U.S. patent application number 11/089368 was filed with the patent office on 2005-10-27 for binding domain-immunoglobulin fusion proteins.
This patent application is currently assigned to Trubion Pharmaceuticals, Inc.. Invention is credited to Hayden-Ledbetter, Martha S., Ledbetter, Jeffrey A..
Application Number | 20050238646 11/089368 |
Document ID | / |
Family ID | 21984904 |
Filed Date | 2005-10-27 |
United States Patent
Application |
20050238646 |
Kind Code |
A1 |
Ledbetter, Jeffrey A. ; et
al. |
October 27, 2005 |
Binding domain-immunoglobulin fusion proteins
Abstract
The invention relates to novel binding domain-immunoglobulin
fusion proteins that feature a binding domain for a cognate
structure such as an antigen, a counterreceptor or the like, a
hinge region polypeptide having either zero or one cysteine
residue, and immunoglobulin CH2 and CH3 domains, and that are
capable of ADCC and/or CDC while occurring predominantly as
monomeric polypeptides. The fusion proteins can be recombinantly
produced at high expression levels. Also provided are related
compositions and methods, including immunotherapeutic
applications.
Inventors: |
Ledbetter, Jeffrey A.;
(Shoreline, WA) ; Hayden-Ledbetter, Martha S.;
(Shoreline, WA) |
Correspondence
Address: |
BUCHANAN INGERSOLL, P.C.
ONE OXFORD CENTRE, 301 GRANT STREET
20TH FLOOR
PITTSBURGH
PA
15219
US
|
Assignee: |
Trubion Pharmaceuticals,
Inc.
Seattle
WA
|
Family ID: |
21984904 |
Appl. No.: |
11/089368 |
Filed: |
March 23, 2005 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11089368 |
Mar 23, 2005 |
|
|
|
10053530 |
Jan 17, 2002 |
|
|
|
60367358 |
Jan 17, 2001 |
|
|
|
Current U.S.
Class: |
424/144.1 |
Current CPC
Class: |
C07K 2317/53 20130101;
C07K 2317/22 20130101; C07K 2317/734 20130101; A61P 29/00 20180101;
C07K 16/2809 20130101; C07K 16/2818 20130101; C07K 16/462 20130101;
A61K 2039/505 20130101; C07K 16/46 20130101; C07K 2317/24 20130101;
C07K 16/2896 20130101; A61P 1/00 20180101; C07K 16/2878 20130101;
C07K 2317/622 20130101; C07K 2319/30 20130101; C07K 2317/64
20130101; A61P 3/10 20180101; C07K 2319/00 20130101; C07K 2317/732
20130101; A61P 35/00 20180101 |
Class at
Publication: |
424/144.1 |
International
Class: |
A61K 039/395 |
Claims
What is claimed is:
1. A method of treatment, comprising administering to a subject in
need thereof a composition comprising a pharmaceutically acceptable
carrier and a therapeutically effective amount of a single chain
protein that binds to a CD37, wherein said single chain protein
comprises: (a) a binding domain polypeptide capable of binding to
CD37, said binding domain polypeptide being joined to (b) a hinge
peptide, said hinge peptide being joined to (c) an immunoglobulin
heavy chain CH2 constant region polypeptide, said CH2 constant
region polypeptide being joined to (d) an immunoglobulin heavy
chain CH3 constant region polypeptide, wherein said single chain
protein is capable of mediating at least one immunological activity
selected from the group consisting of antibody dependent
cell-mediated cytotoxicity and complement fixation.
2. The method of claim 1 wherein said single chain protein is
capable of binding to a human CD37.
3. The method of claim 1 or 2 wherein said binding domain
polypeptide is a single chain Fv.
4. The method of claim 1 wherein said hinge peptide is a naturally
occurring immunoglobulin hinge peptide.
5. The method of claim 4 wherein said hinge peptide is an IgG hinge
peptide.
6. The method of claim 4 wherein said hinge peptide is an IgG1
hinge peptide.
7. The method of claim 4 wherein said hinge peptide is an IgA hinge
peptide.
8. The method of claim 4 wherein said hinge peptide is an IgA1
hinge peptide.
9. The method of any of claims 4-7 or 8, wherein said hinge peptide
is human.
10. The method of claim 1 wherein said hinge peptide is an altered
IgG hinge peptide having two cysteine residues.
11. The method of claim 10 wherein a hinge peptide cysteine residue
has been deleted.
12. The method of claim 10 wherein a hinge peptide cysteine residue
has been substituted with another amino acid.
13. The method of claim 12 wherein said amino acid is serine.
14. The method of claim 13 wherein said hinge is an SCC hinge.
15. The method of claim 13 wherein said hinge is a CSC hinge.
16. The method of claim 13 wherein said hinge is a CCS hinge.
17. The method of claim 1 wherein said hinge peptide is an altered
IgG hinge peptide having one cysteine residue.
18. The method of claim 17 wherein one or two hinge peptide
cysteine residues have been deleted.
19. The method of claim 17 wherein one or two hinge peptide
cysteine residues have been substituted with other amino acids.
20. The method of claim 19 wherein at least one of the hinge
peptide cysteine resides has been substituted with serine.
21. The method of claim 19 wherein both hinge peptide cysteine
resides have been substituted with serine.
22. The method of claim 21 wherein said hinge is an SSC hinge.
23. The method of claim 21 wherein said hinge is an CSS hinge.
24. The method of claim 21 wherein said hinge is an CSC hinge.
25. The method of claim 1 wherein said hinge peptide is an altered
IgG hinge peptide having no cysteine residues.
26. The method of claim 25 wherein one, two, or three hinge peptide
cysteine residues have been deleted.
27. The method of claim 25 wherein one, two, or three hinge peptide
cysteine residues have been substituted with other amino acids.
28. The method of claim 27 wherein at least one of the hinge
peptide cysteine resides has been substituted with serine.
29. The method of claim 27 wherein two hinge peptide cysteine
resides have been substituted with serine.
30. The method of claim 29 wherein three hinge peptide cysteine
resides have been substituted with serine.
31. The method of any of claims 10-15 or 16 wherein said altered
IgG hinge peptide having two cysteine residues is an altered IgG1
hinge peptide
32. The method of any of claims 10-15 or 16 wherein said altered
IgG hinge peptide having two cysteine residues is an altered human
IgG hinge peptide.
33. The method of claim 32 wherein said altered human IgG hinge is
an altered human IgG1 hinge peptide.
34. The method of any of claims 17-23 or 24 wherein said altered
IgG hinge peptide having one cysteine residue is an altered IgG1
hinge peptide.
35. The method of any of claims 17-23 or 24 wherein said altered
IgG hinge peptide having one cysteine residue is an altered human
IgG hinge peptide.
36. The method of claim 35 wherein said altered human IgG hinge is
an altered human IgG1 hinge peptide.
37. The method of any of claims 25-29 or 30 wherein said altered
IgG hinge peptide having no cysteine residues is an altered IgG1
hinge peptide.
38. The method of any of claims 25-29 or 30 wherein said altered
IgG hinge peptide having no cysteine residues is an altered human
IgG hinge peptide.
39. The method of claim 38 wherein said altered human IgG hinge is
an altered human IgG1 hinge peptide.
40. The method of claim 1 wherein said hinge peptide is an altered
IgA hinge peptide having two cysteine residues.
41. The method of claim 1 wherein said hinge peptide is an altered
IgA hinge peptide having one cysteine residue.
42. The method of claim 1 wherein said hinge peptide is an altered
IgA hinge peptide having no cysteine residues.
43. The method of any of claims 40, 41, or 42, wherein at least one
cysteine residue has been deleted.
44. The method of any of claims 40, 41, or 42, wherein another
amino acid has been substituted for at least one cysteine
residue.
45. The method of claim 44 wherein said amino acid is serine.
46. The method of any of claims 40, 41, or 42, wherein said altered
IgA hinge is an altered IgA1 hinge.
47. The method of claim 46 wherein said altered IgA1 hinge peptide
is an altered human IgA1 hinge peptide.
48. The method of claim 1 wherein said heavy chain CH2 constant
region polypeptide is an IgG CH2 constant region polypeptide.
49. The method of claim 1 wherein said heavy chain CH2 constant
region polypeptide is an IgG1 CH2 constant region polypeptide.
50. The method of claim 1 wherein said heavy chain CH2 constant
region polypeptide is an IgA CH2 constant region polypeptide.
51. The method of claim 1 wherein said heavy chain CH2 constant
region polypeptide is an IgA1 CH2 constant region polypeptide.
52. The method of any of claims 48-50 or 51, wherein said CH2
constant region polypeptide is human.
53. The method of claim 1 wherein said heavy chain CH2 constant
region polypeptide is an altered CH2 constant region derived from a
human heavy chain CH2 constant region polypeptide.
54. The method of claim 53, wherein said heavy chain constant
region comprises a CH2 domain in which the amino acid at position
234 has been deleted or replaced with another amino acid.
55. The method of claim 54, wherein leucine has been replaced with
serine at position 234.
56. The method of claim 1 wherein said heavy chain CH3 constant
region polypeptide is an IgG CH3 constant region polypeptide.
57. The method of claim 1 wherein said heavy chain CH3 constant
region polypeptide is an IgG1 CH3 constant region polypeptide.
58. The method of claim 1 wherein said heavy chain CH3 constant
region polypeptide is an IgA CH3 constant region polypeptide.
59. The method of claim 1 wherein said heavy chain CH3 constant
region polypeptide is an IgA1 CH3 constant region polypeptide.
60. The method of any of claims 56-58 or 59, wherein said CH3
constant region polypeptide is human.
61. The method of claim 1 wherein said heavy chain CH2 and CH3
constant region polypeptides are IgG CH2CH3 constant region
polypeptides.
62. The method of claim 1 wherein said heavy chain CH2 and CH3
constant region polypeptides are IgG1 CH2CH3 constant region
polypeptides.
63. The method of claim 1 wherein said heavy chain CH2 and CH3
constant region polypeptides are IgA CH2CH3 constant region
polypeptides.
64. The method of claim 1 wherein said heavy chain CH2 and CH3
constant region polypeptides are IgA1 CH2CH3 constant region
polypeptides.
65. The method of any of claims 61-63 or 64, wherein said CH2 and
CH3 constant region polypeptides are human.
66. The method of claim 1 wherein said heavy chain CH3 constant
region polypeptide is an altered CH3 constant region derived from a
human heavy chain CH3 constant region polypeptide.
67. The method of claim 1 or 2 wherein said single chain protein is
chimeric.
68. The method of claim 67 wherein said subject is human.
69. The method of claim 3, wherein said single chain protein is
chimeric.
70. The method of claim 69 wherein said subject is human.
71. The method of claim 1 or 2 wherein said single chain protein is
humanized.
72. The method of claim 71 wherein said subject is human.
73. The method of claim 3, wherein said single chain protein is
humanized.
74. The method of claim 73 wherein said subject is human.
75. The method of claim 1 or 2 wherein said single chain protein is
designed to minimize immunogenicity upon administration to said
subject.
76. The method of claim 75 wherein said subject is human.
77. The method of claim 3, wherein said single chain protein is
designed to minimize immunogenicity upon administration to said
subject.
78. The method of claim 77 wherein said subject is human.
79. The method of claim 1 or 2 wherein said subject is treated for
a disease involving B cell activity.
80. The method of claim 3 wherein said subject is treated for a
disease involving B cell activity.
81. The method of claim 1 or 2 wherein said subject is treated for
a B-cell disorder.
82. The method of claim 3 wherein said subject is treated for a B
cell disorder.
83. The method of claim 1 or 2 wherein said subject is treated for
a malignant condition.
84. The method of claim 3 wherein said subject is treated for a
malignant condition.
85. The method of claim 83 wherein said malignant condition is
B-cell lymphoma.
86. The method of claim 84 wherein said malignant condition is
B-cell lymphoma.
87. The method of claim 83 wherein said malignant condition is
chronic lymphocytic leukemia.
88. The method of claim 84 wherein said malignant condition is
chronic lymphocytic leukemia.
89. The method of claim 1 or 2 wherein said subject is treated for
an autoimmune disease.
90. The method of claim 3 wherein said subject is treated for an
autoimmune disease.
91. The method of claim 89 wherein autoimmune disease is
characterized in part by autoantibody production.
92. The method of claim 90 wherein autoimmune disease is
characterized in part by autoantibody production.
93. The method of claim 1 or 2 wherein said subject is treated for
rheumatoid arthritis.
94. The method of claim 3 wherein said subject is treated for
rheumatoid arthritis.
95. The method of claim 1 or 2 wherein said subject is treated for
psoriasis.
96. The method of claim 3 wherein said subject is treated for
psoriasis.
97. The method of claim 1 or 2 wherein said subject is treated for
systemic lupus erythematosus.
98. The method of claim 3 wherein said subject is treated for
systemic lupus erythematosus.
99. The method of claim 1 or 2 wherein said subject is treated for
a disease selected from the group consisting of myasthenia gravis,
Grave's disease, type 1 diabetes mellitus, and multiple
sclerosis.
100. The method of claim 3 wherein said subject is treated for a
disease selected from the group consisting of myasthenia gravis,
Grave's disease, type 1 diabetes mellitus, and multiple
sclerosis.
101. The method of claim 1 or 2 wherein said subject is treated for
a disease selected from the group consisting of autoimmune thyroid
disease, Hashimoto's thyroiditis, Sjogren's syndrome, immune
thrombocytopenic purpura, and scleroderma.
102. The method of claim 3 wherein said subject is treated for a
disease selected from the group consisting of autoimmune thyroid
disease, Hashimoto's thyroiditis, Sjogren's syndrome, immune
thrombocytopenic purpura, and scleroderma.
103. The method of claim 1 or 2 wherein said subject is treated for
inflammatory bowel disease.
104. The method of claim 3 wherein said subject is treated for
inflammatory bowel disease.
105. The method of claim 103 wherein said inflammatory bowel
disease is Crohn's disease.
106. The method of claim 104 wherein said inflammatory bowel
disease is Crohn's disease.
107. The method of claim 103 wherein said inflammatory bowel
disease is ulcerative colitis.
108. The method of claim 104 wherein said inflammatory bowel
disease is ulcerative colitis.
109. The method of claim 1 wherein said single chain protein is
G28-1 scFv IgG1H(SSS) IgG1CH2CH3(wt).
110. The method of claim 1 wherein said single chain protein is
G28-1 scFv IgAH(wt) IgG1CH2CH3(wt).
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 10/053,530, filed Jan. 17, 2002, now pending, which claims the
benefit of priority of U.S. Provisional Application No. 60/367,358
(formerly U.S. application Ser. No. 09/765,208, filed Jan. 17,
2001), the contents of which are incorporated by reference in their
entirety.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to immunologically
active, recombinant binding proteins, and in particular, to
molecularly engineered binding domain-immunoglobulin fusion
proteins, including single chain Fv-immunoglobulin fusion proteins.
The present invention also relates to compositions and methods for
treating malignant conditions and B-cell disorders, including
diseases characterized by autoantibody production.
[0003] An immunoglobulin molecule is composed of two identical
light chains and two identical heavy chains that are joined into a
macromolecular complex by interchain disulfide bonds. Intrachain
disulfide bonds join different areas of the same polypeptide chain,
which results in the formation of loops that along with adjacent
amino acids constitute the immunoglobulin domains. Each light chain
and each heavy chain has a single variable region that shows
considerable variation in amino acid composition from one antibody
to another. The light chain variable region, V.sub.L, associates
with the variable region of a heavy chain, V.sub.H, to form the
antigen binding site of the immunoglobulin, Fv. Light chains have a
single constant region domain and heavy chains have several
constant region domains. Classes IgG, IgA, and IgD have three
constant region domains, which are designated CH1, CH2, and CH3,
and the IgM and IgE classes have four constant region domains.
[0004] The heavy chains of immunoglobulins can be divided into
three functional regions: Fd, hinge, and Fc. The Fd region
comprises the V.sub.H and CH1 domains and in combination with the
light chain forms Fab. The Fc fragment is generally considered
responsible for the effector functions of an immunoglobulin, such
as, complement fixation and binding to Fc receptors. The hinge
region, found in IgG, IgA, and IgD classes, acts as a flexible
spacer, allowing the Fab portion to move freely in space. In
contrast to the constant regions, the hinge domains are
structurally diverse, varying in both sequence and length among
immunoglobulin classes and subclasses. For example, three human IgG
subclasses, IgG1, IgG2, and IgG4, have hinge regions of 12-15 amino
acids while IgG3 comprises approximately 62 amino acids, including
21 proline residues and 11 cysteine residues. According to
crystallographic studies, the hinge can be further subdivided
functionally into three regions: the upper hinge, the core, and the
lower hinge (Shin et al., Immunological Reviews 130:87 (1992)). The
upper hinge includes amino acids from the carboxyl end of CH1 to
the first residue in the hinge that restricts motion, generally the
first cysteine residue that forms an interchain disulfide bond
between the two heavy chains. The length of the upper hinge region
correlates with the segmental flexibility of the antibody. The core
hinge region contains the inter-heavy chain disulfide bridges, and
the lower hinge region joins the amino terminal end of the CH2
domain and includes residues in CH2. (Id.) The core hinge region of
human IgG1 contains the sequence, Cys-Pro-Pro-Cys, which when
disulfide bonds are formed results in a cyclic octa-peptide
believed to act as a pivot, thus conferring flexibility. The hinge
region may also contain carbohydrate attachment sites. For example,
IgA1 contains five carbohydrate sites within a 17 amino acid
segment of the hinge region, conferring exception resistance of the
hinge to intestinal proteases, considered an advantageous property
for a secretory immunoglobulin.
[0005] Conformational changes permitted by the structure and
flexibility of the hinge region may affect the effector functions
of the Fc portion of the antibody. Three general categories of
effector functions associated with the Fc region include (1)
activation of the classical complement cascade, (2) interaction
with effector cells, and (3) compartmentalization of
immunoglobulins. The different human IgG subclasses vary in their
relative efficacy to activate and amplify the steps of the
complement cascade. In general, IgG1 and IgG3 most effectively fix
complement, IgG2 is less effective, and IgG4 does not activate
complement. Complement activation is initiated by binding of C1q, a
subunit of the first component C1 in the cascade, to an
antigen-antibody complex. Even though the binding site for C1q is
located in the CH2 domain of the antibody, the hinge region
influences the ability of the antibody to activate the cascade. For
example, recombinant immunoglobulins lacking a hinge region are
unable to activate complement. (Id.) Without the flexibility
conferred by the hinge region, the Fab portion of the antibody
bound to the antigen may not be able to adopt the conformation
required to permit C1q to bind to CH2. (See id.) Studies have
indicated that hinge length and segmental flexibility correlate
with complement activation; however, the correlation is not
absolute. Human IgG3 molecules with altered hinge regions that are
as rigid as IgG4 still effectively activate the cascade.
[0006] Lack of the hinge region also affects the ability of human
IgG immunoglobulins to bind Fc receptors on immune effector cells.
Binding of an immunoglobulin to an Fc receptor facilitates
antibody-dependent cellular cytotoxicity (ADCC), which is presumed
to be an important means to eliminate tumor cells. The human IgG Fc
receptor family is divided into three groups, Fc.gamma.RI (CD64),
which is capable of binding IgG with high affinity, Fc.gamma.RII
(CD32), and Fc.gamma.RIII (CD16), both of which are low affinity
receptors. The molecular interaction between each of the three
receptors and an immunoglobulin has not been defined precisely, but
experiments indicate that residues in the hinge proximal region of
the CH2 domain are important to the specificity of the interaction
between the antibody and the Fc receptor. In addition, IgG1 myeloma
proteins and recombinant IgG3 chimeric antibodies that lack a hinge
region are unable to bind Fc.gamma.RI, likely because accessibility
to CH2 is decreased. (Shin et al., Intern. Rev. Immunol. 10:177,
178-79 (1993)).
[0007] Monoclonal antibody technology and genetic engineering
methods have led to rapid development of immunoglobulin molecules
for diagnosis and treatment of human diseases. Protein engineering
has been applied to improve the affinity of an antibody for its
cognate antigen, to diminish problems related to immunogenicity,
and to alter an antibody's effector functions. The domain structure
of immunoglobulins is amenable to engineering, in that the antigen
binding domains and the domains conferring effector functions may
be exchanged between immunoglobulin classes and subclasses.
[0008] In addition, smaller immunoglobulin molecules have been
constructed to overcome problems associated with whole
immunoglobulin therapy. Single chain Fv (scFv) comprise the heavy
chain variable domain joined via a short linker peptide to the
light chain variable domain (Huston et al. Proc. Natl. Acad. Sci.
USA, 85: 5879-83, 1988). Because of the small size of scFv
molecules, they exhibit very rapid clearance from plasma and
tissues and more effective penetration into tissues than whole
immunoglobulin. An anti-tumor scFv showed more rapid tumor
penetration and more even distribution through the tumor mass than
the corresponding chimeric antibody (Yokota et al., Cancer Res. 52,
3402-08 (1992)). Fusion of an scFv to another molecule, such as a
toxin, takes advantage of the specific antigen-binding activity and
the small size of an scFv to deliver the toxin to a target tissue.
(Chaudary et al., Nature 339:394 (1989); Batra et al., Mol. Cell.
Biol. 11:2200 (1991)).
[0009] Despite the advantages that scFv molecules bring to
serotherapy, several drawbacks to this therapeutic approach exist.
While rapid clearance of scFv may reduce toxic effects in normal
cells, such rapid clearance may prevent delivery of a minimum
effective dose to the target tissue. Manufacturing adequate amounts
of scFv for administration to patients has been challenging due to
difficulties in expression and isolation of scFv that adversely
affect the yield. During expression, scFv molecules lack stability
and often aggregate due to pairing of variable regions from
different molecules. Furthermore, production levels of scFv
molecules in mammalian expression systems are low, limiting the
potential for efficient manufacturing of scFv molecules for therapy
(Davis et al, J. Biol. Chem. 265:10410-18 (1990); Traunecker et
al., EMBO J. 10: 3655-59 (1991)). Strategies for improving
production have been explored, including addition of glycosylation
sites to the variable regions (Jost, C. R. U.S. Pat. No. 5,888,773,
Jost et al, J. Biol. Chem. 269: 26267-73 (1994)).
[0010] Conjugation or fusion of toxins to scFV provides a very
potent molecule, but dosing is limited by toxicity from the toxin
molecule. Toxic effects include elevation of liver enzymes and
vascular leak syndrome. In addition, immunotoxins are highly
immunogenic and host antibodies generated against the toxin limit
its potential for repeated treatment.
[0011] An additional disadvantage to using scFv for therapy is the
lack of effector function. An scFv without the cytolytic functions,
ADCC and complement dependent-cytotoxicity (CDC), associated with
the constant region of an immunoglobulin may be ineffective for
treating disease. Even though development of scFv technology began
over 12 years ago, currently no scFv products are approved for
therapy.
[0012] The benefit of antibody constant region-associated effector
functions to treatment of a disease has prompted development of
fusion proteins in which nonimmunoglobulin sequences are
substituted for the antibody variable region. For example, CD4, the
T cell surface protein recognized by HIV, was recombinantly fused
to an immunoglobulin Fc effector domain. (See Sensel et al., Chem.
Immunol. 65:129-158 (1997)). The biological activity of such a
molecule will depend in part on the class or subclass of the
constant region chosen. An IL-2-IgG1 fusion protein effected
complement-mediated lysis of IL-2 receptor-bearing cells. (See
id.). Use of immunoglobulin constant regions to construct these and
other fusion proteins may also confer improved pharmacokinetic
properties.
[0013] Diseases and disorders thought to be amenable to some type
of immunoglobulin therapy include cancer and immune system
disorders. Cancer includes a broad range of diseases, affecting
approximately one in four individuals worldwide. Rapid and
unregulated proliferation of malignant cells is a hallmark of many
types of cancer, including hematological malignancies. Patients
with a hematologic malignant condition have benefited most from
advances in cancer therapy in the past two decades (Multani et al.,
J. Clin. Oncology 16: 3691-3710, 1998). Although remission rates
have increased, most patients still relapse and succumb to their
disease. Barriers to cure with cytotoxic drugs include tumor cell
resistance and the high toxicity of chemotherapy, which prevents
optimal dosing in many patients. New treatments based on targeting
with molecules that specifically bind to a malignant cell,
including monoclonal antibodies (mAbs), can improve effectiveness
without increasing toxicity.
[0014] Since mAbs were first described in 1975 (Kohler et al.,
Nature 256:495-97 (1975)), many patients have been treated with
mAbs to antigens expressed on tumor cells. These studies have
yielded important lessons regarding the selection of target
antigens suitable for therapy. First and most importantly, the
target antigen should not be expressed by crucial normal tissues.
Fortunately, hematologic malignant cells express many antigens that
are not expressed on stem cells or other essential cells. Treatment
of a hematologic malignant condition that depletes both normal and
malignant cells of hematological origin has been acceptable because
regeneration of normal cells from progenitors occurs after therapy
has ended. Second, the target antigen should be expressed on all
clonogenic populations of tumor cells, and expression should
persist despite the selective pressure from immunoglobulin therapy.
Thus, the choice of surface idiotype for therapy of B cell
malignancy has been limited by the outgrowth of tumor cell variants
with altered surface idiotype expression even though the antigen
exhibits a high degree of tumor selectivity (Meeker et al., N.
Engl. J. Med. 312:1658-65 (1985)). Third, the selected antigen must
traffic properly after an immunoglobulin binds to it. Shedding or
internalization of a target antigen after an immunoglobulin binds
to the antigen may allow tumor cells to escape destruction, thus
limiting the effectiveness of serotherapy. Fourth, binding of an
immunoglobulin to target antigens that transmit activation signals
may result in improved functional responses in tumor cells that
lead to growth arrest and apoptosis. While all of these properties
are important, the triggering of apoptosis after an immunoglobulin
binds to the antigen may be a critical factor in achieving
successful serotherapy.
[0015] Antigens that have been tested as targets for serotherapy of
B and T cell malignancies include Ig idiotype (Brown et al., Blood
73:651-61 (1989)), CD19 (Hekman et al., Cancer Immunol. Immunother.
32:364-72 (1991); Vlasveld et al., Cancer Immunol. Immunother. 40:
37-47 (1995)), CD20 (Press et al., Blood 69: 584-91 (1987); Maloney
et al., J. Clin. Oncol. 15:3266-74, (1997)) CD21 (Scheinberg et.
al., J. Clin. Oncol. 8:792-803, (1990)), CD5 (Dillman et. al., J.
Biol. Respn. Mod 5:394-410 (1986)), and CD52 (CAMPATH) (Pawson et
al., J. Clin. Oncol. 15:2667-72, (1997)). Of these, the most
success has been obtained using CD20 as a target for therapy of B
cell lymphomas. Each of the other targets has been limited by the
biological properties of the antigen. For example, surface idiotype
can be altered through somatic mutation, allowing tumor cell
escape. CD5, CD21, and CD19 are rapidly internalized after mAb
binding allowing tumor cells to escape destruction unless mAbs are
conjugated with toxin molecules. CD22 is expressed on only a subset
of B cell lymphomas, while CD52 is expressed on both T cells and B
cells and generates immunosuppression from T cell depletion.
[0016] CD20 fulfills the basic criteria described above for
selection of an appropriate target antigen for therapy of a B cell
malignant condition. Treatment of patients with low grade or
follicular B cell lymphoma using chimeric CD20 mAb induces partial
or complete responses in many patients (McLaughlin et al, Blood
88:90a (abstract, suppl. 1) (1996); Maloney et al, Blood 90:
2188-95 (1997)). However, tumor relapse commonly occurs within six
months to one year. Therefore, further improvements in serotherapy
are needed to induce more durable responses in low grade B cell
lymphoma, and to allow effective treatment of high grade lymphoma
and other B cell diseases.
[0017] One approach to improving CD20 serotherapy has been to
target radioisotopes to B cell lymphomas using mAbs specific for
CD20. While the effectiveness of therapy is increased, associated
toxicity from the long in vivo half-life of the radioactive
antibody increased also, sometimes requiring that the patient
undergo stem cell rescue (Press et al., N. Eng. J. Med. 329:
1219-1224, 1993; Kaminski et al., N. Eng.J. Med. 329:459-65
(1993)). MAbs to CD20 have been cleaved with proteases to yield
F(ab').sub.2 or Fab fragments prior to attachment of the
radioisotope. This improves penetration of the radioisotope
conjugate into the tumor, and shortens the in vivo half-life, thus
reducing the toxicity to normal tissues. However, the advantages of
effector functions, including complement fixation and ADCC, that
are provided by the Fc region of the CD20 mAb are lost. Therefore,
for improved delivery of radioisotopes, a strategy is needed to
make a CD20 mAb derivative that retains Fc-dependent effector
functions but which is smaller in size, thereby increasing tumor
penetration and shortening mAb half-life.
[0018] CD20 was the first human B cell lineage-specific surface
molecule identified by a monoclonal antibody, but the function of
CD20 in B cell biology is still incompletely understood. CD20 is a
non-glycosylated, hydrophobic 35 kDa phosphoprotein that has both
amino and carboxy ends in the cytoplasm (Einfeld et al, EMBO J.
7:711-17 (1988)). Natural ligands for CD20 have not been
identified. CD20 is expressed by all normal mature B cells, but is
not expressed by precursor B cells.
[0019] CD20 mAbs deliver signals to normal B cells that affect
viability and growth (Clark et al., Proc. Natl. Acad. Sci. USA
83:4494-98 (1986)). Recent data has shown that extensive
cross-linking of CD20 can induce apoptosis of B lymphoma cell lines
(Shan et al., Blood 91:1644-52 (1998)). Cross-linking of CD20 on
the cell surface increases the magnitude and kinetics of signal
transduction, which was detected by measuring phosphorylation of
cellular substrates on tyrosine residues (Deans et al., J. Immunol.
146:846-53 (1993)). Importantly, apoptosis of Ramos B lymphoma
cells was also be induced by cross-linking of CD20 mAbs by addition
of Fc-receptor positive cells (Shan et al., Blood 91: 1644-52
(1998)). Therefore, in addition to cellular depletion by complement
and ADCC mechanisms, Fc-receptor binding by CD20 mAbs in vivo could
promote apoptosis of malignant B cells by CD20 cross-linking. This
theory is consistent with experiments showing that effectiveness of
CD20 therapy of human lymphoma in a SCID mouse model was dependent
upon Fc-receptor binding by the CD20 mAb (Funakoshi et al., J.
Immunotherapy 19:93-101 (1996)).
[0020] The CD20 polypeptide contains four transmembrane domains
(Einfeld et al., EMBO J. 7: 711-17, (1988); Stamenkovic et al., J.
Exp. Med. 167:1975-80 (1988); Tedder et. al., J. Immunol.
141:4388-4394 (1988)). The multiple membrane spanning domains
prevent CD20 internalization after antibody binding. This property
of CD20 was recognized as an important feature for effective
therapy of B cell malignancies when a murine CD20 mAb, IF5, was
injected into patients with B cell lymphoma, resulting in
significant depletion of malignant cells and partial clinical
responses (Press et al., Blood 69: 584-91 (1987)).
[0021] Because normal mature B cells also express CD20, normal B
cells are depleted during CD20 antibody therapy (Reff, M. E. et al,
Blood 83: 435-445, 1994). However, after treatment is completed,
normal B cells are regenerated from CD20 negative B cell
precursors; therefore, patients treated with anti-CD20 therapy do
not experience significant immunosuppression. Depletion of normal B
cells may be beneficial in diseases that involve inappropriate
production of autoantibodies or other diseases where B cells may
play a role. A chimeric mAb specific for CD20, consisting of heavy
and light chain variable regions of mouse origin fused to human
IgG1 heavy chain and human kappa light chain constant regions,
retained binding to CD20 and the ability to mediate ADCC and to fix
complement (Liu et al., J. Immunol, 139:3521-26 (1987); Robinson et
al., U.S. Pat. No. 5,500,362). This work led to development of a
chimeric CD20 mAb, Rituximab.TM., currently approved by the U.S.
Food and Drug Administration for approval for therapy of B cell
lymphomas. While clinical responses are frequently observed after
treatment with Rituximab.TM., patients often relapse after about
6-12 months.
[0022] High doses of Rituximab.TM. are required for intravenous
injection because the molecule is large, approximately 150 kDa, and
diffusion is limited into the lymphoid tissues where many tumor
cells reside. The mechanism of anti-tumor activity of Rituximab.TM.
is thought to be a combination of several activities, including
ADCC, fixation of complement, and triggering of signals in
malignant B cells that promote apoptosis. The large size of
Rituximab.TM. prevents optimal diffusion of the molecule into
lymphoid tissues that contain malignant B cells, thereby limiting
these anti-tumor activities. As discussed above, cleavage of CD20
mAbs with proteases into Fab or F(ab').sub.2 fragments makes them
smaller and allows better penetration into lymphoid tissues, but
the effector functions important for anti-tumor activity are lost.
While CD20 mAb fragments may be more effective than intact antibody
for delivery of radioisotopes, it would be desirable to construct a
CD20 mAb derivative that retains the effector functions of the Fc
portion, but is smaller in size, facilitating better tumor
penetration and resulting in a shorter half-life.
[0023] CD20 is expressed by malignant cells of B cell origin,
including B cell lymphoma and chronic lymphocytic leukemia (CLL).
CD20 is not expressed by malignancies of pre-B cells, such as acute
lymphoblastic leukemia. CD20 is therefore a good target for therapy
of B cell lymphoma, CLL, and other diseases in which B cells are
involved in the disease activity. Other B cell disorders include
autoimmune diseases in which autoantibodies are produced during the
differentiation of B cells into plasma cells. Examples of B cell
disorders include autoimmune thyroid disease, including Graves'
disease and Hashimoto's thyroiditis, rheumatoid arthritis, systemic
lupus erythematosus (SLE), Sjogrens syndrome, immune
thrombocytopenic purpura (ITP), multiple sclerosis (MS), myasthenia
gravis (MG), psoriasis, scleroderma, and inflammatory bowel
disease, including Crohn's disease and ulcerative colitis.
[0024] From the foregoing, a clear need is apparent for improved
compositions and methods to treat malignant conditions and B cell
disorders. The compositions and methods of the present invention
overcome the limitations of the prior art by providing a binding
domain-immunoglobulin fusion protein comprising a binding domain
polypeptide that is fused to an immunoglobulin hinge region
polypeptide, which is fused to an immunoglobulin heavy chain CH2
constant region polypeptide fused to an immunoglobulin heavy chain
CH3 constant region polypeptide, wherein the binding
domain-immunoglobulin fusion protein is capable of mediating ADCC
or complement fixation. Furthermore, the compositions and methods
offer other related advantages.
SUMMARY OF THE INVENTION
[0025] It is an aspect of the present invention to provide a
binding domain-immunoglobulin fusion protein, comprising (a) a
binding domain polypeptide that is fused to an immunoglobulin hinge
region polypeptide, wherein said hinge region polypeptide is
selected from the group consisting of (i) a mutated hinge region
polypeptide that contains no cysteine residues and that is derived
from a wild-type immunoglobulin hinge region polypeptide having one
or more cysteine residues, (ii) a mutated hinge region polypeptide
that contains one cysteine residue and that is derived from a
wild-type immunoglobulin hinge region polypeptide having two or
more cysteine residues, (iii) a wild-type human IgA hinge region
polypeptide, (iv) a mutated human IgA hinge region polypeptide that
contains no cysteine residues and that is derived from a wild-type
human IgA region polypeptide, and (v) a mutated human IgA hinge
region polypeptide that contains one cysteine residue and that is
derived from a wild-type human IgA region polypeptide; (b) an
immunoglobulin heavy chain CH2 constant region polypeptide that is
fused to the hinge region polypeptide; and (c) an immunoglobulin
heavy chain CH3 constant region polypeptide that is fused to the
CH2 constant region polypeptide, wherein: (1) the binding
domain-immunoglobulin fusion protein is capable of at least one
immunological activity selected from the group consisting of
antibody dependent cell-mediated cytotoxicity and complement
fixation, and (2) the binding domain polypeptide is capable of
specifically binding to an antigen. In one embodiment the
immunoglobulin hinge region polypeptide is a mutated hinge region
polypeptide and exhibits a reduced ability to dimerize, relative to
a wild-type human immunoglobulin G hinge region polypeptide. In
another embodiment the binding domain polypeptide comprises at
least one immunoglobulin variable region polypeptide that is an
immunoglobulin light chain variable region polypeptide or an
immunoglobulin heavy chain variable region polypeptide. In a
further embodiment the immunoglobulin variable region polypeptide
is derived from a human immunoglobulin.
[0026] In another embodiment the binding domain Fv-immunoglobulin
fusion protein binding domain polypeptide comprises (a) at least
one immunoglobulin light chain variable region polypeptide; (b) at
least one immunoglobulin heavy chain variable region polypeptide;
and (c) at least one linker peptide that is fused to the
polypeptide of (a) and to the polypeptide of (b). In a further
embodiment the immunoglobulin light chain variable region and heavy
chain variable region polypeptides are derived from human
immunoglobulins.
[0027] In another embodiment at least one of the immunoglobulin
heavy chain CH2 constant region polypeptide and the immunoglobulin
heavy chain CH3 constant region polypeptide is derived from a human
immunoglobulin heavy chain. In another embodiment the
immunoglobulin heavy chain constant region CH2 and CH3 polypeptides
are of an isotype selected from human IgG and human IgA. In another
embodiment the antigen is selected from the group consisting of
CD19, CD20, CD37, CD40 and L6. In certain further embodiments of
the above described fusion protein, the linker polypeptide
comprises at least one polypeptide having as an amino acid sequence
Gly-Gly-Gly-Gly-Ser, and in certain other embodiments the linker
polypeptide comprises at least three repeats of a polypeptide
having as an amino acid sequence Gly-Gly-Gly-Gly-Ser. In certain
embodiments the immunoglobulin hinge region polypeptide comprises a
human IgA hinge region polypeptide. In certain embodiments the
binding domain polypeptide comprises a CD154 extracellular domain.
In certain embodiments the binding domain polypeptide comprises a
CD154 extracellular domain and at least one immunoglobulin variable
region polypeptide.
[0028] In other embodiments the invention provides an isolated
polynucleotide encoding any of the above described binding
domain-immunoglobulin fusion proteins, and in related embodiments
the invention provides a recombinant expression construct
comprising such a polynucleotide, and in certain further
embodiments the invention provides a host cell transformed or
transfected with such a recombinant expression construct. In
another embodiment the invention provides a method of producing a
binding domain-immunoglobulin fusion protein, comprising the steps
of (a) culturing the host cell as just described, under conditions
that permit expression of the binding domain-immunoglobulin fusion
protein; and (b) isolating the binding domain-immunoglobulin fusion
protein from the host cell culture.
[0029] The present invention also provides in certain embodiments a
pharmaceutical composition comprising a binding
domain-immunoglobulin fusion protein as described above, in
combination with a physiologically acceptable carrier. In another
embodiment there is provided a method of treating a subject having
or suspected of having a malignant condition or a B-cell disorder,
comprising administering to a patient a therapeutically effective
amount of an above described binding domain-immunoglobulin fusion
protein. In certain further embodiments the malignant condition or
B-cell disorder is a B-cell lymphoma or a disease characterized by
autoantibody production, and in certain other further embodiments
the malignant condition or B-cell disorder is rheumatoid arthritis,
myasthenia gravis, Grave's disease, type I diabetes mellitus,
multiple sclerosis or an autoimmune disease.
[0030] These and other aspects of the present invention will become
apparent upon reference to the following detailed description and
attached drawings. All references disclosed herein are hereby
incorporated by reference in their entireties as if each was
incorporated individually.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIGS. 1A-1B show DNA and deduced amino acid sequences (SEQ
ID NO: 15) of 2H7scFv-Ig, a binding domain-immunoglobulin fusion
protein capable of specifically binding CD20.
[0032] FIG. 2 shows production levels of 2H7 scFv-Ig by
transfected, stable CHO lines and generation of a standard curve by
binding of purified 2H7 scFv-Ig to CHO cells expressing CD20.
[0033] FIG. 3 shows SDS-PAGE analysis of multiple preparations of
isolated 2H7scFv-Ig protein.
[0034] FIG. 4 shows complement fixation (FIG. 4A) and mediation of
antibody-dependent cellular cytotoxicity (ADCC, FIG. 4B)) by
2H7scFv-Ig.
[0035] FIG. 5 shows the effect of simultaneous ligation of CD20 and
CD40 on growth of normal B cells.
[0036] FIGS. 6A-6B show the effect of simultaneous ligation of CD20
and CD40 on CD95 expression (6A) and induction of apoptosis in a B
lymphoblastoid cell line (6B).
[0037] FIG. 7 shows DNA and deduced amino acid sequences of
2H7scFv-CD154 L2 (FIG. 7A, SEQ ID NOS:21 and 33) and 2H7scFv-CD154
S4 (FIG. 7B, SEQ ID NOS:22 and 34) binding domain-immunoglobulin
fusion proteins capable of specifically binding CD20 and CD40.
[0038] FIG. 8 shows binding of 2H7scFv-CD154 binding
domain-immunoglobulin fusion proteins to CD20+CHO cells by flow
immunocytofluorimetry.
[0039] FIG. 9 shows binding of Annexin V to B cell lines Ramos,
BJAB, and T51 after binding of 2H7scFv-CD154 binding
domain-immunoglobulin fusion protein to cells.
[0040] FIG. 10 shows effects on proliferation of B cell line T51
following binding of 2H7scFv-CD 154 binding domain-immunoglobulin
fusion protein.
[0041] FIG. 11 depicts schematic representations of the structures
of 2H7ScFv-Ig fusion proteins (SEQ ID NOS:17, 16, AND 18) referred
to as CytoxB or CytoxB derivatives: CytoxB-MHWTG1C (2H7 ScFv,
mutant hinge, wild-type human IgG1 Fc domain), CytoxB-MHMG1C (2H7
ScFv, mutant hinge, mutated human IgG1 Fc domain) and
CytoxB-IgAHWTHG1C (2H7 ScFv, human IgA-derived hinge, wild-type
human IgG1 Fc domain) respectively. Arrows indicate position
numbers of amino acid residues believed to contribute to FcR
binding and ADCC activity (heavy arrows), and to complement
fixation (light arrows). Note absence of interchain disulfide
bonds.
[0042] FIG. 12 shows SDS-PAGE analysis of isolated CytoxB and
2H7scFv-CD 154 binding domain-immunoglobulin fusion proteins.
[0043] FIG. 13 shows antibody dependent cell-mediated cytotoxicity
(ADCC) activity of CytoxB derivatives.
[0044] FIG. 14 shows complement dependent cytotoxicity (CDC) of
CytoxB derivatives.
[0045] FIG. 15 shows serum half-life determinations of
CytoxB-MHWTG1C in macaque blood samples.
[0046] FIG. 16 shows effects of CytoxB-MHWTG1C on levels of
circulating, CD40+B cells in macaque blood samples.
[0047] FIG. 17 shows production levels of HD37 (CD19-specific)
ScFv-Ig by transfected mammalian cell lines and generation of a
standard curve by binding of purified HD37 ScFv-Ig to cells
expressing CD19.
[0048] FIG. 18 shows production levels of L6 (carcinoma antigen)
ScFv-Ig by transfected, stable CHO lines and generation of a
standard curve by binding of purified L6 ScFv-Ig to cells
expressing L6 antigen.
[0049] FIGS. 19A-19C show ADCC activity of binding
domain-immunoglobulin fusion proteins 2H7 ScFv-Ig (19A), HD37
ScFv-Ig (19C) and G28-1 (CD37-specific) ScFv-Ig (19B).
[0050] FIG. 20 shows ADCC activity of L6 ScFv-Ig fusion
proteins.
[0051] FIG. 21 shows SDS-PAGE analysis of L6 ScFv-Ig and 2H7
ScFv-Ig fusion proteins.
[0052] FIG. 22 shows SDS-PAGE analysis of G28-1 ScFv-Ig and HD37
ScFv-Ig fusion proteins.
DETAILED DESCRIPTION OF THE INVENTION
[0053] The present invention is directed to binding
domain-immunoglobulin fusion proteins and to related compositions
and methods, which will be useful in immunotherapeutic and
immunodiagnostic applications, and which offer certain advantages
over antigen-specific polypeptides of the prior art. The fusion
proteins of the present invention are preferably single polypeptide
chains that comprise, in pertinent part, the following fused
domains: a binding domain polypeptide, an immunoglobulin hinge
region polypeptide, an immunoglobulin heavy chain CH2 constant
region polypeptide, and an immunoglobulin heavy chain CH3 constant
region polypeptide. In particularly preferred embodiments, the
polypeptide domains of which the binding domain-immunoglobulin
fusion protein is comprised are, or are derived from, polypeptides
that are the products of human gene sequences, but the invention
need not be so limited and may in fact relate to binding
domain-immunoglobulin fusion proteins as provided herein that are
derived from any natural or artificial source, including
genetically engineered and/or mutated polypeptides.
[0054] The present invention relates in part to the surprising
observation that the binding domain-immunoglobulin fusion proteins
described herein are capable of immunological activity. More
specifically, these proteins retain the ability to participate in
well known immunological effector activities including antibody
dependent cell mediated cytotoxicity (ADCC, e.g., subsequent to
antigen binding on a cell surface, engagement and induction of
cytotoxic effector cells bearing appropriate Fc receptors, such as
natural killer (NK) cells bearing FcR.gamma.III, under appropriate
conditions) and/or complement fixation in complement dependent
cytotoxicity (CDC, e.g., subsequent to antigen binding on a cell
surface, recruitment and activation of cytolytic proteins that are
components of the blood complement cascade ), despite having
structures that would not be expected to be capable of promoting
such effector activities. As described in greater detail below,
ADCC and CDC are unexpected functions for monomeric proteins
comprising immunoglobulin heavy chain regions, which are favored by
the structures selected for the subject fusion proteins, and
particularly by the selection of hinge region polypeptides that are
compromised in their ability to form interchain, homodimeric
disulfide bonds.
[0055] Another advantage afforded by the present invention is a
binding domain-immunoglobulin fusion polypeptide that can be
produced in substantial quantities that are typically greater than
those routinely attained with single-chain antibody constructs of
the prior art. In preferred embodiments, the binding
domain-immunoglobulin fusion polypeptides of the present invention
are recombinantly expressed in mammalian expression systems, which
offer the advantage of providing polypeptides that are stable in
vivo (e.g., under physiological conditions). According to
non-limiting theory, such stability may derive in part from
posttranslational modifications, and specifically glycosylation, of
the fusion proteins. Production of the present binding
domain-immunoglobulin fusion proteins via recombinant mammalian
expression has been attained in static cell cultures at a level of
greater than 50 mg protein per liter culture supernatant and has
been routinely observed in such cultures at 10-50 mg/l, such that
preferably at least 10-50 mg/l may be produced under static culture
conditions; also contemplated are enhanced production of the fusion
proteins using art-accepted scale-up methodologies such as "fed
batch" (i.e., non-static) production, where yields of at least
5-500 mg/l, and in some instances at least 0.5-1 gm/l, depending on
the particular protein product, are obtained.
[0056] A binding domain polypeptide according to the present
invention may be any polypeptide that possesses the ability to
specifically recognize and bind to a cognate biological molecule or
complex of more than one molecule or assembly or aggregate, whether
stable or transient, of such a molecule, which includes a protein,
polypeptide, peptide, amino acid, or derivative thereof; a lipid,
fatty acid or the like, or derivative thereof; a carbohydrate,
saccharide or the like or derivative thereof, a nucleic acid,
nucleotide, nucleoside, purine, pyrimidine or related molecule, or
derivative thereof, or the like; or any combination thereof such
as, for example, a glycoprotein, a glycopeptide, a glycolipid, a
lipoprotein, a proteolipid; or any other biological molecule that
may be present in a biological sample. Biological samples may be
provided by obtaining a blood sample, biopsy specimen, tissue
explant, organ culture, biological fluid or any other tissue or
cell preparation from a subject or a biological source. The subject
or biological source may be a human or non-human animal, a primary
cell culture or culture adapted cell line including but not limited
to genetically engineered cell lines that may contain chromosomally
integrated or episomal recombinant nucleic acid sequences,
immortalized or immortalizable cell lines, somatic cell hybrid cell
lines, differentiated or differentiatable cell lines, transformed
cell lines and the like. In certain preferred embodiments of the
invention, the subject or biological source may be suspected of
having or being at risk for having a malignant condition or a
B-cell disorder as provided herein, which in certain further
preferred embodiments may be an autoimmune disease, and in certain
other preferred embodiments of the invention the subject or
biological source may be known to be free of a risk or presence of
such disease.
[0057] A binding domain polypeptide may therefore be any naturally
occurring or recombinantly produced binding partner for a cognate
biological molecule as provided herein that is a target structure
of interest, herein referred to as an "antigen" but intended
according to the present disclosure to encompass any target
biological molecule to which it is desirable to have the subject
invention fusion protein specifically bind. Binding
domain-immunoglobulin fusion proteins are defined to be
"immunospecific" or capable of specifically binding if they bind a
desired target molecule such as an antigen as provided herein, with
a K.sub.a of greater than or equal to about 10.sup.4 M.sup.-1,
preferably of greater than or equal to about 10.sup.5 M.sup.-1,
more preferably of greater than or equal to about 10.sup.6 M.sup.-1
and still more preferably of greater than or equal to about
10.sup.7 M.sup.-1. Affinities of binding domain-immunoglobulin
fusion proteins according to the present invention can be readily
determined using conventional techniques, for example those
described by Scatchard et al., Ann. N.Y. Acad. Sci. 51:660 (1949).
Such determination of fusion protein binding to target antigens of
interest can also be performed using any of a number of known
methods for identifying and obtaining proteins that specifically
interact with other proteins or polypeptides, for example, a yeast
two-hybrid screening system such as that described in U.S. Pat. No.
5,283,173 and U.S. Pat. No. 5,468,614, or the equivalent.
[0058] Preferred embodiments of the subject invention binding
domain-immunoglobulin fusion protein comprise binding domains that
include at least one immunoglobulin variable region polypeptide,
such as all or a portion or fragment of a heavy chain or a light
chain V-region, provided it is capable of specifically binding an
antigen or other desired target structure of interest as described
herein. In other preferred embodiments the binding domain comprises
a single chain immunoglobulin-derived Fv product, which may include
all or a portion of at least one immunoglobulin light chain
V-region and all or a portion of at least one immunoglobulin heavy
chain V-region, and which further comprises a linker fused to the
V-regions; preparation and testing such constructs are described in
greater detail herein and are well known in the art. Other binding
domain polypeptides may comprise any protein or portion thereof
that retains the ability to specifically bind an antigen as
provided herein, including non-immunoglobulins. Accordingly the
invention contemplates fusion proteins comprising binding domain
polypeptides that are derived from polypeptide ligands such as
hormones, cytokines, chemokines, and the like; cell surface or
soluble receptors for such polypeptide ligands; lectins;
intercellular adhesion receptors such as specific leukocyte
integrins, selecting, immunoglobulin gene superfamily members,
intercellular adhesion molecules (ICAM-1, -2, -3) and the like;
histocompatibility antigens; etc.
[0059] Examples of cell surface receptors that may provide a
binding domain polypeptide, and that may also be selected as the
target molecule or antigen to which a binding domain-Ig fusion
protein of the present invention desirably binds, include the
following, or the like: HER1 (e.g., GenBank Accession Nos. U48722,
SEG_HEGFREXS, KO3193), HER2 (Yoshino et al., 1994 J. Immunol.
152:2393; Disis et al., 1994 Canc. Res. 54:16; see also, e.g.,
GenBank Acc. Nos. X03363, M17730, SEG_HUMHER20), HER3 (e.g.,
GenBank Acc. Nos. U29339, M34309), HER4 (Plowman et al., 1993
Nature 366:473; see also e.g., GenBank Acc. Nos. L07868, T64105),
epidermal growth factor receptor (EGFR) (e.g., GenBank Acc. Nos.
U48722, SEG_HEGFREXS, KO3193), vascular endothelial cell growth
factor(e.g., GenBank No. M32977), vascular endothelial cell growth
factor receptor (e.g., GenBank Acc. Nos. AF022375, 1680143, U48801,
X62568), insulin-like growth factor-I (e.g., GenBank Acc. Nos.
X00173, X56774, X56773, X06043, see also European Patent No. GB
2241703), insulin-like growth factor-II (e.g., GenBank Acc. Nos.
X03562, X00910, SEG_HUMGFIA, SEG_HUMGFI2, M17863, M17862),
transferrin receptor (Trowbridge and Omary, 1981 Proc. Nat. Acad.
USA 78:3039; see also e.g., GenBank Acc. Nos. X01060, M11507),
estrogen receptor (e.g., GenBank Acc. Nos. M38651, X03635, X99101,
U47678, M12674), progesterone receptor (e.g., GenBank Acc. Nos.
X51730, X69068, M15716), follicle stimulating hormone receptor
(FSH-R) (e.g., GenBank Acc. Nos. Z34260, M65085), retinoic acid
receptor (e.g., GenBank Acc. Nos. L12060, M60909, X77664, X57280,
X07282, X06538), MUC-1 (Barnes et al., 1989 Proc. Nat. Acad. Sci.
USA 86:7159; see also e.g., GenBank Acc. Nos. SEG_MUSMUCIO, M65132,
M64928) NY-ESO-1 (e.g., GenBank Acc. Nos. AJ003149, U87459), NA
17-A (e.g., European Patent No. WO 96/40039), Melan-A/MART-1
(Kawakami et al., 1994 Proc. Nat. Acad. Sci. USA 91:3515; see also
e.g., GenBank Acc. Nos. U06654, U06452), tyrosinase (Topalian et
al., 1994 Proc. Nat. Acad. Sci. USA 91:9461; see also e.g., GenBank
Acc. Nos. M26729, SEG_HUMTYRO, see also Weber et al., J. Clin.
Invest (1998) 102:1258), Gp-100 (Kawakami et al., 1994 Proc. Nat.
Acad. Sci. USA 91:3515; see also e.g., GenBank Acc. No. S73003, see
also European Patent No. EP 668350; Adema et al., 1994 J. Biol.
Chem. 269:20126), MAGE (van den Bruggen et al., 1991 Science
254:1643; see also e.g, GenBank Acc. Nos. U93163, AF064589, U66083,
D32077, D32076, D32075, U10694, U10693, U10691, U10690, U10689,
U10688, U10687, U10686, U10685, L18877, U10340, U10339, L18920,
U03735, M77481), BAGE (e.g., GenBank Acc. No. U19180, see also U.S.
Pat. Nos. 5,683,886 and 5,571,711), GAGE (e.g., GenBank Acc. Nos.
AF055475, AF055474, AF055473, U19147, U19146, U19145, U19144,
U19143, U19142), any of the CTA class of receptors including in
particular HOM-MEL-40 antigen encoded by the SSX2 gene (e.g.,
GenBank Acc. Nos. X86175, U90842, U90841, X86174), carcinoembyonic
antigen (CEA, Gold and Freedman, 1985 J. Exp. Med. 121:439; see
also e.g., GenBank Acc. Nos. SEG_HUMCEA, M59710, M59255, M29540),
and PyLT (e.g., GenBank Acc. Nos. J02289, J02038).
[0060] Additional cell surface receptors that may be sources of
binding domain polypeptides or that may be cognate antigens include
the following, or the like: CD2 (e.g., GenBank Acc. Nos. Y00023,
SEG_HUMCD2, M16336, M16445, SEG_MUSCD2, M14362), 4-1BB (CDw137,
Kwon et al., 1989 Proc. Nat. Acad. Sci. USA 86:1963, 4-1BB ligand
(Goodwin et al., 1993 Eur. J. Immunol. 23:2361; Melero et al., 1998
Eur. J. Immunol. 3:116), CD5 (e.g., GenBank Acc. Nos. X78985,
X89405), CD10 (e.g., GenBank Acc. Nos. M8159.1, X76732) CD27 (e.g.,
GenBank Acc. Nos. M63928, L24495, L08096), CD28 (June et al., 1990
Immunol. Today 11:211; see also, e.g., GenBank Acc. Nos. J02988,
SEG_HUMCD28, M34563), CTLA-4 (e.g., GenBank Acc. Nos. L15006,
X05719, SEG_HUMIGCTL), CD40 (e.g., GenBank Acc. Nos. M83312,
SEG_MUSC040A0, Y10507, X67878, X96710, U15637, L07414),
interferon-.gamma. (IFN-.gamma.; see, e.g., Farrar et al. 1993 Ann.
Rev. Immunol. 11:571 and references cited therein, Gray et al. 1982
Nature 295:503, Rinderknecht et al. 1984 J. Biol. Chem. 259:6790,
DeGrado et al. 1982 Nature 300:379), interleukin-4 (IL-4; see,
e.g., 53.sup.rd Forum in Immunology, 1993 Research in Immunol.
144:553-643; Banchereau et al., 1994 in The Cytokine Handbook,
2.sup.nd ed., A. Thomson, ed., Academic Press, NY, p. 99; Keegan et
al., 1994 J. Leukocyt. Biol. 55:272, and references cited therein),
interleukin-17 (IL-17) (e.g., GenBank Acc. Nos. U32659, U43088) and
interleukin-17 receptor (IL-17R) (e.g., GenBank Acc. Nos. U31993,
U58917). Notwithstanding the foregoing, the present invention
expressly does not encompass any immunoglobulin fusion protein that
is disclosed in U.S. Pat. No. 5,807,734, U.S. Pat. No. 5,795,572 or
U.S. Pat. No. 5,807,734.
[0061] Additional cell surface receptors that may be sources of
binding domain polypeptides or that may be cognate antigens include
the following, or the like: CD59 (e.g., GenBank Acc. Nos.
SEG_HUMCD590, M95708, M34671), CD48 (e.g., GenBank Acc. Nos.
M59904), CD58/LFA-3 (e.g., GenBank Acc. No. A25933, Y00636, E12817;
see also JP 1997075090-A), CD72 (e.g., GenBank Acc. Nos. AA311036,
S40777, L35772), CD70 (e.g., GenBank Acc. Nos. Y13636, S69339),
CD80/B7.1 (Freeman et al., 1989 J. Immunol. 43:2714; Freeman et
al., 1991 J. Exp. Med. 174:625; see also e.g., GenBank Acc. Nos.
U33208, I683379), CD86/B7.2 (Freeman et al., 1993 J. Exp. Med.
178:2185, Boriello et al., 1995 J. Immunol. 155:5490; see also,
e.g., GenBank Acc. Nos. AF099105, SEG_MMB72G, U39466, U04343,
SEG_HSB725, L25606, L25259), CD40 ligand (e.g., GenBank Acc. Nos.
SEG_HUMCD40L, X67878, X65453, L07414), IL-17 (e.g., GenBank Acc.
Nos. U32659, U43088), CD43 (e.g., GenBank Acc. Nos. X52075, J04536)
and VLA-4 (.alpha..sub.4.beta..sub.7) (e.g., GenBank Acc. Nos.
L12002, X16983, L20788, U97031, L24913, M68892, M95632). The
following cell surface receptors are typically associated with B
cells: CD19 (e.g., GenBank Acc. Nos. SEG_HUMCD19W0, M84371,
SEG_MUSCD19W, M62542), CD20 (e.g., GenBank Acc. Nos. SEG_HUMCD20,
M62541), CD22 (e.g., GenBank Acc. Nos. I680629, Y10210, X59350,
U62631, X52782, L16928), CD30 ligand (e.g., GenBank Acc. Nos.
L09753, M83554), CD37 (e.g., GenBank Acc. Nos. SEG_MMCD37X, X14046,
X53517), CD106 (VCAM-1) (e.g., GenBank Acc. Nos. X53051, X67783,
SEG_MMVCAM1C, see also U.S. Pat. No. 5,596,090), CD54 (ICAM-1)
(e.g., GenBank Acc. Nos. X84737, S82847, X06990, J03132,
SEG_MUSICAM0), interleukin-12 (see, e.g., Reiter et al, 1993 Crit.
Rev. Immunol. 13:1, and references cited therein). Accessory cell
agents may also include any of the following cell surface receptors
typically associated with dendritic cells: CD83 (e.g., GenBank Acc.
Nos. AF001036, AL021918), DEC-205 (e.g., GenBank Acc. Nos.
AF011333, U19271).
[0062] An immunoglobulin hinge region polypeptide, as discussed
above, includes any hinge peptide or polypeptide that occurs
naturally, as an artificial peptide or as the result of genetic
engineering and that is situated in an immunoglobulin heavy chain
polypeptide between the amino acid residues responsible for forming
intrachain immunoglobulin-domain disulfide bonds in CH1 and CH2
regions; hinge region polypeptides for use in the present invention
may also include a mutated hinge region polypeptide. Accordingly,
an immunoglobulin hinge region polypeptide may be derived from, or
may be a portion or fragment of (i.e., one or more amino acids in
peptide linkage, typically 5-65 amino acids, preferably 10-50, more
preferably 15-35, still more preferably 18-32, still more
preferably 20-30, still more preferably 21, 22, 23, 24, 25, 26, 27,
28 or 29 amino acids) an immunoglobulin polypeptide chain region
classically regarded as having hinge function, as described above,
but a hinge region polypeptide for use in the instant invention
need not be so restricted and may include amino acids situated
(according to structural criteria for assigning a particular
residue to a particular domain that may vary, as known in the art)
in an adjoining immunoglobulin domain such as a CH1 domain or a CH2
domain, or in the case of certain artificially engineered
immunoglobulin constructs, an immunoglobulin variable region
domain.
[0063] Wild-type immunoglobulin hinge region polypeptides include
any naturally occurring hinge region that is located between the
constant region domains, CH1 and CH2, of an immunoglobulin. The
wild-type immunoglobulin hinge region polypeptide is preferably a
human immunoglobulin hinge region polypeptide, preferably
comprising a hinge region from a human IgG immunoglobulin, and more
preferably, a hinge region polypeptide from a human IgG1 isotype.
As is known to the art, despite the tremendous overall diversity in
immunoglobulin amino acid sequences, immunoglobulin primary
structure exhibits a high degree of sequence conservation in
particular portions of immunoglobulin polypeptide chains, notably
with regard to the occurrence of cysteine residues which, by virtue
of their sulfyhydryl groups, offer the potential for disulfide bond
formation with other available sulfydryl groups. Accordingly, in
the context of the present invention wild-type immunoglobulin hinge
region polypeptides may be regarded as those that feature one or
more highly conserved (e.g., prevalent in a population in a
statistically significant manner) cysteine residues, and in certain
preferred embodiments a mutated hinge region polypeptide may be
selected that contains zero or one cysteine residue and that is
derived from such a wild-type hinge region.
[0064] A mutated immunoglobulin hinge region polypeptide may
comprise a hinge region that has its origin in an immunoglobulin of
a species, of an immunoglobulin isotype or class, or of an
immunoglobulin subclass that is different from that of the CH2 and
CH3 domains. For instance, in certain embodiments of the invention,
the binding domain-immunoglobulin fusion protein may comprise a
binding domain polypeptide that is fused to an immunoglobulin hinge
region polypeptide comprising a wild-type human IgA hinge region
polypeptide, or a mutated human IgA hinge region polypeptide that
contains zero or only one cysteine residues, as described herein.
Such a hinge region polypeptide may be fused to an immunoglobulin
heavy chain CH2 region polypeptide from a different Ig isotype or
class, for example an IgG subclass, which in certain preferred
embodiments will be the IgG1 subclass.
[0065] For example, and as described in greater detail below, in
certain embodiments of the present invention an immunoglobulin
hinge region polypeptide is selected which is derived from a
wild-type human IgA hinge region that naturally comprises three
cysteines, where the selected hinge region polypeptide is truncated
relative to the complete hinge region such that only one of the
cysteine residues remains (e.g., SEQ ID NO:36). Similarly, in
certain other embodiments of the invention, the binding
domain-immunoglobulin fusion protein comprises a binding domain
polypeptide that is fused to an immunoglobulin hinge region
polypeptide comprising a mutated hinge region polypeptide in which
the number of cysteine residues is reduced by amino acid
substitution or deletion. A mutated hinge region polypeptide may
thus be derived from a wild-type immunoglobulin hinge region that
contains one or more cysteine residues. In certain embodiments, a
mutated hinge region polypeptide may contain zero or only one
cysteine residue, wherein the mutated hinge region polypeptide is
derived from a wild type immunoglobulin hinge region that contains,
respectively, one or more or two or more cysteine residues. In the
mutated hinge region polypeptide, the cysteine residues of the
wild-type immunoglobulin hinge region are preferably substituted
with amino acids that are incapable of forming a disulfide bond. In
one embodiment of the invention, the mutated hinge region
polypeptide is derived from a human IgG wild-type hinge region
polypeptide, which may include any of the four human IgG isotype
subclasses, IgG1, IgG2, IgG3 or IgG4. In certain preferred
embodiments, the mutated hinge region polypeptide is derived from a
human IgG1 wild-type hinge region polypeptide. By way of example, a
mutated hinge region polypeptide derived from a human IgG1
wild-type hinge region polypeptide may comprise mutations at two of
the three cysteine residues in the wild-type immunoglobulin hinge
region, or mutations at all three cysteine residues.
[0066] The cysteine residues that are present in a wild-type
immunoglobulin hinge region and that are removed by mutagenesis
according to particularly preferred embodiments of the present
invention include cysteine residues that form, or that are capable
of forming, interchain disulfide bonds. Without wishing to be bound
by theory, the present invention contemplates that mutation of such
hinge region cysteine residues, which are believed to be involved
in formation of interchain disulfide bridges, reduces the ability
of the subject invention binding domain-immunoglobulin fusion
protein to dimerize (or form higher oligomers) via interchain
disulfide bond formation, while surprisingly not ablating the
ability of the fusion protein to promote antibody dependent
cell-mediated cytotoxicity (ADCC) or to fix complement. In
particular, the Fc receptors (FcR) which mediate ADCC (e.g.,
FcRIII, CD16) exhibit low affinity for immunoglobulin Fc domains,
suggesting that functional binding of Fc to FcR requires avidity
stabilization of the Fc-FcR complex by virtue of the dimeric
structure of heavy chains in a conventional antibody, and/or FcR
aggregation and cross-linking by a conventional Ab Fc structure.
(Sonderman et al., 2000 Nature 406:267; Radaev et al., 2001 J.
Biol. Chem. 276:16469; Radaev et al., 2001 J. Biol. Chem.
276:16478; Koolwijk et al., 1989 J. Immunol. 143:1656; Kato et al.,
2000 Immunol. Today 21:310.) Hence, the binding
domain-immunoglobulin fusion proteins of the present invention
provide the advantages associated with single-chain immunoglobulin
fusion proteins while also unexpectedly retaining immunological
activity. Similarly, the ability to fix complement is typically
associated with immunoglobulins that are dimeric with respect to
heavy chain constant regions such as those that comprise Fc, while
the binding domain-immunoglobulin fusion proteins of the present
invention exhibit the unexpected ability to fix complement.
[0067] As noted above, binding domain-immunoglobulin fusion
proteins are believed, according to non-limiting theory, to be
compromised in their ability to dimerize, and further according to
theory, this property is a consequence of a reduction in the number
of cysteine residues that are present in the immunoglobulin hinge
region polypeptide selected for inclusion in the construction of
the fusion protein. Determination of the relative ability of a
polypeptide to dimerize is well within the knowledge of the
relevant art, where any of a number of established methodologies
may be applied to detect protein dimerization (see, e.g., Scopes,
Protein Purification: Principles and Practice, 1987
Springer-Verlag, New York). For example, biochemical separation
techniques for resolving proteins on the basis of molecular size
(e.g., gel electrophoresis, gel filtration chromatography,
analytical ultracentrifugation, etc.), and/or comparison of protein
physicochemical properties before and after introduction of
sulfhydryl-active (e.g., iodoacetamide, N-ethylmaleimide) or
disulfide-reducing (e.g., 2-mercaptoethanol, dithiothreitol)
agents, or other equivalent methodologies, may all be employed for
determining a degree of polypeptide dimerization or
oligomerization, and for determining possible contribution of
disulfide bonds to such potential quarternary structure. In certain
embodiments, the invention relates to a binding
domain-immunoglobulin fusion protein that exhibits a reduced (i.e.,
in a statistically significant manner relative to an appropriate
IgG-derived control) ability to dimerize, relative to a wild-type
human immunoglobulin G hinge region polypeptide as provided herein.
Accordingly, those familiar with the art will be able readily to
determine whether a particular fusion protein displays such reduced
ability to dimerize.
[0068] Compositions and methods for preparation of immunoglobulin
fusion proteins are well known in the art, as described for
example, in U.S. Pat. No. 5,892,019, which discloses recombinant
antibodies that are the products of a single encoding
polynucleotide but which are not binding domain-immunoglobulin
fusion proteins according to the present invention.
[0069] For an immunoglobulin fusion protein of the invention which
is intended for use in humans, the constant regions will typically
be of human sequence origin, to minimize a potential anti-human
immune response and to provide appropriate effector functions.
Manipulation of sequences encoding antibody constant regions is
described in the PCT publication of Morrison and Oi, WO 89/07142.
In particularly preferred embodiments, the CH1 domain is deleted
and the carboxyl end of the binding domain, or where the binding
domain comprises two immunoglobulin variable region polypeptides,
the second (i.e., more proximal to the C-terminus) variable region
is joined to the amino terminus of CH2 through the hinge region. A
schematic diagram depicting the structures of two exemplary binding
domain-immunoglobulin fusion proteins is shown in FIG. 11, where it
should be noted that in particularly preferred embodiments no
interchain disulfide bonds are present, and in other embodiments a
restricted number of interchain disulfide bonds may be present
relative to the number of such bonds that would be present if
wild-type hinge region polypeptides were instead present, and that
in other embodiments the fusion protein comprises a mutated hinge
region polypeptide that exhibits a reduced ability to dimerize,
relative to a wild-type human IgG hinge region polypeptide. Thus,
the isolated polynucleotide molecule codes for a single chain
immunoglobulin fusion protein having a binding domain that provides
specific binding affinity for a selected antigen.
[0070] As noted above, in certain embodiments the binding
protein-immunoglobulin fusion protein comprises at least one
immunoglobulin variable region polypeptide, which may be a light
chain or a heavy chain variable region polypeptide, and in certain
embodiments the fusion protein comprises at least one such light
chain V-region and one such heavy chain V-region and at least one
linker peptide that is fused to each of the V-regions. Construction
of such binding domains, for example single chain Fv domains, is
well known in the art and is described in greater detail in the
Examples below, and has been described, for example, in U.S. Pat.
No. 5,892,019 and references cited therein; selection and assembly
of single-chain variable regions and of linker polypeptides that
may be fused to each of a heavy chain-derived and a light
chain-derived V region (e.g., to generate a binding domain that
comprises a single-chain Fv polypeptide) is also known to the art
and described herein and, for example, in U.S. Pat. No. 5,869,620,
U.S. Pat. No. 4,704,692 and U.S. Pat. No. 4,946,778. In certain
embodiments all or a portion of an immunoglobulin sequence that is
derived from a non-human source may be "humanized" according to
recognized procedures for generating humanized antibodies, i.e.,
immunoglobulin sequences into which human Ig sequences are
introduced to reduce the degree to which a human immune system
would perceive such proteins as foreign (see, e.g., U.S. Pat. Nos.
5,693,762; 5,585,089; 4,816,567; 5,225,539; 5,530,101; and
references cited therein)
[0071] Once a binding domain-immunoglobulin fusion protein as
provided herein has been designed, DNAs encoding the polypeptide
may be synthesized via oligonucleotide synthesis as described, for
example, in Sinha et al., Nucleic Acids Res., 12, 4539-4557 (1984);
assembled via PCR as described, for example in Innis, Ed., PCR
Protocols, Academic Press (1990) and also in Better et al. J. Biol.
Chem. 267, 16712-16118 (1992); cloned and expressed via standard
procedures as described, for example, in Ausubel et al., Eds.,
Current Protocols in Molecular Biology, John Wiley & Sons, New
York (1989) and also in Robinson et al., Hum. Antibod. Hybridomas,
2, 84-93 (1991); and tested for specific antigen binding activity,
as described, for example, in Harlow et al., Eds., Antibodies: A
Laboratory Manual, Chapter 14, Cold Spring Harbor Laboratory, Cold
Spring Harbor (1988) and Munson et al., Anal. Biochem., 107,
220-239 (1980).
[0072] 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, which is incorporated herein by
reference. In the present invention, single-chain Fv-like molecules
are synthesized by encoding a first variable region of the heavy or
light chain, followed by one or more linkers to the variable region
of the corresponding light or heavy chain, respectively. The
selection of appropriate linker(s) between the two variable regions
is described in U.S. Pat. No. 4,946,778. An exemplary linker
described herein is (Gly-Gly-Gly-Gly-Ser).sub.3. The linker is used
to convert the naturally aggregated but chemically separate heavy
and light chains into the amino terminal antigen binding portion of
a single polypeptide chain, wherein this antigen binding portion
will fold into a structure similar to the original structure made
of two polypeptide chains and thus retain the ability to bind to
the antigen of interest. The nucleotide sequences encoding the
variable regions of the heavy and light chains, joined by a
sequence encoding a linker, are joined to a nucleotide sequence
encoding antibody constant regions. The constant regions are those
which permit the resulting polypeptide to form interchain disulfide
bonds to form a dimer, and which contain desired effector
functions, such as the ability to mediate antibody-dependent
cellular cytotoxicity (ADCC). For an immunoglobulin-like molecule
of the invention which is intended for use in humans, the constant
regions will typically be substantially human to minimize a
potential anti-human immune response and to provide appropriate
effector functions. Manipulation of sequences encoding antibody
constant regions is described in the PCT publication of Morrison
and Oi, WO 89/07142, which is incorporated herein by reference. In
preferred embodiments, the CH1 domain is deleted and the carboxyl
end of the second variable region is joined to the amino terminus
of CH2 through the hinge region. The Cys residue of the hinge which
makes a disulfide bond with a corresponding Cys of the light chain,
to hold the heavy and light chains of the native antibody molecule,
can be deleted or, preferably, is substituted with, e.g., a Pro
residue or the like.
[0073] As described above, the present invention provides
recombinant expression constructs capable of directing the
expression of binding domain-immunoglobulin fusion proteins as
provided herein. The amino acids, which occur in the various amino
acid sequences referred to herein, are identified according to
their well known three letter or one letter abbreviations. The
nucleotides, which occur in the various DNA sequences or fragments
thereof referred herein, are designated with the standard single
letter designations used routinely in the art. A given amino acid
sequence may also encompass similar amino acid sequences having
only minor changes, for example by way of illustration and not
limitation, covalent chemical modifications, insertions, deletions
and substitutions, which may further include conservative
substitutions. Amino acid sequences that are similar to one another
may share substantial regions of sequence homology. In like
fashion, nucleotide sequences may encompass substantially similar
nucleotide sequences having only minor changes, for example by way
of illustration and not limitation, covalent chemical
modifications, insertions, deletions and substitutions, which may
further include silent mutations owing to degeneracy of the genetic
code. Nucleotide sequences that are similar to one another may
share substantial regions of sequence homology.
[0074] The presence of a malignant condition in a subject refers to
the presence of dysplastic, cancerous and/or transformed cells in
the subject, including, for example neoplastic, tumor, non-contact
inhibited or oncogenically transformed cells, or the like. In
preferred embodiments contemplated by the present invention, for
example, such cancer cells are malignant hematopoietic cells, such
as transformed cells of lymphoid lineage and in particular, B-cell
lymphomas and the like; cancer cells may in certain preferred
embodiments also be epithelial cells such as carcinoma cells. The
invention also contemplates B-cell disorders, which may include
certain malignant conditions that affect B-cells (e.g., B-cell
lymphoma) but which is not intended to be so limited, and which is
also intended to encompass autoimmune diseases and in particular,
diseases, disorders and conditions that are characterized by
autoantibody production.
[0075] Autoantibodies are antibodies that react with self antigens.
Autoantibodies are detected in several autoimmune diseases (i.e., a
disease, disorder or condition wherein a host immune system
generates an inappropriate anti-"self" immune reaction) where they
are involved in disease activity. The current treatments for these
autoimmune diseases are immunosuppressive drugs that require
continuing administration, lack specificity, and cause significant
side effects New approaches that can eliminate autoantibody
production with minimal toxicity will address an unmet medical need
for a spectrum of diseases that affect many people. The subject
invention binding domain-immunoglobulin fusion protein is designed
for improved penetration into lymphoid tissues. Depletion of B
lymphocytes interrupts the autoantibody production cycle, and
allows the immune system to reset as new B lymphocytes are produced
from precursors in the bone marrow.
[0076] A number of diseases have been identified for which
beneficial effects are believed, according to non-limiting theory,
to result from B cell depletion therapy; a brief description of
several exemplars of these diseases follows.
[0077] Autoimmune thyroid disease includes Graves' disease and
Hashimoto's thyroiditis. In the United States alone, there are
about 20 million people who have some form of autoimmune thyroid
disease. Autoimmune thyroid disease results from the production of
autoantibodies that either stimulate the thyroid to cause
hyperthyroidism (Graves' disease) or destroy the thyroid to cause
hypothyroidism (Hashimoto's thyroiditis). Stimulation of the
thyroid is caused by autoantibodies that bind and activate the
thyroid stimulating hormone (TSH) receptor. Destruction of the
thyroid is caused by autoantibodies that react with other thyroid
antigens.
[0078] Current therapy for Graves' disease includes surgery,
radioactive iodine, or antithyroid drug therapy. Radioactive iodine
is widely used, since antithyroid medications have significant side
effects and disease recurrence is high. Surgery is reserved for
patients with large goiters or where there is a need for very rapid
normalization of thyroid function. There are no therapies that
target the production of autoantibodies responsible for stimulating
the TSH receptor. Current therapy for Hashimoto's thyroiditis is
levothyroxine sodium, and therapy is usually lifelong because of
the low likelihood of remission. Suppressive therapy has been shown
to shrink goiters in Hashimoto's thryoiditis, but no therapies that
reduce autoantibody production to target the disease mechanism are
known.
[0079] Rheumatoid arthritis (RA) is a chronic disease characterized
by inflammation of the joints, leading to swelling, pain, and loss
of function. RA effects an estimated 2.5 million people in the
United States. RA is caused by a combination of events including an
initial infection or injury, an abnormal immune response, and
genetic factors. While autoreactive T cells and B cells are present
in RA, the detection of high levels of antibodies that collect in
the joints, called rheumatoid factor, is used in the diagnosis of
RA. Current therapy for RA includes many medications for managing
pain and slowing the progression of the disease. No therapy has
been found that can cure the disease. Medications include
nonsteroidal antiinflammatory drugs (NSAIDS), and disease modifying
antirheumatic drugs (DMARDS). NSAIDS are effective in benign
disease, but fail to prevent the progression to joint destruction
and debility in severe RA. Both NSAIDS and DMARDS are associated
with signficant side effects. Only one new DMARD, Leflunomide, has
been approved in over 10 years. Leflunomide blocks production of
autoantibodies, reduces inflammation, and slows progression of RA.
However, this drug also causes severe side effects including
nausea, diarrhea, hair loss, rash, and liver injury.
[0080] Systemic Lupus Erythematosus (SLE) is an autoimmune disease
caused by recurrent injuries to blood vessels in multiple organs,
including the kidney, skin, and joints. SLE effects over 500,000
people in the United States. In patients with SLE, a faulty
interaction between T cells and B cells results in the production
of autoantibodies that attack the cell nucleus. These include
anti-double stranded DNA and anti-Sm antibodies. Autoantibodies
that bind phospholipids are also found in about half of SLE
patients, and are responsible for blood vessel damage and low blood
counts. Immune complexes accumulate the kidneys, blood vessels, and
joints of SLE patients, where they cause inflammation and tissue
damage. No treatment for SLE has been found to cure the disease.
NSAIDS and DMARDS are used for therapy depending upon the severity
of the disease. Plasmapheresis with plasma exchange to remove
autoantibodies can cause temporary improvement in SLE patients.
There is general agreement that autoantibodies are responsible for
SLE, so new therapies that deplete the B cell lineage, allowing the
immune system to reset as new B cells are generated from
precursors, offer hope for long lasting benefit in SLE
patients.
[0081] Sjogrens syndrome is an autoimmune disease characterized by
destruction of the body's moisture producing glands. Sjogrens
syndrome is one of the most prevalent autoimmune disorders,
striking up to 4 million people in the United States. About half of
people with Sjogren's also have a connective tissue disease, such
as rheumatoid arthritis, while the other half have primary
Sjogren's with no other concurrent autoimmune disease.
Autoantibodies, including anti-nuclear antibodies, rheumatoid
factor, anti-fodrin, and anti-muscarinic receptor are often present
in patients with Sjogrens syndrome. Conventional therapy includes
corticosteroids.
[0082] Immune Thrombocytopenic purpura (ITP) is caused by
autoantibodies that bind to blood platelets and cause their
destruction. Some cases of ITP are caused by drugs, and others are
associated with infection, pregnancy, or autoimmune disease such as
SLE. About half of all cases are classified as "idiopathic",
meaning the cause is unknown. The treatment of ITP is determined by
the severity of the symptoms. In some cases, no therapy is needed.
In most cases, immunosuppressive drugs, including corticosteroids
or intravenous infusions of immune globulin to deplete T cells.
Another treatment that usually results in an increased number of
platelets is removal of the spleen, the organ that destroys
antibody-coated platelets. More potent immunosuppressive drugs,
including cyclosporine, cyclophosphamide, or azathioprine are used
for patients with severe cases. Removal of autoantibodies by
passage of patients' plasma over a Protein A column is used as a
second line treatment in patients with severe disease.
[0083] Multiple Sclerosis (MS) is an autoimmune disease
characterized by inflammation of the central nervous system and
destruction of myelin, which insulates nerve cell fibers in the
brain, spinal cord, and body. Although the cause of MS is unknown,
it is widely believed that autoimmune T cells are primary
contributors to the pathogenesis of the disease. However, high
levels of antibodies are present in the cerebral spinal fluid of
patients with MS, and some theories predict that the B cell
response leading to antibody production is important for mediating
the disease. No B cell depletion therapies have been studies in
patients with MS. There is no cure for MS. Current therapy is
corticosteroids, which can reduce the duration and severity of
attacks, but do not affect the course of MS over time. New
biotechnology interferon (IFN) therapies for MS have recently been
approved.
[0084] Myasthenia Gravis (MG) is a chronic autoimmune neuromuscular
disorder that is characterized by weakness of the voluntary muscle
groups. MG effects about 40,000 people in the United States. MG is
caused by autoantibodies that bind to acetylcholine receptors
expressed at neuromuscular junctions. The autoantibodies reduce or
block acetylcholine receptors, preventing the transmission of
signals from nerves to muscles. There is no known cure for MG.
Common treatments include immunosuppression with corticosteroids,
cyclosporine, cyclophosphamide, or azathioprine. Surgical removal
of the thymus is often used to blunt the autoimmune response.
Plasmapheresis, used to reduce autoantibody levels in the blood, is
effective in MG, but is short-lived because the production of
autoantibodies continues. Plasmapheresis is usually reserved for
severe muscle weakness prior to surgery.
[0085] Psoriasis effects approximately five million people.
Autoimmune inflammation in the skin. Psoriasis associated with
arthritis in 30% (psoriatic arthritis). Many treatments, including
steroids, UV light retenoids, vitamin D derivatives, cyclosporine,
methotrexate.
[0086] Scleroderma is a chronic autoimmune disease of the
connective tissue that is also known as systemic sclerosis.
Scleroderma is characterized by an overproduction of collagen,
resulting in a thickening of the skin. Approximately 300,000 people
in the United States have scleroderma.
[0087] Inflammatory Bowel Disease including Crohn's disease and
Ulcerative colitis, are autoimmune diseases of the digestive
system.
[0088] The present invention further relates to constructs encoding
binding domain-immunoglobulin fusion proteins, and in particular to
methods for administering recombinant constructs encoding such
proteins that may be expressed, for example, as fragments, analogs
and derivatives of such polypeptides. The terms "fragment,"
"derivative" and "analog" when referring to binding
domain-immunoglobulin fusion polypeptides or fusion proteins,
refers to any binding domain-immunoglobulin fusion polypeptide or
fusion protein that retains essentially the same biological
function or activity as such polypeptide. Thus, an analog includes
a proprotein which can be activated by cleavage of the proprotein
portion to produce an active binding domain-immunoglobulin fusion
polypeptide.
[0089] A fragment, derivative or analog of an binding
domain-immunoglobulin fusion polypeptide or fusion protein,
including binding domain-immunoglobulin fusion polypeptides or
fusion proteins encoded by the cDNAs referred to herein, may be (i)
one in which one or more of the amino acid residues are substituted
with a conserved or non-conserved amino acid residue (preferably a
conserved amino acid residue) and such substituted amino acid
residue may or may not be one encoded by the genetic code, or (ii)
one in which one or more of the amino acid residues includes a
substituent group, or (iii) one in which additional amino acids are
fused to the binding domain-immunoglobulin fusion polypeptide,
including amino acids that are employed for detection or specific
functional alteration of the binding domain-immunoglobulin fusion
polypeptide or a proprotein sequence. Such fragments, derivatives
and analogs are deemed to be within the scope of those skilled in
the art from the teachings herein.
[0090] The polypeptides of the present invention include binding
domain-immunoglobulin fusion polypeptides and fusion proteins
having binding domain polypeptide amino acid sequences that are
identical or similar to sequences known in the art, or fragments or
portions thereof. For example by way of illustration and not
limitation, the human CD154 molecule extracellular domain is
contemplated for use according to the instant invention, as are
polypeptides having at least 70% similarity (preferably a 70%
identity) and more preferably 90% similarity (more preferably a 90%
identity) to the reported polypeptide and still more preferably a
95% similarity (still more preferably a 95% identity) to the
reported polypeptides and to portions of such polypeptides, wherein
such portions of a binding domain-immunoglobulin fusion polypeptide
generally contain at least 30 amino acids and more preferably at
least 50 amino acids.
[0091] As known in the art "similarity" between two polypeptides is
determined by comparing the amino acid sequence and conserved amino
acid substitutes thereto of the polypeptide to the sequence of a
second polypeptide. Fragments or portions of the nucleic acids
encoding polypeptides of the present invention may be used to
synthesize full-length nucleic acids of the present invention. As
used herein, "% identity" refers to the percentage of identical
amino acids situated at corresponding amino acid residue positions
when two or more polypeptide are aligned and their sequences
analyzed using a gapped BLAST algorithm (e.g., Altschul et al.,
1997 Nucl. Ac. Res. 25:3389) which weights sequence gaps and
sequence mismatches according to the default weightings provided by
the National Institutes of Health/NCBI database (National Center
for Biotechnology Information, National Library of Medicine,
Building 38A, Bethesda, Md. 20894).
[0092] The term "isolated" means that the material is removed from
its original environment (e.g., the natural environment if it is
naturally occurring). For example, a naturally occurring nucleic
acid or polypeptide present in a living animal is not isolated, but
the same nucleic acid or polypeptide, separated from some or all of
the co-existing materials in the natural system, is isolated. Such
nucleic acids could be part of a vector and/or such nucleic acids
or polypeptides could be part of a composition, and still be
isolated in that such vector or composition is not part of its
natural environment.
[0093] The term "gene" means the segment of DNA involved in
producing a polypeptide chain; it includes regions preceding and
following the coding region "leader and trailer" as well as
intervening sequences (introns) between individual coding segments
(exons).
[0094] As described herein, the invention provides binding
domain-immunoglobulin fusion proteins encoded by nucleic acids that
have the binding domain coding sequence fused in frame to an
additional immunoglobulin domain encoding sequence to provide for
expression of a binding domain polypeptide sequence fused to an
additional functional polypeptide sequence that permits, for
example by way of illustration and not limitation, detection,
functional alteration, isolation and/or purification of the fusion
protein. Such fusion proteins may permit functional alteration of a
binding domain by containing additional immunoglobulin-derived
polypeptide sequences that influence behavior of the fusion
product, for example (and as described above) by reducing the
availability of sufhydryl groups for participation in disulfide
bond formation, and by conferring the ability to potentiate ADCC
and/or CDC.
[0095] Modification of the polypeptide may be effected by any means
known to those of skill in this art. The preferred methods herein
rely on modification of DNA encoding the fusion protein and
expression of the modified DNA. DNA encoding one of the binding
domain-immunoglobulin fusions discussed above may be mutagenized
using standard methodologies, including those described below. For
example, cysteine residues that may otherwise facilitate multimer
formation or promote particular molecular conformations can be
deleted from a polypeptide or replaced, e.g., cysteine residues
that are responsible for aggregate formation. If necessary, the
identity of cysteine residues that contribute to aggregate
formation may be determined empirically, by deleting and/or
replacing a cysteine residue and ascertaining whether the resulting
protein aggregates in solutions containing physiologically
acceptable buffers and salts. In addition, fragments of binding
domain-immunoglobulin fusions may be constructed and used. As noted
above, the counterreceptor/ligand binding domains for many
candidate binding domain-immunoglobulin fusion have been
delineated, such that one having ordinary skill in the art may
readily select appropriate polypeptide domains for inclusion in the
encoded products of the instant expression constructs.
[0096] Conservative substitutions of amino acids are well-known and
may be made generally without altering the biological activity of
the resulting binding domain-immunoglobulin fusion protein
molecule. For example, such substitutions are generally made by
interchanging within the groups of polar residues, charged
residues, hydrophobic residues, small residues, and the like. If
necessary, such substitutions may be determined empirically merely
by testing the resulting modified protein for the ability to bind
to the appropriate cell surface receptors in in vitro biological
assays, or to bind to appropriate antigens or desired target
molecules.
[0097] The present invention further relates to nucleic acids which
hybridize to binding domain-immunoglobulin fusion protein encoding
polynucleotide sequences as provided herein, or their complements,
as will be readily apparent to those familiar with the art, if
there is at least 70%, preferably at least 90%, and more preferably
at least 95% identity between the sequences. The present invention
particularly relates to nucleic acids which hybridize under
stringent conditions to the binding domain-immunoglobulin fusion
encoding nucleic acids referred to herein. As used herein, the term
"stringent conditions" means hybridization will occur only if there
is at least 95% and preferably at least 97% identity between the
sequences. The nucleic acids which hybridize to binding
domain-immunoglobulin fusion encoding nucleic acids referred to
herein, in preferred embodiments, encode polypeptides which retain
substantially the same biological function or activity as the
binding domain-immunoglobulin fusion polypeptides encoded by the
cDNAs of the references cited herein.
[0098] As used herein, to "hybridize" under conditions of a
specified stringency is used to describe the stability of hybrids
formed between two single-stranded nucleic acid molecules.
Stringency of hybridization is typically expressed in conditions of
ionic strength and temperature at which such hybrids are annealed
and washed. Typically "high", "medium" and "low" stringency
encompass the following conditions or equivalent conditions
thereto: high stringency: 0.1.times.SSPE or SSC, 0.1% SDS,
65.degree. C.; medium stringency: 0.2.times.SSPE or SSC, 0.1% SDS,
50.degree. C.; and low stringency: 1.0.times.SSPE or SSC, 0.1% SDS,
50.degree. C. As known to those having ordinary skill in the art,
variations in stringency of hybridization conditions may be
achieved by altering the time, temperature and/or concentration of
the solutions used for prehybridization, hybridization and wash
steps, and suitable conditions may also depend in part on the
particular nucleotide sequences of the probe used, and of the
blotted, proband nucleic acid sample. Accordingly, it will be
appreciated that suitably stringent conditions can be readily
selected without undue experimentation where a desired selectivity
of the probe is identified, based on its ability to hybridize to
one or more certain proband sequences while not hybridizing to
certain other proband sequences.
[0099] The nucleic acids of the present invention, also referred to
herein as polynucleotides, may be in the form of RNA or in the form
of DNA, which DNA includes cDNA, genomic DNA, and synthetic DNA.
The DNA may be double-stranded or single-stranded, and if single
stranded may be the coding strand or non-coding (anti-sense)
strand. A coding sequence which encodes an binding
domain-immunoglobulin fusion polypeptide for use according to the
invention may be identical to the coding sequence known in the art
for any given binding domain-immunoglobulin fusion, or may be a
different coding sequence, which, as a result of the redundancy or
degeneracy of the genetic code, encodes the same binding
domain-immunoglobulin fusion polypeptide.
[0100] The nucleic acids which encode binding domain-immunoglobulin
fusion polypeptides for use according to the invention may include,
but are not limited to: only the coding sequence for the binding
domain-immunoglobulin fusion polypeptide; the coding sequence for
the binding domain-immunoglobulin fusion polypeptide and additional
coding sequence; the coding sequence for the binding
domain-immunoglobulin fusion polypeptide (and optionally additional
coding sequence) and non-coding sequence, such as introns or
non-coding sequences 5' and/or 3' of the coding sequence for the
binding domain-immunoglobulin fusion polypeptide, which for example
may further include but need not be limited to one or more
regulatory nucleic acid sequences that may be a regulated or
regulatable promoter, enhancer, other transcription regulatory
sequence, repressor binding sequence, translation regulatory
sequence or any other regulatory nucleic acid sequence. Thus, the
term "nucleic acid encoding" or "polynucleotide encoding" a binding
domain-immunoglobulin fusion protein encompasses a nucleic acid
which includes only coding sequence for a binding
domain-immunoglobulin fusion polypeptide as well as a nucleic acid
which includes additional coding and/or non-coding sequence(s).
[0101] Nucleic acids and oligonucleotides for use as described
herein can be synthesized by any method known to those of skill in
this art (see, e.g., WO 93/01286, U.S. application Ser. No.
07/723,454; U.S. Pat. No. 5,218,088; U.S. Pat. No. 5,175,269; U.S.
Pat. No. 5,109,124). Identification of oligonucleotides and nucleic
acid sequences for use in the present invention involves methods
well known in the art. For example, the desirable properties,
lengths and other characteristics of useful oligonucleotides are
well known. In certain embodiments, synthetic oligonucleotides and
nucleic acid sequences may be designed that resist degradation by
endogenous host cell nucleolytic enzymes by containing such
linkages as: phosphorothioate, methylphosphonate, sulfone, sulfate,
ketyl, phosphorodithioate, phosphoramidate, phosphate esters, and
other such linkages that have proven useful in antisense
applications (see, e.g., Agrwal et al., Tetrehedron Lett.
28:3539-3542 (1987); Miller et al., J. Am. Chem. Soc. 93:6657-6665
(1971); Stec et al., Tetrehedron Lett. 26:2191-2194 (1985); Moody
et al., Nucl. Acids Res. 12:4769-4782 (1989); Uznanski et al.,
Nucl. Acids Res. (1989); Letsinger et al., Tetrahedron 40:137-143
(1984); Eckstein, Annu. Rev. Biochem. 54:367-402 (1985); Eckstein,
Trends Biol. Sci. 14:97-100 (1989); Stein In:
Oligodeoxynucleotides. Antisense Inhibitors of Gene Expression,
Cohen, Ed, Macmillan Press, London, pp. 97-117 (1989); Jager et
al., Biochemistry 27:7237-7246 (1988)).
[0102] In one embodiment, the present invention provides truncated
components (e.g., binding domain polypeptide, hinge region
polypeptide, linker, etc.) for use in a binding
domain-immunoglobulin fusion protein, and in another embodiment the
invention provides nucleic acids encoding a binding
domain-immunoglobulin fusion protein having such truncated
components. A truncated molecule may be any molecule that comprises
less than a full length version of the molecule. Truncated
molecules provided by the present invention may include truncated
biological polymers, and in preferred embodiments of the invention
such truncated molecules may be truncated nucleic acid molecules or
truncated polypeptides. Truncated nucleic acid molecules have less
than the full length nucleotide sequence of a known or described
nucleic acid molecule, where such a known or described nucleic acid
molecule may be a naturally occurring, a synthetic or a recombinant
nucleic acid molecule, so long as one skilled in the art would
regard it as a full length molecule. Thus, for example, truncated
nucleic acid molecules that correspond to a gene sequence contain
less than the full length gene where the gene comprises coding and
non-coding sequences, promoters, enhancers and other regulatory
sequences, flanking sequences and the like, and other functional
and non-functional sequences that are recognized as part of the
gene. In another example, truncated nucleic acid molecules that
correspond to a mRNA sequence contain less than the full length
mRNA transcript, which may include various translated and
non-translated regions as well as other functional and
non-functional sequences.
[0103] In other preferred embodiments, truncated molecules are
polypeptides that comprise less than the full length amino acid
sequence of a particular protein or polypeptide component. As used
herein "deletion" has its common meaning as understood by those
familiar with the art, and may refer to molecules that lack one or
more of a portion of a sequence from either terminus or from a
non-terminal region, relative to a corresponding full length
molecule, for example, as in the case of truncated molecules
provided herein. Truncated molecules that are linear biological
polymers such as nucleic acid molecules or polypeptides may have
one or more of a deletion from either terminus of the molecule or a
deletion from a non-terminal region of the molecule, where such
deletions may be deletions of 1-1500 contiguous nucleotide or amino
acid residues, preferably 1-500 contiguous nucleotide or amino acid
residues and more preferably 1-300 contiguous nucleotide or amino
acid residues. In certain particularly preferred embodiments
truncated nucleic acid molecules may have a deletion of 270-330
contiguous nucleotides. In certain other particularly preferred
embodiments truncated polypeptide molecules may have a deletion of
80-140 contiguous amino acids.
[0104] The present invention further relates to variants of the
herein referenced nucleic acids which encode fragments, analogs
and/or derivatives of a binding domain-immunoglobulin fusion
polypeptide. The variants of the nucleic acids encoding binding
domain-immunoglobulin fusion may be naturally occurring allelic
variants of the nucleic acids or non-naturally occurring variants.
As is known in the art, an allelic variant is an alternate form of
a nucleic acid sequence which may have at least one of a
substitution, a deletion or an addition of one or more nucleotides,
any of which does not substantially alter the function of the
encoded binding domain-immunoglobulin fusion polypeptide.
[0105] Variants and derivatives of binding domain-immunoglobulin
fusion may be obtained by mutations of nucleotide sequences
encoding binding domain-immunoglobulin fusion polypeptides.
Alterations of the native amino acid sequence may be accomplished
by any of a number of conventional methods. Mutations can be
introduced at particular loci by synthesizing oligonucleotides
containing a mutant sequence, flanked by restriction sites enabling
ligation to fragments of the native sequence. Following ligation,
the resulting reconstructed sequence encodes an analog having the
desired amino acid insertion, substitution, or deletion.
[0106] Alternatively, oligonucleotide-directed site-specific
mutagenesis procedures can be employed to provide an altered gene
wherein predetermined codons can be altered by substitution,
deletion or insertion. Exemplary methods of making such alterations
are disclosed by Walder et al. (Gene 42:133, 1986); Bauer et al.
(Gene 37:73, 1985); Craik (BioTechniques, January 1985, 12-19);
Smith et al. (Genetic Engineering: Principles and Methods
BioTechniques, January 1985, 12-19); Smith et al. (Genetic
Engineering: Principles and Methods, Plenum Press, 1981); Kunkel
(Proc. Natl. Acad. Sci. USA 82:488, 1985); Kunkel et al. (Methods
in Enzymol. 154:367, 1987); and U.S. Pat. Nos. 4,518,584 and
4,737,462.
[0107] As an example, modification of DNA may be performed by
site-directed mutagenesis of DNA encoding the protein combined with
the use of DNA amplification methods using primers to introduce and
amplify alterations in the DNA template, such as PCR splicing by
overlap extension (SOE). Site-directed mutagenesis is typically
effected using a phage vector that has single- and double-stranded
forms, such as M13 phage vectors, which are well-known and
commercially available. Other suitable vectors that contain a
single-stranded phage origin of replication may be used (see, e.g.,
Veira et al., Meth. Enzymol. 15:3, 1987). In general, site-directed
mutagenesis is performed by preparing a single-stranded vector that
encodes the protein of interest (e.g., all or a component portion
of a given binding domain-immunoglobulin fusion protein). An
oligonucleotide primer that contains the desired mutation within a
region of homology to the DNA in the single-stranded vector is
annealed to the vector followed by addition of a DNA polymerase,
such as E. coli DNA polymerase I (Klenow fragment), which uses the
double stranded region as a primer to produce a heteroduplex in
which one strand encodes the altered sequence and the other the
original sequence. The heteroduplex is introduced into appropriate
bacterial cells and clones that include the desired mutation are
selected. The resulting altered DNA molecules may be expressed
recombinantly in appropriate host cells to produce the modified
protein.
[0108] Equivalent DNA constructs that encode various additions or
substitutions of amino acid residues or sequences, or deletions of
terminal or internal residues or sequences not needed for
biological activity are also encompassed by the invention. For
example, and as discussed above, sequences encoding Cys residues
that are not desirable or essential for biological activity can be
altered to cause the Cys residues to be deleted or replaced with
other amino acids, preventing formation of incorrect intramolecular
disulfide bridges upon renaturation.
[0109] Host organisms include those organisms in which recombinant
production of binding domain-immunoglobulin fusion products encoded
by the recombinant constructs of the present invention may occur,
such as bacteria (for example, E. coli), yeast (for example,
Saccharomyces cerevisiae and Pichia pastoris), insect cells and
mammals, including in vitro and in vivo expression. Host organisms
thus may include organisms for the construction, propagation,
expression or other steps in the production of the compositions
provided herein; hosts also include subjects in which immune
responses take place, as described above. Presently preferred host
organisms are E. coli bacterial strains, inbred murine strains and
murine cell lines, and human cells, subjects and cell lines.
[0110] The DNA construct encoding the desired binding
domain-immunogloblulin fusion is introduced into a plasmid for
expression in an appropriate host. In preferred embodiments, the
host is a bacterial host. The sequence encoding the ligand or
nucleic acid binding domain is preferably codon-optimized for
expression in the particular host. Thus, for example, if a human
binding domain-immunoglobulin fusion is expressed in bacteria, the
codons would be optimized for bacterial usage. For small coding
regions, the gene can be synthesized as a single oligonucleotide.
For larger proteins, splicing of multiple oligonucleotides,
mutagenesis, or other techniques known to those in the art may be
used. The sequences of nucleotides in the plasmids that are
regulatory regions, such as promoters and operators, are
operationally associated with one another for transcription. The
sequence of nucleotides encoding a binding domain-immunoglobulin
fusion protein may also include DNA encoding a secretion signal,
whereby the resulting peptide is a precursor protein. The resulting
processed protein may be recovered from the periplasmic space or
the fermentation medium.
[0111] In preferred embodiments, the DNA plasmids also include a
transcription terminator sequence. As used herein, a "transcription
terminator region" is a sequence that signals transcription
termination. The entire transcription terminator may be obtained
from a protein-encoding gene, which may be the same or different
from the inserted binding domain-immunoglobulin fusion encoding
gene or the source of the promoter. Transcription terminators are
optional components of the expression systems herein, but are
employed in preferred embodiments.
[0112] The plasmids used herein include a promoter in operative
association with the DNA encoding the protein or polypeptide of
interest and are designed for expression of proteins in a suitable
host as described above (e.g., bacterial, murine or human)
depending upon the desired use of the plasmid (e.g., administration
of a vaccine containing binding domain-immunoglobulin fusion
encoding sequences). Suitable promoters for expression of proteins
and polypeptides herein are widely available and are well known in
the art. Inducible promoters or constitutive promoters that are
linked to regulatory regions are preferred. Such promoters include,
but are not limited to, the T7 phage promoter and other T7-like
phage promoters, such as the T3, T5 and SP6 promoters, the trp,
lpp, and lac promoters, such as the lacUV5, from E. coli; the P10
or polyhedrin gene promoter of baculovirus/insect cell expression
systems (see, e.g., U.S. Pat. Nos. 5,243,041, 5,242,687, 5,266,317,
4,745,051, and 5,169,784) and inducible promoters from other
eukaryotic expression systems. For expression of the proteins such
promoters are inserted in a plasmid in operative linkage with a
control region such as the lac operon.
[0113] Preferred promoter regions are those that are inducible and
functional in E. coli. Examples of suitable inducible promoters and
promoter regions include, but are not limited to: the E. coli lac
operator responsive to isopropyl .beta.-D-thiogalactopyranoside
(IPTG; see Nakamura et al., Cell 18:1109-1117, 1979); the
metallothionein promoter metal-regulatory-elements responsive to
heavy-metal (e.g., zinc) induction (see, e.g., U.S. Pat. No.
4,870,009 to Evans et al.); the phage T7lac promoter responsive to
IPTG (see, e.g., U.S. Pat. No. 4,952,496; and Studier et al., Meth.
Enzymol. 185:60-89, 1990) and the TAC promoter.
[0114] The plasmids may optionally include a selectable marker gene
or genes that are functional in the host. A selectable marker gene
includes any gene that confers a phenotype on bacteria that allows
transformed bacterial cells to be identified and selectively grown
from among a vast majority of untransformed cells. Suitable
selectable marker genes for bacterial hosts, for example, include
the ampicillin resistance gene (Amp.sup.r), tetracycline resistance
gene (Tc.sup.r) and the kanamycin resistance gene (Kan.sup.r). The
kanamycin resistance gene is presently preferred.
[0115] The plasmids may also include DNA encoding a signal for
secretion of the operably linked protein. Secretion signals
suitable for use are widely available and are well known in the
art. Prokaryotic and eukaryotic secretion signals functional in E.
coli may be employed. The presently preferred secretion signals
include, but are not limited to, those encoded by the following E.
coli genes: ompA, ompT, ompF, ompC, beta-lactamase, and alkaline
phosphatase, and the like (von Heijne, J. Mol. Biol. 184:99-105,
1985). In addition, the bacterial pelB gene secretion signal (Lei
et al., J. Bacteriol. 169:4379, 1987), the phoA secretion signal,
and the cek2 functional in insect cell may be employed. The most
preferred secretion signal is the E. coli ompA secretion signal.
Other prokaryotic and eukaryotic secretion signals known to those
of skill in the art may also be employed (see, e.g., von Heijne, J.
Mol. Biol. 184:99-105, 1985). Using the methods described herein,
one of skill in the art can substitute secretion signals that are
functional in either yeast, insect or mammalian cells to secrete
proteins from those cells.
[0116] Preferred plasmids for transformation of E. coli cells
include the pET expression vectors (e.g., pET-11a, pET-12a-c,
pET-15b; see U.S. Pat. No. 4,952,496; available from Novagen,
Madison, Wis.). Other preferred plasmids include the pKK plasmids,
particularly pKK 223-3, which contains the tac promoter (Brosius et
al., Proc. Natl. Acad. Sci. 81:6929, 1984; Ausubel et al., Current
Protocols in Molecular Biology; U.S. Pat. Nos. 5,122,463,
5,173,403, 5,187,153, 5,204,254, 5,212,058, 5,212,286, 5,215,907,
5,220,013, 5,223,483, and 5,229,279). Plasmid pKK has been modified
by replacement of the ampicillin resistance gene with a kanamycin
resistance gene. (Available from Pharmacia; obtained from pUC4K,
see, e.g., Vieira et al. (Gene 19:259-268, 1982; and U.S. Pat. No.
4,719,179.) Baculovirus vectors, such as pBlueBac (also called
pJVETL and derivatives thereof), particularly pBlueBac III (see,
e.g., U.S. Pat. Nos. 5,278,050, 5,244,805, 5,243,041, 5,242,687,
5,266,317, 4,745,051, and 5,169,784; available from Invitrogen, San
Diego) may also be used for expression of the polypeptides in
insect cells. Other plasmids include the pIN-IIIompA plasmids (see
U.S. Pat. No. 4,575,013; see also Duffaud et al., Meth. Enz.
153:492-507, 1987), such as pIN-IIIompA2.
[0117] Preferably, the DNA molecule is replicated in bacterial
cells, preferably in E. coli. The preferred DNA molecule also
includes a bacterial origin of replication, to ensure the
maintenance of the DNA molecule from generation to generation of
the bacteria. In this way, large quantities of the DNA molecule can
be produced by replication in bacteria. Preferred bacterial origins
of replication include, but are not limited to, the fl-ori and col
E1 origins of replication. Preferred hosts contain chromosomal
copies of DNA encoding T7 RNA polymerase operably linked to an
inducible promoter, such as the lacUV promoter (see U.S. Pat. No.
4,952,496). Such hosts include, but are not limited to, lysogens E.
coli strains HMS174(DE3)pLysS, BL21(DE3)pLysS, HMS174(DE3) and
BL21(DE3). Strain BL21(DE3) is preferred. The pLys strains provide
low levels of T7 lysozyme, a natural inhibitor of T7 RNA
polymerase.
[0118] The DNA molecules provided may also contain a gene coding
for a repressor protein. The repressor protein is capable of
repressing the transcription of a promoter that contains sequences
of nucleotides to which the repressor protein binds. The promoter
can be derepressed by altering the physiological conditions of the
cell. For example, the alteration can be accomplished by adding to
the growth medium a molecule that inhibits the ability to interact
with the operator or with regulatory proteins or other regions of
the DNA or by altering the temperature of the growth media.
Preferred repressor proteins include, but are not limited to the E.
coli lacI repressor responsive to IPTG induction, the temperature
sensitive .lambda. cI857 repressor, and the like. The E. coli lacI
repressor is preferred.
[0119] In general, recombinant constructs of the subject invention
will also contain elements necessary for transcription and
translation. In particular, such elements are preferred where the
recombinant expression construct containing nucleic acid sequences
encoding binding domain-immunoglobulin fusion proteins is intended
for expression in a host cell or organism. In certain embodiments
of the present invention, cell type preferred or cell type specific
expression of a cell binding domain-immunoglobulin fusion encoding
gene may be achieved by placing the gene under regulation of a
promoter. The choice of the promoter will depend upon the cell type
to be transformed and the degree or type of control desired.
Promoters can be constitutive or active and may further be cell
type specific, tissue specific, individual cell specific, event
specific, temporally specific or inducible. Cell-type specific
promoters and event type specific promoters are preferred. Examples
of constitutive or nonspecific promoters include the SV40 early
promoter (U.S. Pat. No. 5,118,627), the SV40 late promoter (U.S.
Pat. No. 5,118,627), CMV early gene promoter (U.S. Pat. No.
5,168,062), and adenovirus promoter. In addition to viral
promoters, cellular promoters are also amenable within the context
of this invention. In particular, cellular promoters for the
so-called housekeeping genes are useful. Viral promoters are
preferred, because generally they are stronger promoters than
cellular promoters. Promoter regions have been identified in the
genes of many eukaryotes including higher eukaryotes, such that
suitable promoters for use in a particular host can be readily
selected by those skilled in the art.
[0120] Inducible promoters may also be used. These promoters
include MMTV LTR (PCT WO 91/13160), inducible by dexamethasone;
metallothionein promoter, inducible by heavy metals; and promoters
with cAMP response elements, inducible by cAMP. By using an
inducible promoter, the nucleic acid sequence encoding a binding
domain-immunoglobulin fusion protein may be delivered to a cell by
the subject invention expression construct and will remain
quiescent until the addition of the inducer. This allows further
control on the timing of production of the gene product.
[0121] Event-type specific promoters are active or up-regulated
only upon the occurrence of an event, such as tumorigenicity or
viral infection. The HIV LTR is a well known example of an
event-specific promoter. The promoter is inactive unless the tat
gene product is present, which occurs upon viral infection. Some
event-type promoters are also tissue-specific.
[0122] Additionally, promoters that are coordinately regulated with
a particular cellular gene may be used. For example, promoters of
genes that are coordinately expressed may be used when expression
of a particular binding domain-immunoglobulin fusion
protein-encoding gene is desired in concert with expression of one
or more additional endogenous or exogenously introduced genes. This
type of promoter is especially useful when one knows the pattern of
gene expression relevant to induction of an immune response in a
particular tissue of the immune system, so that specific
immunocompetent cells within that tissue may be activated or
otherwise recruited to participate in the immune response.
[0123] In addition to the promoter, repressor sequences, negative
regulators, or tissue-specific silencers may be inserted to reduce
non-specific expression of binding domain-immunoglobulin fusion
protein encoding genes in certain situations, such as, for example,
a host that is transiently immunocompromised as part of a
therapeutic strategy. Multiple repressor elements may be inserted
in the promoter region. Repression of transcription is independent
on the orientation of repressor elements or distance from the
promoter. One type of repressor sequence is an insulator sequence.
Such sequences inhibit transcription (Dunaway et al., Mol Cell Biol
17: 182-9, 1997; Gdula et al., Proc Natl Acad Sci USA 93:9378-83,
1996, Chan et al., J Virol 70: 5312-28, 1996; Scott and Geyer, EMBO
J 14:6258-67, 1995; Kalos and Fournier, Mol Cell Biol 15:198-207,
1995; Chung et al., Cell 74: 505-14, 1993) and will silence
background transcription.
[0124] Repressor elements have also been identified in the promoter
regions of the genes for type II (cartilage) collagen, choline
acetyltransferase, albumin (Hu et al., J. Cell Growth Differ.
3(9):577-588, 1992), phosphoglycerate kinase (PGK-2) (Misuno et
al., Gene 119(2):293-297, 1992), and in the
6-phosphofructo-2-kinase/fructose-2,6-b- isphosphatase gene.
(Lemaigre et al., Mol. Cell Biol. 11(2):1099-1106.) Furthermore,
the negative regulatory element Tse-1 has been identified in a
number of liver specific genes, and has been shown to block cAMP
response element- (CRE) mediated induction of gene activation in
hepatocytes. (Boshart et al., Cell 61(5):905-916, 1990).
[0125] In preferred embodiments, elements that increase the
expression of the desired product are incorporated into the
construct. Such elements include internal ribosome binding sites
(IRES; Wang and Siddiqui, Curr. Top. Microbiol. Immunol 203:99,
1995; Ehrenfeld and Semler, Curr. Top. Microbiol. Immunol. 203:65,
1995; Rees et al., Biotechniques 20:102, 1996; Sugimoto et al.,
Biotechnology 12:694, 1994). IRES increase translation efficiency.
As well, other sequences may enhance expression. For some genes,
sequences especially at the 5' end inhibit transcription and/or
translation. These sequences are usually palindromes that can form
hairpin structures. Any such sequences in the nucleic acid to be
delivered are generally deleted. Expression levels of the
transcript or translated product are assayed to confirm or
ascertain which sequences affect expression. Transcript levels may
be assayed by any known method, including Northern blot
hybridization, RNase probe protection and the like. Protein levels
may be assayed by any known method, including ELISA, western blot,
immunocytochemistry or other well known techniques.
[0126] Other elements may be incorporated into the binding
domain-immunoglobulin fusion protein encoding constructs of the
present invention. In preferred embodiments, the construct includes
a transcription terminator sequence, including a polyadenylation
sequence, splice donor and acceptor sites, and an enhancer. Other
elements useful for expression and maintenance of the construct in
mammalian cells or other eukaryotic cells may also be incorporated
(e.g., origin of replication). Because the constructs are
conveniently produced in bacterial cells, elements that are
necessary for, or that enhance, propagation in bacteria are
incorporated. Such elements include an origin of replication, a
selectable marker and the like.
[0127] As provided herein, an additional level of controlling the
expression of nucleic acids encoding binding domain-immunoglobulin
fusion proteins delivered to cells using the constructs of the
invention may be provided by simultaneously delivering two or more
differentially regulated nucleic acid constructs. The use of such a
multiple nucleic acid construct approach may permit coordinated
regulation of an immune response such as, for example,
spatiotemporal coordination that depends on the cell type and/or
presence of another expressed encoded component. Those familiar
with the art will appreciate that multiple levels of regulated gene
expression may be achieved in a similar manner by selection of
suitable regulatory sequences, including but not limited to
promoters, enhancers and other well known gene regulatory
elements.
[0128] The present invention also relates to vectors, and to
constructs prepared from known vectors that include nucleic acids
of the present invention, and in particular to "recombinant
expression constructs" that include any nucleic acids encoding
binding domain-immunoglobulin fusion proteins and polypeptides
according to the invention as provided above; to host cells which
are genetically engineered with vectors and/or constructs of the
invention and to methods of administering expression constructs
comprising nucleic acid sequences encoding such binding
domain-immunoglobulin fusion polypeptides and fusion proteins of
the invention, or fragments or variants thereof, by recombinant
techniques. Binding domain-immunoglobulin fusion proteins can be
expressed in virtually any host cell under the control of
appropriate promoters, depending on the nature of the construct
(e.g., type of promoter, as described above), and on the nature of
the desired host cell (e.g., whether postmitotic terminally
differentiated or actively dividing; e.g., whether the expression
construct occurs in host cell as an episome or is integrated into
host cell genome). Appropriate cloning and expression vectors for
use with prokaryotic and eukaryotic hosts are described by
Sambrook, et al., Molecular Cloning: A Laboratory Manual, Second
Edition, Cold Spring Harbor, N.Y., (1989); as noted above, in
particularly preferred embodiments of the invention, recombinant
expression is conducted in mammalian cells that have been
transfected or transformed with the subject invention recombinant
expression construct.
[0129] Typically, the constructs are derived from plasmid vectors.
A preferred construct is a modified pNASS vector (Clontech, Palo
Alto, Calif.), which has nucleic acid sequences encoding an
ampicillin resistance gene, a polyadenylation signal and a T7
promoter site. Other suitable mammalian expression vectors are well
known (see, e.g., Ausubel et al., 1995; Sambrook et al., supra; see
also, e.g., catalogues from Invitrogen, San Diego, Calif.; Novagen,
Madison, Wis.; Pharmacia, Piscataway, N.J.; and others). Presently
preferred constructs may be prepared that include a dihydrofolate
reductase (DHFR) encoding sequence under suitable regulatory
control, for promoting enhanced production levels of the binding
domain-immunoglobulin fusion protei, which levels result from gene
amplification following application of an appropriate selection
agent (e.g., methetrexate).
[0130] Generally, recombinant expression vectors will include
origins of replication and selectable markers permitting
transformation of the host cell, and a promoter derived from a
highly-expressed gene to direct transcription of a downstream
structural sequence, as described above. The heterologous
structural sequence is assembled in appropriate phase with
translation initiation and termination sequences. Thus, for
example, the binding domain-immunoglobulin fusion protein encoding
nucleic acids as provided herein may be included in any one of a
variety of expression vector constructs as a recombinant expression
construct for expressing a binding domain-immunoglobulin fusion
polypeptide in a host cell. In certain preferred embodiments the
constructs are included in formulations that are administered in
vivo. Such vectors and constructs include chromosomal,
nonchromosomal and synthetic DNA sequences, e.g., derivatives of
SV40; bacterial plasmids; phage DNA; yeast plasmids; vectors
derived from combinations of plasmids and phage DNA, viral DNA,
such as vaccinia, adenovirus, fowl pox virus, and pseudorabies, or
replication deficient retroviruses as described below. However, any
other vector may be used for preparation of a recombinant
expression construct, and in preferred embodiments such a vector
will be replicable and viable in the host.
[0131] The appropriate DNA sequence(s) may be inserted into the
vector by a variety of procedures. In general, the DNA sequence is
inserted into an appropriate restriction endonuclease site(s) by
procedures known in the art. Standard techniques for cloning, DNA
isolation, amplification and purification, for enzymatic reactions
involving DNA ligase, DNA polymerase, restriction endonucleases and
the like, and various separation techniques are those known and
commonly employed by those skilled in the art. A number of standard
techniques are described, for example, in Ausubel et al. (1993
Current Protocols in Molecular Biology, Greene Publ. Assoc. Inc.
& John Wiley & Sons, Inc., Boston, Mass.); Sambrook et al.
(1989 Molecular Cloning, Second Ed., Cold Spring Harbor Laboratory,
Plainview, N.Y.); Maniatis et al. (1982 Molecular Cloning, Cold
Spring Harbor Laboratory, Plainview, N.Y.); Glover (Ed.) (1985 DNA
Cloning Vol. I and II, IRL Press, Oxford, UK); Hames and Higgins
(Eds.), (1985 Nucleic Acid Hybridization, IRL Press, Oxford, UK);
and elsewhere.
[0132] The DNA sequence in the expression vector is operatively
linked to at least one appropriate expression control sequences
(e.g., a constitutive promoter or a regulated promoter) to direct
mRNA synthesis. Representative examples of such expression control
sequences include promoters of eukaryotic cells or their viruses,
as described above. Promoter regions can be selected from any
desired gene using CAT (chloramphenicol transferase) vectors or
other vectors with selectable markers. Eukaryotic promoters include
CMV immediate early, HSV thymidine kinase, early and late SV40,
LTRs from retrovirus, and mouse metallothionein-I. Selection of the
appropriate vector and promoter is well within the level of
ordinary skill in the art, and preparation of certain particularly
preferred recombinant expression constructs comprising at least one
promoter or regulated promoter operably linked to a nucleic acid
encoding an binding domain-immunoglobulin fusion polypeptide is
described herein.
[0133] Transcription of the DNA encoding the polypeptides of the
present invention by higher eukaryotes may be increased by
inserting an enhancer sequence into the vector. Enhancers are
cis-acting elements of DNA, usually about from 10 to 300 bp that
act on a promoter to increase its transcription. Examples including
the SV40 enhancer on the late side of the replication origin bp 100
to 270, a cytomegalovirus early promoter enhancer, the polyoma
enhancer on the late side of the replication origin, and adenovirus
enhancers.
[0134] As provided herein, in certain embodiments the vector may be
a viral vector such as a retroviral vector. (Miller et al., 1989
BioTechniques 7:980; Coffin and Varmus, 1996 Retroviruses, Cold
Spring Harbor Laboratory Press, N.Y.) For example, retroviruses
from which the retroviral plasmid vectors may be derived include,
but are not limited to, Moloney Murine Leukemia Virus, spleen
necrosis virus, retroviruses such as Rous Sarcoma Virus, Harvey
Sarcoma virus, avian leukosis virus, gibbon ape leukemia virus,
human immunodeficiency virus, adenovirus, Myeloproliferative
Sarcoma Virus, and mammary tumor virus.
[0135] Retroviruses are RNA viruses which can replicate and
integrate into the genome of a host cell via a DNA intermediate.
This DNA intermediate, or provirus, may be stably integrated into
the host cell DNA. According to certain embodiments of the present
invention, an expression construct may comprise a retrovirus into
which a foreign gene that encodes a foreign protein is incorporated
in place of normal retroviral RNA. When retroviral RNA enters a
host cell coincident with infection, the foreign gene is also
introduced into the cell, and may then be integrated into host cell
DNA as if it were part of the retroviral genome. Expression of this
foreign gene within the host results in expression of the foreign
protein.
[0136] Most retroviral vector systems which have been developed for
gene therapy are based on murine retroviruses. Such retroviruses
exist in two forms, as free viral particles referred to as virions,
or as proviruses integrated into host cell DNA. The virion form of
the virus contains the structural and enzymatic proteins of the
retrovirus (including the enzyme reverse transcriptase), two RNA
copies of the viral genome, and portions of the source cell plasma
membrane containing viral envelope glycoprotein. The retroviral
genome is organized into four main regions: the Long Terminal
Repeat (LTR), which contains cis-acting elements necessary for the
initiation and termination of transcription and is situated both 5'
and 3' of the coding genes, and the three coding genes gag, pol,
and env. These three genes gag, pol, and env encode, respectively,
internal viral structures, enzymatic proteins (such as integrase),
and the envelope glycoprotein (designated gp70 and p15e) which
confers infectivity and host range specificity of the virus, as
well as the "R" peptide of undetermined function.
[0137] Separate packaging cell lines and vector producing cell
lines have been developed because of safety concerns regarding the
uses of retroviruses, including their use in expression constructs
as provided by the present invention. Briefly, this methodology
employs the use of two components, a retroviral vector and a
packaging cell line (PCL). The retroviral vector contains long
terminal repeats (LTRs), the foreign DNA to be transferred and a
packaging sequence (y). This retroviral vector will not reproduce
by itself because the genes which encode structural and envelope
proteins are not included within the vector genome. The PCL
contains genes encoding the gag, pol, and env proteins, but does
not contain the packaging signal "y". Thus, a PCL can only form
empty virion particles by itself. Within this general method, the
retroviral vector is introduced into the PCL, thereby creating a
vector-producing cell line (VCL). This VCL manufactures virion
particles containing only the retroviral vector's (foreign) genome,
and therefore has previously been considered to be a safe
retrovirus vector for therapeutic use.
[0138] "Retroviral vector construct" refers to an assembly which
is, within preferred embodiments of the invention, capable of
directing the expression of a sequence(s) or gene(s) of interest,
such as binding domain-immunoglobulin fusion encoding nucleic acid
sequences. Briefly, the retroviral vector construct must include a
5' LTR, a tRNA binding site, a packaging signal, an origin of
second strand DNA synthesis and a 3' LTR. A wide variety of
heterologous sequences may be included within the vector construct,
including for example, sequences which encode a protein (e.g.,
cytotoxic protein, disease-associated antigen, immune accessory
molecule, or replacement gene), or which are useful as a molecule
itself (e.g., as a ribozyme or antisense sequence).
[0139] Retroviral vector constructs of the present invention may be
readily constructed from a wide variety of retroviruses, including
for example, B, C, and D type retroviruses as well as spumaviruses
and lentiviruses (see, e.g., RNA Tumor Viruses, Second Edition,
Cold Spring Harbor Laboratory, 1985). Such retroviruses may be
readily obtained from depositories or collections such as the
American Type Culture Collection ("ATCC"; Rockville, Md.), or
isolated from known sources using commonly available techniques.
Any of the above retroviruses may be readily utilized in order to
assemble or construct retroviral vector constructs, packaging
cells, or producer cells of the present invention given the
disclosure provided herein, and standard recombinant techniques
(e.g., Sambrook et al, Molecular Cloning: A Laboratory Manual, 2d
ed., Cold Spring Harbor Laboratory Press, 1989; Kunkle, PNAS
82:488, 1985).
[0140] Suitable promoters for use in viral vectors generally may
include, but are not limited to, the retroviral LTR; the SV40
promoter; and the human cytomegalovirus (CMV) promoter described in
Miller, et al., Biotechniques 7:980-990 (1989), or any other
promoter (e.g., cellular promoters such as eukaryotic cellular
promoters including, but not limited to, the histone, pol III, and
.beta.-actin promoters). Other viral promoters which may be
employed include, but are not limited to, adenovirus promoters,
thymidine kinase (TK) promoters, and B19 parvovirus promoters. The
selection of a suitable promoter will be apparent to those skilled
in the art from the teachings contained herein, and may be from
among either regulated promoters or promoters as described
above.
[0141] As described above, the retroviral plasmid vector is
employed to transduce packaging cell lines to form producer cell
lines. Examples of packaging cells which may be transfected
include, but are not limited to, the PE501, PA317, .psi.-2,
.psi.-AM, PA12, T19-14X, VT-19-17-H2, .psi.CRE, .psi.CRIP, GP+E-86,
GP+envAm12, and DAN cell lines as described in Miller, Human Gene
Therapy, 1:5-14 (1990). The vector may transduce the packaging
cells through any means known in the art. Such means include, but
are not limited to, electroporation, the use of liposomes, and
CaPO.sub.4 precipitation. In one alternative, the retroviral
plasmid vector may be encapsulated into a liposome, or coupled to a
lipid, and then administered to a host.
[0142] The producer cell line generates infectious retroviral
vector particles which include the nucleic acid sequence(s)
encoding the binding domain-immunoglobulin fusion polypeptides or
fusion proteins. Such retroviral vector particles then may be
employed, to transduce eukaryotic cells, either in vitro or in
vivo. The transduced eukaryotic cells will express the nucleic acid
sequence(s) encoding the binding domain-immunoglobulin fusion
polypeptide or fusion protein. Eukaryotic cells which may be
transduced include, but are not limited to, embryonic stem cells,
as well as hematopoietic stem cells, hepatocytes, fibroblasts,
circulating peripheral blood mononuclear and polymorphonuclear
cells including myelomonocytic cells, lymphocytes, myoblasts,
tissue macrophages, dendritic cells, Kupffer cells, lymphoid and
reticuloendothelia cells of the lymph nodes and spleen,
keratinocytes, endothelial cells, and bronchial epithelial
cells.
[0143] As another example of an embodiment of the invention in
which a viral vector is used to prepare the recombinant binding
domain-immunoglobulin fusion expression construct, in one preferred
embodiment, host cells transduced by a recombinant viral construct
directing the expression of binding domain-immunoglobulin fusion
polypeptides or fusion proteins may produce viral particles
containing expressed binding domain-immunoglobulin fusion
polypeptides or fusion proteins that are derived from portions of a
host cell membrane incorporated by the viral particles during viral
budding.
[0144] In another aspect, the present invention relates to host
cells containing the above described recombinant binding
domain-immunoglobulin fusion expression constructs. Host cells are
genetically engineered (transduced, transformed or transfected)
with the vectors and/or expression constructs of this invention
which may be, for example, a cloning vector, a shuttle vector or an
expression construct. The vector or construct may be, for example,
in the form of a plasmid, a viral particle, a phage, etc. The
engineered host cells can be cultured in conventional nutrient
media modified as appropriate for activating promoters, selecting
transformants or amplifying particular genes such as genes encoding
binding domain-immunoglobulin fusion polypeptides or binding
domain-immunoglobulin fusion proteins. The culture conditions for
particular host cells selected for expression, such as temperature,
pH and the like, will be readily apparent to the ordinarily skilled
artisan.
[0145] The host cell can be a higher eukaryotic cell, such as a
mammalian cell, or a lower eukaryotic cell, such as a yeast cell,
or the host cell can be a prokaryotic cell, such as a bacterial
cell. Representative examples of appropriate host cells according
to the present invention include, but need not be limited to,
bacterial cells, such as E. coli, Streptomyces, Salmonella
typhimurium; fungal cells, such as yeast; insect cells, such as
Drosophila S2 and Spodoptera Sf9; animal cells, such as CHO, COS or
293 cells; adenoviruses; plant cells, or any suitable cell already
adapted to in vitro propagation or so established de novo. The
selection of an appropriate host is deemed to be within the scope
of those skilled in the art from the teachings herein.
[0146] Various mammalian cell culture systems can also be employed
to express recombinant protein. Examples of mammalian expression
systems include the COS-7 lines of monkey kidney fibroblasts,
described by Gluzman, Cell 23:175 (1981), and other cell lines
capable of expressing a compatible vector, for example, the C127,
3T3, CHO, HeLa and BHK cell lines. Mammalian expression vectors
will comprise an origin of replication, a suitable promoter and
enhancer, and also any necessary ribosome binding sites,
polyadenylation site, splice donor and acceptor sites,
transcriptional termination sequences, and 5' flanking
nontranscribed sequences, for example as described herein regarding
the preparation of binding domain-immunoglobulin fusion expression
constructs. DNA sequences derived from the SV40 splice, and
polyadenylation sites may be used to provide the required
nontranscribed genetic elements. Introduction of the construct into
the host cell can be effected by a variety of methods with which
those skilled in the art will be familiar, including but not
limited to, for example, calcium phosphate transfection,
DEAE-Dextran mediated transfection, or electroporation (Davis et
al., 1986 Basic Methods in Molecular Biology).
[0147] The present invention binding domain-immunoglobulin fusion
proteins may be formulated into pharmaceutical compositions for
administration according to well known methodologies.
Pharmaceutical compositions generally comprise one or more
recombinant expression constructs, and/or expression products of
such constructs, in combination with a pharmaceutically acceptable
carrier, excipient or diluent. Such carriers will be nontoxic to
recipients at the dosages and concentrations employed. For nucleic
acid-based formulations, or for formulations comprising expression
products of the subject invention recombinant constructs, about
0.01 .mu.g/kg to about 100 mg/kg body weight will be administered,
typically by the intradermal, subcutaneous, intramuscular or
intravenous route, or by other routes. A preferred dosage is about
1 .mu.g/kg to about 1 mg/kg, with about 5 .mu.g/kg to about 200
.mu.g/kg particularly preferred. It will be evident to those
skilled in the art that the number and frequency of administration
will be dependent upon the response of the host.
[0148] "Pharmaceutically acceptable carriers" for therapeutic use
are well known in the pharmaceutical art, and are described, for
example, in Remingtons Pharmaceutical Sciences, Mack Publishing Co.
(A. R. Gennaro edit. 1985). For example, sterile saline and
phosphate-buffered saline at physiological pH may be used.
Preservatives, stabilizers, dyes and even flavoring agents may be
provided in the pharmaceutical composition. For example, sodium
benzoate, sorbic acid and esters of p-hydroxybenzoic acid may be
added as preservatives. Id. at 1449. In addition, antioxidants and
suspending agents may be used. Id.
[0149] "Pharmaceutically acceptable salt" refers to salts of the
compounds of the present invention derived from the combination of
such compounds and an organic or inorganic acid (acid addition
salts) or an organic or inorganic base (base addition salts). The
compounds of the present invention may be used in either the free
base or salt forms, with both forms being considered as being
within the scope of the present invention.
[0150] The pharmaceutical compositions that contain one or more
binding domain-immunoglobulin fusion protein encoding constructs
(or their expressed products) may be in any form which allows for
the composition to be administered to a patient. For example, the
composition may be in the form of a solid, liquid or gas (aerosol).
Typical routes of administration include, without limitation, oral,
topical, parenteral (e.g., sublingually or buccally), sublingual,
rectal, vaginal, and intranasal. The term parenteral as used herein
includes subcutaneous injections, intravenous, intramuscular,
intrasternal, intracavernous, intrathecal, intrameatal,
intraurethral injection or infusion techniques. The pharmaceutical
composition is formulated so as to allow the active ingredients
contained therein to be bioavailable upon administration of the
composition to a patient. Compositions that will be administered to
a patient take the form of one or more dosage units, where for
example, a tablet may be a single dosage unit, and a container of
one or more compounds of the invention in aerosol form may hold a
plurality of dosage units.
[0151] For oral administration, an excipient and/or binder may be
present. Examples are sucrose, kaolin, glycerin, starch dextrins,
sodium alginate, carboxymethylcellulose and ethyl cellulose.
Coloring and/or flavoring agents may be present. A coating shell
may be employed.
[0152] The composition may be in the form of a liquid, e.g., an
elixir, syrup, solution, emulsion or suspension. The liquid may be
for oral administration or for delivery by injection, as two
examples. When intended for oral administration, preferred
compositions contain, in addition to one or more binding
domain-immunoglobulin fusion construct or expressed product, one or
more of a sweetening agent, preservatives, dye/colorant and flavor
enhancer. In a composition intended to be administered by
injection, one or more of a surfactant, preservative, wetting
agent, dispersing agent, suspending agent, buffer, stabilizer and
isotonic agent may be included.
[0153] A liquid pharmaceutical composition as used herein, whether
in the form of a solution, suspension or other like form, may
include one or more of the following adjuvants: sterile diluents
such as water for injection, saline solution, preferably
physiological saline, Ringer's solution, isotonic sodium chloride,
fixed oils such as synthetic mono or digylcerides which may serve
as the solvent or suspending medium, polyethylene glycols,
glycerin, propylene glycol or other solvents; antibacterial agents
such as benzyl alcohol or methyl paraben; antioxidants such as
ascorbic acid or sodium bisulfite; chelating agents such as
ethylenediaminetetraacetic acid; buffers such as acetates, citrates
or phosphates and agents for the adjustment of tonicity such as
sodium chloride or dextrose. The parenteral preparation can be
enclosed in ampoules, disposable syringes or multiple dose vials
made of glass or plastic. Physiological saline is a preferred
adjuvant. An injectable pharmaceutical composition is preferably
sterile.
[0154] It may also be desirable to include other components in the
preparation, such as delivery vehicles including but not limited to
aluminum salts, water-in-oil emulsions, biodegradable oil vehicles,
oil-in-water emulsions, biodegradable microcapsules, and liposomes.
Examples of immunostimulatory substances (adjuvants) for use in
such vehicles include N-acetylmuramyl-L-alanine-D-isoglutamine
(MDP), lipopoly-saccharides (LPS), glucan, IL-12, GM-CSF, gamma
interferon and IL-15.
[0155] While any suitable carrier known to those of ordinary skill
in the art may be employed in the pharmaceutical compositions of
this invention, the type of carrier will vary depending on the mode
of administration and whether a sustained release is desired. For
parenteral administration, such as subcutaneous injection, the
carrier preferably comprises water, saline, alcohol, a fat, a wax
or a buffer. For oral administration, any of the above carriers or
a solid carrier, such as mannitol, lactose, starch, magnesium
stearate, sodium saccharine, talcum, cellulose, glucose, sucrose,
and magnesium carbonate, may be employed. Biodegradable
microspheres (e.g., polylactic galactide) may also be employed as
carriers for the pharmaceutical compositions of this invention.
Suitable-biodegradable microspheres are disclosed, for example, in
U.S. Pat. Nos. 4,897,268 and 5,075,109. In this regard, it is
preferable that the microsphere be larger than approximately 25
microns.
[0156] Pharmaceutical compositions may also contain diluents such
as buffers, antioxidants such as ascorbic acid, low molecular
weight (less than about 10 residues) polypeptides, proteins, amino
acids, carbohydrates including glucose, sucrose or dextrins,
chelating agents such as EDTA, glutathione and other stabilizers
and excipients. Neutral buffered saline or saline mixed with
nonspecific serum albumin are exemplary appropriate diluents.
Preferably, product is formulated as a lyophilizate using
appropriate excipient solutions (e.g., sucrose) as diluents.
[0157] As described above, the subject invention includes
compositions capable of delivering nucleic acid molecules encoding
binding domain-immunoglobulin fusion proteins. Such compositions
include recombinant viral vectors (e.g., retroviruses (see WO
90/07936, WO 91/02805, WO 93/25234, WO 93/25698, and WO 94/03622),
adenovirus (see Berkner, Biotechniques 6:616-627, 1988; Li et al.,
Hum. Gene Ther. 4:403-409, 1993; Vincent et al., Nat. Genet.
5:130-134, 1993; and Kolls et al., Proc. Natl. Acad. Sci. USA
91:215-219, 1994), pox virus (see U.S. Pat. No. 4,769,330; U.S.
Pat. No. 5,017,487; and WO 89/01973)), recombinant expression
construct nucleic acid molecules complexed to a polycationic
molecule (see WO 93/03709), and nucleic acids associated with
liposomes (see Wang et al., Proc. Natl. Acad. Sci. USA 84:7851,
1987). In certain embodiments, the DNA may be linked to killed or
inactivated adenovirus (see Curiel et al., Hum. Gene Ther.
3:147-154, 1992; Cotton et al., Proc. Natl. Acad. Sci. USA 89:6094,
1992). Other suitable compositions include DNA-ligand (see Wu et
al., J. Biol. Chem. 264:16985-16987, 1989) and lipid-DNA
combinations (see Felgner et al., Proc. Natl. Acad. Sci. USA
84:7413-7417, 1989).
[0158] In addition to direct in vivo procedures, ex vivo procedures
may be used in which cells are removed from a host, modified, and
placed into the same or another host animal. It will be evident
that one can utilize any of the compositions noted above for
introduction of binding domain-immunoglobulin fusion proteins or of
binding domain-immunoglobulin fusion protein encoding nucleic acid
molecules into tissue cells in an ex vivo context. Protocols for
viral, physical and chemical methods of uptake are well known in
the art.
[0159] Accordingly, the present invention is useful for treating a
patient having a B-cell disorder or a malignant condition, or for
treating a cell culture derived from such a patient. As used
herein, the term "patient" refers to any warm-blooded animal,
preferably a human. A patient may be afflicted with cancer, such as
B-cell lymphoma, or may be normal (i.e., free of detectable disease
and infection). A "cell culture" is any preparation amenable to ex
vivo treatment, for example a preparation containing
immunocompetent cells or isolated cells of the immune system
(including, but not limited to, T cells, macrophages, monocytes, B
cells and dendritic cells). Such cells may be isolated by any of a
variety of techniques well known to those of ordinary skill in the
art (e.g., Ficoll-hypaque density centrifugation). The cells may
(but need not) have been isolated from a patient afflicted with a
B-cell disorder or a malignancy, and may be reintroduced into a
patient after treatment.
[0160] A liquid composition intended for either parenteral or oral
administration should contain an amount of binding
domain-immunoglobulin fusion protein encoding construct or
expressed product such that a suitable dosage will be obtained.
Typically, this amount is at least 0.01 wt % of a binding
domain-immunoglobulin fusion construct or expressed product in the
composition. When intended for oral administration, this amount may
be varied to be between 0.1 and about 70% of the weight of the
composition. Preferred oral compositions contain between about 4%
and about 50% of binding domain-immunoglobulin fusion construct or
expressed product(s). Preferred compositions and preparations are
prepared so that a parenteral dosage unit contains between 0.01 to
1% by weight of active compound.
[0161] The pharmaceutical composition may be intended for topical
administration, in which case the carrier may suitably comprise a
solution, emulsion, ointment or gel base. The base, for example,
may comprise one or more of the following: petrolatum, lanolin,
polyethylene glycols, beeswax, mineral oil, diluents such as water
and alcohol, and emulsifiers and stabilizers. Thickening agents may
be present in a pharmaceutical composition for topical
administration. If intended for transdermal administration, the
composition may include a transdermal patch or iontophoresis
device. Topical formulations may contain a concentration of the
binding domain-immunoglobulin fusion construct or expressed product
of from about 0.1 to about 10% w/v (weight per unit volume).
[0162] The composition may be intended for rectal administration,
in the form, e.g., of a suppository which will melt in the rectum
and release the drug. The composition for rectal administration may
contain an oleaginous base as a suitable nonirritating excipient.
Such bases include, without limitation, lanolin, cocoa butter and
polyethylene glycol.
[0163] In the methods of the invention, the binding
domain-immunoglobulin fusion encoding constructs or expressed
product(s) may be administered through use of insert(s), bead(s),
timed-release formulation(s), patch(es) or fast-release
formulation(s).
[0164] The following Examples are offered by way of illustration
and not by way of limitation.
EXAMPLES
Example 1
Cloning of the 2H7 Variable Regions and Construction and Sequencing
of 2H7scFv-IG
[0165] This Example illustrates the cloning of cDNA molecules that
encode the heavy chain and light chain variable regions of the
monoclonal antibody 2H7. This Example also demonstrates the
construction, sequencing, and expression of 2H7scFv-Ig.
[0166] Hybridoma cells expressing 2H7 monoclonal antibody that
specifically bound to CD20 were provided by Ed Clark at the
University of Washington, Seattle, Wash. Prior to harvesting,
hybridoma cells were kept in log phase growth for several days in
RPMI 1640 media (Life Technologies, Gaithersburg, Md.) supplemented
with glutamine, pyruvate, DMEM non-essential amino acids, and
penicillin-streptomycin. Cells were pelleted by centrifugation from
the culture medium, and 2.times.10.sup.7 cells were used to prepare
RNA. RNA was isolated from the 2H7-producing hybridoma cells using
the Pharmingen (San Diego, Calif.) total RNA isolation kit (Catalog
# 45520K) according to the manufacturer's instructions accompanying
the kit. One microgram (1 .mu.g) of total RNA was used as template
to prepare cDNA by reverse transcription. The RNA and 300 ng random
primers were combined and denatured at 72.degree. C. for 10 minutes
prior to addition of enzyme. Superscript II reverse transcriptase
(Life Technologies) was added to the RNA plus primer mixture in a
total volume of 25 .mu.l in the presence of 5.times.second strand
buffer and 0.1 M DTT provided with the enzyme. The reverse
transcription reaction was allowed to proceed at 42.degree. C. for
one hour.
[0167] The 2H7 cDNA generated in the randomly primed reverse
transcriptase reaction and V region specific primers were used to
amplify by PCR the variable regions for the light and heavy chain
of the 2H7 antibody. The V region specific primers were designed
using the published sequence (Genbank accession numbers M17954 for
V.sub.L and M17953 for V.sub.H) as a guide. The two variable chains
were designed with compatible end sequences so that an scFv could
be assembled by ligation of the two V regions after amplification
and restriction enzyme digestion.
[0168] A (gly.sub.4ser).sub.3 peptide linker to be inserted between
the two V regions was incorporated by adding the extra nucleotides
to the antisense primer for the V.sub.L of 2H7. A Sac I restriction
site was also introduced at the junction between the two V regions.
The sense primer used to amplify the 2H7 V.sub.L, that included a
HindIII restriction site and the light chain leader peptide was
5'-gtc aag ctt gcc gcc atg gat ttt caa gtg cag att ttt cag c-3'
(SEQ ID NO:23). The antisense primer was 5'-gtc gtc gag ctc cca cct
cct cca gat cca cca ccg ccc gag cca ccg cca cct ttc agc tcc agc ttg
gtc cc-3' (SEQ ID NO:24). The reading frame of the V region is
indicated as a bold, underlined codon. The Hind III and SacI sites
are indicated by underlined italicized sequences.
[0169] The V.sub.H domain was amplified without a leader peptide,
but included a 5' SacI restriction site for fusion to the V.sub.L
and a BclI restriction site at the 3' end for fusion to various
tails, including the human IgG1 Fc domain and the truncated forms
of CD40 ligand, CD154. The sense primer was 5'-gct gct gag ctc tca
ggc tta tct aca gca agt ctg g-3' (SEQ ID NO:25). The SacI site is
indicated in italicized and underlined font, and the reading frame
of the codon for the first amino acid of the V.sub.H domain is
indicated in bold, underlined type. The antisense primer was 5'-gtt
gtc tga tca gag acg gtg acc gtg gtc cc-3' (SEQ ID NO:26). The BclI
site is indicated in italicized, underlined type, and the last
serine of the V.sub.H domain sequence is indicated in bold,
underlined type.
[0170] The scFv-Ig was assembled by inserting the 2H7 scFv
HindIII-BclI fragment into pUC19 containing the human IgG1 hinge,
CH2, and CH3 regions, which was digested with restriction enzymes,
HindIII and BclI. After ligation, the ligation products were
transformed into DH5.alpha. bacteria. Positive clones were screened
for the properly inserted fragments using the SacI site at the
V.sub.L-V.sub.H junction of 2H7 as a diagnostic site. The
2H7scFv-Ig cDNA was subjected to cycle sequencing on a PE 9700
thermocycler using a 25-cycle program by denaturing at 96.degree.
C. for 10 seconds, annealing at 50.degree. C. for 30 seconds, and
extending at 72.degree. C. for 4 minutes. The sequencing primers
were pUC forward and reverse primers and an internal primer that
annealed to the CH2 domain human in the IgG constant region
portion. Sequencing reactions were performed using the Big Dye
Terminator Ready Sequencing Mix (PE-Applied Biosystems, Foster
City, Calif.) according to the manufacturer's instructions. Samples
were subsequently purified using Centrisep columns (Catalog #
CS-901, Princeton Separations, Adelphia, N.J.), the eluates dried
in a Savant vacuum dryer, denatured in Template Suppression Reagent
(PE-ABI), and analyzed on an ABI 310 Genetic Analyzer (PE-Applied
Biosystems). The sequence was edited, translated, and analyzed
using Vector Nti version 6.0 (Informax, North Bethesda, Md.). FIG.
1 shows the cDNA and predicted amino acid sequence of the
2H7scFv-Ig construct.
Example 2
Expression of 2H7 ScFv-IG in Stable CHO Cell Lines
[0171] This Example illustrates expression of 2H7scFv-Ig in a
eukaryotic cell line and characterization of the expressed
2H7scFv-Ig by SDS-PAGE and by functional assays, including ADCC and
complement fixation.
[0172] The 2H7scFv-Ig HindIII-XbaI (.about.1.6 kb) fragment with
correct sequence was inserted into the mammalian expression vector
pD18, and DNA from positive clones was amplified using QIAGEN
plasmid preparation kits (QIAGEN, Valencia, Calif.). The
recombinant plasmid DNA (100 .mu.g) was then linearized in a
nonessential region by digestion with AscI, purified by phenol
extraction, and resuspended in tissue culture media, Excell 302
(Catalog # 14312-79P, JRH Biosciences, Lenexa, Kans.). Cells for
transfection, CHO DG44 cells, were kept in logarithmic growth, and
10.sup.7 cells harvested for each transfection reaction. Linearized
DNA was added to the CHO cells in a total volume of 0.8 ml for
electroporation.
[0173] Stable production of the 2H7 scFv-Ig fusion protein (SEQ. ID
NO: 15) was achieved by electroporation of a selectable,
amplifiable plasmid, pD18, containing the 2H7 scFv-Ig cDNA under
the control of the CMV promoter, into Chinese Hamster Ovary (CHO)
cells (all cell lines from American Type Culture Collection,
Manassas, Va., unless otherwise noted). The 2H7 expression cassette
was subcloned downstream of the CMV promoter into the vector
multiple cloning site as a .about.1.6 kb HindIII-XbaI fragment. The
pD18 vector is a modified version of pcDNA3 encoding the DHFR
selectable marker with an attenuated promoter to increase selection
pressure for the plasmid. Plasmid DNA was prepared using Qiagen
maxiprep kits, and purified plasmid was linearized at a unique AscI
site prior to phenol extraction and ethanol precipitation. Salmon
sperm DNA (Sigma-Aldrich, St. Louis, Mo.) was added as carrier DNA,
and 100 .mu.g each of plasmid and carrier DNA was used to transfect
10.sup.7 CHO DG44 cells by electroporation. Cells were grown to
logarithmic phase in Excell 302 media (JRH Biosciences) containing
glutamine (4 mM), pyruvate, recombinant insulin,
penicillin-streptomycin, and 2.times.DMEM nonessential amino acids
(all from Life Technologies, Gaithersburg, Md.), hereafter referred
to as "Excell 302 complete" media. Media for untransfected cells
also contained HT (diluted from a 100.times.solution of
hypoxanthine and thymidine) (Life Technologies). Media for
transfections under selection contained varying levels of
methotrexate (Sigma-Aldrich) as selective agent, ranging from 50 nM
to 5 .mu.M. Electroporations were performed at 275 volts, 950
.mu.F. Transfected cells were allowed to recover overnight in
non-selective media prior to selective plating in 96 well flat
bottom plates (Costar) at varying serial dilutions ranging from 125
cells/well to 2000 cells/well. Culture media for cell cloning was
Excell 302 complete, containing 100 nM methotrexate. Once clonal
outgrowth was sufficient, serial dilutions of culture supernatants
from master wells were screened for binding to CD20-CHO transfected
cells. The clones with the highest production of the fusion protein
were expanded into T25 and then T75 flasks to provide adequate
numbers of cells for freezing and for scaling up production of the
2H7scFvIg. Production levels were further increased in cultures
from three clones by progressive amplification in methotrexate
containing culture media. At each successive passage of cells, the
Excell 302 complete media contained an increased concentration of
methotrexate, such that only the cells that amplified the DHFR
plasmid could survive.
[0174] Supernatants were collected from CHO cells expressing the
2H7scFv-Ig, filtered through 0.2 .mu.m PES express filters
(Nalgene, Rochester, N.Y.) and were passed over a Protein A-agarose
(IPA 300 crosslinked agarose) column (Repligen, Needham, Mass.).
The column was washed with PBS, and then bound protein was eluted
using 0.1 M citrate buffer, pH 3.0. Fractions were collected and
eluted protein was neutralized using 1M Tris, pH 8.0, prior to
dialysis overnight in PBS. Concentration of the purified 2H7scFv-Ig
(SEQ ID NO:15) was determined by absorption at 280 nm. An
extinction coefficient of 1.77 was determined using the protein
analysis tools in the Vector Nti Version 6.0 Software package
(Informax, North Bethesda, Md.). This program uses the amino acid
composition data to calculate extinction coefficients.
[0175] Production levels of 2H7scFv-Ig by transfected, stable CHO
cells were analyzed by flow cytometry. Purified 2H7scFv-Ig to CHO
cells was allowed to bind to CHO cells that expressed CD20 (CD20
CHO) and analyzed by flow cytometry using a fluorescein-conjugated
anti-human IgG second step reagent (Catalog Numbers H10101 and
H10501, CalTag, Burlingame, Calif.). FIG. 2 (top) shows a standard
curve generated by titration of 2H7scFv-Ig binding to CD20 CHO. At
each concentration of 2H7scFv-Ig, the mean brightness of the
fluorescein signal in linear units is shown. Supernatants collected
from T flasks containing stable CHO cell clones expressing
2H7scFv-Ig were then allowed to bind to CD20 CHO and the binding
was analyzed by flow cytometry. The fluorescein signal generated by
2H7scFv-Ig contained in the supernatants was measured and the
2H7scFv-Ig concentration in the supernatants was calculated from
the standard curve (FIG. 2, bottom).
[0176] Purified 2H7scFv-Ig (SEQ ID NO:15) was analyzed by
electrophoresis on SDS-Polyacrylamide gels. Samples of 2H7scFv-Ig,
purified by independent Protein A Agarose column runs, were boiled
in SDS sample buffer without reduction of disulfide bonds and
applied to SDS 10% Tris-BIS gels (Catalog # NP0301, Novex,
Carlsbad, Calif.). Twenty micrograms of each purified batch was
loaded on the gels. The proteins were visualized after
electrophoresis by Coomassie Blue staining (Pierce Gel Code Blue
Stain Reagent, Catalog #24590, Pierce, Rockford, Ill.), and
destaining in distilled water. Molecular weight markers were
included on the same gel (Kaleidoscope Prestained Standards,
Catalog # 161-0324, Bio-Rad, Hercules, Calif.). The results are
presented in FIG. 3. The numbers above the lanes designate
independent purification batches. The molecular weights in
kilodaltons of the size markers are indicated on the left side of
the figure. Further experiments with alternative sample preparation
conditions indicated that reduction of disulfide bonds by boiling
the protein in SDS sample buffer containing DTT or
2-mercaptoethanol caused the 2H7scFv-Ig to aggregate.
[0177] Any number of other immunological parameters may be
monitored using routine assays that are well known in the art.
These may include, for example, antibody dependent cell-mediated
cytotoxicity (ADCC) assays, secondary in vitro antibody responses,
flow immunocytofluorimetric analysis of various peripheral blood or
lymphoid mononuclear cell subpopulations using well established
marker antigen systems, immunohistochemistry or other relevant
assays. These and other assays may be found, for example, in Rose
et al. (Eds.), Manual of Clinical Laboratory Immunology, 5.sup.th
Ed., 1997 American Society of Microbiology, Washington, D.C.
[0178] The ability of 2H7scFv-Ig to kill CD20 positive cells in the
presence of complement was tested using B cell lines Ramos and
Bjab. Rabbit complement (Pel-Freez, Rogers, AK) was used in the
assay at a final dilution of {fraction (1/10)}. Purified 2H7scFv-Ig
was incubated with B cells and complement for 45 minutes at
37.degree. C., followed by counting of live and dead cells by
trypan blue exclusion. The results in FIG. 4A show that in the
presence of rabbit complement, 2H7scFv-Ig lysed B cells expressing
CD20.
[0179] The ability of 2H7scFv-Ig to kill CD20 positive cells in the
presence of peripheral blood mononuclear cells (PBMC) was tested by
measuring the release of .sup.51Cr from labeled Bjab cells in a
4-hour assay using a 100:1 ratio of PBMC to Bjab cells. The results
shown in FIG. 4B indicated that 2H7scFv-Ig can mediate antibody
dependent cellular cytotoxicity (ADCC) because the release of
.sup.51Cr was higher in the presence of both PBMC and 2H7scFv-Ig
than in the presence of either PBMC or 2H7scFv-Ig alone.
Example 3
Effect of Simultaneous Ligation of CD20 and CD40 on Growth of
Normal B Cells, and on CD95 Expression, and Induction of
Apoptosis
[0180] This example illustrates the effect of cross-linking of CD20
and CD40 expressed on the cell surface on cell proliferation.
[0181] Dense resting B cells were isolated from human tonsil by a
Percoll step gradient and T cells were removed by E-rosetting.
Proliferation of resting, dense tonsillar B cells was measured by
uptake of .sup.3[H]-thymidine during the last 12 hours of a 4-day
experiment. Proliferation was measured in quadruplicate cultures
with means and standard deviations as shown. Murine anti-human CD20
mAb 1F5 (anti-CD20) was used alone or was cross-linked with
anti-murine .kappa. mAb 187.1 (anti-CD20XL). CD40 activation was
accomplished using soluble human CD154 fused with murine CD8
(CD154) (Hollenbaugh et al., EMBO J. 11: 4212-21 (1992)), and CD40
cross-linking was accomplished using anti-murine CD8 mAb 53-6
(CD154XL). This procedure allowed simultaneous cross-linking of
CD20 and CD40 on the cell surface. The results are presented in
FIG. 5.
[0182] The effect of CD20 and CD40 cross-linking on Ramos cells, a
B lymphoma cell line, was examined. Ramos cells were analyzed for
CD95 (Fas) expression and percent apoptosis eighteen hours after
treatment (no goat anti-mouse IgG (GAM)) and/or cross-linking
(+GAM) using murine mAbs that specifically bind CD20 (1F5) and CD40
(G28-5). Control cells were treated with a non-binding isotype
control (64.1) specific for CD3.
[0183] Treated Ramos cells were harvested, incubated with
FITC-anti-CD95, and analyzed by flow cytometry to determine the
relative expression level of Fas on the cell surface after CD20 or
CD40 cross-linking. Data is plotted as mean fluorescence of cells
after treatment with the stimuli indicated (FIG. 6A).
[0184] Treated Ramos cells from the same experiment were harvested
and binding of annexin V was measured to indicate the percentage
apoptosis in the treated cultures. Apoptosis was measured by
binding of Annexin V 18 hours after cross-linking of CD20 and CD40
using 1F5 and G28-5 followed by cross-linking with GAM. Binding of
Annexin V was measured using a FITC-Annexin V kit (Catalog #
PN-IM2376, Immunotech, Marseille, France,). Annexin V binding is
known to be an early event in progression of cells into apoptosis.
Apoptosis, or programmed cell death, is a process characterized by
a cascade of catabolic reactions leading to cell death by suicide.
In the early phase of apoptosis, before cells change morphology and
hydrolyze DNA, the integrity of the cell membrane is maintained but
cells lose the asymmetry of their membrane phospholipids, exposing
negatively charged phospholipids, such as phosphatidylserine, at
the cell surface. Annexin V, a calcium and phopholipid binding
protein, binds preferentially and with high affinity to
phosphatidylserine. Results demonstrating the effect of
cross-linking both CD20 and CD40 on expression of the FAS receptor
(CD95) are presented in FIG. 6B. The effect of cross-linking of
both CD20 and CD40 on Annexin V binding to cells is shown in FIG.
6B.
Example 4
Construction and Characterization of 2H7 ScFv-CD 154 Fusion
Proteins
[0185] To construct a molecule capable of binding to both CD20 and
CD40, cDNA encoding the 2H7 scFv was fused with cDNA encoding
CD154, the CD40 ligand. The 2H7 scFv cDNA encoded on the
HindIII-BclI fragment was removed from the 2H7 scFvIg construct,
and inserted into a pD18 vector along with a BamHI-XbaI cDNA
fragment encoding the extracellular domain of human CD154. The
extracellular domain is encoded at the carboxy terminus of CD154,
similar to other type II membrane proteins.
[0186] The extracellular domain of human CD154 was PCR amplified
using cDNA generated with random primers and RNA from human T
lymphocytes activated with PHA (phytohemagglutinin). The primer
sets included two different 5' or sense primers that created fusion
junctions at two different positions within the extracellular
domain of CD154. Two different fusion junctions were designed that
resulted in a short or truncated form (form S4) including amino
acids 108 (Glu)-261 (Leu)+(Glu), and a long or complete form (form
L2) including amino acids 48 (Arg)-261 (Leu)+(Glu), of the
extracellular domain of CD154, both constructed as BamHI-XbaI
fragments. The sense primer which fuses the two different truncated
extracellular domains to the 2H7scFv includes a BamHI site for
cloning. The sense primer for the S4 form of the CD154 cDNA is
designated SEQUENCE ID NO:27 or CD154BAM108 and encodes a 34 mer
with the following sequence: 5'-gtt gtc gga tcc aga aaa cag ctt tga
aat gca a-3', while the antisense primer is designated SEQUENCE ID
NO:28 or CD154XBA and encodes a 44 mer with the following sequence:
5'-gtt gtt tct aga tta tca ctc gag ttt gag taa gcc aaa gga
cg-3'.
[0187] The oligonucleotide primers used in amplifying the long form
(L2) of the CD154 extracellular domain encoding amino acids 48
(Arg)-261 (Leu)+(Glu), were as follows: The sense primer designated
CD154 BAM48 (SEQUENCE ID NO:29) encoded a 35-mer with the following
sequence: 5'-gtt gtc gga tcc aag aag gtt gga caa gat aga ag-3'. The
antisense primer designated CD154XBA (SEQUENCE ID NO:28) encoded
the 44-mer: 5'-gtt gtt tct aga tta tca ctc gag ttt gag taa gcc aaa
gga cg-3'. Other PCR reaction conditions were identical to those
used for amplifying the 2H7 scFv (see Example 1). PCR fragments
were purified by PCR quick kits (QIAGEN, San Diego, Calif.), eluted
in 30 .mu.l ddH.sub.2O, and digested with BamHI and XbaI (Roche)
restriction endonucleases in a 40 .mu.l reaction volume at
37.degree. C. for 3 hours. Fragments were gel purified, purified
using QIAEX kits according to the manufacturer's instructions
(QIAGEN), and ligated along with the 2H7 HindIII-Bell fragment into
the pD18 expression vector digested with HindIII+XbaI. Ligation
reactions were transformed into DH5-alpha chemically competent
bacteria and plated onto LB plates containing 100 .mu.g/ml
ampicillin. Transformants were grown overnight at 37.degree. C.,
and isolated colonies used to inoculate 3 ml liquid cultures in
Luria Broth containing 100 .mu.g/ml ampicillin. Clones were
screened after mini-plasmid preparations (QIAGEN) for insertion of
both the 2H7 scFv and the CD154 extracellular domain fragments.
[0188] The 2H7scFv-CD154 construct cDNAs were subjected to cycle
sequencing on a PE 9700 thermocycler using a 25-cycle program that
included denaturating at 96.degree. C., 10 seconds, annealing at
50.degree. C. for 5 seconds, and extension at 60.degree. C., for 4
minutes. The sequencing primers used were pD18 forward (SEQ ID
NO:30: 5'-gtctatataagcagagctctggc-3') and pD18 reverse (SEQ ID
NO:31: 5'-cgaggctgatcagcgagctctagca-3') primers. In addition, an
internal primer was used that had homology to the human CD154
sequence (SEQ ID NO:32: 5'-ccgcaatttgaggattctgatcacc-3').
Sequencing reactions included primers at 3.2 pmol, approximately
200 ng DNA template, and 8 .mu.l sequencing mix. Sequencing
reactions were performed using the Big Dye Terminator Ready
Sequencing Mix (PE-Applied Biosystems, Foster City, Calif.)
according to the manufacturer's instructions. Samples were
subsequently purified using Centrisep columns (Princeton
Separations, Adelphia, N.J.). The eluates were dried in a Savant
speed-vacuum dryer, denatured in 20 .mu.l template Suppression
Reagent (ABI) at 95.degree. C. for 2 minutes, and analyzed on an
ABI 310 Genetic Analyzer (PE-Applied Biosystems). The sequence was
edited, translated, and analyzed using Vector Nti version 6.0
(Informax, North Bethesda, Md.). The 2H7scFv-CD154 L2 cDNA sequence
and predicted amino acid sequence is presented in FIG. 7A, and
2H7scFv-CD 154 S4 cDNA sequence and predicted amino acid sequence
is presented in FIG. 7B.
[0189] The binding activity of the 2H7 scFv-CD154 fusion proteins
(SEQ ID NO:33 and 34) to CD20 and CD40 simultaneously was
determined by flow cytometry. The assay used CHO cell targets that
express CD20. After a 45-minute incubation of CD20 CHO cells with
supernatants from cells transfected with the 2H7 scFv-CD154
expression plasmid, the CD20 CHO cells were washed twice and
incubated with biotin-conjugated CD40-Ig fusion protein in PBS/2%
FBS. After 45 min, cells were washed twicc and incubated with
phycoerythrin (PE)-labeled strepavidin at 1:100 in PBS/2% FBS
(Molecular Probes, Eugene Oreg.). After an additional 30 min
incubation, cells were washed 2.times. and were analyzed by flow
cytometry. The results show that the 2H7 scFv-CD154 molecule was
able to bind to CD20 on the cell surface and to capture
biotin-conjugated CD40 from solution (FIG. 8).
[0190] To determine the effect of the 2H7scFv-CD154 on growth and
viability of B lymphoma and lymphoblastoid cell lines, cells were
incubated with 2H7scFv-CD154 L2 (SEQ. ID NO:33) for 12 hours and
then examined for binding of Annexin V. Binding of Annexin V was
measured using a FITC-Annexin V kit (Immunotech, Marseille, France,
Catalog # PN-IM2376). B cell lines were incubated in 1 ml cultures
with dilutions of concentrated, dialyzed supernatants from cells
expressing secreted forms of the 2H7scFv-CD154 fusion proteins. The
results are presented in FIG. 9.
[0191] The growth rate of the Ramos B lymphoma cell line in the
presence of 2H7scFv-CD154 was examined by uptake of
.sup.3H-thymidine for the last 6 hours of a 24-hour culture. The
effect of 2H7scFv-CD154 on cell proliferation is shown in FIG.
10.
Example 5
Construction and Characterization of CytoxB Antibody
Derivatives
[0192] CytoxB antibodies were derived from the 2H7 scFv-IgG
polypeptide. The 2H7 scFv (see Example 1) was linked to the human
IgG1 Fc domain via an altered hinge domain (see FIG. 11). Cysteine
residues in the hinge region were substituted with serine residues
by site-directed mutagenesis and other methods known in the art.
The mutant hinge was fused either to a wild-type Fc domain to
create one construct, designated CytoB-MHWTG1C, or was fused to a
mutated Fc domain (CytoxB-MHMG1C) that had additional mutations
introduced into the CH2 domain. Amino acid residues in CH2 that are
implicated in effector function are illustrated in FIG. 11.
Mutations of one or more of these residues may reduce FcR binding
and mediation of effector functions. In this example, the leucine
residue 234 known in the art to be important to Fc receptor
binding, was mutated in the 2H7 scFv fusion protein,
CytoxB-[MG1H/MG1C]. In another construct, the human IgG1 hinge
region was substituted with a portion of the human IgA hinge, which
was fused to wild-type human Fc domain (CytoxB-IgAHWTHG1C). (See
FIG. 11). This mutated hinge region allows expression of a mixture
of monomeric and dimeric molecules that retain functional
properties of the human IgG1 CH2 and CH3 domains. Synthetic,
recombinant cDNA expression cassettes for these molecules were
constructed and polypeptides were expressed in CHODG44 cells
according to methods described in Example 2.
[0193] Purified fusion protein derivatives of CytoxB-scFvIg
molecules were analyzed by SDS-PAGE according to the methods
described in Example 2. Polyacrylamide gels were run under
non-reducing and reducing conditions. Two different molecule weight
marker sets, BioRad prestained markers, (BioRad, Hercules, Calif.)
and Novex Multimark molecular weight markers were loaded onto each
gel. The migration patterns of the different constructs and of
Rituximab.TM. are presented in FIG. 12.
[0194] The ability of the different derivatives of CytoxB-scFvIg
molecules to mediated ADCC was measured using the Bjab B lymphoma
cells as the target and freshly prepared human PBMCs as effector
cells. (See Example 2). Effector to target ratios were varied as
follows: 70:1, 35:1, and 18:1, with the number of Bjab cells per
well remaining constant but the number of PBMCs were varied. Bjab
cells were labeled for 2 hours with .sup.5Cr and aliquoted at a
cell density of 5.times.10.sup.4 cells/well to each well of
flat-bottom 96 well plates. Purified fusion proteins or rituximab
were added at a concentration of 10 mg/ml to the various dilutions
of PBMCs. Spontaneous release was measured without addition of PBMC
or fusion protein, and maximal release was measured by the addition
of detergent (1% NP-40) to the appropriate wells. Reactions were
incubated for 4 hours, and 100 .mu.l of culture supernatant was
harvested to a Lumaplate (Packard Instruments) and allowed to dry
overnight prior to counting cpm released. The results are presented
in FIG. 13.
[0195] Complement dependent cytotoxicity (CDC) activity of the
CytoxB derivatives was also measured. Reactions were performed
essentially as described in Example 2. The results are presented in
FIG. 14 as percent of dead cells to total cells for each
concentration of fusion protein.
Example 6
In Vivo Studies in Macaques
[0196] Initial in vivo studies with CytoxB derivatives have been
performed in nonhuman primates. FIG. 15 shows data characterizing
the serum half-life of CytoxB in monkeys. Measurements were
performed on serum samples obtained from two different macaques
(J99231 and K99334) after doses of 6 mg/kg were administered to
each monkey on the days indicated by arrows. For each sample, the
level of 2H7scFvIg present was estimated by comparison to a
standard curve generated by binding of purified CytoxB-(MHWTG1C)-Ig
fusion protein to CD20 CHO cells (see Example 2). The data are
tabulated in the bottom panel of the FIG. 15.
[0197] The effect of CytoxB-(MHWTG1C)Ig fusion protein on levels of
circulating CD40+cells in macaques was investigated. Complete blood
counts were performed at each of the days indicated in FIG. 16. In
addition, FACS (fluorescence activated cell sorter) assays were
performed on peripheral blood lymphocytes using a CD40-specific
fluorescein conjugated antibody to detect B cells among the cell
population. The percentage of positive cells was then used to
calculate the number of B cells in the original samples. The data
are graphed as thousands of B cells per microliter of blood
measured at the days indicated after injection (FIG. 16).
Example 7
Construction and Expression of an Anti-CD19 ScFv-IG Fusion
Protein
[0198] An anti-CD19 scFv-Ig fusion protein was constructed,
transfected into eukaryotic cells, and expressed according to
methods presented in Examples 1, 2, and 5 and standard in the art.
The variable heavy chain regions and variable light chain regions
were cloned from RNA isolated from hybridoma cells producing
antibody HD37, which specifically binds to CD19. Expression levels
of a HD37scFv-IgAHWTG1C and a HD37scFv-IgMHWTG1C were measured and
compared to a standard curve generated using purified HD37 scFvIg.
The results are presented in FIG. 17.
Example 8
Construction and Expression of an Anti-L6 scFv-IG Fusion
Protein
[0199] An scFv-Ig fusion protein was constructed using variable
regions derived from an anti-carcinoma mAb, L6. The fusion protein
was constructed, transfected into eukaryotic cells, and expressed
according to methods presented in Examples 1, 2, and 5 and standard
in the art. Expression levels of L6scFv-IgAHWTG1C and
L6scFv-IgMHWTG1C were measured and compared to a standard curve
generated using purified HD37 scFvIg. The results are presented in
FIG. 18.
Example 9
Characterization of Various ScFv-IG Fusion Proteins
[0200] In addition to the scFv-Ig fusion protein already described,
G28-1 (anti-CD37) scFv-Ig fusion proteins were prepared essentially
as described in Examples 1 and 5. The variable regions of the heavy
and light chains were cloned according to methods known in the art.
ADCC activity of 2H7-MHWTG1C, 2H7-IgAHWTG1C, G28-1-MHWTG1C, G28-1
IgAHWTG1C, HD37-MHWTG1C, and HD37-IgAHWTG1C was determined
according to methods described above (see Example 2). Results are
presented in FIG. 19. ADCC activity of L6scFv-IgAHWTG1C and
L6scFv-IgMHWTG1C was measured using the 2981 human lung carcinoma
cell line. The results are presented in FIG. 20. The murine L6
monoclonal antibody is known not to exhibit ADCC activity.
[0201] The purified proteins were analyzed by SDS-PAGE under
reducing and non-reducing conditions. Samples were prepared and
gels run essentially as described in Examples 2 and 5. The results
for the L6 and 2H7 scFv-Ig fusion proteins are presented in FIG. 21
and the results for the G28-1 and HD37 scFv-Ig fusion proteins are
presented in FIG. 22.
[0202] From the foregoing, it will be appreciated that, although
specific embodiments of the invention have been described herein
for the purpose of illustration, various modifications may be made
without deviating from the spirit and scope of the invention.
Accordingly, the present invention is not limited except as by the
appended claims.
Sequence CWU 1
1
38 1 812 DNA Artificial Sequence SYNTHETIC MOUSE SCFV FUSION GENE 1
aagcttgccg ccatggattt tcaagtgcag attttcagct tcctgctaat cagtgcttca
60 gtcataattg ccagaggaca aattgttctc tcccagtctc cagcaatcct
gtctgcatct 120 ccaggggaga aggtcacaat gacttgcagg gccagctcaa
gtgtaagtta catgcactgg 180 taccagcaga agccaggatc ctcccccaaa
ccctggattt atgccccatc caacctggct 240 tctggagtcc ctgctcgctt
cagtggcagt gggtctggga cctcttactc tctcacaatc 300 agcagagtgg
aggctgaaga tgctgccact tattactgcc agcagtggag ttttaaccca 360
cccacgttcg gtgctgggac caagctggag ctgaaaggtg gcggtggctc gggcggtggt
420 ggatctggag gaggtgggag ctctcaggct tatctacagc agtctggggc
tgagctggtg 480 aggcctgggg cctcagtgaa gatgtcctgc aaggcttctg
gctacacatt taccagttac 540 aatatgcact gggtaaagca gacacctaga
cagggcctgg aatggattgg agctatttat 600 ccaggaaatg gtgatacttc
ctacaatcag aagttcaagg gcaaggccac actgactgta 660 gacaaatcct
ccagcacagc ctacatgcag ctcagcagcc tgacatctga agactctgcg 720
gtctatttct gtgcaagagt ggtgtactat agtaactctt actggtactt cgatgtctgg
780 ggcacaggga ccacggtcac cgtctctgat ca 812 2 1518 DNA Artificial
Sequence SYNTHETIC MOUSE HUMAN CHIMERIC FUSION GENE 2 aagcttgccg
ccatggattt tcaagtgcag attttcagct tcctgctaat cagtgcttca 60
gtcataattg ccagaggaca aattgttctc tcccagtctc cagcaatcct gtctgcatct
120 ccaggggaga aggtcacaat gacttgcagg gccagctcaa gtgtaagtta
catgcactgg 180 taccagcaga agccaggatc ctcccccaaa ccctggattt
atgccccatc caacctggct 240 tctggagtcc ctgctcgctt cagtggcagt
gggtctggga cctcttactc tctcacaatc 300 agcagagtgg aggctgaaga
tgctgccact tattactgcc agcagtggag ttttaaccca 360 cccacgttcg
gtgctgggac caagctggag ctgaaagatg gcggtggctc gggcggtggt 420
ggatctggag gaggtgggag ctctcaggct tatctacagc agtctggggc tgagctggtg
480 aggcctgggg cctcagtgaa gatgtcctgc aaggcttctg gctacacatt
taccagttac 540 aatatgcact gggtaaagca gacacctaga cagggcctgg
aatggattgg agctatttat 600 ccaggaaatg gtgatacttc ctacaatcag
aagttcaagg gcaaggccac actgactgta 660 gacaaatcct ccagcacagc
ctacatgcag ctcagcagcc tgacatctga agactctgcg 720 gtctatttct
gtgcaagagt ggtgtactat agtaactctt actggtactt cgatgtctgg 780
ggcacaggga ccacggtcac cgtctctgat caggagccca aatcttgtga caaaactcac
840 acatgcccac cgtgcccagc acctgaactc ctggggggac cgtcagtctt
cctcttcccc 900 ccaaaaccca aggacaccct catgatctcc cggacccctg
aggtcacatg cgtggtggtg 960 gacgtgagcc acgaagaccc tgaggtcaag
ttcaactggt acgtggacgg cgtggaggtg 1020 cataatgcca agacaaagcc
gcgggaggag cagtacaaca gcacgtaccg tgtggtcagc 1080 gtcctcaccg
tcctgcacca ggactggctg aatggcaagg agtacaagtg caaggtctcc 1140
aacaaagccc tcccagcccc catcgagaaa acaatctcca aagccaaagg gcagccccga
1200 gaaccacagg tgtacaccct gcccccatcc cgggatgagc tgaccaagaa
ccaggtcagc 1260 ctgacctgcc tggtcaaagg cttctatccc agcgacatcg
ccgtggagtg ggagagcaat 1320 gggcagccgg agaacaacta caagaccacg
cctcccgtgc tggactccga cggctccttc 1380 ttcctctaca gcaagctcac
cgtggacaag agcaggtggc agcaggggaa cgtcttctca 1440 tgctccgtga
tgcatgaggc tctgcacaac cactacacgc agaagagcct ctccctgtct 1500
ccgggtaaat gatctaga 1518 3 1518 DNA Artificial Sequence SYNTHETIC
MOUSE-HUMAN CHIMERIC FUSION GENE 3 aagcttgccg ccatggattt tcaagtgcag
attttcagct tcctgctaat cagtgcttca 60 gtcataattg ccagaggaca
aattgttctc tcccagtctc cagcaatcct gtctgcatct 120 ccaggggaga
aggtcacaat gacttgcagg gccagctcaa gtgtaagtta catgcactgg 180
taccagcaga agccaggatc ctcccccaaa ccctggattt atgccccatc caacctggct
240 tctggagtcc ctgctcgctt cagtggcagt gggtctggga cctcttactc
tctcacaatc 300 agcagagtgg aggctgaaga tgctgccact tattactgcc
agcagtggag ttttaaccca 360 cccacgttcg gtgctgggac caagctggag
ctgaaagatg gcggtggctc gggcggtggt 420 ggatctggag gaggtgggag
ctctcaggct tatctacagc agtctggggc tgagctggtg 480 aggcctgggg
cctcagtgaa gatgtcctgc aaggcttctg gctacacatt taccagttac 540
aatatgcact gggtaaagca gacacctaga cagggcctgg aatggattgg agctatttat
600 ccaggaaatg gtgatacttc ctacaatcag aagttcaagg gcaaggccac
actgactgta 660 gacaaatcct ccagcacagc ctacatgcag ctcagcagcc
tgacatctga agactctgcg 720 gtctatttct gtgcaagagt ggtgtactat
agtaactctt actggtactt cgatgtctgg 780 ggcacaggga ccacggtcac
cgtctctgat caggagccca aatcttctga caaaactcac 840 acatccccac
cgtccccagc acctgaactc ctggggggat cgtcagtctt cctcttcccc 900
ccaaaaccca aggacaccct catgatctcc cggacccctg aggtcacatg cgtggtggtg
960 gacgtgagcc acgaagaccc tgaggtcaag ttcaactggt acgtggacgg
cgtggaggtg 1020 cataatgcca agacaaagcc gcgggaggag cagtacaaca
gcacgtaccg tgtggtcagc 1080 gtcctcaccg tcctgcacca ggactggctg
aatggcaagg agtacaagtg caaggtctcc 1140 aacaaagccc tcccagcccc
catcgagaaa acaatctcca aagccaaagg gcagccccga 1200 gaaccacagg
tgtacaccct gcccccatcc cgggatgagc tgaccaagaa ccaggtcagc 1260
ctgacctgcc tggtcaaagg cttctatccc agcgacatcg ccgtggagtg ggagagcaat
1320 gggcagccgg agaacaacta caagaccacg cctcccgtgc tggactccga
cggctccttc 1380 ttcctctaca gcaagctcac cgtggacaag agcaggtggc
agcaggggaa cgtcttctca 1440 tgctccgtga tgcatgaggc tctgcacaac
cactacacgc agaagagcct ctccctgtct 1500 ccgggtaaat gatctaga 1518 4
1518 DNA Artificial Sequence SYNTHETIC MOUSE-HUMAN CHIMERIC FUSION
GENE 4 aagcttgccg ccatggattt tcaagtgcag attttcagct tcctgctaat
cagtgcttca 60 gtcataattg ccagaggaca aattgttctc tcccagtctc
cagcaatcct gtctgcatct 120 ccaggggaga aggtcacaat gacttgcagg
gccagctcaa gtgtaagtta catgcactgg 180 taccagcaga agccaggatc
ctcccccaaa ccctggattt atgccccatc caacctggct 240 tctggagtcc
ctgctcgctt cagtggcagt gggtctggga cctcttactc tctcacaatc 300
agcagagtgg aggctgaaga tgctgccact tattactgcc agcagtggag ttttaaccca
360 cccacgttcg gtgctgggac caagctggag ctgaaagatg gcggtggctc
gggcggtggt 420 ggatctggag gaggtgggag ctctcaggct tatctacagc
agtctggggc tgagctggtg 480 aggcctgggg cctcagtgaa gatgtcctgc
aaggcttctg gctacacatt taccagttac 540 aatatgcact gggtaaagca
gacacctaga cagggcctgg aatggattgg agctatttat 600 ccaggaaatg
gtgatacttc ctacaatcag aagttcaagg gcaaggccac actgactgta 660
gacaaatcct ccagcacagc ctacatgcag ctcagcagcc tgacatctga agactctgcg
720 gtctatttct gtgcaagagt ggtgtactat agtaactctt actggtactt
cgatgtctgg 780 ggcacaggga ccacggtcac cgtctctgat caggagccca
aatcttctga caaaactcac 840 acatccccac cgtccccagc acctgaactc
ctggggggac cgtcagtctt cctcttcccc 900 ccaaaaccca aggacaccct
catgatctcc cggacccctg aggtcacatg cgtggtggtg 960 gacgtgagcc
acgaagaccc tgaggtcaag ttcaactggt acgtggacgg cgtggaggtg 1020
cataatgcca agacaaagcc gcgggaggag cagtacaaca gcacgtaccg tgtggtcagc
1080 gtcctcaccg tcctgcacca ggactggctg aatggcaagg agtacaagtg
caaggtctcc 1140 aacaaagccc tcccagcccc catcgagaaa acaatctcca
aagccaaagg gcagccccga 1200 gaaccacagg tgtacaccct gcccccatcc
cgggatgagc tgaccaagaa ccaggtcagc 1260 ctgacctgcc tggtcaaagg
cttctatccc agcgacatcg ccgtggagtg ggagagcaat 1320 gggcagccgg
agaacaacta caagaccacg cctcccgtgc tggactccga cggctccttc 1380
ttcctctaca gcaagctcac cgtggacaag agcaggtggc agcaggggaa cgtcttctca
1440 tgctccgtga tgcatgaggc tctgcacaac cactacacgc agaagagcct
ctccctgtct 1500 ccgggtaaat gatctaga 1518 5 1524 DNA Artificial
Sequence SYNTHETIC MOUSE HUMAN CHIMERIC FUSION GENE 5 atggattttc
aagtgcagat tttcagcttc ctgctaatca gtgcttcagt cataattgcc 60
agaggacaaa ttgttctctc ccagtctcca gcaatcctgt ctgcatctcc aggggagaag
120 gtcacaatga cttgcagggc cagctcaagt gtaagttaca tgcactggta
ccagcagaag 180 ccaggatcct cccccaaacc ctggatttat gccccatcca
acctggcttc tggagtccct 240 gctcgcttca gtggcagtgg gtctgggacc
tcttactctc tcacaatcag cagagtggag 300 gctgaagatg ctgccactta
ttactgccag cagtggagtt ttaacccacc cacgttcggt 360 gctgggacca
agctggagct gaaagatggc ggtggctcgg gcggtggtgg atctggagga 420
ggtgggagct ctcaggctta tctacagcag tctggggctg agctggtgag gcctggggcc
480 tcagtgaaga tgtcctgcaa ggcttctggc tacacattta ccagttacaa
tatgcactgg 540 gtaaagcaga cacctagaca gggcctggaa tggattggag
ctatttatcc aggaaatggt 600 gatacttcct acaatcagaa gttcaagggc
aaggccacac tgactgtaga caaatcctcc 660 agcacagcct acatgcagct
cagcagcctg acatctgaag actctgcggt ctatttctgt 720 gcaagagtgg
tgtactatag taactcttac tggtacttcg atgtctgggg cacagggacc 780
acggtcaccg tctctgatca gccagttccc tcaactccac ctaccccatc tccctcaact
840 ccacctaccc catctccctc atgcgcacct gaactcctgg ggggaccgtc
agtcttcctc 900 ttccccccaa aacccaagga caccctcatg atctcccgga
cccctgaggt cacatgcgtg 960 gtggtggacg tgagccacga agaccctgag
gtcaagttca actggtacgt ggacggcgtg 1020 gaggtgcata atgccaagac
aaagccgcgg gaggagcagt acaacagcac gtaccgtgtg 1080 gtcagcgtcc
tcaccgtcct gcaccaggac tggctgaatg gcaaggagta caagtgcaag 1140
gtctccaaca aagccctccc agcccccatc gagaaaacaa tctccaaagc caaagggcag
1200 ccccgagaac cacaggtgta caccctgccc ccatcccggg atgagctgac
caagaaccag 1260 gtcagcctga cctgcctggt caaaggcttc tatcccagcg
acatcgccgt ggagtgggag 1320 agcaatgggc agccggagaa caactacaag
accacgcctc ccgtgctgga ctccgacggc 1380 tccttcttcc tctacagcaa
gctcaccgtg gacaagagca ggtggcagca ggggaacgtc 1440 ttctcatgct
ccgtgatgca tgaggctctg cacaaccact acacgcagaa gagcctctcc 1500
ctgtctccgg gtaaatgatc taga 1524 6 711 DNA Artificial Sequence
SYNTHETIC HUMAN PARTIAL FUSION GENE 6 gatcaggagc ccaaatcttc
tgacaaaact cacacatccc caccgtcccc agcacctgaa 60 ctcctggggg
gaccgtcagt cttcctcttc cccccaaaac ccaaggacac cctcatgatc 120
tcccggaccc ctgaggtcac atgcgtggtg gtggacgtga gccacgaaga ccctgaggtc
180 aagttcaact ggtacgtgga cggcgtggag gtgcataatg ccaagacaaa
gccgcgggag 240 gagcagtaca acagcacgta ccgtgtggtc agcgtcctca
ccgtcctgca ccaggactgg 300 ctgaatggca aggagtacaa gtgcaaggtc
tccaacaaag ccctcccagc ccccatcgag 360 aaaacaatct ccaaagccaa
agggcagccc cgagaaccac aggtgtacac cctgccccca 420 tcccgggatg
agctgaccaa gaaccaggtc agcctgacct gcctggtcaa aggcttctat 480
cccagcgaca tcgccgtgga gtgggagagc aatgggcagc cggagaacaa ctacaagacc
540 acgcctcccg tgctggactc cgacggctcc ttcttcctct acagcaagct
caccgtggac 600 aagagcaggt ggcagcaggg gaacgtcttc tcatgctccg
tgatgcatga ggctctgcac 660 aaccactaca cgcagaagag cctctccctg
tctccgggta aatgatctag a 711 7 729 DNA Artificial Sequence SYNTHETIC
HUMAN PARTIAL FUSION GENE 7 gatcagccag ttccctcaac tccacctacc
ccatctccct caactccacc taccccatct 60 ccctcatgcg cacctgaact
cctgggggga ccgtcagtct tcctcttccc cccaaaaccc 120 aaggacaccc
tcatgatctc ccggacccct gaggtcacat gcgtggtggt ggacgtgagc 180
cacgaagacc ctgaggtcaa gttcaactgg tacgtggacg gcgtggaggt gcataatgcc
240 aagacaaagc cgcgggagga gcagtacaac agcacgtacc gtgtggtcag
cgtcctcacc 300 gtcctgcacc aggactggct gaatggcaag gagtacaagt
gcaaggtctc caacaaagcc 360 ctcccagccc ccatcgagaa aacaatctcc
aaagccaaag ggcagccccg agaaccacag 420 gtgtacaccc tgcccccatc
ccgggatgag ctgaccaaga accaggtcag cctgacctgc 480 ctggtcaaag
gcttctatcc cagcgacatc gccgtggagt gggagagcaa tgggcagccg 540
gagaacaact acaagaccac gcctcccgtg ctggactccg acggctcctt cttcctctac
600 agcaagctca ccgtggacaa gagcaggtgg cagcagggga acgtcttctc
atgctccgtg 660 atgcatgagg ctctgcacaa ccactacacg cagaagagcc
tctccctgtc tccgggtaaa 720 tgatctaga 729 8 825 DNA Artificial
Sequence SYNTHETIC MOUSE SCFV FUSION GENE 8 aagcttgccg ccatggagac
agacacactc ctgctatggg tgctgctgct ctgggttcca 60 ggctccactg
gtgacattgt gctgacccaa tctccagctt ctttggctgt gtctctaggg 120
cagagggcca ccatctcctg caaggccagc caaagtgttg attatgatgg tgatagttat
180 ttgaactggt accaacagat tccaggacag ccacccaaac tcctcatcta
tgatgcatcc 240 aatctagttt ctgggatccc acccaggttt agtggcagtg
ggtctgggac agacttcacc 300 ctcaacatcc atcctgtgga gaaggtggat
gctgcaacct atcactgtca gcaaagtact 360 gaggatccgt ggacgttcgg
tggaggcacc aagctggaaa tcaaaggtgg cggtggctcg 420 ggcggtggtg
ggtcgggtgg cggcggatcg tcacaggttc agctgcagca gtctggggct 480
gagctggtga ggcctgggtc ctcagtgaag atttcctgca aggcttctgg ctatgcattc
540 agtagctact ggatgaactg ggtgaagcag aggcctggac agggtcttga
gtggattgga 600 cagatttggc ctggagatgg tgatactaac tacaatggaa
agttcaaggg taaagccact 660 ctgactgcag acgaatcctc cagcacagcc
tacatgcaac tcagcagcct agcatctgag 720 gactctgcgg tctatttctg
tgcaagacgg gagactacga cggtaggccg ttattactat 780 gctatggact
actggggtca aggaacctca gtcaccgtct cctca 825 9 795 DNA Artificial
Sequence SYNTHETIC MOUSE SCFV FUSION GENE 9 aagcttgccg ccatggtatc
cacagctcag ttccttgggt tgctgctgct gtggcttaca 60 ggtggcagat
gtgacatcca gatgactcag tctccagcct ccctatctgc atctgtggga 120
gagactgtca ccatcacatg tcgaacaagt gaaaatgttt acagttattt ggcttggtat
180 cagcagaaac agggaaaatc tcctcagctc ctggtctctt ttgcaaaaac
cttagcagaa 240 ggtgtgccat caaggttcag tggcagtgga tcaggcacac
agttttctct gaagatcagc 300 agcctgcagc ctgaagattc tggaagttat
ttctgtcaac atcattccga taatccgtgg 360 acgttcggtg gaggcaccga
actggagatc aaaggtggcg gtggctcggg cggtggtggg 420 tcgggtggcg
gcggatcgtc agcggtccag ctgcagcagt ctggacctga gctggaaaag 480
cctggcgctt cagtgaagat ttcctgcaag gcttctggtt actcattcac tggctacaat
540 atgaactggg tgaagcagaa taatggaaag agccttgagt ggattggaaa
tattgatcct 600 tattatggtg gtactaccta caaccggaag ttcaagggca
aggccacatt gactgtagac 660 aaatcctcca gcacagccta catgcagctc
aagagtctga catctgagga ctctgcagtc 720 tattactgtg caagatcggt
cggccctatg gactactggg gtcaaggaac ctcagtcacc 780 gtctcttctg atcag
795 10 824 DNA Artificial Sequence SYNTHETIC MOUSE FUSION GENE 10
atggagtcac attcccaggt ctttctctcc ctgctgctct gggtatctgg tacctgtggg
60 aacattatga tgacacagtc gccatcatct ctggctgtgt cagcaggaga
aaaggtcact 120 atgaactgta agtccagtca aagtgttttc tacagttcaa
atcagaggaa ttatttggcc 180 tggtatcagc agaaaccagg gcagtctccc
aaattgctga tctactgggc atctactagg 240 gaatctggtg tccctgatcg
cttcacaggc agtggatccg ggacagactt tactcttacc 300 atcagcagtg
tacatactga agacctggca gtttattact gtcatcaatt cctctcttcg 360
tggacgttcg gtggaggcac caagctggaa atcaaaggcg gtggtggttc gggtggtggt
420 ggttcgggtg gcggcggatc ttctcaggtc caactgcagc agcctggggc
tgaactggtg 480 aagcctggga cttcagtgaa gctgtcctgc aaggcctctg
gctacacctt caccaactac 540 tggatggtct gggtgaagca gacgcctgga
gaaggccttg agtggattgg agaaattatt 600 cctagcaacg gtcgtactaa
atacaatgag aagttcaaga gcaaggccac actgactgca 660 gacaaatcct
cccgcacagc ctacatgcaa ctcagcagcc tggcatctga ggactctgcg 720
gtctattatt gtgcaagaga gatgtccatt attactacgg tactgactcc cggtttgctt
780 actggggcca agggactctg gtcactgtct ctgcagcctg atca 824 11 266 PRT
Mus musculus INIT_MET (1)..(1) SIGNAL (1)..(22) DOMAIN (23)..(128)
LIGHT CHAIN VARIABLE DOMAIN FOR MOUSE ANTI-HUMAN CD20 11 Met Asp
Phe Gln Val Gln Ile Phe Ser Phe Leu Leu Ile Ser Ala Ser 1 5 10 15
Val Ile Ile Ala Arg Gly Gln Ile Val Leu Ser Gln Ser Pro Ala Ile 20
25 30 Leu Ser Ala Ser Pro Gly Glu Lys Val Thr Met Thr Cys Arg Ala
Ser 35 40 45 Ser Ser Val Ser Tyr Met His Trp Tyr Gln Gln Lys Pro
Gly Ser Ser 50 55 60 Pro Lys Pro Trp Ile Tyr Ala Pro Ser Asn Leu
Ala Ser Gly Val Pro 65 70 75 80 Ala Arg Phe Ser Gly Ser Gly Ser Gly
Thr Ser Tyr Ser Leu Thr Ile 85 90 95 Ser Arg Val Glu Ala Glu Asp
Ala Ala Thr Tyr Tyr Cys Gln Gln Trp 100 105 110 Ser Phe Asn Pro Pro
Thr Phe Gly Ala Gly Thr Lys Leu Glu Leu Lys 115 120 125 Asp Gly Gly
Gly Ser Gly Gly Gly Gly Ser Gly Gly Gly Gly Ser Ser 130 135 140 Gln
Ala Tyr Leu Gln Gln Ser Gly Ala Glu Leu Val Arg Pro Gly Ala 145 150
155 160 Ser Val Lys Met Ser Cys Lys Ala Ser Gly Tyr Thr Phe Thr Ser
Tyr 165 170 175 Asn Met His Trp Val Lys Gln Thr Pro Arg Gln Gly Leu
Glu Trp Ile 180 185 190 Gly Ala Ile Tyr Pro Gly Asn Gly Asp Thr Ser
Tyr Asn Gln Lys Phe 195 200 205 Lys Gly Lys Ala Thr Leu Thr Val Asp
Lys Ser Ser Ser Thr Ala Tyr 210 215 220 Met Gln Leu Ser Ser Leu Thr
Ser Glu Asp Ser Ala Val Tyr Phe Cys 225 230 235 240 Ala Arg Val Val
Tyr Tyr Ser Asn Ser Tyr Trp Tyr Phe Asp Val Trp 245 250 255 Gly Thr
Gly Thr Thr Val Thr Val Ser Asp 260 265 12 271 PRT Mus musculus
SITE (1)..(271) MOUSE ANTI-HUMAN CD19 SCFV 12 Met Glu Thr Asp Thr
Leu Leu Leu Trp Val Leu Leu Leu Trp Val Pro 1 5 10 15 Gly Ser Thr
Gly Asp Ile Val Leu Thr Gln Ser Pro Ala Ser Leu Ala 20 25 30 Val
Ser Leu Gly Gln Arg Ala Thr Ile Ser Cys Lys Ala Ser Gln Ser 35 40
45 Val Asp Tyr Asp Gly Asp Ser Tyr Leu Asn Trp Tyr Gln Gln Ile Pro
50 55 60 Gly Gln Pro Pro Lys Leu Leu Ile Tyr Asp Ala Ser Asn Leu
Val Ser 65 70 75 80 Gly Ile Pro Pro Arg Phe Ser Gly Ser Gly Ser Gly
Thr Asp Phe Thr 85 90 95 Leu Asn Ile His Pro Val Glu Lys Val Asp
Ala Ala Thr Tyr His Cys 100 105 110 Gln Gln Ser Thr Glu Asp Pro Trp
Thr Phe Gly Gly Gly Thr Lys Leu 115 120 125 Glu Ile Lys Gly Gly Gly
Gly Ser Gly Gly Gly Gly Ser Gly Gly Gly 130 135 140 Gly Ser Ser Gln
Val Gln Leu Gln Gln Ser Gly Ala Glu Leu Val Arg 145 150 155 160 Pro
Gly Ser Ser Val Lys Ile Ser Cys Lys Ala Ser Gly Tyr Ala Phe 165 170
175 Ser Ser Tyr Trp Met Asn Trp Val Lys Gln Arg Pro Gly Gln Gly Leu
180 185 190 Glu Trp Ile Gly Gln Ile Trp Pro Gly Asp Gly Asp Thr Asn
Tyr Asn 195 200 205 Gly Lys Phe Lys Gly Lys Ala Thr Leu Thr Ala Asp
Glu Ser Ser Ser 210 215 220 Thr Ala Tyr Met Gln Leu Ser Ser Leu Ala
Ser Glu Asp Ser Ala Val 225 230 235 240 Tyr Phe Cys Ala Arg Arg Glu
Thr Thr Thr Val Gly Arg Tyr Tyr Tyr 245 250
255 Ala Met Asp Tyr Trp Gly Gln Gly Thr Ser Val Thr Val Ser Ser 260
265 270 13 259 PRT Mus musculus SITE (1)..(259) MOUSE ANTI-HUMAN
CD37 SCFV 13 Met Val Ser Thr Ala Gln Phe Leu Gly Leu Leu Leu Leu
Trp Leu Thr 1 5 10 15 Gly Gly Arg Cys Asp Ile Gln Met Thr Gln Ser
Pro Ala Ser Leu Ser 20 25 30 Ala Ser Val Gly Glu Thr Val Thr Ile
Thr Cys Arg Thr Ser Glu Asn 35 40 45 Val Tyr Ser Tyr Leu Ala Trp
Tyr Gln Gln Lys Gln Gly Lys Ser Pro 50 55 60 Gln Leu Leu Val Ser
Phe Ala Lys Thr Leu Ala Glu Gly Val Pro Ser 65 70 75 80 Arg Phe Ser
Gly Ser Gly Ser Gly Thr Gln Phe Ser Leu Lys Ile Ser 85 90 95 Ser
Leu Gln Pro Glu Asp Ser Gly Ser Tyr Phe Cys Gln His His Ser 100 105
110 Asp Asn Pro Trp Thr Phe Gly Gly Gly Thr Glu Leu Glu Ile Lys Gly
115 120 125 Gly Gly Gly Ser Gly Gly Gly Gly Ser Gly Gly Gly Gly Ser
Ser Ala 130 135 140 Val Gln Leu Gln Gln Ser Gly Pro Glu Leu Glu Lys
Pro Gly Ala Ser 145 150 155 160 Val Lys Ile Ser Cys Lys Ala Ser Gly
Tyr Ser Phe Thr Gly Tyr Asn 165 170 175 Met Asn Trp Val Lys Gln Asn
Asn Gly Lys Ser Leu Glu Trp Ile Gly 180 185 190 Asn Ile Asp Pro Tyr
Tyr Gly Gly Thr Thr Tyr Asn Arg Lys Phe Lys 195 200 205 Gly Lys Ala
Thr Leu Thr Val Asp Lys Ser Ser Ser Thr Ala Tyr Met 210 215 220 Gln
Leu Lys Ser Leu Thr Ser Glu Asp Ser Ala Val Tyr Tyr Cys Ala 225 230
235 240 Arg Ser Val Gly Pro Met Asp Tyr Trp Gly Gln Gly Thr Ser Val
Thr 245 250 255 Val Ser Ser 14 272 PRT Mus musculus SITE (1)..(272)
MOUSE ANTI-HUMAN CD22 SCFV 14 Met Glu Ser His Ser Gln Val Phe Leu
Ser Leu Leu Leu Trp Val Ser 1 5 10 15 Gly Thr Cys Gly Asn Ile Met
Met Thr Gln Ser Pro Ser Ser Leu Ala 20 25 30 Val Ser Ala Gly Glu
Lys Val Thr Met Asn Cys Lys Ser Ser Gln Ser 35 40 45 Val Phe Tyr
Ser Ser Asn Gln Arg Asn Tyr Leu Ala Trp Tyr Gln Gln 50 55 60 Lys
Pro Gly Gln Ser Pro Lys Leu Leu Ile Tyr Trp Ala Ser Thr Arg 65 70
75 80 Glu Ser Gly Val Pro Asp Arg Phe Thr Gly Ser Gly Ser Gly Thr
Asp 85 90 95 Phe Thr Leu Thr Ile Ser Ser Val His Thr Glu Asp Leu
Ala Val Tyr 100 105 110 Tyr Cys His Gln Phe Leu Ser Ser Trp Thr Phe
Gly Gly Gly Thr Lys 115 120 125 Leu Glu Ile Lys Gly Gly Gly Gly Ser
Gly Gly Gly Gly Ser Gly Gly 130 135 140 Gly Gly Ser Ser Gln Val Gln
Leu Gln Gln Pro Gly Ala Glu Leu Val 145 150 155 160 Lys Pro Gly Thr
Ser Val Lys Leu Ser Cys Lys Ala Ser Gly Tyr Thr 165 170 175 Phe Thr
Asn Tyr Trp Met Val Trp Val Lys Gln Thr Pro Gly Glu Gly 180 185 190
Leu Glu Trp Ile Gly Glu Ile Ile Pro Ser Asn Gly Arg Thr Lys Tyr 195
200 205 Asn Glu Lys Phe Lys Ser Lys Ala Thr Leu Thr Ala Asp Lys Ser
Ser 210 215 220 Arg Thr Ala Tyr Met Gln Leu Ser Ser Leu Ala Ser Glu
Asp Ser Ala 225 230 235 240 Val Tyr Tyr Cys Ala Arg Glu Met Ser Ile
Ile Thr Thr Val Leu Thr 245 250 255 Pro Gly Leu Leu Thr Gly Ala Lys
Gly Leu Trp Ser Leu Ser Leu Gln 260 265 270 15 499 PRT Artificial
Sequence MOUSE-HUMAN HYBRID FUSION PROTEIN 15 Met Asp Phe Gln Val
Gln Ile Phe Ser Phe Leu Leu Ile Ser Ala Ser 1 5 10 15 Val Ile Ile
Ala Arg Gly Gln Ile Val Leu Ser Gln Ser Pro Ala Ile 20 25 30 Leu
Ser Ala Ser Pro Gly Glu Lys Val Thr Met Thr Cys Arg Ala Ser 35 40
45 Ser Ser Val Ser Tyr Met His Trp Tyr Gln Gln Lys Pro Gly Ser Ser
50 55 60 Pro Lys Pro Trp Ile Tyr Ala Pro Ser Asn Leu Ala Ser Gly
Val Pro 65 70 75 80 Ala Arg Phe Ser Gly Ser Gly Ser Gly Thr Ser Tyr
Ser Leu Thr Ile 85 90 95 Ser Arg Val Glu Ala Glu Asp Ala Ala Thr
Tyr Tyr Cys Gln Gln Trp 100 105 110 Ser Phe Asn Pro Pro Thr Phe Gly
Ala Gly Thr Lys Leu Glu Leu Lys 115 120 125 Asp Gly Gly Gly Ser Gly
Gly Gly Gly Ser Gly Gly Gly Gly Ser Ser 130 135 140 Gln Ala Tyr Leu
Gln Gln Ser Gly Ala Glu Leu Val Arg Pro Gly Ala 145 150 155 160 Ser
Val Lys Met Ser Cys Lys Ala Ser Gly Tyr Thr Phe Thr Ser Tyr 165 170
175 Asn Met His Trp Val Lys Gln Thr Pro Arg Gln Gly Leu Glu Trp Ile
180 185 190 Gly Ala Ile Tyr Pro Gly Asn Gly Asp Thr Ser Tyr Asn Gln
Lys Phe 195 200 205 Lys Gly Lys Ala Thr Leu Thr Val Asp Lys Ser Ser
Ser Thr Ala Tyr 210 215 220 Met Gln Leu Ser Ser Leu Thr Ser Glu Asp
Ser Ala Val Tyr Phe Cys 225 230 235 240 Ala Arg Val Val Tyr Tyr Ser
Asn Ser Tyr Trp Tyr Phe Asp Val Trp 245 250 255 Gly Thr Gly Thr Thr
Val Thr Val Ser Asp Gln Glu Pro Lys Ser Cys 260 265 270 Asp Lys Thr
His Thr Cys Pro Pro Cys Pro Ala Pro Glu Leu Leu Gly 275 280 285 Gly
Pro Ser Val Phe Leu Phe Pro Pro Lys Pro Lys Asp Thr Leu Met 290 295
300 Ile Ser Arg Thr Pro Glu Val Thr Cys Val Val Val Asp Val Ser His
305 310 315 320 Glu Asp Pro Glu Val Lys Phe Asn Trp Tyr Val Asp Gly
Val Glu Val 325 330 335 His Asn Ala Lys Thr Lys Pro Arg Glu Glu Gln
Tyr Asn Ser Thr Tyr 340 345 350 Arg Val Val Ser Val Leu Thr Val Leu
His Gln Asp Trp Leu Asn Gly 355 360 365 Lys Glu Tyr Lys Cys Lys Val
Ser Asn Lys Ala Leu Pro Ala Pro Ile 370 375 380 Glu Lys Thr Ile Ser
Lys Ala Lys Gly Gln Pro Arg Glu Pro Gln Val 385 390 395 400 Tyr Thr
Leu Pro Pro Ser Arg Asp Glu Leu Thr Lys Asn Gln Val Ser 405 410 415
Leu Thr Cys Leu Val Lys Gly Phe Tyr Pro Ser Asp Ile Ala Val Glu 420
425 430 Trp Glu Ser Asn Gly Gln Pro Glu Asn Asn Tyr Lys Thr Thr Pro
Pro 435 440 445 Val Leu Asp Ser Asp Gly Ser Phe Phe Leu Tyr Ser Lys
Leu Thr Val 450 455 460 Asp Lys Ser Arg Trp Gln Gln Gly Asn Val Phe
Ser Cys Ser Val Met 465 470 475 480 His Glu Ala Leu His Asn His Tyr
Thr Gln Lys Ser Leu Ser Leu Ser 485 490 495 Pro Gly Lys 16 499 PRT
Artificial Sequence MOUSE-HUMAN HYBRID FUSION PROTEIN 16 Met Asp
Phe Gln Val Gln Ile Phe Ser Phe Leu Leu Ile Ser Ala Ser 1 5 10 15
Val Ile Ile Ala Arg Gly Gln Ile Val Leu Ser Gln Ser Pro Ala Ile 20
25 30 Leu Ser Ala Ser Pro Gly Glu Lys Val Thr Met Thr Cys Arg Ala
Ser 35 40 45 Ser Ser Val Ser Tyr Met His Trp Tyr Gln Gln Lys Pro
Gly Ser Ser 50 55 60 Pro Lys Pro Trp Ile Tyr Ala Pro Ser Asn Leu
Ala Ser Gly Val Pro 65 70 75 80 Ala Arg Phe Ser Gly Ser Gly Ser Gly
Thr Ser Tyr Ser Leu Thr Ile 85 90 95 Ser Arg Val Glu Ala Glu Asp
Ala Ala Thr Tyr Tyr Cys Gln Gln Trp 100 105 110 Ser Phe Asn Pro Pro
Thr Phe Gly Ala Gly Thr Lys Leu Glu Leu Lys 115 120 125 Asp Gly Gly
Gly Ser Gly Gly Gly Gly Ser Gly Gly Gly Gly Ser Ser 130 135 140 Gln
Ala Tyr Leu Gln Gln Ser Gly Ala Glu Leu Val Arg Pro Gly Ala 145 150
155 160 Ser Val Lys Met Ser Cys Lys Ala Ser Gly Tyr Thr Phe Thr Ser
Tyr 165 170 175 Asn Met His Trp Val Lys Gln Thr Pro Arg Gln Gly Leu
Glu Trp Ile 180 185 190 Gly Ala Ile Tyr Pro Gly Asn Gly Asp Thr Ser
Tyr Asn Gln Lys Phe 195 200 205 Lys Gly Lys Ala Thr Leu Thr Val Asp
Lys Ser Ser Ser Thr Ala Tyr 210 215 220 Met Gln Leu Ser Ser Leu Thr
Ser Glu Asp Ser Ala Val Tyr Phe Cys 225 230 235 240 Ala Arg Val Val
Tyr Tyr Ser Asn Ser Tyr Trp Tyr Phe Asp Val Trp 245 250 255 Gly Thr
Gly Thr Thr Val Thr Val Ser Asp Gln Glu Pro Lys Ser Ser 260 265 270
Asp Lys Thr His Thr Ser Pro Pro Ser Pro Ala Pro Glu Leu Leu Gly 275
280 285 Gly Ser Ser Val Phe Leu Phe Pro Pro Lys Pro Lys Asp Thr Leu
Met 290 295 300 Ile Ser Arg Thr Pro Glu Val Thr Cys Val Val Val Asp
Val Ser His 305 310 315 320 Glu Asp Pro Glu Val Lys Phe Asn Trp Tyr
Val Asp Gly Val Glu Val 325 330 335 His Asn Ala Lys Thr Lys Pro Arg
Glu Glu Gln Tyr Asn Ser Thr Tyr 340 345 350 Arg Val Val Ser Val Leu
Thr Val Leu His Gln Asp Trp Leu Asn Gly 355 360 365 Lys Glu Tyr Lys
Cys Lys Val Ser Asn Lys Ala Leu Pro Ala Pro Ile 370 375 380 Glu Lys
Thr Ile Ser Lys Ala Lys Gly Gln Pro Arg Glu Pro Gln Val 385 390 395
400 Tyr Thr Leu Pro Pro Ser Arg Asp Glu Leu Thr Lys Asn Gln Val Ser
405 410 415 Leu Thr Cys Leu Val Lys Gly Phe Tyr Pro Ser Asp Ile Ala
Val Glu 420 425 430 Trp Glu Ser Asn Gly Gln Pro Glu Asn Asn Tyr Lys
Thr Thr Pro Pro 435 440 445 Val Leu Asp Ser Asp Gly Ser Phe Phe Leu
Tyr Ser Lys Leu Thr Val 450 455 460 Asp Lys Ser Arg Trp Gln Gln Gly
Asn Val Phe Ser Cys Ser Val Met 465 470 475 480 His Glu Ala Leu His
Asn His Tyr Thr Gln Lys Ser Leu Ser Leu Ser 485 490 495 Pro Gly Lys
17 499 PRT Artificial Sequence MOUSE-HUMAN HYBRID FUSION PROTEIN 17
Met Asp Phe Gln Val Gln Ile Phe Ser Phe Leu Leu Ile Ser Ala Ser 1 5
10 15 Val Ile Ile Ala Arg Gly Gln Ile Val Leu Ser Gln Ser Pro Ala
Ile 20 25 30 Leu Ser Ala Ser Pro Gly Glu Lys Val Thr Met Thr Cys
Arg Ala Ser 35 40 45 Ser Ser Val Ser Tyr Met His Trp Tyr Gln Gln
Lys Pro Gly Ser Ser 50 55 60 Pro Lys Pro Trp Ile Tyr Ala Pro Ser
Asn Leu Ala Ser Gly Val Pro 65 70 75 80 Ala Arg Phe Ser Gly Ser Gly
Ser Gly Thr Ser Tyr Ser Leu Thr Ile 85 90 95 Ser Arg Val Glu Ala
Glu Asp Ala Ala Thr Tyr Tyr Cys Gln Gln Trp 100 105 110 Ser Phe Asn
Pro Pro Thr Phe Gly Ala Gly Thr Lys Leu Glu Leu Lys 115 120 125 Asp
Gly Gly Gly Ser Gly Gly Gly Gly Ser Gly Gly Gly Gly Ser Ser 130 135
140 Gln Ala Tyr Leu Gln Gln Ser Gly Ala Glu Leu Val Arg Pro Gly Ala
145 150 155 160 Ser Val Lys Met Ser Cys Lys Ala Ser Gly Tyr Thr Phe
Thr Ser Tyr 165 170 175 Asn Met His Trp Val Lys Gln Thr Pro Arg Gln
Gly Leu Glu Trp Ile 180 185 190 Gly Ala Ile Tyr Pro Gly Asn Gly Asp
Thr Ser Tyr Asn Gln Lys Phe 195 200 205 Lys Gly Lys Ala Thr Leu Thr
Val Asp Lys Ser Ser Ser Thr Ala Tyr 210 215 220 Met Gln Leu Ser Ser
Leu Thr Ser Glu Asp Ser Ala Val Tyr Phe Cys 225 230 235 240 Ala Arg
Val Val Tyr Tyr Ser Asn Ser Tyr Trp Tyr Phe Asp Val Trp 245 250 255
Gly Thr Gly Thr Thr Val Thr Val Ser Asp Gln Glu Pro Lys Ser Ser 260
265 270 Asp Lys Thr His Thr Ser Pro Pro Ser Pro Ala Pro Glu Leu Leu
Gly 275 280 285 Gly Pro Ser Val Phe Leu Phe Pro Pro Lys Pro Lys Asp
Thr Leu Met 290 295 300 Ile Ser Arg Thr Pro Glu Val Thr Cys Val Val
Val Asp Val Ser His 305 310 315 320 Glu Asp Pro Glu Val Lys Phe Asn
Trp Tyr Val Asp Gly Val Glu Val 325 330 335 His Asn Ala Lys Thr Lys
Pro Arg Glu Glu Gln Tyr Asn Ser Thr Tyr 340 345 350 Arg Val Val Ser
Val Leu Thr Val Leu His Gln Asp Trp Leu Asn Gly 355 360 365 Lys Glu
Tyr Lys Cys Lys Val Ser Asn Lys Ala Leu Pro Ala Pro Ile 370 375 380
Glu Lys Thr Ile Ser Lys Ala Lys Gly Gln Pro Arg Glu Pro Gln Val 385
390 395 400 Tyr Thr Leu Pro Pro Ser Arg Asp Glu Leu Thr Lys Asn Gln
Val Ser 405 410 415 Leu Thr Cys Leu Val Lys Gly Phe Tyr Pro Ser Asp
Ile Ala Val Glu 420 425 430 Trp Glu Ser Asn Gly Gln Pro Glu Asn Asn
Tyr Lys Thr Thr Pro Pro 435 440 445 Val Leu Asp Ser Asp Gly Ser Phe
Phe Leu Tyr Ser Lys Leu Thr Val 450 455 460 Asp Lys Ser Arg Trp Gln
Gln Gly Asn Val Phe Ser Cys Ser Val Met 465 470 475 480 His Glu Ala
Leu His Asn His Tyr Thr Gln Lys Ser Leu Ser Leu Ser 485 490 495 Pro
Gly Lys 18 505 PRT Artificial Sequence MOUSE-HUMAN FUSION PROTEIN
18 Met Asp Phe Gln Val Gln Ile Phe Ser Phe Leu Leu Ile Ser Ala Ser
1 5 10 15 Val Ile Ile Ala Arg Gly Gln Ile Val Leu Ser Gln Ser Pro
Ala Ile 20 25 30 Leu Ser Ala Ser Pro Gly Glu Lys Val Thr Met Thr
Cys Arg Ala Ser 35 40 45 Ser Ser Val Ser Tyr Met His Trp Tyr Gln
Gln Lys Pro Gly Ser Ser 50 55 60 Pro Lys Pro Trp Ile Tyr Ala Pro
Ser Asn Leu Ala Ser Gly Val Pro 65 70 75 80 Ala Arg Phe Ser Gly Ser
Gly Ser Gly Thr Ser Tyr Ser Leu Thr Ile 85 90 95 Ser Arg Val Glu
Ala Glu Asp Ala Ala Thr Tyr Tyr Cys Gln Gln Trp 100 105 110 Ser Phe
Asn Pro Pro Thr Phe Gly Ala Gly Thr Lys Leu Glu Leu Lys 115 120 125
Asp Gly Gly Gly Ser Gly Gly Gly Gly Ser Gly Gly Gly Gly Ser Ser 130
135 140 Gln Ala Tyr Leu Gln Gln Ser Gly Ala Glu Leu Val Arg Pro Gly
Ala 145 150 155 160 Ser Val Lys Met Ser Cys Lys Ala Ser Gly Tyr Thr
Phe Thr Ser Tyr 165 170 175 Asn Met His Trp Val Lys Gln Thr Pro Arg
Gln Gly Leu Glu Trp Ile 180 185 190 Gly Ala Ile Tyr Pro Gly Asn Gly
Asp Thr Ser Tyr Asn Gln Lys Phe 195 200 205 Lys Gly Lys Ala Thr Leu
Thr Val Asp Lys Ser Ser Ser Thr Ala Tyr 210 215 220 Met Gln Leu Ser
Ser Leu Thr Ser Glu Asp Ser Ala Val Tyr Phe Cys 225 230 235 240 Ala
Arg Val Val Tyr Tyr Ser Asn Ser Tyr Trp Tyr Phe Asp Val Trp 245 250
255 Gly Thr Gly Thr Thr Val Thr Val Ser Asp Gln Pro Val Pro Ser Thr
260 265 270 Pro Pro Thr Pro Ser Pro Ser Thr Pro Pro Thr Pro Ser Pro
Ser Cys 275 280 285 Ala Pro Glu Leu Leu Gly Gly Pro Ser Val Phe Leu
Phe Pro Pro Lys 290 295 300 Pro Lys Asp Thr Leu Met Ile Ser Arg Thr
Pro Glu Val Thr Cys Val 305 310 315 320 Val Val Asp Val Ser His Glu
Asp Pro Glu Val Lys Phe Asn Trp Tyr 325 330 335 Val Asp Gly Val Glu
Val His Asn Ala Lys Thr Lys Pro Arg Glu Glu 340 345 350 Gln Tyr Asn
Ser
Thr Tyr Arg Val Val Ser Val Leu Thr Val Leu His 355 360 365 Gln Asp
Trp Leu Asn Gly Lys Glu Tyr Lys Cys Lys Val Ser Asn Lys 370 375 380
Ala Leu Pro Ala Pro Ile Glu Lys Thr Ile Ser Lys Ala Lys Gly Gln 385
390 395 400 Pro Arg Glu Pro Gln Val Tyr Thr Leu Pro Pro Ser Arg Asp
Glu Leu 405 410 415 Thr Lys Asn Gln Val Ser Leu Thr Cys Leu Val Lys
Gly Phe Tyr Pro 420 425 430 Ser Asp Ile Ala Val Glu Trp Glu Ser Asn
Gly Gln Pro Glu Asn Asn 435 440 445 Tyr Lys Thr Thr Pro Pro Val Leu
Asp Ser Asp Gly Ser Phe Phe Leu 450 455 460 Tyr Ser Lys Leu Thr Val
Asp Lys Ser Arg Trp Gln Gln Gly Asn Val 465 470 475 480 Phe Ser Cys
Ser Val Met His Glu Ala Leu His Asn His Tyr Thr Gln 485 490 495 Lys
Ser Leu Ser Leu Ser Pro Gly Lys 500 505 19 234 PRT Homo sapiens
DOMAIN (1)..(234) MUTANT IGG1 HINGE (AMINO ACIDS 7, 13, 16) WILD
TYPE CH2 AND CH3 DOMAINS ALTERNATIVE CARBOXY TERMINUS OF SCFVIG
FUSION PROTEINS 19 Asp Gln Glu Pro Lys Ser Ser Asp Lys Thr His Thr
Ser Pro Pro Ser 1 5 10 15 Pro Ala Pro Glu Leu Leu Gly Gly Pro Ser
Val Phe Leu Phe Pro Pro 20 25 30 Lys Pro Lys Asp Thr Leu Met Ile
Ser Arg Thr Pro Glu Val Thr Cys 35 40 45 Val Val Val Asp Val Ser
His Glu Asp Pro Glu Val Lys Phe Asn Trp 50 55 60 Tyr Val Asp Gly
Val Glu Val His Asn Ala Lys Thr Lys Pro Arg Glu 65 70 75 80 Glu Gln
Tyr Asn Ser Thr Tyr Arg Val Val Ser Val Leu Thr Val Leu 85 90 95
His Gln Asp Trp Leu Asn Gly Lys Glu Tyr Lys Cys Lys Val Ser Asn 100
105 110 Lys Ala Leu Pro Ala Pro Ile Glu Lys Thr Ile Ser Lys Ala Lys
Gly 115 120 125 Gln Pro Arg Glu Pro Gln Val Tyr Thr Leu Pro Pro Ser
Arg Asp Glu 130 135 140 Leu Thr Lys Asn Gln Val Ser Leu Thr Cys Leu
Val Lys Gly Phe Tyr 145 150 155 160 Pro Ser Asp Ile Ala Val Glu Trp
Glu Ser Asn Gly Gln Pro Glu Asn 165 170 175 Asn Tyr Lys Thr Thr Pro
Pro Val Leu Asp Ser Asp Gly Ser Phe Phe 180 185 190 Leu Tyr Ser Lys
Leu Thr Val Asp Lys Ser Arg Trp Gln Gln Gly Asn 195 200 205 Val Phe
Ser Cys Ser Val Met His Glu Ala Leu His Asn His Tyr Thr 210 215 220
Gln Lys Ser Leu Ser Leu Ser Pro Gly Lys 225 230 20 240 PRT Homo
sapiens SITE (1)..(23) ALTERNATIVE CARBOXY TERMINUS OF SCFVIG
FUSION PROTEINS 20 Asp Gln Pro Val Pro Ser Thr Pro Pro Thr Pro Ser
Pro Ser Thr Pro 1 5 10 15 Pro Thr Pro Ser Pro Ser Cys Ala Pro Glu
Leu Leu Gly Gly Pro Ser 20 25 30 Val Phe Leu Phe Pro Pro Lys Pro
Lys Asp Thr Leu Met Ile Ser Arg 35 40 45 Thr Pro Glu Val Thr Cys
Val Val Val Asp Val Ser His Glu Asp Pro 50 55 60 Glu Val Lys Phe
Asn Trp Tyr Val Asp Gly Val Glu Val His Asn Ala 65 70 75 80 Lys Thr
Lys Pro Arg Glu Glu Gln Tyr Asn Ser Thr Tyr Arg Val Val 85 90 95
Ser Val Leu Thr Val Leu His Gln Asp Trp Leu Asn Gly Lys Glu Tyr 100
105 110 Lys Cys Lys Val Ser Asn Lys Ala Leu Pro Ala Pro Ile Glu Lys
Thr 115 120 125 Ile Ser Lys Ala Lys Gly Gln Pro Arg Glu Pro Gln Val
Tyr Thr Leu 130 135 140 Pro Pro Ser Arg Asp Glu Leu Thr Lys Asn Gln
Val Ser Leu Thr Cys 145 150 155 160 Leu Val Lys Gly Phe Tyr Pro Ser
Asp Ile Ala Val Glu Trp Glu Ser 165 170 175 Asn Gly Gln Pro Glu Asn
Asn Tyr Lys Thr Thr Pro Pro Val Leu Asp 180 185 190 Ser Asp Gly Ser
Phe Phe Leu Tyr Ser Lys Leu Thr Val Asp Lys Ser 195 200 205 Arg Trp
Gln Gln Gly Asn Val Phe Ser Cys Ser Val Met His Glu Ala 210 215 220
Leu His Asn His Tyr Thr Gln Lys Ser Leu Ser Leu Ser Pro Gly Lys 225
230 235 240 21 1470 DNA Artificial Sequence MOUSE-HUMAN HYBRID 21
aagcttgccg ccatggattt tcaagtgcag attttcagct tcctgctaat cagtgcttca
60 gtcataattg ccagaggaca aattgttctc tcccagtctc cagcaatcct
gtctgcatct 120 ccaggggaga aggtcacaat gacttgcagg gccagctcaa
gtgtaagtta catgcactgg 180 taccagcaga agccaggatc ctcccccaaa
ccctggattt atgccccatc caacctggct 240 tctggagtcc ctgctcgctt
cagtggcagt gggtctggga cctcttactc tctcacaatc 300 agcagagtgg
aggctgaaga tgctgccact tattactgcc agcagtggag ttttaaccca 360
cccacgttcg gtgctgggac caagctggag ctgaaagatg gcggtggctc gggcggtggt
420 ggatctggag gaggtgggag ctctcaggct tatctacagc agtctggggc
tgagctggtg 480 aggcctgggg cctcagtgaa gatgtcctgc aaggcttctg
gctacacatt taccagttac 540 aatatgcact gggtaaagca gacacctaga
cagggcctgg aatggattgg agctatttat 600 ccaggaaatg gtgatacttc
ctacaatcag aagttcaagg gcaaggccac actgactgta 660 gacaaatcct
ccagcacagc ctacatgcag ctcagcagcc tgacatctga agactctgcg 720
gtctatttct gtgcaagagt ggtgtactat agtaactctt actggtactt cgatgtctgg
780 ggcacaggga ccacggtcac cgtctctgat ccaagaaggt tggacaagat
agaagatgaa 840 aggaatcttc atgaagattt tgtattcatg aaaacgatac
agagatgcaa cacaggagaa 900 agatccttat ccttactgaa ctgtgaggag
attaaaagcc agtttgaagg ctttgtgaag 960 gatataatgt taaacaaaga
ggagacgaag aaagaaaaca gctttgaaat gcaaaaaggt 1020 gatcagaatc
ctcaaattgc ggcacatgtc ataagtgagg ccagcagtaa aacaacatct 1080
gtgttacagt gggctgaaaa aggatactac accatgagca acaacttggt aaccctggaa
1140 aatgggaaac agctgaccgt taaaagacaa ggactctatt atatctatgc
ccaagtcacc 1200 ttctgttcca atcgggaagc ttcgagtcaa gctccattta
tagccagcct ctgcctaaag 1260 tcccccggta gattcgagag aatcttactc
agagctgcaa atacccacag ttccgccaaa 1320 ccttgcgggc aacaatccat
tcacttggga ggagtatttg aattgcaacc aggtgcttcg 1380 gtgtttgtca
atgtgactga tccaagccaa gtgagccatg gcactggctt cacgtccttt 1440
ggcttactca aactcgagtg ataatctaga 1470 22 1290 DNA Artificial
Sequence MOUSE-HUMAN HYBRID 22 aagcttgccg ccatggattt tcaagtgcag
attttcagct tcctgctaat cagtgcttca 60 gtcataattg ccagaggaca
aattgttctc tcccagtctc cagcaatcct gtctgcatct 120 ccaggggaga
aggtcacaat gacttgcagg gccagctcaa gtgtaagtta catgcactgg 180
taccagcaga agccaggatc ctcccccaaa ccctggattt atgccccatc caacctggct
240 tctggagtcc ctgctcgctt cagtggcagt gggtctggga cctcttactc
tctcacaatc 300 agcagagtgg aggctgaaga tgctgccact tattactgcc
agcagtggag ttttaaccca 360 cccacgttcg gtgctgggac caagctggag
ctgaaagatg gcggtggctc gggcggtggt 420 ggatctggag gaggtgggag
ctctcaggct tatctacagc agtctggggc tgagctggtg 480 aggcctgggg
cctcagtgaa gatgtcctgc aaggcttctg gctacacatt taccagttac 540
aatatgcact gggtaaagca gacacctaga cagggcctgg aatggattgg agctatttat
600 ccaggaaatg gtgatacttc ctacaatcag aagttcaagg gcaaggccac
actgactgta 660 gacaaatcct ccagcacagc ctacatgcag ctcagcagcc
tgacatctga agactctgcg 720 gtctatttct gtgcaagagt ggtgtactat
agtaactctt actggtactt cgatgtctgg 780 ggcacaggga ccacggtcac
cgtctctgat ccagaaaaca gctttgaaat gcaaaaaggt 840 gatcagaatc
ctcaaattgc ggcacatgtc ataagtgagg ccagcagtaa aacaacatct 900
gtgttacagt gggctgaaaa aggatactac accatgagca acaacttggt aaccctggaa
960 aatgggaaac agctgaccgt taaaagacaa ggactctatt atatctatgc
ccaagtcacc 1020 ttctgttcca atcgggaagc ttcgagtcaa gctccattta
tagccagcct ctgcctaaag 1080 tcccccggta gattcgagag aatcttactc
agagctgcaa atacccacag ttccgccaaa 1140 ccttgcgggc aacaatccat
tcacttggga ggagtatttg aattgcaacc aggtgcttcg 1200 gtgtttgtca
atgtgactga tccaagccaa gtgagccatg gcactggctt cacgtccttt 1260
ggcttactca aactcgagtg ataatctaga 1290 23 43 DNA Artificial Sequence
OLIGONUCLEOTIDE 23 gtcaagcttg ccgccatgga ttttcaagtg cagatttttc agc
43 24 74 DNA Artificial Sequence OLIGONUCLEOTIDE 24 gtcgtcgagc
tcccacctcc tccagatcca ccaccgcccg agccaccgcc acctttcagc 60
tccagcttgg tccc 74 25 37 DNA Artificial Sequence OLIGONUCLEOTIDE 25
gctgctgagc tctcaggctt atctacagca agtctgg 37 26 32 DNA Artificial
Sequence OLIGONUCLEOTIDE 26 gttgtctgat cagagacggt gaccgtggtc cc 32
27 34 DNA Artificial Sequence OLIGONUCLEOTIDE 27 gttgtcggat
ccagaaaaca gctttgaaat gcaa 34 28 44 DNA Artificial Sequence
OLIGONUCLEOTIDE 28 gttgtttcta gattatcact cgagtttgag taagccaaag gacg
44 29 35 DNA Artificial Sequence OLIGONUCLEOTIDE 29 gttgtcggat
ccaagaaggt tggacaagat agaag 35 30 23 DNA Artificial Sequence
OLIGONUCLEOTIDE 30 gtctatataa gcagagctct ggc 23 31 25 DNA
Artificial Sequence OLIGONUCLEOTIDE 31 cgaggctgat cagcgagctc tagca
25 32 25 DNA Artificial Sequence OLIGONUCLEOTIDE 32 ccgcaatttg
aggattctga tcacc 25 33 482 PRT Artificial Sequence MOUSE-HUMAN
HYBRID FUSION PROTEIN 33 Met Asp Phe Gln Val Gln Ile Phe Ser Phe
Leu Leu Ile Ser Ala Ser 1 5 10 15 Val Ile Ile Ala Arg Gly Gln Ile
Val Leu Ser Gln Ser Pro Ala Ile 20 25 30 Leu Ser Ala Ser Pro Gly
Glu Lys Val Thr Met Thr Cys Arg Ala Ser 35 40 45 Ser Ser Val Ser
Tyr Met His Trp Tyr Gln Gln Lys Pro Gly Ser Ser 50 55 60 Pro Lys
Pro Trp Ile Tyr Ala Pro Ser Asn Leu Ala Ser Gly Val Pro 65 70 75 80
Ala Arg Phe Ser Gly Ser Gly Ser Gly Thr Ser Tyr Ser Leu Thr Ile 85
90 95 Ser Arg Val Glu Ala Glu Asp Ala Ala Thr Tyr Tyr Cys Gln Gln
Trp 100 105 110 Ser Phe Asn Pro Pro Thr Phe Gly Ala Gly Thr Lys Leu
Glu Leu Lys 115 120 125 Asp Gly Gly Gly Ser Gly Gly Gly Gly Ser Gly
Gly Gly Gly Ser Ser 130 135 140 Gln Ala Tyr Leu Gln Gln Ser Gly Ala
Glu Leu Val Arg Pro Gly Ala 145 150 155 160 Ser Val Lys Met Ser Cys
Lys Ala Ser Gly Tyr Thr Phe Thr Ser Tyr 165 170 175 Asn Met His Trp
Val Lys Gln Thr Pro Arg Gln Gly Leu Glu Trp Ile 180 185 190 Gly Ala
Ile Tyr Pro Gly Asn Gly Asp Thr Ser Tyr Asn Gln Lys Phe 195 200 205
Lys Gly Lys Ala Thr Leu Thr Val Asp Lys Ser Ser Ser Thr Ala Tyr 210
215 220 Met Gln Leu Ser Ser Leu Thr Ser Glu Asp Ser Ala Val Tyr Phe
Cys 225 230 235 240 Ala Arg Val Val Tyr Tyr Ser Asn Ser Tyr Trp Tyr
Phe Asp Val Trp 245 250 255 Gly Thr Gly Thr Thr Val Thr Val Ser Asp
Pro Arg Arg Leu Asp Lys 260 265 270 Ile Glu Asp Glu Arg Asn Leu His
Glu Asp Phe Val Phe Met Lys Thr 275 280 285 Ile Gln Arg Cys Asn Thr
Gly Glu Arg Ser Leu Ser Leu Leu Asn Cys 290 295 300 Glu Glu Ile Lys
Ser Gln Phe Glu Gly Phe Val Lys Asp Ile Met Leu 305 310 315 320 Asn
Lys Glu Glu Thr Lys Lys Glu Asn Ser Phe Glu Met Gln Lys Gly 325 330
335 Asp Gln Asn Pro Gln Ile Ala Ala His Val Ile Ser Glu Ala Ser Ser
340 345 350 Lys Thr Thr Ser Val Leu Gln Trp Ala Glu Lys Gly Tyr Tyr
Thr Met 355 360 365 Ser Asn Asn Leu Val Thr Leu Glu Asn Gly Lys Gln
Leu Thr Val Lys 370 375 380 Arg Gln Gly Leu Tyr Tyr Ile Tyr Ala Gln
Val Thr Phe Cys Ser Asn 385 390 395 400 Arg Glu Ala Ser Ser Gln Ala
Pro Phe Ile Ala Ser Leu Cys Leu Lys 405 410 415 Ser Pro Gly Arg Phe
Glu Arg Ile Leu Leu Arg Ala Ala Asn Thr His 420 425 430 Ser Ser Ala
Lys Pro Cys Gly Gln Gln Ser Ile His Leu Gly Gly Val 435 440 445 Phe
Glu Leu Gln Pro Gly Ala Ser Val Phe Val Asn Val Thr Asp Pro 450 455
460 Ser Gln Val Ser His Gly Thr Gly Phe Thr Ser Phe Gly Leu Leu Lys
465 470 475 480 Leu Glu 34 422 PRT Artificial Sequence MOUSE-HUMAN
HYBRID FUSION PROTEIN 34 Met Asp Phe Gln Val Gln Ile Phe Ser Phe
Leu Leu Ile Ser Ala Ser 1 5 10 15 Val Ile Ile Ala Arg Gly Gln Ile
Val Leu Ser Gln Ser Pro Ala Ile 20 25 30 Leu Ser Ala Ser Pro Gly
Glu Lys Val Thr Met Thr Cys Arg Ala Ser 35 40 45 Ser Ser Val Ser
Tyr Met His Trp Tyr Gln Gln Lys Pro Gly Ser Ser 50 55 60 Pro Lys
Pro Trp Ile Tyr Ala Pro Ser Asn Leu Ala Ser Gly Val Pro 65 70 75 80
Ala Arg Phe Ser Gly Ser Gly Ser Gly Thr Ser Tyr Ser Leu Thr Ile 85
90 95 Ser Arg Val Glu Ala Glu Asp Ala Ala Thr Tyr Tyr Cys Gln Gln
Trp 100 105 110 Ser Phe Asn Pro Pro Thr Phe Gly Ala Gly Thr Lys Leu
Glu Leu Lys 115 120 125 Asp Gly Gly Gly Ser Gly Gly Gly Gly Ser Gly
Gly Gly Gly Ser Ser 130 135 140 Gln Ala Tyr Leu Gln Gln Ser Gly Ala
Glu Leu Val Arg Pro Gly Ala 145 150 155 160 Ser Val Lys Met Ser Cys
Lys Ala Ser Gly Tyr Thr Phe Thr Ser Tyr 165 170 175 Asn Met His Trp
Val Lys Gln Thr Pro Arg Gln Gly Leu Glu Trp Ile 180 185 190 Gly Ala
Ile Tyr Pro Gly Asn Gly Asp Thr Ser Tyr Asn Gln Lys Phe 195 200 205
Lys Gly Lys Ala Thr Leu Thr Val Asp Lys Ser Ser Ser Thr Ala Tyr 210
215 220 Met Gln Leu Ser Ser Leu Thr Ser Glu Asp Ser Ala Val Tyr Phe
Cys 225 230 235 240 Ala Arg Val Val Tyr Tyr Ser Asn Ser Tyr Trp Tyr
Phe Asp Val Trp 245 250 255 Gly Thr Gly Thr Thr Val Thr Val Ser Asp
Pro Glu Asn Ser Phe Glu 260 265 270 Met Gln Lys Gly Asp Gln Asn Pro
Gln Ile Ala Ala His Val Ile Ser 275 280 285 Glu Ala Ser Ser Lys Thr
Thr Ser Val Leu Gln Trp Ala Glu Lys Gly 290 295 300 Tyr Tyr Thr Met
Ser Asn Asn Leu Val Thr Leu Glu Asn Gly Lys Gln 305 310 315 320 Leu
Thr Val Lys Arg Gln Gly Leu Tyr Tyr Ile Tyr Ala Gln Val Thr 325 330
335 Phe Cys Ser Asn Arg Glu Ala Ser Ser Gln Ala Pro Phe Ile Ala Ser
340 345 350 Leu Cys Leu Lys Ser Pro Gly Arg Phe Glu Arg Ile Leu Leu
Arg Ala 355 360 365 Ala Asn Thr His Ser Ser Ala Lys Pro Cys Gly Gln
Gln Ser Ile His 370 375 380 Leu Gly Gly Val Phe Glu Leu Gln Pro Gly
Ala Ser Val Phe Val Asn 385 390 395 400 Val Thr Asp Pro Ser Gln Val
Ser His Gly Thr Gly Phe Thr Ser Phe 405 410 415 Gly Leu Leu Lys Leu
Glu 420 35 63 DNA Homo sapiens N_region (1)..(63) PORTION OF HUMAN
IGA HINGE DOMAIN CONTAINING ONLY 1 CYSTEINE 35 ccagttccct
caactccacc taccccatct ccctcaactc cacctacccc atctccctca 60 tgc 63 36
21 PRT Homo sapiens 36 Pro Val Pro Ser Thr Pro Pro Thr Pro Ser Pro
Ser Thr Pro Pro Thr 1 5 10 15 Pro Ser Pro Ser Cys 20 37 763 DNA
Homo sapiens misc_feature (1)..(6) BCLI SITE FOR FUSION TO AMINO
TERMINAL SCFVS 37 tgatcagcca gttccctcaa ctccacctac cccatctccc
tcaactccac ctaccccatc 60 tccctcatgc tgccaccccc gactgtcact
gcaccgaccg gccctcgagg acctgctctt 120 aggttcagaa gcgatcctca
cgtgcacact gaccggcctg agagatgcct caggtgtcac 180 cttcacctgg
acgccctcaa gtgggaagag cgctgttcaa ggaccacctg accgtgacct 240
ctgtggctgc tacagcgtgt ccagtgtcct gccgggctgt gccgagccat ggaaccatgg
300 gaagaccttc acttgcactg ctgcctaccc cgagtccaag accccgctaa
ccgccaccct 360 ctcaaaatcc ggaaacacat tccggcccga ggtccacctg
ctgccgccgc cgtcggagga 420 gctggccctg aacgagctgg tgacgctgac
gtgcctggca cgtggcttca gccccaagga 480 tgtgctggtt cgctggctgc
aggggtcaca ggagctgccc cgcgagaagt acctgacttg 540 ggcatcccgg
caggagccca gccagggcac caccaccttc gctgtgacca gcatactgcg 600
cgtggcagcc gaggactgga agaaggggga caccttctcc tgcatggtgg gccacgaggc
660 cctgccgctg gccttcacac agaagaccat cgaccgcttg gcgggtaaac
ccacccatgt 720 caatgtgtct gttgtcatgg cggaggtgga ctgataatct aga 763
38 250 PRT Homo sapiens DOMAIN (3)..(250) TRUNCATED FORM, REMOVAL
OF LAST THREE
AMINO ACIDS THAT MEDIATE ATTACHMENT TO SECRETORY COMPONENT 38 Asp
Gln Pro Val Pro Ser Thr Pro Pro Thr Pro Ser Pro Ser Thr Pro 1 5 10
15 Pro Thr Pro Ser Pro Ser Cys Cys His Pro Arg Leu Ser Leu His Arg
20 25 30 Pro Ala Leu Glu Asp Leu Leu Leu Gly Ser Glu Ala Ile Leu
Thr Cys 35 40 45 Thr Leu Thr Gly Leu Arg Asp Ala Ser Gly Val Thr
Phe Thr Trp Thr 50 55 60 Pro Ser Ser Gly Lys Ser Ala Val Gln Gly
Pro Pro Asp Arg Asp Leu 65 70 75 80 Cys Gly Cys Tyr Ser Val Ser Ser
Val Leu Pro Gly Cys Ala Glu Pro 85 90 95 Trp Asn His Gly Lys Thr
Phe Thr Cys Thr Ala Ala Tyr Pro Glu Ser 100 105 110 Lys Thr Pro Leu
Thr Ala Thr Leu Ser Lys Ser Gly Asn Thr Phe Arg 115 120 125 Pro Glu
Val His Leu Leu Pro Pro Pro Ser Glu Glu Leu Ala Leu Asn 130 135 140
Glu Leu Val Thr Leu Thr Cys Leu Ala Arg Gly Phe Ser Pro Lys Asp 145
150 155 160 Val Leu Val Arg Trp Leu Gln Gly Ser Gln Glu Leu Pro Arg
Glu Lys 165 170 175 Tyr Leu Thr Trp Ala Ser Arg Gln Glu Pro Ser Gln
Gly Thr Thr Thr 180 185 190 Phe Ala Val Thr Ser Ile Leu Arg Val Ala
Ala Glu Asp Trp Lys Lys 195 200 205 Gly Asp Thr Phe Ser Cys Met Val
Gly His Glu Ala Leu Pro Leu Ala 210 215 220 Phe Thr Gln Lys Thr Ile
Asp Arg Leu Ala Gly Lys Pro Thr His Val 225 230 235 240 Asn Val Ser
Val Val Met Ala Glu Val Asp 245 250
* * * * *