO: 14) HuCC49 V2 PAP 90 99
(connecting peptide SEQ ID NO: 14) HuCC49 G1/G3/PAP 98 Not done
(connecting peptide SEQ ID NO: 9) HuCC49 V2 G1/G3/PAP 96 Not done
(connecting peptide SEQ ID NO: 9)
[0417] These data show that novel, engineered synthetic hinge
region connecting peptides can be used to preferentially favor the
formation of the A or B isoform. These studies also reveal the
importance of the cysteine residues at position 242 (Kabat
numbering system) in synthesizing the CH2 domain-deleted antibody
Form A isoform. Substituting the cysteine at either position 239 or
242 with serine (e.g., using connecting peptides shown in SEQ ID
NOs: 10, 11, 12, or 13) shifts CH2 domain-deleted antibody
biosynthesis to the Form B isoform. Accordingly, in one embodiment,
a connecting peptide of the invention comprises a cysteine at at
least one of position 239 or 242. The use of connecting peptides
which increase the proportion of Form A produced will lead to a
beneficial improvement in process, yield and/or stability. These
synthetic hinge region connecting peptides are useful for favoring
synthesis of CH2 domain deleted antibody Form A isoform for any
antibody isotype, e.g., IgG1, IgG2, IgG3, or IgG4, based on the
extremely high degree of homology among the CH3 domains for all
four human isotypes. Including identical and conserved amino acid
residues, IgG1 CH3 domain is 98.13% homologous to IgG2 CH3, 97.20%
homologous to IgG3 CH3, and 96.26% homologous to IgG4 CH3.
Example 4
Purification of Form A and Form B from a Monoclonal Antibody
Mixture Containing both Isoforms
[0418] 10 mL of ddCC49 supernatant was titrated with 1 M Tris pH
9.0 to a final pH of 7.5. This material was filtered through a
series of Sol-Vac 0.8.mu. and 0.4.mu. membranes. A 100 mL XK50
Protein G column was pre-equilibrated with 1.times.PBS at a flow
rate of 80 ml/min. The titrated, filtered supernatant was loaded
onto the column at 80 ml/min. Bound protein was washed with the
equilibrium buffer for 2 column volumes and then eluted with 100 mM
Glycine at pH 3.0. The fractions containing the ddCC49 peak were
collected and immediately titrated with 1 M Tris pH 9.0 to a final
pH of 7.0.
[0419] A Toso Biosep Phenyl 5PW-HR column was pre-equilibrated with
20 mM Phosphate pH 7.2; 1 M Ammonium Sulfate. The Protein G eluate
was titrated to 1 M Ammonium Sulfate using a 3.5 M Ammonium Sulfate
pH 7.2 stock and loaded at a concentration of 2 mg/ml of gel bed.
Bound protein was washed with a 20 mM Phosphate pH 4 or 7.2
Ammonium Sulfate to adjust the conductivity to 116.4 mS/cm. The
material eluted from this condition has an apparent molecular
weight about 120 kD (Form A) on a non-reducing SDS-PAGE. The
remaining bound antibody was further eluted with a linear gradient
of reducing Ammonium Sulfate content in the Phosphate buffer. This
method separates Forms A and B in two separate peaks. The latter
eluted antibody apparently lacks the disulfide linkage between the
heavy chains and its molecular weight is about 60 kDa (Form B).
[0420] Both of the above purified materials can be recaptured by
bringing the ammonium sulfate concentration to 1M and reloading it
onto the cleaned Phenyl 5PW-HR column. Bound protein is eluted with
20 mM Phosphate pH 7.2 and dialyzed into 1.times.PBS.
Example 5
Comparison of Stability of Form A and Form B
[0421] The biologic activity of Forms A and B (as measured in
preliminary experiments e.g., using direct binding or competition
studies) revealed that Forms A and B have similar biologic
activity.
[0422] The stability of Forms A and B was also compared. Purified
ddCC49 molecules were concentrated to about 5 mg/ml by Amicon
concentrator fitted with YM30 membrane (Millipore). The
concentrated materials were equally divided into four portions for
each isoforms and each fraction was put into 10K dialysis cassette
(Pierce, cat #66410) for 16 h dialysis in the following buffers: 1)
10 mM Sodium Phosphate, pH3; 2) 10 mM Sodium acetate, pH 5; 3) 10
mM Sodium Phosphate, pH 7; and 4) 10 mM Sodium Borate, pH 9. After
dialysis, the protein concentration of each solution was adjusted
to 3 mg/ml. In addition to the pure A and B isoform solution, a
portion of A and B solutions from each pH were mixed to create a
mixture containing 50% each isoform. Total of 12 formulations were
created (four pH levels times 3 antibody solutions). The solutions
were filtered and filled in 3 ml Type-1 glass serum vials (West
Pharmaceuticals) with gray butyl stopper.
[0423] Three temperatures, 2-8.degree. C., 20-25.degree. C., and
38-42.degree. C. were chosen to store the protein solutions for
stability testing. Prior to storage, 500 .mu.l samples were drawn
from each formulation for physical and chemical analyses, these
zero-time point data were referred to as control. Once in storage,
samples were drawn at the following schedule, 2 weeks, 1 month, 2
months and 3 months and submitted for testing immediately.
[0424] To evaluate the physical and chemical stability of the two
isoforms, the following methods were used: turbidity measured at
OD.sub.320, non-reducing SDS-PAGE, and size-exclusion
chromatography.
[0425] Non-reducing SDS-PAGE was performed on for samples stored at
2-8.degree. C., 20-25.degree. C. and 38-42.degree. C. for various
time points. Both A and B form are relatively stable at pH 5 when
stored at 2-8.degree. C.. However, when formulated at pH 7 and 9,
both A and B forms showed degradation as indicated by increasing in
number of bands that were smaller than the original major bands
(120 kDa for form A and 60 kDa for form B). It was noticed that,
particularly for pH 7 and 9 samples stored at low and intermediate
temperatures, the intensity and number of bands that were less than
55 kDa were higher in B-isoform than A. This indicated that under
these conditions the A-isoform is more stable than B-isoform.
However, this seems not to be the case for A-isoform in pH 5 and
stored at 20-25.degree. C.. This sample seemed to have more
fragments than B-isoform. This appears to have been an artifact due
to microbial contamination (discussed in more detail below). At
high storage temperature, both forms at pH 9 were significantly
degraded and there was almost no difference in gel patterns among
the samples. Under this condition, trace amount of smear bands
showed up at top of the gel which indicated the formation of
aggregates. Because aggregates could be dissolved by SDS, the
aggregation was investigated using the methods described in the
following sections.
[0426] Table 4A through Table 4C list the turbidity data for ddCC49
stored at three different temperatures. The turbidity measures both
the soluble and non-soluble aggregates and it is based on the
amount of light scattered by these particles. When present,
aggregates will scatter light and result in an increase in
A.sub.320. As showed in Table 4A-C, the turbidity of ddCC49
molecules stored at 2-8.degree. C. increases as pH increased for
both A and B isoforms, with the former being less turbid than the
latter. This trend held true for samples stored for less than a
month at higher temperatures (20-25.degree. C. and 38-40.degree.
C.). As storage time reached 3 months, the turbidity increased
significantly for samples at high pH and temperature, and the
difference between A and B forms diminished. These results parallel
those of SDS-PAGE and indicate that both isoforms are relatively
stable (in terms of not forming aggregates) at pH 3 and 5, and that
A-isoform is less susceptible to aggregation than the B
isoform.
4TABLE 4A Turbidity measured at A.sub.320 for ddCC49 samples stored
at 2-8.degree. C. Time A-isoform B-isoform Mixture (month) pH = 3 5
7 9 3 5 7 9 3 5 7 9 0 0.030 0.038 0.044 0.056 0.034 0.042 0.046
0.066 0.036 0.042 0.051 0.061 1/2 0.029 0.029 0.046 0.045 0.030
0.038 0.048 0.058 0.034 0.033 0.043 0.055 1 0.033 0.039 0.035 0.055
0.033 0.035 0.044 0.059 0.032 0.040 0.039 0.066 2 0.042 0.022 0.042
0.044 0.039 0.037 0.055 0.067 0.042 0.024 0.040 0.058 3 0.035 0.047
0.051 0.050 0.038 0.041 0.066 0.081 0.027 0.048 0.051 0.065
[0427]
5TABLE 4B Turbidity measured at A.sub.320 for ddCC49 samples stored
at 20-25.degree. C. Time A-isoform B-isoform Mixture (month) pH = 3
5 7 9 3 5 7 9 3 5 7 9 1/2 0.031 0.032 0.056 0.066 0.039 0.034 0.064
0.083 0.034 0.039 0.060 0.071 1 0.025 0.043 0.055 0.090 0.034 0.042
0.070 0.084 0.028 0.039 0.055 0.094 2 0.034 0.053 0.077 0.113 0.046
0.032 0.090 0.087 0.037 0.038 0.066 0.108 3 0.036 0.056 0.156 0.143
0.029 0.060 0.121 0.125 0.044 0.050 0.101 0.142
[0428]
6TABLE 4C Turbidity measured at A.sub.320 for ddCC49 samples stored
at 38-42.degree. C. Time A-isoform B-isoform Mixture (month) pH = 3
5 7 9 3 5 7 9 3 5 7 9 1/2 0.041 0.042 0.068 0.063 0.041 0.044 0.080
0.067 0.041 0.039 0.070 0.064 1 0.041 0.043 0.071 0.065 0.036 0.040
0.079 0.069 0.032 0.048 0.078 0.070 2 0.047 0.030 0.066 0.060 0.046
0.045 0.087 0.082 0.051 0.034 0.078 0.079 3 0.058 0.051 0.098 0.105
0.046 0.057 0.101 0.157 0.056 0.057 0.101 0.126
[0429] Size exclusion chromatography (SEC) is a powerful method for
revealing the percent of intact molecules and the degraded products
(both fragments and soluble aggregates) and is highly reproducible.
In Table 4A-C the percent of intact monomer of A-isoform, B-isoform
and the mixture stored at different temperatures are listed. For
samples stored at 2-8.degree. C., it is clear that Form A has a
higher percentage of monomer as compared to Form B, and the mixture
of Form A and Form B was somewhere in between. At this storage
temperature, both forms were relatively stable at pH 3, 5 and 7
(with pH 5 being the most stable condition) for about three months.
However, at pH 9 there was a significant decrease in percentage of
monomer for Form B but only a slight decrease for Form A.
[0430] At elevated temperatures, all samples showed a significant
decrease in percent of monomer as storage time increased; the
A-isoform out performed the B-isoform. However there was an
exception, the sample of A-isoform in pH 5 stored at room
temperature exhibited much more degradation than the B-isoform or
the mixture under similar storage conditions. A close examination
of this particular A-isoform vial, the data from SDS-PAGE, and SEC
of the sample suggested that microbial contamination might have
caused this unexpected result. First, both the SEC and SDS-PAGE
results indicated that the degradation for this sample was
primarily accounted for by a increase in fragmentation, presumably
resulting from microbial digestion, otherwise some degree of
increase in aggregation would have been expected. Second, the fact
that the mixture sample, which contained 50% each of A and
B-isoform, showed a better stability profile than B-isoform
indicating that a more stable A-isoform must have contributed to
the higher percent of monomer. Finally, A-isoform in pH 5 stored at
2-8.degree. C. and 38-42.degree. C. both showed higher percent of
monomer than B-isoform under similar conditions. Therefore,
intermediate storage temperature should have yielded similar
results. Due to the limited amount of sample, an assay for
microbial contamination could not be performed.
[0431] It was also noted that for both isoforms of IDEC-159 stored
in high pH (9) and at 40.degree. C., the percent of monomer reduced
to about 30%. Under these severe conditions, the stability
differences between the two isoforms disappeared. This SEC result
mirrors of the results found using SDS-PAGE. Both results indicate
that, although some chemical and physical characteristics differ
between the two isoforms, the mechanism and by-products of
degradation for both isoforms are similar, if not identical.
[0432] In summary, the SEC results indicate that both A and
B-isoforms have optimal pH at about 5, and that A-isoform is more
stable than B-isoform in terms of retaining higher percent of
intact monomer at similar storage conditions.
7TABLE 5A Percent of monomer for ddCC49 samples stored at
2-8.degree. C. Time A-isoform B-isoform Mixture (month) pH = 3 5 7
9 3 5 7 9 3 5 7 9 0 98.81 99.13 98.16 97.93 97.02 97.70 96.88 93.51
97.83 98.27 97.44 95.81 1/2 98.98 99.16 98.25 98.00 97.15 97.87
96.96 91.95 98.15 98.49 97.68 95.59 1 98.80 99.20 97.99 97.11 97.02
97.81 96.62 88.99 98.04 98.45 97.41 94.45 2 98.74 99.01 98.00 95.67
97.15 97.69 95.50 84.84 98.06 98.34 96.81 92.17 3 98.28 98.89 97.88
95.31 96.69 98.14 95.37 85.98 97.61 98.15 96.65 89.90
[0433]
8TABLE 5B Percent of monomer for ddCC49 samples stored at
20-25.degree. C. Time A-isoform B-isoform Mixture (month) pH = 3 5
7 9 3 5 7 9 3 5 7 9 1/2 97.83 99.04 97.12 93.65 95.84 97.62 93.71
79.61 96.75 98.30 95.37 87.67 1 96.60 96.63 95.65 88.09 94.38 97.23
90.69 72.26 95.36 97.99 93.05 80.92 2 93.62 92.79 93.17 80.06 91.71
96.96 85.51 66.53 92.78 97.51 89.33 73.91 3 92.81 89.56 x 74.31
89.30 96.04 82.57 63.25 90.46 97.02 86.80 69.36
[0434]
9TABLE 5C Percent of monomer for ddCC49 samples stored at
38-42.degree. C. Time A-isoform B-isoform Mixture (month) pH = 3 5
7 9 3 5 7 9 3 5 7 9 1/2 86.31 97.50 85.06 66.42 79.85 94.29 69.68
63.64 82.09 95.70 76.24 63.95 1 78.71 95.19 73.77 51.55 66.73 89.37
54.70 50.10 68.53 92.02 62.93 49.28 2 66.64 91.63 60.45 38.43 60.29
81.08 42.98 37.09 61.33 85.81 51.08 36.68 3 57.87 86.99 52.82 30.81
43.61 74.23 36.68 29.73 46.75 80.93 44.35 30.18
Example 7
Preparative Purification of Forms A and B
[0435] IDEC-159 (ddCC49) is a CH2 domain deleted monoclonal
antibody directed against TAG-72 antigen, which is expressed on the
surface of tumors. IDEC-159 contains two isoforms of the antibody,
called Form A and Form B. The current cell culture process for
IDEC-159 produces an approximate 50:50 ratio of Form A to Form B.
The Form A isoform is an antibody with a deleted CH2 region in the
Fc portion of the heavy chain. In addition to having a deleted CH2
region, Form B also lacks the disulfide bond linkage across the Fc
region and is only held together by hydrophobic interactions and
salt bridges.
[0436] The third and final chromatography step in the IDEC-159
purification process was developed to separate the two isoforms of
IDEC-159. The separation is achieved by hydrophobic interaction
chromatography (HIC), using a Phenyl TSKgel 5PW-HR adsorbent. Since
form B is more hydrophobic than form A, it adsorbs irreversibly to
the stationary phase using approximately 0.73 M Ammonium Sulfate/20
mM Sodium Phosphate, pH 4.0-pH 7.0 as the mobile phase. Form A
binds to a lesser extent to the stationary phase under these
conditions and is therefore eluted isocratically, i.e. it leaves
the column with the flowthrough fraction. Subsequent to the
isocratic elution of Form A, omitting Ammonium sulfate from the
mobile phase desorbs Form B. The following method was used to
separate the two isoforms of IDEC-159:
[0437] The column was sanitized using .gtoreq.3 CVs of 0.5 N NaOH,
at .ltoreq.150 cm/hr.
[0438] The column was equilibrated using .gtoreq.5 CVs of 0.73 M
Ammonium Sulfate/20 mM Sodium Phosphate, pH 4.0, at .ltoreq.150
cm/hr.
[0439] The column was loaded with room temperature TMAE Flowthrough
that has been adjusted to include 0.43 volumes of 2.5 M Ammonium
Sulfate/20 mM Sodium Phosphate, pH 4.0 liquid stock solution, at 5
mg per ml of resin.
[0440] The antibody was loaded onto the column at pH 4.0, at
.ltoreq.100 cm/hr.
[0441] Collection of the antibody started when the outlet O.D. at
280 nm reaches 10 mAU.
[0442] The column was washed using 15 CVs of 0.73 M Ammonium
Sulfate/20 mM Sodium Phosphate, pH 4.0, at .ltoreq.100 cm/hr.,
[0443] Continue antibody collection throughout the 15 CV wash, then
the outlet was diverted back to waste.
[0444] The column was stripped using .gtoreq.5CVs of 20 mM Sodium
Phosphate, pH 4.0, at .ltoreq.100 cm/hr. 6. The column was cleaned
with .gtoreq.3 CVs 0.5 N NaOH, at .ltoreq.150 cm/hr.
[0445] The column was equilibrated with .gtoreq.3 CVs of 0.73 M
Ammonium Sulfate/20 mM Sodium Phosphate, pH 4.0, at .ltoreq.150
cm/hr.
[0446] The column was stored in .gtoreq.3 CVs of 20% Ethanol, at
.gtoreq.150 cm/hr.
[0447] The separation of the two forms at a preparative scale (5 L
column volume, total IDEC-159 load approximately 20 g) is shown in
FIGS. 13 (A and B). The first two peaks comprise the isocratic
elution of Form A, the second peak shows the eluted Form B, while
the third peak contains impurities, which are removed from the
stationary phase during cleaning.
[0448] The capability of this method to separate Forms A and B at
preparative scale was also demonstrated by SDS PAGE.
Example 8
Preparation of a CH2 Domain-Deleted Tetravalent Antibody
[0449] HuCC49 CH2 domain-deleted sc(Fv)2 tetravalent antibody
design was based on appending a huCC49 single chain Fv (scFv) to
the carboxyl terminus of the HuCC49 CH2 domain-deleted antibody CH3
domain. A schematic diagram of HuCC49 CH2 domain-deleted sc(Fv)2
tetravalent antibody is shown in FIG. 4. An equivalent reference to
this design is C-scFv Tetravalent CH2 Domain Deleted antibody. The
preparation of single polypeptide chain binding molecules of the Fv
region, single-chain Fv molecules, is described in U.S. Pat. No.
4,946,778. A CC49 scFv immunoglobulin-like antibody is described in
U.S. Pat. No. 5,892,019. The huCC49 scFv is comprised of a VL and a
VH region sequence tethered by a short synthetic linker
(VL.fwdarw.(Gly.sub.4Ser).sub.3 linker.fwdarw.VH orientation) and
was synthesized by PCR amplification. The 5' VL PCR primer included
a BamHI restriction endonuclease site followed by sequence encoding
a (Gly.sub.4Ser).sub.2 linker peptide. The 3' VL PCR primer
included sequence partially encoding a (Gly.sub.4Ser).sub.3 linker
peptide used to connect the two VL and VH regions. The 5' VH PCR
primer also included sequence partially encoding a
(Gly.sub.4Ser).sub.3 linker peptide used to connect the VL and VH
regions. Finally, the 3' VH PCR primer included a stop codon
followed by a BamHI site. The two V regions were amplified with the
two sets of PCR primers from plasmid DNA substrate containing
huCC49 CH2 domain-deleted antibody and assembly of the scFv was
accomplished in a second PCR reaction through the common
overlapping sequences encoding the (Gly.sub.4Ser).sub.3 linker. The
huCC49 scFv gene fragment was gel isolated, digested with BamHI
restriction endonuclease and cloned into a single BamHI site
previously introduced into the huCC49 CH2 domain-deleted antibody
Polycistronic expression vector. (See US 2003 0157641 A1.).
Briefly, the vector was modified by removing an existing stop codon
at the 3' end of the gene coding for the CH3 domain and replacing
with nucleotides coding for the amino acid sequence Ser-Gly-Gly-Gly
immediately followed by a BamHI restriction endonuclease site
(coding for Gly-Ser). The BamHI digested huCC49 scFv fragment was
cloned into the BamHI site of the vector resulting in a fusion
product of the huCC49 scFv to the carboxyl terminus of the huCC49
CH2 domain-deleted antibody CH3 domain through a 16 amino acid
Ser(Gly.sub.4Ser).sub.3 linker. Correct sequences were confirmed by
DNA sequence analysis. Plasmid DNA was used to transform CHO DG44
cells for stable production of antibody protein. The engineered
antibody was designated huCC49 domain-deleted sc(Fv)2 tetravalent
antibody. FIG. 8A shows the DNA sequence of heavy chain huCC49
domain-deleted sc(Fv)2 tetravalent antibody. FIG. 8C shows the DNA
sequence of light chain huCC49 domain-deleted sc(Fv)2 tetravalent
antibody. FIG. 9A shows the amino acid sequence of heavy chain
huCC49 domain-deleted sc(Fv)2 tetravalent antibody. FIG. 9C shows
the amino sequence of light chain huCC49 domain-deleted sc(Fv)2
tetravalent antibody.
[0450] Supernatants were collected from isolated cell lines and
concentration of antibody in the culture supernatants determined by
immunoassay. Supernatants were analyzed by non-reducing SDS-PAGE
electrophoresis followed by Western Blot with anti-human kappa-HRP
conjugated antibody to detect huCC49 CH2 domain-deleted sc(Fv)2
tetravalent antibody Form A and Form B isoforms. Under these
conditions, Form A was observed to migrate as a single .about.170
kDa homodimer and Form B as a .about.85 kDa doublet in
approximately a 50:50 ratio of A to B isoform. As shown in FIG. 18,
five individually isolated clones were all found to produce an A
and B CH2 domain-deleted sc(Fv)2 tetravalent antibody isoform. One
of the clones was selected for antibody production and purification
using HIC chromatography as described in Example 4. Purified huCC49
CH2 domain-deleted sc(Fv)2 tetravalent antibody Forms A and B were
analyzed by non-reducing and reducing SDS-PAGE and the results are
shown in FIG. 19. Form A huCC49 domain-deleted sc(Fv)2 tetravalent
antibody was effectively separated from Form B in excess of 95%
purity. As expected, both purified Forms behaved identically under
reducing SDS-PAGE conditions. HuCC49 CH2 domain-deleted sc(Fv)2
tetravalent antibody Form A was examined by size exclusion
chromatography and found to elute primarily as a single peak (96%)
indicating that there was no significant aggregation or
decomposition of antibody product (FIG. 20).
Example 9
Biodistribution Profile of HuCC49 CH2 Domain-Deleted Tetravalent
Antibody
[0451] HuCC49 CH2 domain-deleted sc(Fv)2 tetravalent antibody Form
A was tested in a competitive binding assay for it's ability to
bind to bovine submaxillary mucine, a source of the TAG-72 antigen,
by time-resolved flourometric immunoassay using a Delphia
fluorimeter (Wallac Inc., Gaithersburg, Md.). Competitive binding
curves are shown in FIG. 21. HuCC49 CH2 domain-deleted sc(Fv)2
tetravalent antibody Form A and control parent CH2 domain-deleted
huCC49 (referred to as HuCC49 or IDEC 159) antibodies were
evaluated. Relative binding activity for the tetravalent antibody
was found to be 5-fold more avid than the control parent CC49
antibody (GraphPad Prism 4.0 for Windows, GraphPad, Software, San
Diego Calif. USA. www.graphpad.com), consistent with an expected
increase in the number of antigen binding sites.
[0452] Biodistribution of .sup.90Y-radiolabeled huCC49 CH2
domain-deleted sc(Fv)2 tetravalent antibody was compared to results
previously generated with control parent huCC49 antibody in athymic
nude mice bearing LS-174T human tumor xenografts. HuCC49 CH2
domain-deleted sc(Fv)2 tetravalent antibody was conjugated with the
chelator Chx-DTPA and binding activity assessed. Conjugated huCC49
CH2 domain-deleted sc(Fv)2 tetravalent antibody showed a 5-6 fold
higher avidity than the conjugated control parent huCC49
demonstrating that the tetravalent antibody could be derivatized
without losing significant binding activity. HuCC49 CH2
domain-deleted sc(Fv)2 tetravalent antibody was labeled with
.sup.90Y and a single dose of radiolabeled antibody was
administered by i.v. tail vein injection to mice presenting
pre-established tumors of approximately 250 mm.sup.3. Samples were
harvested and processed for beta counting. Percentage injected dose
(% ID) of .sup.90Y radiolabeled antibody per gram of tumor or
normal tissue was determined from 3 to 72 hours and is shown in
Table 6.
10TABLE 6 5-7 mice/group % ID/gm-tissue Blood Spleen Kidney Liver
Tumor HuCC49 (domain deleted) 3-5 hrs 18.24 5.39 9.15 8.83 13.66 12
hrs 3.21 5.01 15.50 14.20 17.33 24 hrs 1.03 6.21 14.09 10.84 20.53
48 hrs 0.17 6.92 11.15 11.85 13.17 72 hrs 0.10 6.22 9.01 10.59
10.55 Tetravalent HuCC49 3 hrs 20.3 12.60 7.60 9.60 10.80 6 hrs
15.4 12.20 6.70 12.40 12.10 12 hrs 7.20 15.10 5.10 13.90 13.10 24
hrs 2.40 9.50 3.90 12.10 14.00 48 hrs 0.50 10.00 2.60 11.90 11.50
72 hrs 0.10 ** 1.90 12.70 6.40 Data represent mean values +/-
standard errors. **technical problem with sample
[0453] HuCC49 CH2 domain-deleted sc(Fv)2 tetravalent (C-scFv
tetravalent CH2 domain deleted) antibody showed lower accumulation
in the kidney than control huCC49 antibody, likely due to the
increased molecular mass of the antibody. Tumor accumulation of
huCC49 CH2 domain-deleted sc(Fv)2 tetravalent antibody was similar
to that achieved with the control parent huCC49 (Table 6). However,
as mentioned, these two biodistribution studies were not conducted
simultaneously and are subject to experimental variation. A figure
showing tumor retention for control parent huCC49 and huCC49 CH2
domain-deleted sc(Fv)2 tetravalent antibody as measured by % ID/gm
is shown in FIG. 35. FIG. 35 also shows the same tumor retention
data normalized to peak accumulation of radioactivity. AUC analysis
of the two normalized retention curves in FIG. 35 was calculated
using GraphPad Prism 4.0 for Windows, GraphPad, Software, San Diego
Calif. USA. www.graphpad.com. Control parent huCC49 had a Total
Peak Area of 2037 units and huCC49 CH2 domain-deleted sc(Fv)2
tetravalent antibody had a Total Peak Area of 2562 units
representing a 25.8% increase in area for the tetravalent protein.
Representation of the data in this format suggests that there is
improved retention of tetravalent antibody in the tumor compartment
compared to the parent divalent molecule.
[0454] The tetrameric HuCC49 construct affords certain advantages
for pretargeting, e.g., radioimmunotherapeutic (RIT) pretargeting.
This advantage is defined by three observations derived from Table
6. First, the tetrameric HuCC49 CH2 domain-deleted construct has a
blood clearance rate comparable to that of the current CH2
domain-deleted HuCC49 construct. This fast blood clearance may
obviate the need for a "clearing agent" to expedite removal of the
antibody from the blood prior to administration of the radiolabeled
ligand that localizes to the tumor-bound antibody. Elimination of
the clearing agent significantly reduces the complexity of this
modality of treatment in the clinical setting. Second, tumor
retention for the tetrameric construct is comparable to the current
dimeric construct. Therefore, radiation dose delivered will be
comparable for the two constructs ((Table 6). Third, the lower
kidney and liver uptake compared to the CH2 domain-deleted HuCC49
may enable larger input doses of the radiolabeled ligand before
reaching organ-limiting toxicity.
Example 10
Preparation of a HuCC49 CH2 Domain-Deleted Tetravalent Antibody
Comprising a Novel Connecting Peptide and Preferential Synthesis of
Isoform A
[0455] A huCC49 CH2 domain-deleted sc(Fv)2 tetravalent antibody
similar to the design shown in the bottom half of FIG. 4 but
containing the G1/G3/Pro243Ala244Pro245+[Gly/Ser] synthetic
connecting peptide indicated in Table 2 was constructed. Briefly,
gene sequences coding for partial
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide was
synthesized by PCR amplification using a 5' connecting peptide PCR
primer encoding a SalI restriction endonuclease site and a 3'
connecting peptide PCR primer encoding an XhoI site. Plasmid DNA
containing the gene sequence coding for the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide was used as
substrate. The PCR product encodes all of G1/G3/Pro243Ala244Pro245
and part of [Gly/Ser] connecting peptide. The
G1/G3/Pro243Ala244Pro245 hinge fragment was gel isolated, digested
with SalI and XhoI restriction endonucleases and cloned into the
SalI and XhoI vector sites reconstituting the full length
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide. Correct
sequences were confirmed by DNA sequence analysis. Plasmid DNA was
used to transform CHO DG44 cells for stable production of antibody
protein. FIG. 8B shows the DNA sequence of heavy chain huCC49
domain-deleted sc(Fv)2 tetravalent antibody containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide. FIG. 8C
shows the DNA sequence of light chain huCC49 domain-deleted sc(Fv)2
tetravalent antibody containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide. FIG. 9B
shows the amino acid sequence of heavy chain huCC49 domain-deleted
sc(Fv)2 tetravalent antibody containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide. FIG. 9C
shows the amino sequence of light chain huCC49 domain-deleted
sc(Fv)2 tetravalent antibody containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide.
[0456] Supernatants were collected from isolated cell lines and
concentration of antibody in the culture supernatants determined by
immunoassay. Supernatants were analyzed by non-reducing SDS-PAGE
electrophoresis followed by Western Blot with anti-IgG-HRP
conjugated antibody to detect huCC49 CH2 domain-deleted sc(Fv)2
tetravalent (C-scFv tetravalent CH2 domain-deleted) antibody Form A
and Form B isoforms. Under these conditions, Form A is expected to
migrate as a single .about.170 kDa homodimer and Form B as a
.about.85 kDa doublet in approximately a 50:50 ratio of A to B
isoform. As shown in FIG. 22, a representative CH2 domain-deleted
sc(Fv)2 tetravalent antibody containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide was found to
produce all Form A tetravalent antibody isoform.
[0457] A cell line containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] (SEQ ID NO:9) connecting peptide
introduced into the huCC49 CH2 domain-deleted sc(Fv)2 tetravalent
antibody sequence was used for antibody production. Antibody was
produced and purified using methods described in Example 4 above.
HuCC49 CH2 domain-deleted sc(Fv)2 tetravalent antibody containing
the G1/G3/Pro243Ala244Pro245+[Gly/Ser] (SEQ ID NO:9) connecting
peptide was purified using only the Protein G column, eluted
essentially as a single peak at 96% purity without further HIC
purification. Reduced and non-reduced purified protein samples were
analyzed by SDS-PAGE electrophoresis. Under non-reducing
conditions, Form A is expected to migrate as a single 170 kDa
homodimer and Form B as a 85 kDa doublet. The connecting peptide
shown in SEQ ID NO: 9 was found to substantially increase the
proportion of Form A produced. Exemplary results are shown in FIG.
23. This result shows that the G1/G3/Pro243Ala244Pro245+[Gly/Ser]
hinge (SEQ ID NO:9) resulted in the production of essentially all
Form A huCC49 CH2 domain-deleted sc(Fv)2 tetravalent (C-scFv
tetravalent CH2 domain deleted) antibody with little or no
detectable Form B, demonstrating that the utility of this hinge for
producing the Form A isoform is generally applicable to complex
antibodies such as multivalent antibodies. It is clear that this
invention is also applicable to bispecific tetravalent antibody
formats as well. HuCC49 CH2 domain-deleted sc(Fv)2 tetravalent
G1/G3/Pro243Ala244Pro245 antibody was examined by size exclusion
chromatography and found to essentially elute as a single peak
containing 84% monomer. The fraction containing the residual
aggregates was removed by preparative size exclusion chromatography
with the resulting preparation containing essentially 95% monomer
(FIG. 24) HuCC49 CH2 domain-deleted sc(Fv)2 tetravalent
G1I/G3/Pro243Ala244Pro245 antibody was tested in a competitive
binding assay for it's ability to bind to bovine submaxillary
mucine, a source of the TAG-72 antigen, by time-resolved
flourometric immunoassay using a Delphia fluorimeter (Wallac Inc.,
Gaithersburg, Md.). Competitive binding curves are shown in FIG.
25. HuCC49 CH2 domain-deleted sc(Fv)2 tetravalent antibody Form A
and control parent CH2 domain-deleted huCC49 (referred to as HuCC49
or IDEC 159) antibodies were evaluated. Relative binding activity
for the tetravalent antibody was found to be 8-fold more avid than
the control parent HuCC49 antibody (GraphPad Prism 4.0 for Windows,
GraphPad, Software, San Diego Calif. USA. www.graphpad.com),
consistent with an expected increase in the number of antigen
binding sites.
[0458] These results show that the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide (SEQ ID NO:9)
resulted in the production of essentially all Form A huCC49 CH2
domain-deleted sc(Fv)2 tetravalent antibody with no detectable Form
B. The purified antibody demonstrated an increase in avidity
towards antigen.
Example 11
Preparation of a CH2 Domain-Deleted Tetravalent Antibody
[0459] A huCC49 minibody and a huCC49 2 sc(Fv)2 tetravalent
antibody (N-scFv tetravalent minibody) as shown in FIG. 2 were both
constructed. Briefly, huCC49 2 sc(Fv)2 tetravalent antibody (N-scFv
tetravalent minibody) design was based on inserting a huCC49 single
chain Fv (scFv) between the carboxyl end of the first scFv domain
and the amino-end of the hinge connecting peptide in the huCC49
minibody. The preparation of single polypeptide chain binding
molecules of the Fv region, single-chain Fv molecules, is described
in U.S. Pat. No. 4,946,778. A CC49 scFv immunoglobulin-like
antibody is described in U.S. Pat. No. 5,892,019. The preparation
of a minibody construct is described in U.S. Pat. No. 5,837,821.
The huCC49 scFv is comprised of a VL and a VH region sequence
tethered by a short synthetic linker
(VL.fwdarw.(Gly.sub.4Ser).sub.3 linker.fwdarw.VH orientation) and
was synthesized by PCR amplification and used to construct a huCC49
minibody. Second, the minibody vector was modified by adding a
modified (Gly.sub.4Ser).sub.5 linker to the carboxyl end of the
amino-terminal scFv domain of the huCC49 minibody by PCR
amplification, replacing nucleotides coding for the last two amino
acids residues of the linker with an Nhe I restriction endonuclease
site. This results in a (Gly.sub.4Ser).sub.4-Gly.sub.3-Ala-Ser
linker followed by a Sal I restriction endonuclease site separated
by several nucleotides. A second huCC49 scFv was amplified using
PCR from plasmid DNA substrate containing huCC49 scFv gene with the
5' VL PCR primer encoding an Nhe I restriction endonuclease site
and the 3' VH PCR primer encoding a Sal I site. The huCC49 scFv
fragment was gel isolated, digested with Nhe I and Sal I
restriction endonucleases and cloned into Nhe I and Sal I sites
between the first scFv and the hinge connecting peptide. This
results in a fusion product consisting of a leader peptide to two
serial huCC49 scFvs to a hinge connecting peptide to a CH3 domain.
Correct sequences were confirmed by DNA sequence analysis. Plasmid
DNA was used to transform CHO DG44 cells for stable production of
antibody protein. FIG. 10A shows the DNA sequence of huCC49
tetravalent (N-scFv tetravalent) minibody gene. FIG. 11A shows the
amino acid sequence of huCC49 tetravalent (N-scFv tetravalent)
minibody.
[0460] Supernatants were collected from isolated cell lines and
concentration of antibody in the culture supernatants determined by
immunoassay. Supernatants were analyzed by non-reducing SDS-PAGE
electrophoresis followed by Western Blot with anti-IgG-HRP
conjugated antibody to detect heavy chain constant sequences in the
Form A and Form B isoforms. Under these conditions, huCC49 minibody
Form A is expected to migrate as a single .about.82 kDa homodimer
and half molecules or Form B as a .about.41 kDa doublet. HuCC49 2
sc(Fv)2 tetravalent minibody Form A is expected to migrate as a
single .about.138 kDa homodimer and Form B as a .about.69 kDa
doublet in approximately a 50:50 ratio of A to B isoform. By
comparison, huCC49 CH2 domain deleted antibody (expected to migrate
as a single .about.120 kDa homodimer and Form B as a .about.60 kDa
doublet in approximately a 50:50 ratio of A to B isoform) was used
as control. As shown in FIG. 26, representative isolated minibody
and 2 sc(Fv)2 tetravalent minibody clones were found to secrete
both A and B isoforms consistent with the expected molecular masses
under both non-reducing and reducing SDS-PAGE conditions.
Example 12
Preparation of a HuCC49 CH2 Domain-Deleted Tetravalent Antibody
Comprising a Novel Connecting Peptide and Preferential Synthesis of
Isoform A
[0461] A huCC49 2 sc(Fv)2 tetravalent antibody (N-scFv tetravalent
minibody) similar to the design shown in the bottom of FIG. 2 but
containing the G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting
peptide indicated in Table 2 was constructed. Briefly, gene
sequences coding for partial G1/G3/Pro243Ala244Pro245+[Gly/Ser]
connecting peptide was synthesized by PCR amplification using a 5'
connecting peptide PCR primer encoding a Sal I restriction
endonuclease site and a 3' connecting peptide PCR primer encoding
an Xho I site. Plasmid DNA containing the gene sequence coding for
the G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide was used
as substrate. The PCR product encodes all of
G1/G3/Pro243Ala244Pro245 and part of [Gly/Ser] connecting peptide.
The G1/G3/Pro243Ala244Pro245 hinge fragment was gel isolated,
digested with Sal I and Xho I restriction endonucleases and cloned
into the Sal I and Xho I vector sites reconstituting the full
length G1/G3/Pro243Ala244Pro24- 5+[Gly/Ser] connecting peptide.
Correct sequences were confirmed by DNA sequence analysis. Plasmid
DNA was used to transform CHO DG44 cells for stable production of
antibody protein. FIG. 10B shows the DNA sequence of huCC49 2
sc(Fv)2 tetravalent antibody (N-scFv tetravalent minibody) gene
containing the G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting
peptide. FIG. 11B shows the amino acid sequence of huCC49 2 sc(Fv)2
tetravalent antibody (N-scFv tetravalent minibody) gene containing
the G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide.
[0462] Supernatants were collected from isolated cell lines and
concentration of antibody in the culture supernatants determined by
immunoassay. Supernatants were analyzed by non-reducing SDS-PAGE
electrophoresis followed by Western Blot with anti-IgG-HRP
conjugated antibody to anti-IgG-HRP conjugated antibody to detect
huCC49 2 sc(Fv)2 tetravalent minibody (N-scFv tetravalent minibody)
Form A and Form B isoforms. Under these conditions, huCC49 2
sc(Fv)2 tetravalent minibody Form A is expected to migrate as a
single .about.138 kDa homodimer and Form B as a .about.69 kDa
doublet in approximately a 50:50 ratio of A to B isoform. As shown
in FIG. 27, a representative huCC49 2 sc(Fv)2 tetravalent minibody
containing the G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting
peptide was found to produce essentially all Form A tetravalent
minibody isoform.
[0463] A cell line containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] (SEQ ID NO:9) connecting peptide
introduced into the huCC49 2 sc(Fv)2 tetravalent minibody sequence
was used for antibody production. Because huCC49 2 sc(Fv)2
tetravalent minibody lacks a CH1 domain, protein cannot be purified
using Protein G chromatography. Antibody was subsequently purified
using a combination of anion exchange, hydrophobic interaction, and
size exclusion chromatography methods. HuCC49 2 sc(Fv)2 tetravalent
minibody containing the G1/G3/Pro243Ala244Pro245+[Gly/Ser] (SEQ ID
NO:9) connecting peptide was purified essentially as a single peak
at 97.6% purity. Reduced and non-reduced purified protein samples
were analyzed by SDS-PAGE electrophoresis. Under non-reducing
conditions, Form A is expected to migrate as a single .about.138
kDa homodimer and Form B as a .about.69 kDa doublet. The connecting
peptide shown in SEQ ID NO: 9 was found to substantially increase
the proportion of Form A produced. Exemplary results are shown in
FIG. 28. This result shows that the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] hinge (SEQ ID NO:9) resulted in
the production of essentially all Form A huCC49 2 sc(Fv)2
tetravalent minibody (N-scFv tetravalent minibody) with little or
no detectable Form B, demonstrating that the utility of this hinge
for producing the Form A isoform is generally applicable to complex
antibodies such as multivalent antibodies. It is clear that this
invention is also applicable to bispecific tetravalent antibody
formats as well. Purified huCC49 2 sc(Fv)2 tetravalent
G1/G3/Pro243Ala244Pro245 minibody was examined by size exclusion
chromatography and found to essentially elute as a single peak
containing 97.6% monomer (FIG. 29).
[0464] Purified huCC49 2 sc(Fv)2 tetravalent
G1/G3/Pro243Ala244Pro245 minibody was tested in a competitive
binding assay for it's ability to bind to bovine submaxillary
mucine, a source of the TAG-72 antigen, by time-resolved
flourometric immunoassay using a Delphia fluorimeter (Wallac Inc.,
Gaithersburg, Md.). Competitive binding curves are shown in FIG.
30. HuCC49 2 sc(Fv)2 tetravalent G1/G3/Pro243Ala244Pro245 minibody,
huCC49 minibody, huCC49 CH2 domain-deleted sc(Fv)2 tetravalent
G1/G3/Pro243Ala244Pro245 antibody, and control parent CH2
domain-deleted huCC49 (referred to as HuCC49 or IDEC 159)
antibodies were evaluated. Relative binding activities for both
tetravalent antibodies were found to be more avid than the control
parent huCC49 antibody or minibody (GraphPad Prism 4.0 for Windows,
GraphPad, Software, San Diego Calif. USA. www.graphpad.com),
consistent with an expected increase in the number of antigen
binding sites.
Example 13
Preparation of a PRIMATIZED.RTM. p5E8 CH2 Domain-Deleted
Tetravalent Antibody Comprising a Novel Connecting Peptide and
Preferential Synthesis of Isoform A
[0465] PRIMATIZED.RTM. p5E8G1 is a chimeric macaque/human
(PRIMATIZED.RTM.) monoclonal antibody containing macaque heavy and
light variable regions fused to human gamma 1 and kappa constant
regions, respectively. PRIMATIZED.RTM. p5E8G1 binds to human CD23,
the low affinity receptor for IgE (Fc.epsilon.RII) (Mavromatis and
Cheson. 2003. J. Clin. Oncol. 21:1874; US Patent Application
20030059424). CH2 domain-deleted PRIMATIZED.RTM. p5E8 sc(Fv)2
tetravalent antibody containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] synthetic connecting peptide
indicated in Table 2 (SEQ ID NO:9) was constructed using a similar
strategy as that described in Example 10. The PRIMATIZED.RTM. p5E8
scFv used for constructing the sc(Fv)2 tetravalent antibody is
comprised of a p5E8 VL and a VH region sequence tethered by a short
synthetic linker in the VL.fwdarw.(Gly.sub.4Ser).sub.3
linker.fwdarw.VH orientation and is described in greater detail in
Example 12. Correct sequences were confirmed by DNA sequence
analysis. Plasmid DNA was used to transform CHO DG44 cells for
stable production of antibody protein. FIG. 12A shows the DNA
sequence of heavy chain CH2 domain-deleted PRIMATIZED.RTM. p5E8
sc(Fv)2 tetravalent antibody containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide. FIG. 12B
shows the DNA sequence of light chain CH2 domain-deleted
PRIMATIZED.RTM. p5E8 sc(Fv)2 tetravalent antibody. FIG. 13A shows
the amino acid sequence of heavy chain CH2 domain-deleted
PRIMATIZED.RTM. p5E8 sc(Fv)2 tetravalent antibody containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide. FIG. 13B
shows the amino sequence of light chain CH2 domain-deleted
PRIMATIZED.RTM. p5E8 sc(Fv)2 tetravalent antibody containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide.
[0466] Supernatant was collected from a stably transfected cell
line and concentration of antibody in the culture supernatant
determined by immunoassay. Supernatant was analyzed by non-reducing
SDS-PAGE electrophoresis followed by Western Blot with anti-human
IgG-HRP conjugated antibody to detect Form A and Form B isoforms of
CH2 domain-deleted PRIMATIZED.RTM. p5E8 sc(Fv)2 tetravalent
antibody containing the G1/G3/Pro243Ala244Pro245+[Gly/Ser]
connecting peptide. Under these conditions, Form A is expected to
migrate as a single .about.170 kDa homodimer and Form B as a
.about.85 kDa doublet. The connecting peptide shown in SEQ ID NO: 9
was found to substantially increase the proportion of Form A
tetravalent antibody produced. Exemplary results are shown in FIG.
31. These results show that the G1/G3/Pro243Ala244Pro245+[Gly/Ser]
connecting peptide (SEQ ID NO:9) resulted in the production of
essentially all Form A CH2 domain-deleted PRIMATIZED.RTM. p5E8
sc(Fv)2 tetravalent antibody with no detectable Form B,
demonstrating that the utility of this hinge for producing the Form
A isoform CH2 domain-deleted sc(Fv)2 tetravalent antibodies is
generally applicable to antibodies of varying specificities.
Example 14
Preparation of PRIMATIZED.RTM. p5E8 Minibodies Comprising a Novel
Connecting Peptide and Preferential Synthesis of Isoform A
[0467] Minibodies are single chain polypeptides consisting of an
scFv fused to immunoglobulin hinge region and CH3 domain. The
preparation of minibody single polypeptide chain binding molecules
is described in U.S. Pat. No. 5,837,821. Normally, in intact IgG
molecules the cysteine residue at position 230 in the hinge region
forms a covalent disulfide bond with the carboxyl-terminal light
chain constant domain cysteine residue at position 214, joining
heavy and light chain polypeptides (Kabat numbering system). In the
minibody design the light chain constant domain is absent,
eliminating one of the two cysteines that participate in forming
the disulfide bond. The single remaining cysteine in the hinge
region at position 230, however, has been proposed to participate
in a homotypic interchain disulfide bond possibly contributing to
hinge region structure and therefore was left in place.
[0468] Minibodies, which lack a CH2 domain, are secreted from cells
and accumulate in culture supernatant as a mixture containing Form
A and Form B isoforms and perhaps unassembled half molecules as
shown in FIG. 32. The ratio of these forms is highly variable and
presents a challenge for preparing a reproducibly pure product. The
absence of the immunoglobulin CH1/CL domains precludes isolation of
total minibody using Protein G immunoaffinity matrices. While the
unassembled half molecules (MW.about.40-45 kD) can be separated
from the homodimers (MW.about.80-90 kD) using a number of
chromatographic strategies, the remaining intact A and B isoforms
cannot be efficiently separated from one another using techniques
such as HIC chromatography (described herein) also due to the
absence of CH1/CL domains. These isoforms also cannot be separated
by size exclusion chromatography because the molecular masses of
the two isoforms are nearly identical, prohibiting separation based
on this characteristic. Thus the composition of minibody
preparations may actually be complex, consisting of a mixture of A
and B isoforms. The production of CH2 domain-deleted
PRIMATIZED.RTM. p5E8 minibodies engineered to contain the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide indicated in
Table 2 (SEQ ID NO:9) was examined.
[0469] PRIMATIZED.RTM. p5E8 scFvs were constructed by PCR
amplification. ScFvs were built in both orientations
(VL.fwdarw.(Gly.sub.4Ser).sub.3 linker.fwdarw.VH (VL/VH) and
VH.fwdarw.(Gly.sub.4Ser).sub.3 linker.fwdarw.VL (VH/VL)).
Oligonucleotides used in the construction are shown the tables
below:
[0470] Table 7. PCR primers used to construct CH2 domain-deleted
PRIMATIZED.RTM. p5E8 VL/VH minibody containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide. In SEQ ID
NO:37 the BspLU11 I restriction endonuclease site is underlined. In
SEQ ID NO:40 the Sal I restriction endonuclease site is
underlined.
11 N-23VL-1F 5'-AGAGAGACATGTGGCGACATCCAGATGACCCAG- TC-3' (SEQ ID
NO:37) 23-VL-1R
5'-GGAGCCACCCCCACCGGACCCGCCACCGCCTTTGATTTCCACCTTGGTCC-3' (SEQ ID
NO:38) 23-VH-2F 5'-GGGTCCGGTGGGGGTGGCTCCGGGGGCGGTG-
GCTCCGAGGTGCAGCTGGT (SEQ ID NO:39) GGAGTC-3' N-23-VH-2R
5'-AGAGAGGTCGACTGAGGAGACGGTGACCAGGAC-3' (SEQ ID NO:40)
[0471] Table 8. PCR primers used to construct CH2 domain-deleted
PRIMATIZED.RTM. p5E8 VH/VL minibody containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide. In SEQ ID
NO:41 the BspLU11 I restriction endonuclease site is underlined. In
SEQ ID NO:44 the Sal I restriction endonuclease site is
underlined.
12 N-23VH-1F 5'-AGAGAGACATGTGGCGAGGTGCAGCTGGTGGAG- TC-3' (SEQ ID
NO:41) 23-VH-1R
5'-GGAGCCACCCCCACCGGACCCGCCACCGCCTGAGGAGACGGTGACCAGG (SEQ ID NO:42)
AC-3' 23-VL-2F
5'-GGGTCCGGTGGGGGTGGCTCCGGGGGCGGTGGCTCCGACATCCAGATGAC (SEQ ID
NO:43) CCAGTC-3' N-23-VL-2R 5'-AGAGAGGTCGACTTTGATTTCCACCTTGGTCC-3
(SEQ ID NO:44)
[0472] The VL/VH scFv was constructed in two steps. The 5' VL PCR
forward primer N-23VL-1F (SEQ ID NO:37) included a BspLU11 I
restriction endonuclease site to permit joining of the scFv to the
immunoglobulin signal peptide in the expression vector. The 3' VL
PCR reverse primer 23-VL-1R (SEQ ID NO:38) included sequence
partially encoding the (Gly.sub.4Ser).sub.3 linker peptide used to
join the VL and VH regions. The 5' forward VH PCR primer 23-VH-2F
(SEQ ID NO:30) also included sequence partially encoding a
(Gly.sub.4Ser).sub.3 linker peptide used to connect the VL and VH
regions and the 3' VH PCR reverse primer N-23-VH-2R (SEQ ID NO:40)
included a Sal I restriction endonuclease site to join the scFv to
the hinge region. The two V regions were amplified with the two
sets of PCR primers from plasmid DNA substrate containing
PRIMATIZED.RTM. p5E8G1 antibody and assembly of the scFv was
accomplished in a second PCR reaction through the common
overlapping sequences encoding the (Gly.sub.4Ser).sub.3 linker. The
PRIMATIZED.RTM. p5E8 scFv gene fragment was gel isolated, digested
with BspLU11 I and Sal I restriction endonucleases and cloned into
the BspLU11 I and Sal I double-digested CH2 domain-deleted antibody
Polycistronic expression vector containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide. The
PRIMATIZED.RTM. p5E8 VH/VL scFv was constructed in a similar manner
using PCR primer pairs N-23VH-1F (SEQ ID NO:41) and 23-VH-1R (SEQ
ID NO:36) and 23-VL-2F (SEQ ID NO:43) and N-23-VL-2R (SEQ ID NO:44)
shown in Tables 7 and 8. Correct sequences of both completed
constructs were confirmed by DNA sequence analysis. Plasmid DNA was
used to transform CHO DG44 cells for transient production of
antibody protein. FIG. 14 shows the DNA sequence of CH2
domain-deleted PRIMATIZED.RTM. p5E8 VL/VH minibody containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide in the
VL.fwdarw.VH orientation (VL/VH). FIG. 15 shows the DNA sequence of
CH2 domain-deleted PRIMATIZED.RTM. p5E8 VH/VL minibody containing
the G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide in the
VH.fwdarw.VL orientation (VH/VL). FIG. 16 shows the amino acid
sequence of CH2 domain-deleted PRIMATIZED.RTM. p5E8 VL/VH minibody
containing the G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting
peptide. FIG. 17 shows the amino acid sequence of CH2
domain-deleted PRIMATIZED.RTM. p5E8 VH/VL minibody containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide.
[0473] Supernatant was collected from the transfected cell lines
and concentration of antibody in the culture supernatant determined
by immunoassay. Minibody molecules present in culture supernatant
were analyzed for binding to soluble CD23 antigen immobilized on
plastic microtiter plates by ELISA. Results shown in FIG. 33
demonstrate that both PRIMATIZED.RTM. p5E8 VH/VL and VL/VH
minibodies containing the G1/G3/Pro243Ala244Pro245+[Gly/Ser]
connecting peptide are equally capable of binding to the CD23
antigen in a dose-responsive manner.
[0474] Supernatants were analyzed by non-reducing SDS-PAGE
electrophoresis followed by Western Blot with anti-human IgG-HRP
conjugated antibody to detect Form A and Form B isoforms of CH2
domain-deleted PRIMATIZED.RTM. p5E8 minibodies containing the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide. Under these
conditions, Form A is expected to migrate as a single .about.80-90
kDa homodimer and Form B as a .about.40-45 kDa doublet. The
connecting peptide shown in SEQ ID NO: 9 was found to substantially
increase the proportion of Form A for both minibodies produced.
Exemplary results are shown in FIG. 34. These results show that the
G1/G3/Pro243Ala244Pro245+[Gly/Ser] connecting peptide (SEQ ID NO:9)
resulted in the production of essentially all Form A CH2
domain-deleted PRIMATIZED.RTM. p5E8 minibody with no detectable
Form B.
[0475] Equivalents
[0476] Those skilled in the art will recognize, or be able to
ascertain using no more than routine experimentation, many
equivalents to the specific embodiments of the invention described
herein. Such equivalents are intended to be encompassed by the
following claims.
Sequence CWU 1
1
53 1 10 PRT Artificial Sequence Synthetic construct 1 Gly Gly Gly
Ser Ser Gly Gly Gly Ser Gly 1 5 10 2 10 PRT Artificial Sequence
Synthetic construct 2 Glu Pro Lys Ser Cys Asp Lys Thr His Thr 1 5
10 3 5 PRT Artificial Sequence Synthetic construct 3 Cys Pro Pro
Cys Pro 1 5 4 8 PRT Artificial Sequence Synthetic construct 4 Ala
Pro Glu Leu Leu Gly Gly Pro 1 5 5 12 PRT Artificial Sequence
Synthetic construct 5 Glu Leu Lys Thr Pro Leu Gly Asp Thr Thr His
Thr 1 5 10 6 20 PRT Artificial Sequence Synthetic construct 6 Cys
Pro Arg Cys Pro Glu Pro Lys Ser Cys Asp Thr Pro Pro Pro Cys 1 5 10
15 Pro Arg Cys Pro 20 7 24 PRT Artificial Sequence Synthetic
construct 7 Glu Pro Lys Ser Cys Asp Lys Thr His Thr Cys Pro Pro Cys
Gly Gly 1 5 10 15 Gly Ser Ser Gly Gly Gly Ser Gly 20 8 40 PRT
Artificial Sequence Synthetic construct 8 Glu Pro Lys Ser Cys Asp
Lys Thr His Thr Cys Pro Pro Cys Pro Glu 1 5 10 15 Pro Lys Ser Cys
Asp Thr Pro Pro Pro Cys Pro Arg Cys Pro Gly Gly 20 25 30 Gly Ser
Ser Gly Gly Gly Ser Gly 35 40 9 42 PRT Artificial Sequence
Synthetic construct 9 Glu Pro Lys Ser Cys Asp Lys Thr His Thr Cys
Pro Pro Cys Pro Glu 1 5 10 15 Pro Lys Ser Cys Asp Thr Pro Pro Pro
Cys Pro Arg Cys Pro Ala Pro 20 25 30 Gly Gly Gly Ser Ser Gly Gly
Gly Ser Gly 35 40 10 25 PRT Artificial Sequence Synthetic construct
10 Glu Pro Lys Ser Cys Asp Lys Thr His Thr Ser Pro Pro Cys Pro Gly
1 5 10 15 Gly Gly Ser Ser Gly Gly Gly Ser Gly 20 25 11 27 PRT
Artificial Sequence Synthetic construct 11 Glu Pro Lys Ser Cys Asp
Lys Thr His Thr Ser Pro Pro Cys Pro Ala 1 5 10 15 Pro Gly Gly Gly
Ser Ser Gly Gly Gly Ser Gly 20 25 12 25 PRT Artificial Sequence
Synthetic construct 12 Glu Pro Lys Ser Cys Asp Lys Thr His Thr Cys
Pro Pro Ser Pro Gly 1 5 10 15 Gly Gly Ser Ser Gly Gly Gly Ser Gly
20 25 13 27 PRT Artificial Sequence Synthetic construct 13 Glu Pro
Lys Ser Cys Asp Lys Thr His Thr Cys Pro Pro Ser Pro Ala 1 5 10 15
Pro Gly Gly Gly Ser Ser Gly Gly Gly Ser Gly 20 25 14 27 PRT
Artificial Sequence Synthetic construct 14 Glu Pro Lys Ser Cys Asp
Lys Thr His Thr Cys Pro Pro Cys Pro Ala 1 5 10 15 Pro Gly Gly Gly
Ser Ser Gly Gly Gly Ser Gly 20 25 15 25 PRT Artificial Sequence
Synthetic construct 15 Glu Pro Lys Ser Cys Asp Lys Thr His Thr Cys
Pro Pro Cys Pro Gly 1 5 10 15 Gly Gly Ser Ser Gly Gly Gly Ser Gly
20 25 16 1044 DNA Artificial Sequence Synthetic construct 16
caggtccagc tggtgcagtc cggcgctgag gtggtgaaac ctggggcttc cgtgaagatt
60 tcctgcaagg caagcggcta caccttcact gatcacgcaa tccactgggt
gaaacagaat 120 cctggacagc gcctggagtg gattggatat ttctctcccg
gaaacgatga ttttaagtac 180 aatgagaggt tcaagggcaa ggccacactg
actgcagaca catctgccag cactgcctac 240 gtggagctct ccagcctgag
atccgaggat actgcagtgt acttctgcac aagatccctg 300 aatatggcct
actggggaca gggaaccctg gtcaccgtct ccagcgctag caccaagggc 360
ccatcggtct tccccctggc accctcctcc aagagcacct ctgggggcac agcggccctg
420 ggctgcctgg tcaaggacta cttccccgaa ccggtgacgg tgtcgtggaa
ctcaggcgcc 480 ctgaccagcg gcgtgcacac cttcccggct gtcctacagt
cctcaggact ctactccctc 540 agcagcgtgg tgaccgtgcc ctccagcagc
ttgggcaccc agacctacat ctgcaacgtg 600 aatcacaagc ccagcaacac
caaggtggac aagaaagttg agcccaaatc ttgtgacaaa 660 actcacacat
gcccaccgtg cccagcacct ggaggtggct cgagtggagg cggatccgga 720
gggcagcccc gagaaccaca ggtgtacacc ctgcccccat cccgggatga gctgaccaag
780 aaccaggtca gcctgacctg cctggtcaaa ggcttctatc ccagcgacat
cgccgtggag 840 tgggagagca atgggcagcc ggagaacaac tacaagacca
cgcctcccgt gctggactcc 900 gacggctcct tcttcctcta cagcaagctc
accgtggaca agagcaggtg gcagcagggg 960 aacgtcttct catgctccgt
gatgcatgag gctctgcaca accactacac gcagaagagc 1020 ctctccctgt
ctccgggtaa atga 1044 17 663 DNA Artificial Sequence Synthetic
construct 17 gacatcgtga tgagccagtc tccagactcc ctggccgtgt ccctgggcga
gagggtgact 60 ctgaattgca agtccagcca gtccctgctc tatagcggaa
atcagaagaa ctatctcgcc 120 tggtatcagc agaaaccagg gcagagccct
aaactgctga tttactgggc atccgctagg 180 gaatccggcg tgcctgatcg
cttcagcggc agcggatctg ggacagactt cactctgaca 240 atcagcagcg
tgcaggcaga agacgtggca gtctattatt gtcagcagta ttatagctat 300
cccctcacat tcggcgctgg caccaagctg gaactgaaac gtacggtggc tgcaccatct
360 gtcttcatct tcccgccatc tgatgagcag ttgaaatctg gaactgcctc
tgttgtgtgc 420 ctgctgaata acttctatcc cagagaggcc aaagtacagt
ggaaggtgga taacgccctc 480 caatcgggta actcccagga gagtgtcaca
gagcaggaca gcaaggacag cacctacagc 540 ctcagcagca ccctgacgct
gagcaaagca gactacgaga aacacaaagt ctacgcctgc 600 gaagtcaccc
atcagggcct gagctcgccc gtcacaaaga gcttcaacag gggagagtgt 660 tga 663
18 347 PRT Artificial Sequence Synthetic construct 18 Gln Val Gln
Leu Val Gln Ser Gly Ala Glu Val Val Lys Pro Gly Ala 1 5 10 15 Ser
Val Lys Ile Ser Cys Lys Ala Ser Gly Tyr Thr Phe Thr Asp His 20 25
30 Ala Ile His Trp Val Lys Gln Asn Pro Gly Gln Arg Leu Glu Trp Ile
35 40 45 Gly Tyr Phe Ser Pro Gly Asn Asp Asp Phe Lys Tyr Asn Glu
Arg Phe 50 55 60 Lys Gly Lys Ala Thr Leu Thr Ala Asp Thr Ser Ala
Ser Thr Ala Tyr 65 70 75 80 Val Glu Leu Ser Ser Leu Arg Ser Glu Asp
Thr Ala Val Tyr Phe Cys 85 90 95 Thr Arg Ser Leu Asn Met Ala Tyr
Trp Gly Gln Gly Thr Leu Val Thr 100 105 110 Val Ser Ser Ala Ser Thr
Lys Gly Pro Ser Val Phe Pro Leu Ala Pro 115 120 125 Ser Ser Lys Ser
Thr Ser Gly Gly Thr Ala Ala Leu Gly Cys Leu Val 130 135 140 Lys Asp
Tyr Phe Pro Glu Pro Val Thr Val Ser Trp Asn Ser Gly Ala 145 150 155
160 Leu Thr Ser Gly Val His Thr Phe Pro Ala Val Leu Gln Ser Ser Gly
165 170 175 Leu Tyr Ser Leu Ser Ser Val Val Thr Val Pro Ser Ser Ser
Leu Gly 180 185 190 Thr Gln Thr Tyr Ile Cys Asn Val Asn His Lys Pro
Ser Asn Thr Lys 195 200 205 Val Asp Lys Lys Val Glu Pro Lys Ser Cys
Asp Lys Thr His Thr Cys 210 215 220 Pro Pro Cys Pro Ala Pro Gly Gly
Gly Ser Ser Gly Gly Gly Ser Gly 225 230 235 240 Gly Gln Pro Arg Glu
Pro Gln Val Tyr Thr Leu Pro Pro Ser Arg Asp 245 250 255 Glu Leu Thr
Lys Asn Gln Val Ser Leu Thr Cys Leu Val Lys Gly Phe 260 265 270 Tyr
Pro Ser Asp Ile Ala Val Glu Trp Glu Ser Asn Gly Gln Pro Glu 275 280
285 Asn Asn Tyr Lys Thr Thr Pro Pro Val Leu Asp Ser Asp Gly Ser Phe
290 295 300 Phe Leu Tyr Ser Lys Leu Thr Val Asp Lys Ser Arg Trp Gln
Gln Gly 305 310 315 320 Asn Val Phe Ser Cys Ser Val Met His Glu Ala
Leu His Asn His Tyr 325 330 335 Thr Gln Lys Ser Leu Ser Leu Ser Pro
Gly Lys 340 345 19 220 PRT Artificial Sequence Synthetic construct
19 Asp Ile Val Met Ser Gln Ser Pro Asp Ser Leu Ala Val Ser Leu Gly
1 5 10 15 Glu Arg Val Thr Leu Asn Cys Lys Ser Ser Gln Ser Leu Leu
Tyr Ser 20 25 30 Gly Asn Gln Lys Asn Tyr Leu Ala Trp Tyr Gln Gln
Lys Pro Gly Gln 35 40 45 Ser Pro Lys Leu Leu Ile Tyr Trp Ala Ser
Ala Arg Glu Ser Gly Val 50 55 60 Pro Asp Arg Phe Ser Gly Ser Gly
Ser Gly Thr Asp Phe Thr Leu Thr 65 70 75 80 Ile Ser Ser Val Gln Ala
Glu Asp Val Ala Val Tyr Tyr Cys Gln Gln 85 90 95 Tyr Tyr Ser Tyr
Pro Leu Thr Phe Gly Ala Gly Thr Lys Leu Glu Leu 100 105 110 Lys Arg
Thr Val Ala Ala Pro Ser Val Phe Ile Phe Pro Pro Ser Asp 115 120 125
Glu Gln Leu Lys Ser Gly Thr Ala Ser Val Val Cys Leu Leu Asn Asn 130
135 140 Phe Tyr Pro Arg Glu Ala Lys Val Gln Trp Lys Val Asp Asn Ala
Leu 145 150 155 160 Gln Ser Gly Asn Ser Gln Glu Ser Val Thr Glu Gln
Asp Ser Lys Asp 165 170 175 Ser Thr Tyr Ser Leu Ser Ser Thr Leu Thr
Leu Ser Lys Ala Asp Tyr 180 185 190 Glu Lys His Lys Val Tyr Ala Cys
Glu Val Thr His Gln Gly Leu Ser 195 200 205 Ser Pro Val Thr Lys Ser
Phe Asn Arg Gly Glu Cys 210 215 220 20 1083 DNA Artificial Sequence
Synthetic construct 20 caggtccagc tggtgcagtc cggcgctgag gtggtgaaac
ctggggcttc cgtgaagatt 60 tcctgcaagg caagcggcta caccttcact
gatcacgcaa tccactgggt gaaacagaat 120 cctggacagc gcctggagtg
gattggatat ttctctcccg gaaacgatga ttttaagtac 180 aatgagaggt
tcaagggcaa ggccacactg actgcagaca catctgccag cactgcctac 240
gtggagctct ccagcctgag atccgaggat actgcagtgt acttctgcac aagatccctg
300 aatatggcct actggggaca gggaaccctg gtcaccgtct ccagcgctag
caccaagggc 360 ccatcggtct tccccctggc accctcctcc aagagcacct
ctgggggcac agcggccctg 420 ggctgcctgg tcaaggacta cttccccgaa
ccggtgacgg tgtcgtggaa ctcaggcgcc 480 ctgaccagcg gcgtgcacac
cttcccggct gtcctacagt cctcaggact ctactccctc 540 agcagcgtgg
tgaccgtgcc ctccagcagc ttgggcaccc agacctacat ctgcaacgtg 600
aatcacaagc ccagcaacac caaggtggac aagaaagttg agcccaaatc ttgtgacaaa
660 actcacacat gcccaccgtg cccagagccc aaatcttgtg acacacctcc
cccatgccca 720 cggtgcccag gaggtggctc gagtggaggc ggatccggag
ggcagccccg agaaccacag 780 gtgtacaccc tgcccccatc ccgggatgag
ctgaccaaga accaggtcag cctgacctgc 840 ctggtcaaag gcttctatcc
cagcgacatc gccgtggagt gggagagcaa tgggcagccg 900 gagaacaact
acaagaccac gcctcccgtg ctggactccg acggctcctt cttcctctac 960
agcaagctca ccgtggacaa gagcaggtgg cagcagggga acgtcttctc atgctccgtg
1020 atgcatgagg ctctgcacaa ccactacacg cagaagagcc tctccctgtc
tccgggtaaa 1080 tga 1083 21 1089 DNA Artificial Sequence Synthetic
construct 21 caggtccagc tggtgcagtc cggcgctgag gtggtgaaac ctggggcttc
cgtgaagatt 60 tcctgcaagg caagcggcta caccttcact gatcacgcaa
tccactgggt gaaacagaat 120 cctggacagc gcctggagtg gattggatat
ttctctcccg gaaacgatga ttttaagtac 180 aatgagaggt tcaagggcaa
ggccacactg actgcagaca catctgccag cactgcctac 240 gtggagctct
ccagcctgag atccgaggat actgcagtgt acttctgcac aagatccctg 300
aatatggcct actggggaca gggaaccctg gtcaccgtct ccagcgctag caccaagggc
360 ccatcggtct tccccctggc accctcctcc aagagcacct ctgggggcac
agcggccctg 420 ggctgcctgg tcaaggacta cttccccgaa ccggtgacgg
tgtcgtggaa ctcaggcgcc 480 ctgaccagcg gcgtgcacac cttcccggct
gtcctacagt cctcaggact ctactccctc 540 agcagcgtgg tgaccgtgcc
ctccagcagc ttgggcaccc agacctacat ctgcaacgtg 600 aatcacaagc
ccagcaacac caaggtggac aagaaagttg agcccaaatc ttgtgacaaa 660
actcacacat gcccaccgtg cccagagccc aaatcttgtg acacacctcc cccatgccca
720 cggtgcccag cacctggagg tggctcgagt ggaggcggat ccggagggca
gccccgagaa 780 ccacaggtgt acaccctgcc cccatcccgg gatgagctga
ccaagaacca ggtcagcctg 840 acctgcctgg tcaaaggctt ctatcccagc
gacatcgccg tggagtggga gagcaatggg 900 cagccggaga acaactacaa
gaccacgcct cccgtgctgg actccgacgg ctccttcttc 960 ctctacagca
agctcaccgt ggacaagagc aggtggcagc aggggaacgt cttctcatgc 1020
tccgtgatgc atgaggctct gcacaaccac tacacgcaga agagcctctc cctgtctccg
1080 ggtaaatga 1089 22 360 PRT Artificial Sequence Synthetic
construct 22 Gln Val Gln Leu Val Gln Ser Gly Ala Glu Val Val Lys
Pro Gly Ala 1 5 10 15 Ser Val Lys Ile Ser Cys Lys Ala Ser Gly Tyr
Thr Phe Thr Asp His 20 25 30 Ala Ile His Trp Val Lys Gln Asn Pro
Gly Gln Arg Leu Glu Trp Ile 35 40 45 Gly Tyr Phe Ser Pro Gly Asn
Asp Asp Phe Lys Tyr Asn Glu Arg Phe 50 55 60 Lys Gly Lys Ala Thr
Leu Thr Ala Asp Thr Ser Ala Ser Thr Ala Tyr 65 70 75 80 Val Glu Leu
Ser Ser Leu Arg Ser Glu Asp Thr Ala Val Tyr Phe Cys 85 90 95 Thr
Arg Ser Leu Asn Met Ala Tyr Trp Gly Gln Gly Thr Leu Val Thr 100 105
110 Val Ser Ser Ala Ser Thr Lys Gly Pro Ser Val Phe Pro Leu Ala Pro
115 120 125 Ser Ser Lys Ser Thr Ser Gly Gly Thr Ala Ala Leu Gly Cys
Leu Val 130 135 140 Lys Asp Tyr Phe Pro Glu Pro Val Thr Val Ser Trp
Asn Ser Gly Ala 145 150 155 160 Leu Thr Ser Gly Val His Thr Phe Pro
Ala Val Leu Gln Ser Ser Gly 165 170 175 Leu Tyr Ser Leu Ser Ser Val
Val Thr Val Pro Ser Ser Ser Leu Gly 180 185 190 Thr Gln Thr Tyr Ile
Cys Asn Val Asn His Lys Pro Ser Asn Thr Lys 195 200 205 Val Asp Lys
Lys Val Glu Pro Lys Ser Cys Asp Lys Thr His Thr Cys 210 215 220 Pro
Pro Cys Pro Glu Pro Lys Ser Cys Asp Thr Pro Pro Pro Cys Pro 225 230
235 240 Arg Cys Pro Gly Gly Gly Ser Ser Gly Gly Gly Ser Gly Gly Gln
Pro 245 250 255 Arg Glu Pro Gln Val Tyr Thr Leu Pro Pro Ser Arg Asp
Glu Leu Thr 260 265 270 Lys Asn Gln Val Ser Leu Thr Cys Leu Val Lys
Gly Phe Tyr Pro Ser 275 280 285 Asp Ile Ala Val Glu Trp Glu Ser Asn
Gly Gln Pro Glu Asn Asn Tyr 290 295 300 Lys Thr Thr Pro Pro Val Leu
Asp Ser Asp Gly Ser Phe Phe Leu Tyr 305 310 315 320 Ser Lys Leu Thr
Val Asp Lys Ser Arg Trp Gln Gln Gly Asn Val Phe 325 330 335 Ser Cys
Ser Val Met His Glu Ala Leu His Asn His Tyr Thr Gln Lys 340 345 350
Ser Leu Ser Leu Ser Pro Gly Lys 355 360 23 362 PRT Artificial
Sequence Synthetic construct 23 Gln Val Gln Leu Val Gln Ser Gly Ala
Glu Val Val Lys Pro Gly Ala 1 5 10 15 Ser Val Lys Ile Ser Cys Lys
Ala Ser Gly Tyr Thr Phe Thr Asp His 20 25 30 Ala Ile His Trp Val
Lys Gln Asn Pro Gly Gln Arg Leu Glu Trp Ile 35 40 45 Gly Tyr Phe
Ser Pro Gly Asn Asp Asp Phe Lys Tyr Asn Glu Arg Phe 50 55 60 Lys
Gly Lys Ala Thr Leu Thr Ala Asp Thr Ser Ala Ser Thr Ala Tyr 65 70
75 80 Val Glu Leu Ser Ser Leu Arg Ser Glu Asp Thr Ala Val Tyr Phe
Cys 85 90 95 Thr Arg Ser Leu Asn Met Ala Tyr Trp Gly Gln Gly Thr
Leu Val Thr 100 105 110 Val Ser Ser Ala Ser Thr Lys Gly Pro Ser Val
Phe Pro Leu Ala Pro 115 120 125 Ser Ser Lys Ser Thr Ser Gly Gly Thr
Ala Ala Leu Gly Cys Leu Val 130 135 140 Lys Asp Tyr Phe Pro Glu Pro
Val Thr Val Ser Trp Asn Ser Gly Ala 145 150 155 160 Leu Thr Ser Gly
Val His Thr Phe Pro Ala Val Leu Gln Ser Ser Gly 165 170 175 Leu Tyr
Ser Leu Ser Ser Val Val Thr Val Pro Ser Ser Ser Leu Gly 180 185 190
Thr Gln Thr Tyr Ile Cys Asn Val Asn His Lys Pro Ser Asn Thr Lys 195
200 205 Val Asp Lys Lys Val Glu Pro Lys Ser Cys Asp Lys Thr His Thr
Cys 210 215 220 Pro Pro Cys Pro Glu Pro Lys Ser Cys Asp Thr Pro Pro
Pro Cys Pro 225 230 235 240 Arg Cys Pro Ala Pro Gly Gly Gly Ser Ser
Gly Gly Gly Ser Gly Gly 245 250 255 Gln Pro Arg Glu Pro Gln Val Tyr
Thr Leu Pro Pro Ser Arg Asp Glu 260 265 270 Leu Thr Lys Asn Gln Val
Ser Leu Thr Cys Leu Val Lys Gly Phe Tyr 275 280 285 Pro Ser Asp Ile
Ala Val Glu Trp Glu Ser Asn Gly Gln Pro Glu Asn 290 295 300 Asn Tyr
Lys Thr Thr Pro Pro Val Leu Asp Ser Asp Gly Ser Phe Phe 305 310 315
320 Leu Tyr Ser Lys Leu Thr Val Asp Lys Ser Arg Trp Gln Gln Gly Asn
325 330 335 Val Phe Ser Cys Ser Val Met His Glu Ala Leu His Asn His
Tyr Thr 340 345 350 Gln Lys Ser Leu
Ser Leu Ser Pro Gly Lys 355 360 24 1089 DNA Artificial Sequence
Synthetic construct 24 caggtccagc tggtgcagtc cggcgctgag gtggtgaaac
ctggggcttc cgtgaagatt 60 tcctgcaagg caagcggcta caccttcact
gatcacgcaa tccactgggt gaaacagaat 120 cctggacagc gcctggagtg
gattggatat ttctctcccg gaaacgatga ttttaagtac 180 aatgagaggt
tcaagggcaa ggccacaatc actgcagaca catctgccag cactgcctac 240
gtggagctct ccagcctgag atccgaggat actgcagtgt acttctgcgc cagatccctg
300 aatatggcct actggggaca gggaaccctg gtcaccgtct ccagcgctag
caccaagggc 360 ccatcggtct tccccctggc accctcctcc aagagcacct
ctgggggcac agcggccctg 420 ggctgcctgg tcaaggacta cttccccgaa
ccggtgacgg tgtcgtggaa ctcaggcgcc 480 ctgaccagcg gcgtgcacac
cttcccggct gtcctacagt cctcaggact ctactccctc 540 agcagcgtgg
tgaccgtgcc ctccagcagc ttgggcaccc agacctacat ctgcaacgtg 600
aatcacaagc ccagcaacac caaggtggac aagaaagttg agcccaaatc ttgtgacaaa
660 actcacacat gcccaccgtg cccagagccc aaatcttgtg acacacctcc
cccatgccca 720 cggtgcccag cacctggagg tggctcgagt ggaggcggat
ccggagggca gccccgagaa 780 ccacaggtgt acaccctgcc cccatcccgg
gatgagctga ccaagaacca ggtcagcctg 840 acctgcctgg tcaaaggctt
ctatcccagc gacatcgccg tggagtggga gagcaatggg 900 cagccggaga
acaactacaa gaccacgcct cccgtgctgg actccgacgg ctccttcttc 960
ctctacagca agctcaccgt ggacaagagc aggtggcagc aggggaacgt cttctcatgc
1020 tccgtgatgc atgaggctct gcacaaccac tacacgcaga agagcctctc
cctgtctccg 1080 ggtaaatga 1089 25 663 DNA Artificial Sequence
Synthetic construct 25 gacatcgtga tgagccagtc tccagactcc ctggccgtgt
ccctgggcga gagggtgact 60 ctgaattgca agtccagcca gtccctgctc
tatagcggaa atcagaagaa ctatctcgcc 120 tggtatcagc agaaaccagg
gcagccccct aaactgctga tttactgggc atccgctagg 180 gaatccggcg
tgcctgatcg cttcagcggc agcggatctg ggacagactt cactctgaca 240
atcagcagcg tgcaggcaga agacgtggca gtctattatt gtcagcagta ttatagctat
300 cccctcacat tcggcgctgg caccaagctg gaactgaaac gtacggtggc
tgcaccatct 360 gtcttcatct tcccgccatc tgatgagcag ttgaaatctg
gaactgcctc tgttgtgtgc 420 ctgctgaata acttctatcc cagagaggcc
aaagtacagt ggaaggtgga taacgccctc 480 caatcgggta actcccagga
gagtgtcaca gagcaggaca gcaaggacag cacctacagc 540 ctcagcagca
ccctgacgct gagcaaagca gactacgaga aacacaaagt ctacgcctgc 600
gaagtcaccc atcagggcct gagctcgccc gtcacaaaga gcttcaacag gggagagtgt
660 tga 663 26 362 PRT Artificial Sequence Synthetic construct 26
Gln Val Gln Leu Val Gln Ser Gly Ala Glu Val Val Lys Pro Gly Ala 1 5
10 15 Ser Val Lys Ile Ser Cys Lys Ala Ser Gly Tyr Thr Phe Thr Asp
His 20 25 30 Ala Ile His Trp Val Lys Gln Asn Pro Gly Gln Arg Leu
Glu Trp Ile 35 40 45 Gly Tyr Phe Ser Pro Gly Asn Asp Asp Phe Lys
Tyr Asn Glu Arg Phe 50 55 60 Lys Gly Lys Ala Thr Ile Thr Ala Asp
Thr Ser Ala Ser Thr Ala Tyr 65 70 75 80 Val Glu Leu Ser Ser Leu Arg
Ser Glu Asp Thr Ala Val Tyr Phe Cys 85 90 95 Ala Arg Ser Leu Asn
Met Ala Tyr Trp Gly Gln Gly Thr Leu Val Thr 100 105 110 Val Ser Ser
Ala Ser Thr Lys Gly Pro Ser Val Phe Pro Leu Ala Pro 115 120 125 Ser
Ser Lys Ser Thr Ser Gly Gly Thr Ala Ala Leu Gly Cys Leu Val 130 135
140 Lys Asp Tyr Phe Pro Glu Pro Val Thr Val Ser Trp Asn Ser Gly Ala
145 150 155 160 Leu Thr Ser Gly Val His Thr Phe Pro Ala Val Leu Gln
Ser Ser Gly 165 170 175 Leu Tyr Ser Leu Ser Ser Val Val Thr Val Pro
Ser Ser Ser Leu Gly 180 185 190 Thr Gln Thr Tyr Ile Cys Asn Val Asn
His Lys Pro Ser Asn Thr Lys 195 200 205 Val Asp Lys Lys Val Glu Pro
Lys Ser Cys Asp Lys Thr His Thr Cys 210 215 220 Pro Pro Cys Pro Glu
Pro Lys Ser Cys Asp Thr Pro Pro Pro Cys Pro 225 230 235 240 Arg Cys
Pro Ala Pro Gly Gly Gly Ser Ser Gly Gly Gly Ser Gly Gly 245 250 255
Gln Pro Arg Glu Pro Gln Val Tyr Thr Leu Pro Pro Ser Arg Asp Glu 260
265 270 Leu Thr Lys Asn Gln Val Ser Leu Thr Cys Leu Val Lys Gly Phe
Tyr 275 280 285 Pro Ser Asp Ile Ala Val Glu Trp Glu Ser Asn Gly Gln
Pro Glu Asn 290 295 300 Asn Tyr Lys Thr Thr Pro Pro Val Leu Asp Ser
Asp Gly Ser Phe Phe 305 310 315 320 Leu Tyr Ser Lys Leu Thr Val Asp
Lys Ser Arg Trp Gln Gln Gly Asn 325 330 335 Val Phe Ser Cys Ser Val
Met His Glu Ala Leu His Asn His Tyr Thr 340 345 350 Gln Lys Ser Leu
Ser Leu Ser Pro Gly Lys 355 360 27 220 PRT Artificial Sequence
Synthetic construct 27 Asp Ile Val Met Ser Gln Ser Pro Asp Ser Leu
Ala Val Ser Leu Gly 1 5 10 15 Glu Arg Val Thr Leu Asn Cys Lys Ser
Ser Gln Ser Leu Leu Tyr Ser 20 25 30 Gly Asn Gln Lys Asn Tyr Leu
Ala Trp Tyr Gln Gln Lys Pro Gly Gln 35 40 45 Pro Pro Lys Leu Leu
Ile Tyr Trp Ala Ser Ala Arg Glu Ser Gly Val 50 55 60 Pro Asp Arg
Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr 65 70 75 80 Ile
Ser Ser Val Gln Ala Glu Asp Val Ala Val Tyr Tyr Cys Gln Gln 85 90
95 Tyr Tyr Ser Tyr Pro Leu Thr Phe Gly Ala Gly Thr Lys Leu Glu Leu
100 105 110 Lys Arg Thr Val Ala Ala Pro Ser Val Phe Ile Phe Pro Pro
Ser Asp 115 120 125 Glu Gln Leu Lys Ser Gly Thr Ala Ser Val Val Cys
Leu Leu Asn Asn 130 135 140 Phe Tyr Pro Arg Glu Ala Lys Val Gln Trp
Lys Val Asp Asn Ala Leu 145 150 155 160 Gln Ser Gly Asn Ser Gln Glu
Ser Val Thr Glu Gln Asp Ser Lys Asp 165 170 175 Ser Thr Tyr Ser Leu
Ser Ser Thr Leu Thr Leu Ser Lys Ala Asp Tyr 180 185 190 Glu Lys His
Lys Val Tyr Ala Cys Glu Val Thr His Gln Gly Leu Ser 195 200 205 Ser
Pro Val Thr Lys Ser Phe Asn Arg Gly Glu Cys 210 215 220 28 113 PRT
Artificial Sequence Synthetic construct 28 Asp Ile Val Met Ser Gln
Ser Pro Ser Ser Leu Pro Val Ser Val Gly 1 5 10 15 Glu Lys Val Thr
Leu Ser Cys Lys Ser Ser Gln Ser Leu Leu Tyr Ser 20 25 30 Gly Asn
Gln Lys Asn Tyr Leu Ala Trp Tyr Gln Gln Lys Pro Gly Gln 35 40 45
Ser Pro Lys Leu Leu Ile Tyr Trp Ala Ser Ala Arg Glu Ser Gly Val 50
55 60 Pro Asp Arg Phe Thr Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu
Ser 65 70 75 80 Ile Ser Ser Val Lys Thr Glu Asp Leu Ala Val Tyr Tyr
Cys Gln Gln 85 90 95 Tyr Tyr Ser Tyr Pro Leu Thr Phe Gly Ala Gly
Thr Lys Leu Val Leu 100 105 110 Lys 29 113 PRT Artificial Sequence
Synthetic construct 29 Asp Ile Val Met Thr Gln Ser Pro Asp Ser Leu
Ala Val Ser Leu Gly 1 5 10 15 Glu Arg Ala Thr Ile Asn Cys Lys Ser
Ser Gln Ser Val Leu Tyr Ser 20 25 30 Ser Asn Ser Lys Asn Tyr Leu
Ala Trp Tyr Gln Gln Lys Pro Gly Gln 35 40 45 Pro Pro Lys Leu Leu
Ile Tyr Trp Ala Ser Thr Arg Glu Ser Gly Val 50 55 60 Pro Asp Arg
Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr 65 70 75 80 Ile
Ser Ser Leu Gln Ala Glu Asp Val Ala Val Tyr Tyr Cys Gln Gln 85 90
95 Tyr Tyr Ser Thr Pro Tyr Ser Phe Gly Gln Gly Thr Lys Leu Glu Ile
100 105 110 Lys 30 113 PRT Artificial Sequence Synthetic construct
30 Asp Ile Val Met Ser Gln Ser Pro Asp Ser Leu Ala Val Ser Leu Gly
1 5 10 15 Glu Arg Val Thr Leu Asn Cys Lys Ser Ser Gln Ser Leu Leu
Tyr Ser 20 25 30 Gly Asn Gln Lys Asn Tyr Leu Ala Trp Tyr Gln Gln
Lys Pro Gly Gln 35 40 45 Ser Pro Lys Leu Leu Ile Tyr Trp Ala Ser
Ala Arg Glu Ser Gly Val 50 55 60 Pro Asp Arg Phe Ser Gly Ser Gly
Ser Gly Thr Asp Phe Thr Leu Thr 65 70 75 80 Ile Ser Ser Val Gln Ala
Glu Asp Val Ala Val Tyr Tyr Cys Gln Gln 85 90 95 Tyr Tyr Ser Tyr
Pro Leu Thr Phe Gly Ala Gly Thr Lys Leu Glu Leu 100 105 110 Lys 31
113 PRT Artificial Sequence Synthetic construct 31 Asp Ile Val Met
Ser Gln Ser Pro Asp Ser Leu Ala Val Ser Leu Gly 1 5 10 15 Glu Arg
Val Thr Leu Asn Cys Lys Ser Ser Gln Ser Leu Leu Tyr Ser 20 25 30
Gly Asn Gln Lys Asn Tyr Leu Ala Trp Tyr Gln Gln Lys Pro Gly Gln 35
40 45 Pro Pro Lys Leu Leu Ile Tyr Trp Ala Ser Ala Arg Glu Ser Gly
Val 50 55 60 Pro Asp Arg Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe
Thr Leu Thr 65 70 75 80 Ile Ser Ser Val Gln Ala Glu Asp Val Ala Val
Tyr Tyr Cys Gln Gln 85 90 95 Tyr Tyr Ser Tyr Pro Leu Thr Phe Gly
Ala Gly Thr Lys Leu Glu Leu 100 105 110 Lys 32 115 PRT Artificial
Sequence Synthetic construct 32 Gln Val Gln Leu Gln Gln Ser Asp Ala
Glu Leu Val Lys Pro Gly Ala 1 5 10 15 Ser Val Lys Ile Ser Cys Lys
Ala Ser Gly Tyr Thr Phe Thr Asp His 20 25 30 Ala Ile His Trp Val
Lys Gln Asn Pro Glu Gln Gly Leu Glu Trp Ile 35 40 45 Gly Tyr Phe
Ser Pro Gly Asn Asp Asp Phe Lys Tyr Asn Glu Arg Phe 50 55 60 Lys
Gly Lys Ala Thr Leu Thr Ala Asp Lys Ser Ser Ser Thr Ala Tyr 65 70
75 80 Val Gln Leu Asn Ser Leu Thr Ser Glu Asp Ser Ala Val Tyr Phe
Cys 85 90 95 Thr Arg Ser Leu Asn Met Ala Tyr Trp Gly Gln Gly Thr
Ser Val Thr 100 105 110 Val Ser Ser 115 33 119 PRT Artificial
Sequence Synthetic construct 33 Gln Val Gln Leu Val Gln Ser Gly Ala
Glu Val Lys Lys Pro Gly Ala 1 5 10 15 Ser Val Lys Val Ser Cys Lys
Ala Ser Gly Tyr Thr Phe Thr Ser Tyr 20 25 30 Ala Met His Trp Val
Arg Gln Ala Pro Gly Gln Arg Leu Glu Trp Met 35 40 45 Gly Trp Ile
Asn Ala Gly Asn Gly Asn Thr Lys Tyr Ser Gln Lys Phe 50 55 60 Gln
Gly Arg Val Thr Ile Thr Arg Asp Thr Ser Ala Ser Thr Ala Tyr 65 70
75 80 Met Glu Leu Ser Ser Leu Arg Ser Glu Asp Thr Ala Val Tyr Tyr
Cys 85 90 95 Ala Arg Gly Gly Tyr Tyr Gly Ser Gly Ser Asn Tyr Trp
Gly Gln Gly 100 105 110 Thr Leu Val Thr Val Ser Ser 115 34 115 PRT
Artificial Sequence Synthetic construct 34 Gln Val Gln Leu Val Gln
Ser Gly Ala Glu Val Val Lys Pro Gly Ala 1 5 10 15 Ser Val Lys Ile
Ser Cys Lys Ala Ser Gly Tyr Thr Phe Thr Asp His 20 25 30 Ala Ile
His Trp Val Lys Gln Asn Pro Gly Gln Arg Leu Glu Trp Ile 35 40 45
Gly Tyr Phe Ser Pro Gly Asn Asp Asp Phe Lys Tyr Asn Glu Arg Phe 50
55 60 Lys Gly Lys Ala Thr Leu Thr Ala Asp Thr Ser Ala Ser Thr Ala
Tyr 65 70 75 80 Val Glu Leu Ser Ser Leu Arg Ser Glu Asp Thr Ala Val
Tyr Phe Cys 85 90 95 Thr Arg Ser Leu Asn Met Ala Tyr Trp Gly Gln
Gly Thr Leu Val Thr 100 105 110 Val Ser Ser 115 35 115 PRT
Artificial Sequence Synthetic construct 35 Gln Val Gln Leu Val Gln
Ser Gly Ala Glu Val Val Lys Pro Gly Ala 1 5 10 15 Ser Val Lys Ile
Ser Cys Lys Ala Ser Gly Tyr Thr Phe Thr Asp His 20 25 30 Ala Ile
His Trp Val Lys Gln Asn Pro Gly Gln Arg Leu Glu Trp Ile 35 40 45
Gly Tyr Phe Ser Pro Gly Asn Asp Asp Phe Lys Tyr Asn Glu Arg Phe 50
55 60 Lys Gly Lys Ala Thr Ile Thr Ala Asp Thr Ser Ala Ser Thr Ala
Tyr 65 70 75 80 Val Glu Leu Ser Ser Leu Arg Ser Glu Asp Thr Ala Val
Tyr Phe Cys 85 90 95 Ala Arg Ser Leu Asn Met Ala Tyr Trp Gly Gln
Gly Thr Leu Val Thr 100 105 110 Val Ser Ser 115 36 10 PRT
Artificial Sequence Synthetic construct 36 Ile Gly Lys Thr Ile Ser
Lys Lys Ala Lys 1 5 10 37 15 PRT Artificial Sequence Synthetic
construct 37 Cys Pro Glu Pro Lys Ser Cys Asp Thr Pro Pro Pro Cys
Pro Arg 1 5 10 15 38 1095 DNA Artificial Sequence Synthetic
construct 38 gaggtgcagc tggtggagtc tgggggcggc ttggcaaagc ctggggggtc
cctgagactc 60 tcctgcgcag cctccgggtt caggttcacc ttcaataact
actacatgga ctgggtccgc 120 caggctccag ggcaggggct ggagtgggtc
tcacgtatta gtagtagtgg tgatcccaca 180 tggtacgcag actccgtgaa
gggcagattc accatctcca gagagaacgc caagaacaca 240 ctgtttcttc
aaatgaacag cctgagagct gaggacacgg ctgtctatta ctgtgcgagc 300
ttgactacag ggtctgactc ctggggccag ggagtcctgg tcaccgtctc ctcagctagc
360 accaagggcc catcggtctt ccccctggca ccctcctcca agagcacctc
tgggggcaca 420 gcggccctgg gctgcctggt caaggactac ttccccgaac
cggtgacggt gtcgtggaac 480 tcaggcgccc tgaccagcgg cgtgcacacc
ttcccggctg tcctacagtc ctcaggactc 540 tactccctca gcagcgtggt
gaccgtgccc tccagcagct tgggcaccca gacctacatc 600 tgcaacgtga
atcacaagcc cagcaacacc aaggtggaca agaaagttga gcccaaatct 660
tgtgacaaaa ctcacacatg cccaccgtgc ccagagccca aatcttgtga cacacctccc
720 ccatgcccac ggtgcccagc acctggaggt ggctcgagtg gaggcggttc
cggagggcag 780 ccccgagaac cacaggtgta caccctgccc ccatcccggg
atgagctgac caagaaccag 840 gtcagcctga cctgcctggt caaaggcttc
tatcccagcg acatcgccgt ggagtgggag 900 agcaatgggc agccggagaa
caactacaag accacgcctc ccgtgctgga ctccgacggc 960 tccttcttcc
tctacagcaa gctcaccgtg gacaagagca ggtggcagca ggggaacgtc 1020
ttctcatgct ccgtgatgca tgaggctctg cacaaccact acacgcagaa gagcctctcc
1080 ctgtctccgg gtaaa 1095 39 642 DNA Artificial Sequence Synthetic
construct 39 gacatccaga tgacccagtc tccatcttcc ctgtctgcat ctgtagggga
cagagtcacc 60 atcacttgca gggcaagtca ggacattagg tattatttaa
attggtatca gcagaaacca 120 ggaaaagctc ctaagctcct gatctatgtt
gcatccagtt tgcaaagtgg ggtcccatca 180 aggttcagcg gcagtggatc
tgggacagag ttcactctca ccgtcagcag cctgcagcct 240 gaagattttg
cgacttatta ctgtctacag gtttatagta cccctcggac gttcggccaa 300
gggaccaagg tggaaatcaa acgtacggtg gctgcaccat ctgtcttcat cttcccgcca
360 tctgatgagc agttgaaatc tggaactgcc tctgttgtgt gcctgctgaa
taacttctat 420 cccagagagg ccaaagtaca gtggaaggtg gataacgccc
tccaatcggg taactcccag 480 gagagtgtca cagagcagga cagcaaggac
agcacctaca gcctcagcag caccctgacg 540 ctgagcaaag cagactacga
gaaacacaaa gtctacgcct gcgaagtcac ccatcagggc 600 ctgagctcgc
ccgtcacaaa gagcttcaac aggggagagt gt 642 40 365 PRT Artificial
Sequence Synthetic construct 40 Glu Val Gln Leu Val Glu Ser Gly Gly
Gly Leu Ala Lys Pro Gly Gly 1 5 10 15 Ser Leu Arg Leu Ser Cys Ala
Ala Ser Gly Phe Arg Phe Thr Phe Asn 20 25 30 Asn Tyr Tyr Met Asp
Trp Val Arg Gln Ala Pro Gly Gln Gly Leu Glu 35 40 45 Trp Val Ser
Arg Ile Ser Ser Ser Gly Asp Pro Thr Trp Tyr Ala Asp 50 55 60 Ser
Val Lys Gly Arg Phe Thr Ile Ser Arg Glu Asn Ala Lys Asn Thr 65 70
75 80 Leu Phe Leu Gln Met Asn Ser Leu Arg Ala Glu Asp Thr Ala Val
Tyr 85 90 95 Tyr Cys Ala Ser Leu Thr Thr Gly Ser Asp Ser Trp Gly
Gln Gly Val 100 105 110 Leu Val Thr Val Ser Ser Ala Ser Thr Lys Gly
Pro Ser Val Phe Pro 115 120 125 Leu Ala Pro Ser Ser Lys Ser Thr Ser
Gly Gly Thr Ala Ala Leu Gly 130 135 140 Cys Leu Val Lys Asp Tyr Phe
Pro Glu Pro Val Thr Val Ser Trp Asn 145 150 155 160 Ser Gly Ala Leu
Thr Ser Gly Val His Thr Phe Pro Ala Val Leu Gln 165 170 175 Ser Ser
Gly Leu Tyr Ser Leu Ser Ser Val Val Thr Val Pro Ser Ser 180 185
190
Ser Leu Gly Thr Gln Thr Tyr Ile Cys Asn Val Asn His Lys Pro Ser 195
200 205 Asn Thr Lys Val Asp Lys Lys Val Glu Pro Lys Ser Cys Asp Lys
Thr 210 215 220 His Thr Cys Pro Pro Cys Pro Glu Pro Lys Ser Cys Asp
Thr Pro Pro 225 230 235 240 Pro Cys Pro Arg Cys Pro Ala Pro Gly Gly
Gly Ser Ser Gly Gly Gly 245 250 255 Ser Gly Gly Gln Pro Arg Glu Pro
Gln Val Tyr Thr Leu Pro Pro Ser 260 265 270 Arg Asp Glu Leu Thr Lys
Asn Gln Val Ser Leu Thr Cys Leu Val Lys 275 280 285 Gly Phe Tyr Pro
Ser Asp Ile Ala Val Glu Trp Glu Ser Asn Gly Gln 290 295 300 Pro Glu
Asn Asn Tyr Lys Thr Thr Pro Pro Val Leu Asp Ser Asp Gly 305 310 315
320 Ser Phe Phe Leu Tyr Ser Lys Leu Thr Val Asp Lys Ser Arg Trp Gln
325 330 335 Gln Gly Asn Val Phe Ser Cys Ser Val Met His Glu Ala Leu
His Asn 340 345 350 His Tyr Thr Gln Lys Ser Leu Ser Leu Ser Pro Gly
Lys 355 360 365 41 214 PRT Artificial Sequence Synthetic construct
41 Asp Ile Gln Met Thr Gln Ser Pro Ser Ser Leu Ser Ala Ser Val Gly
1 5 10 15 Asp Arg Val Thr Ile Thr Cys Arg Ala Ser Gln Asp Ile Arg
Tyr Tyr 20 25 30 Leu Asn Trp Tyr Gln Gln Lys Pro Gly Lys Ala Pro
Lys Leu Leu Ile 35 40 45 Tyr Val Ala Ser Ser Leu Gln Ser Gly Val
Pro Ser Arg Phe Ser Gly 50 55 60 Ser Gly Ser Gly Thr Glu Phe Thr
Leu Thr Val Ser Ser Leu Gln Pro 65 70 75 80 Glu Asp Phe Ala Thr Tyr
Tyr Cys Leu Gln Val Tyr Ser Thr Pro Arg 85 90 95 Thr Phe Gly Gln
Gly Thr Lys Val Glu Ile Lys Arg Thr Val Ala Ala 100 105 110 Pro Ser
Val Phe Ile Phe Pro Pro Ser Asp Glu Gln Leu Lys Ser Gly 115 120 125
Thr Ala Ser Val Val Cys Leu Leu Asn Asn Phe Tyr Pro Arg Glu Ala 130
135 140 Lys Val Gln Trp Lys Val Asp Asn Ala Leu Gln Ser Gly Asn Ser
Gln 145 150 155 160 Glu Ser Val Thr Glu Gln Asp Ser Lys Asp Ser Thr
Tyr Ser Leu Ser 165 170 175 Ser Thr Leu Thr Leu Ser Lys Ala Asp Tyr
Glu Lys His Lys Val Tyr 180 185 190 Ala Cys Glu Val Thr His Gln Gly
Leu Ser Ser Pro Val Thr Lys Ser 195 200 205 Phe Asn Arg Gly Glu Cys
210 42 1095 DNA Artificial Sequence Synthetic construct 42
caggtccaac tgcagcaggt tggggctgaa ctggtgaagc ctggggcttc agtgaagctg
60 tcctgcaagg cttctggcta caccttcacc agctactgga tacactgggt
gaagcagagg 120 cctggacagg gccttgagtg gattggagag aatgatccta
gcaacggtcg tactaactac 180 aatgagaagt tcaagaacaa ggccacactg
actgtagaca aatcctccag cacagcctac 240 atgcatctca gcagcctgac
atctgaggac tctgcggtct attactgttc aaggggccct 300 aattacttct
attctatgga ctactggggt caaggaacct cagtcaccgt ctcctcagct 360
agcaccaagg gcccatcggt cttccccctg gcaccctcct ccaagagcac ctctgggggc
420 acagcggccc tgggctgcct ggtcaaggac tacttccccg aaccggtgac
ggtgtcgtgg 480 aactcaggcg ccctgaccag cggcgtgcac accttcccgg
ctgtcctaca gtcctcagga 540 ctctactccc tcagcagcgt ggtgaccgtg
ccctccagca gcttgggcac ccagacctac 600 atctgcaacg tgaatcacaa
gcccagcaac accaaggtgg acaagaaagt tgagcccaaa 660 tcttgtgaca
aaactcacac atgcccaccg tgcccagagc ccaaatcttg tgacacacct 720
cccccatgcc cacggtgccc agcacctgga ggtggctcga gtggaggcgg ttccggaggg
780 cagccccgag aaccacaggt gtacaccctg cccccatccc gggatgagct
gaccaagaac 840 caggtcagcc tgacctgcct ggtcaaaggc ttctatccca
gcgacatcgc cgtggagtgg 900 gagagcaatg ggcagccgga gaacaactac
aagaccacgc ctcccgtgct ggactccgac 960 ggctccttct tcctctacag
caagctcacc gtggacaaga gcaggtggca gcaggggaac 1020 gtcttctcat
gctccgtgat gcatgaggct ctgcacaacc actacacgca gaagagcctc 1080
tccctgtctc cgggt 1095 43 657 DNA Artificial Sequence Synthetic
construct 43 gattttttga tgacccaaac tccactctcc ctgcctgtca gtcttggaga
tcaagcctcc 60 atctcttgca gatcaagtca gagcattgta catagtaatg
gaaacaccta tttagaatgg 120 tacctgcaga aaccaggcca gtctccaaag
ctcctcatct acaaagtttc caaccgattt 180 tctggggtcc cagacaggtt
cagtggcagt ggatcaggga cagatttcac actcaagatc 240 agcagagtgg
aggctgagga tctgggagtt tattactgct ttcaaggttc acatgttcct 300
ctcacgttcg gtgctgggac caagctggag ctgaagcgta cggtggctgc accatctgtc
360 ttcatcttcc cgccatctga tgagcagttg aaatctggaa ctgcctctgt
tgtgtgcctg 420 ctgaataact tctatcccag agaggccaaa gtacagtgga
aggtggataa cgccctccaa 480 tcgggtaact cccaggagag tgtcacagag
caggacagca aggacagcac ctacagcctc 540 agcagcaccc tgacgctgag
caaagcagac tacgagaaac acaaagtcta cgcctgcgaa 600 gtcacccatc
agggcctgag ctcgcccgtc acaaagagct tcaacagggg agagtgt 657 44 365 PRT
Artificial Sequence Synthetic construct 44 Gln Val Gln Leu Gln Gln
Val Gly Ala Glu Leu Val Lys Pro Gly Ala 1 5 10 15 Ser Val Lys Leu
Ser Cys Lys Ala Ser Gly Tyr Thr Phe Thr Ser Tyr 20 25 30 Trp Ile
His Trp Val Lys Gln Arg Pro Gly Gln Gly Leu Glu Trp Ile 35 40 45
Gly Glu Asn Asp Pro Ser Asn Gly Arg Thr Asn Tyr Asn Glu Lys Phe 50
55 60 Lys Asn Lys Ala Thr Leu Thr Val Asp Lys Ser Ser Ser Thr Ala
Tyr 65 70 75 80 Met His Leu Ser Ser Leu Thr Ser Glu Asp Ser Ala Val
Tyr Tyr Cys 85 90 95 Ser Arg Gly Pro Asn Tyr Phe Tyr Ser Met Asp
Tyr Trp Gly Gln Gly 100 105 110 Thr Ser Val Thr Val Ser Ser Ala Ser
Thr Lys Gly Pro Ser Val Phe 115 120 125 Pro Leu Ala Pro Ser Ser Lys
Ser Thr Ser Gly Gly Thr Ala Ala Leu 130 135 140 Gly Cys Leu Val Lys
Asp Tyr Phe Pro Glu Pro Val Thr Val Ser Trp 145 150 155 160 Asn Ser
Gly Ala Leu Thr Ser Gly Val His Thr Phe Pro Ala Val Leu 165 170 175
Gln Ser Ser Gly Leu Tyr Ser Leu Ser Ser Val Val Thr Val Pro Ser 180
185 190 Ser Ser Leu Gly Thr Gln Thr Tyr Ile Cys Asn Val Asn His Lys
Pro 195 200 205 Ser Asn Thr Lys Val Asp Lys Lys Val Glu Pro Lys Ser
Cys Asp Lys 210 215 220 Thr His Thr Cys Pro Pro Cys Pro Glu Pro Lys
Ser Cys Asp Thr Pro 225 230 235 240 Pro Pro Cys Pro Arg Cys Pro Ala
Pro Gly Gly Gly Ser Ser Gly Gly 245 250 255 Gly Ser Gly Gly Gln Pro
Arg Glu Pro Gln Val Tyr Thr Leu Pro Pro 260 265 270 Ser Arg Asp Glu
Leu Thr Lys Asn Gln Val Ser Leu Thr Cys Leu Val 275 280 285 Lys Gly
Phe Tyr Pro Ser Asp Ile Ala Val Glu Trp Glu Ser Asn Gly 290 295 300
Gln Pro Glu Asn Asn Tyr Lys Thr Thr Pro Pro Val Leu Asp Ser Asp 305
310 315 320 Gly Ser Phe Phe Leu Tyr Ser Lys Leu Thr Val Asp Lys Ser
Arg Trp 325 330 335 Gln Gln Gly Asn Val Phe Ser Cys Ser Val Met His
Glu Ala Leu His 340 345 350 Asn His Tyr Thr Gln Lys Ser Leu Ser Leu
Ser Pro Gly 355 360 365 45 219 PRT Artificial Sequence Synthetic
construct 45 Asp Phe Leu Met Thr Gln Thr Pro Leu Ser Leu Pro Val
Ser Leu Gly 1 5 10 15 Asp Gln Ala Ser Ile Ser Cys Arg Ser Ser Gln
Ser Ile Val His Ser 20 25 30 Asn Gly Asn Thr Tyr Leu Glu Trp Tyr
Leu Gln Lys Pro Gly Gln Ser 35 40 45 Pro Lys Leu Leu Ile Tyr Lys
Val Ser Asn Arg Phe Ser Gly Val Pro 50 55 60 Asp Arg Phe Ser Gly
Ser Gly Ser Gly Thr Asp Phe Thr Leu Lys Ile 65 70 75 80 Ser Arg Val
Glu Ala Glu Asp Leu Gly Val Tyr Tyr Cys Phe Gln Gly 85 90 95 Ser
His Val Pro Leu Thr Phe Gly Ala Gly Thr Lys Leu Glu Leu Lys 100 105
110 Arg Thr Val Ala Ala Pro Ser Val Phe Ile Phe Pro Pro Ser Asp Glu
115 120 125 Gln Leu Lys Ser Gly Thr Ala Ser Val Val Cys Leu Leu Asn
Asn Phe 130 135 140 Tyr Pro Arg Glu Ala Lys Val Gln Trp Lys Val Asp
Asn Ala Leu Gln 145 150 155 160 Ser Gly Asn Ser Gln Glu Ser Val Thr
Glu Gln Asp Ser Lys Asp Ser 165 170 175 Thr Tyr Ser Leu Ser Ser Thr
Leu Thr Leu Ser Lys Ala Asp Tyr Glu 180 185 190 Lys His Lys Val Tyr
Ala Cys Glu Val Thr His Gln Gly Leu Ser Ser 195 200 205 Pro Val Thr
Lys Ser Phe Asn Arg Gly Glu Cys 210 215 46 1107 DNA Artificial
Sequence Synthetic construct 46 caggtacaac tgcagcagcc tggggctgag
ctggtgaagc ctggggcctc agtgaagatg 60 tcctgcaagg cttctggcta
cacatttacc agttacaata tgcactgggt aaaacagaca 120 cctggtcggg
gcctggaatg gattggagct atttatcccg gaaatggtga tacttcctac 180
aatcagaagt tcaaaggcaa ggccacattg actgcagaca aatcctccag cacagcctac
240 atgcagctca gcagcctgac atctgaggac tctgcggtct attactgtgc
aagatcgact 300 tactacggcg gtgactggta cttcaatgtc tggggcgcag
ggaccacggt caccgtctct 360 gcagctagca ccaagggccc atcggtcttc
cccctggcac cctcctccaa gagcacctct 420 gggggcacag cggccctggg
ctgcctggtc aaggactact tccccgaacc ggtgacggtg 480 tcgtggaact
caggcgccct gaccagcggc gtgcacacct tcccggctgt cctacagtcc 540
tcaggactct actccctcag cagcgtggtg accgtgccct ccagcagctt gggcacccag
600 acctacatct gcaacgtgaa tcacaagccc agcaacacca aggtggacaa
gaaagttgag 660 cccaaatctt gtgacaaaac tcacacatgc ccaccgtgcc
cagagcccaa atcttgtgac 720 acacctcccc catgcccacg gtgcccagca
cctggaggtg gctcgagtgg aggcggttcc 780 ggagggcagc cccgagaacc
acaggtgtac accctgcccc catcccggga tgagctgacc 840 aagaaccagg
tcagcctgac ctgcctggtc aaaggcttct atcccagcga catcgccgtg 900
gagtgggaga gcaatgggca gccggagaac aactacaaga ccacgcctcc cgtgctggac
960 tccgacggct ccttcttcct ctacagcaag ctcaccgtgg acaagagcag
gtggcagcag 1020 gggaacgtct tctcatgctc cgtgatgcat gaggctctgc
acaaccacta cacgcagaag 1080 agcctctccc tgtctccggg taaatga 1107 47
368 PRT Artificial Sequence Synthetic construct 47 Gln Val Gln Leu
Gln Gln Pro Gly Ala Glu Leu Val Lys Pro Gly Ala 1 5 10 15 Ser Val
Lys Met Ser Cys Lys Ala Ser Gly Tyr Thr Phe Thr Ser Tyr 20 25 30
Asn Met His Trp Val Lys Gln Thr Pro Gly Arg Gly Leu Glu Trp Ile 35
40 45 Gly Ala Ile Tyr Pro Gly Asn Gly Asp Thr Ser Tyr Asn Gln Lys
Phe 50 55 60 Lys Gly Lys Ala Thr Leu Thr Ala Asp Lys Ser Ser Ser
Thr Ala Tyr 65 70 75 80 Met Gln Leu Ser Ser Leu Thr Ser Glu Asp Ser
Ala Val Tyr Tyr Cys 85 90 95 Ala Arg Ser Thr Tyr Tyr Gly Gly Asp
Trp Tyr Phe Asn Val Trp Gly 100 105 110 Ala Gly Thr Thr Val Thr Val
Ser Ala Ala Ser Thr Lys Gly Pro Ser 115 120 125 Val Phe Pro Leu Ala
Pro Ser Ser Lys Ser Thr Ser Gly Gly Thr Ala 130 135 140 Ala Leu Gly
Cys Leu Val Lys Asp Tyr Phe Pro Glu Pro Val Thr Val 145 150 155 160
Ser Trp Asn Ser Gly Ala Leu Thr Ser Gly Val His Thr Phe Pro Ala 165
170 175 Val Leu Gln Ser Ser Gly Leu Tyr Ser Leu Ser Ser Val Val Thr
Val 180 185 190 Pro Ser Ser Ser Leu Gly Thr Gln Thr Tyr Ile Cys Asn
Val Asn His 195 200 205 Lys Pro Ser Asn Thr Lys Val Asp Lys Lys Val
Glu Pro Lys Ser Cys 210 215 220 Asp Lys Thr His Thr Cys Pro Pro Cys
Pro Glu Pro Lys Ser Cys Asp 225 230 235 240 Thr Pro Pro Pro Cys Pro
Arg Cys Pro Ala Pro Gly Gly Gly Ser Ser 245 250 255 Gly Gly Gly Ser
Gly Gly Gln Pro Arg Glu Pro Gln Val Tyr Thr Leu 260 265 270 Pro Pro
Ser Arg Asp Glu Leu Thr Lys Asn Gln Val Ser Leu Thr Cys 275 280 285
Leu Val Lys Gly Phe Tyr Pro Ser Asp Ile Ala Val Glu Trp Glu Ser 290
295 300 Asn Gly Gln Pro Glu Asn Asn Tyr Lys Thr Thr Pro Pro Val Leu
Asp 305 310 315 320 Ser Asp Gly Ser Phe Phe Leu Tyr Ser Lys Leu Thr
Val Asp Lys Ser 325 330 335 Arg Trp Gln Gln Gly Asn Val Phe Ser Cys
Ser Val Met His Glu Ala 340 345 350 Leu His Asn His Tyr Thr Gln Lys
Ser Leu Ser Leu Ser Pro Gly Lys 355 360 365 48 642 DNA Artificial
Sequence Synthetic construct 48 caaattgttc tctcccagtc tccagcaatc
ctgtctgcat ctccagggga gaaggtcaca 60 atgacttgca gggccagctc
aagtgtaagt tacatccact ggttccagca gaagccagga 120 tcgtccccca
aaccctggat ttatgccaca tccaacctgg cttctggagt ccctgttcgc 180
ttcagtggca gtgggtctgg gacttcttac tctctcacaa tcagcagagt ggaggctgaa
240 gatgctgcca cttattactg ccagcagtgg actagtaacc cacccacgtt
cggagggggg 300 accaagctgg aaatcaaacg tacggtggct gcaccatctg
tcttcatctt cccgccatct 360 gatgagcagt tgaaatctgg aactgcctct
gttgtgtgcc tgctgaataa cttctatccc 420 agagaggcca aagtacagtg
gaaggtggat aacgccctcc aatcgggtaa ctcccaggag 480 agtgtcacag
agcaggacag caaggacagc acctacagcc tcagcagcac cctgacgctg 540
agcaaagcag actacgagaa acacaaagtc tacgcctgcg aagtcaccca tcagggcctg
600 agctcgcccg tcacaaagag cttcaacagg ggagagtgtt ga 642 49 213 PRT
Artificial Sequence Synthetic construct 49 Gln Ile Val Leu Ser Gln
Ser Pro Ala Ile Leu Ser Ala Ser Pro Gly 1 5 10 15 Glu Lys Val Thr
Met Thr Cys Arg Ala Ser Ser Ser Val Ser Tyr Ile 20 25 30 His Trp
Phe Gln Gln Lys Pro Gly Ser Ser Pro Lys Pro Trp Ile Tyr 35 40 45
Ala Thr Ser Asn Leu Ala Ser Gly Val Pro Val Arg Phe Ser Gly Ser 50
55 60 Gly Ser Gly Thr Ser Tyr Ser Leu Thr Ile Ser Arg Val Glu Ala
Glu 65 70 75 80 Asp Ala Ala Thr Tyr Tyr Cys Gln Gln Trp Thr Ser Asn
Pro Pro Thr 85 90 95 Phe Gly Gly Gly Thr Lys Leu Glu Ile Lys Arg
Thr Val Ala Ala Pro 100 105 110 Ser Val Phe Ile Phe Pro Pro Ser Asp
Glu Gln Leu Lys Ser Gly Thr 115 120 125 Ala Ser Val Val Cys Leu Leu
Asn Asn Phe Tyr Pro Arg Glu Ala Lys 130 135 140 Val Gln Trp Lys Val
Asp Asn Ala Leu Gln Ser Gly Asn Ser Gln Glu 145 150 155 160 Ser Val
Thr Glu Gln Asp Ser Lys Asp Ser Thr Tyr Ser Leu Ser Ser 165 170 175
Thr Leu Thr Leu Ser Lys Ala Asp Tyr Glu Lys His Lys Val Tyr Ala 180
185 190 Cys Glu Val Thr His Gln Gly Leu Ser Ser Pro Val Thr Lys Ser
Phe 195 200 205 Asn Arg Gly Glu Cys 210 50 7 PRT Artificial
Sequence Synthetic construct 50 Glu Ser Lys Tyr Gly Pro Pro 1 5 51
5 PRT Artificial Sequence Synthetic construct 51 Cys Pro Ser Cys
Pro 1 5 52 8 PRT Artificial Sequence Synthetic construct 52 Ala Pro
Glu Phe Leu Gly Gly Pro 1 5 53 29 PRT Artificial Sequence Synthetic
construct 53 Glu Ser Lys Tyr Gly Pro Pro Cys Pro Ser Cys Pro Glu
Pro Lys Ser 1 5 10 15 Cys Asp Thr Pro Pro Pro Cys Pro Arg Cys Pro
Ala Pro 20 25
* * * * *
References