U.S. patent application number 15/870449 was filed with the patent office on 2018-08-23 for antibodies recognizing a carbohydrate containing epitope on cd-43 and cea expressed on cancer cells and methods using same.
The applicant listed for this patent is BioAlliance C.V.. Invention is credited to Shu-Hua LEE, Leewen LIN, Rong-Hwa LIN, Shih-Yao LIN.
Application Number | 20180238895 15/870449 |
Document ID | / |
Family ID | 38832425 |
Filed Date | 2018-08-23 |
United States Patent
Application |
20180238895 |
Kind Code |
A1 |
LIN; Rong-Hwa ; et
al. |
August 23, 2018 |
ANTIBODIES RECOGNIZING A CARBOHYDRATE CONTAINING EPITOPE ON CD-43
AND CEA EXPRESSED ON CANCER CELLS AND METHODS USING SAME
Abstract
The present invention provides novel antibodies specifically
bind to an epitope on CD43 and CEA expressed on nonhematopoietic
cancer cells, but do not specifically bind to a CD43 expressed by a
leukocyte or by a Jurkat cell, and is capable of inducing apoptosis
of the nonhematopoietic cancer cell after binding to the epitope on
cell surface of the nonhematopoietic cancer cell in the absence of
cytotoxin conjugation and immune effector function, wherein the
epitope comprises a carbohydrate structure and the binding of the
antibody to the epitope is inhibited by a carbohydrate comprising a
Le.sup.a structure, a Le.sup.a-lactose structure, a LNDFH II
structure, or a LNT structure. In addition, the present invention
also provides use of the antibodies described herein for diagnostic
and therapeutic purposes.
Inventors: |
LIN; Rong-Hwa; (Palo Alto,
CA) ; LIN; Leewen; (Taipei, TW) ; LIN;
Shih-Yao; (Taipei, TW) ; LEE; Shu-Hua;
(Taipei, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BioAlliance C.V. |
Alkmaar |
|
NL |
|
|
Family ID: |
38832425 |
Appl. No.: |
15/870449 |
Filed: |
January 12, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14918490 |
Oct 20, 2015 |
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15870449 |
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12690846 |
Jan 20, 2010 |
9193794 |
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14918490 |
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11811303 |
Jun 7, 2007 |
7674605 |
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12690846 |
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60811850 |
Jun 7, 2006 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01N 2333/70503
20130101; C07K 2317/73 20130101; C07K 2317/21 20130101; G01N
2333/70596 20130101; A61K 2039/505 20130101; C07K 2317/56 20130101;
G01N 33/57492 20130101; C07K 16/30 20130101; C07K 2317/565
20130101; C07K 16/2896 20130101; C07K 2317/24 20130101; C07K
2317/34 20130101; A61K 39/39558 20130101; C07K 16/2803 20130101;
C07K 16/3007 20130101; A61P 35/00 20180101 |
International
Class: |
G01N 33/574 20060101
G01N033/574; C07K 16/30 20060101 C07K016/30; C07K 16/28 20060101
C07K016/28 |
Claims
1-34. (canceled)
35: A method to determine if an individual having cancer may be
treated with a monoclonal antibody that binds to an epitope on the
extracellular domain of a human CD43 or a human CEA expressed by
nonhematopoietic cancer cells, but does not specifically bind to a
human CD43 expressed on the cell surface of human peripheral T
cells or Jurkat cells, wherein epitope comprises a carbohydrate and
the binding of the antibody to the epitope is inhibited by
oligosaccharides Le.sup.a, Le.sup.a-lactose, and
Lacto-N-difucohexaose II (LNDFH II), the method comprising
contacting a sample from the individual with a monoclonal antibody;
wherein the monoclonal antibody binds to an epitope on the
extracellular domain of a human CD43 or a human CEA expressed by
nonhematopoietic cancer cells, but does not specifically bind to a
human CD43 expressed on the cell surface of human peripheral T
cells or Jurkat cells, and wherein epitope comprises a carbohydrate
and the binding of the antibody to the epitope is inhibited by
oligosaccharides Le.sup.a, Le.sup.a-lactose, and
Lacto-N-difucohexaose II (LNDFH II); wherein the presence of
binding between the antibody and a cell in the sample indicates
that the individual having cancer may be treated with the
antibody.
36: The method of claim 35, wherein the epitope comprises a
fucose.
37: The method of claim 35, wherein the binding of the antibody to
the epitope is inhibited by oligosaccharide LNT.
38: The method of claim 35, wherein the monoclonal antibody
competes for binding to nonhematopoietic cancer cells with an
antibody comprising a heavy chain variable region comprising the
three CDRs from the amino acid sequence of SEQ ID NO:1, and a light
chain variable region comprising the three CDRs from the amino acid
sequence of SEQ ID NO:2.
39: The method of claim 35, wherein the monoclonal antibody
competes for binding to nonhematopoietic cancer cells with an
antibody comprising a heavy chain variable region comprising the
three CDRs from the amino acid sequence of SEQ ID NO:3, and a light
chain variable region comprising the three CDRs from the amino acid
sequence of SEQ ID NO:4.
40: The method of claim 35, wherein the monoclonal antibody
competes for binding to nonhematopoietic cancer cells with an
antibody comprising a heavy chain variable region comprising the
three CDRs from the amino acid sequence of SEQ ID NO:5, and a light
chain variable region comprising the three CDRs from the amino acid
sequence of SEQ ID NO:6.
41: The method of claim 35, wherein the monoclonal antibody
comprises a heavy chain variable region comprising the three CDRs
from the amino acid sequence of SEQ ID NO:1, and a light chain
variable region comprising the three CDRs from the amino acid
sequence of SEQ ID NO:2.
42: The method of claim 41, wherein the monoclonal antibody
comprises the heavy chain variable region sequence from the amino
acid sequence of SEQ ID NO:1, and the light chain variable region
sequence from the amino acid sequence of SEQ ID NO:2.
43: The method of claim 35, wherein the monoclonal antibody
comprises a heavy chain variable region sequence comprising the
three CDRs from the amino acid sequence of SEQ ID NO:3, and a light
chain variable region sequence comprising the three CDRs from the
amino acid sequence of SEQ ID NO:4.
44: The method of claim 43, wherein the monoclonal antibody
comprises the heavy chain variable region sequence from the amino
acid sequence of SEQ ID NO:3, and the light chain variable region
sequence from the amino acid sequence of SEQ ID NO:4.
45: The method of claim 35, wherein the monoclonal antibody
comprises the three CDRs from the amino acid sequence of SEQ ID
NO:5, and the light chain variable region sequence comprising the
three CDRs from the amino acid sequence of SEQ ID NO:6.
46: The method of claim 45, wherein the monoclonal antibody
comprises the heavy chain variable region sequence from the amino
acid sequence of SEQ ID NO:5, and the light chain variable region
sequence from the amino acid sequence of SEQ ID NO:6.
47: The method of claim 35, wherein the monoclonal antibody
comprises the heavy chain variable region sequence from the amino
acid sequence of SEQ ID NO:7, and the light chain variable region
sequence from the amino acid sequence of SEQ ID NO:8.
48: The method of claim 35, wherein the cancer is human colorectal
cancer, human pancreatic cancer, human gastric cancer, human
ovarian cancer, human esophageal cancer, or human endometrial
cancer.
49: The method of claim 35, wherein the monoclonal antibody is a
humanized antibody.
50: The method of claim 35, wherein the monoclonal antibody is a
chimeric antibody.
51: The method of claim 35, wherein the monoclonal antibody is a
human antibody.
52: The method of claim 35, wherein the monoclonal antibody is
conjugated to a label.
53: The method of claim 52, wherein the label is selected from the
group consisting of an enzyme, a fluorescent molecule, a
chemiluminescent molecule, a radioactive molecule, and biotin.
54: The method of claim 53, wherein the label is selected from the
group consisting of .sup.3H, .sup.14C, .sup.15N, .sup.35S,
.sup.90Y, .sup.99Tc, .sup.111In, .sup.125I, .sup.131I, fluorescein
isothiocyanate (FITC), rhodamine, lanthanide phosphors,
phycoerythrin (PE), horseradish peroxidase, .beta.-galactosidase,
luciferase, alkaline phosphatase, glucose oxidase,
glucose-6-phosphate dehydrogenase, alcohol dehyrogenase, malate
dehyrogenase, penicillinase, and luciferase.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. patent
application Ser. No. 14/918,490, filed Oct. 20, 2015, which is a
continuation application of U.S. patent application Ser. No.
12/690,846, filed Jan. 20, 2010, now U.S. Pat. No. 9,193,794, which
is a divisional application of U.S. patent application Ser. No.
11/811,303, filed Jun. 7, 2007, now U.S. Pat. No. 7,674,605, which
claims the priority benefit of U.S. Provisional Application No.
60/811,850, filed Jun. 7, 2006, each of which is incorporated
herein by reference in its entirety.
SUBMISSION OF SEQUENCE LISTING ON ASCII TEXT FILE
[0002] The content of the following submission on ASCII text file
is incorporated herein by reference in its entirety: a computer
readable form (CRF) of the Sequence Listing (file name:
606592000212seqlist.txt, date recorded: Jan. 12, 2018, size: 18
KB).
FIELD OF THE INVENTION
[0003] The present invention relates to novel monoclonal antibodies
that recognize a carbohydrate containing epitope on CD43 and
carcinoembryonic antigen (CEA) expressed on nonhematopoietic tumor
or cancer cells. These antibodies have the property of inducing
cell death (e.g., apoptosis) in these nonhematopoietic tumor or
cancer cells in the absence of cytotoxin conjugation and immune
effector function. These monoclonal antibodies are useful as
diagnostic and therapeutic agents.
BACKGROUND OF THE INVENTION
[0004] CD43 (also named as sialophorin or leukosialin), a heavily
sialylated molecule expresses at high levels on most human
leukocytes including all T cells and platelets with a molecular
weight ranging from 115,000 to 135,000. CD43 expression is
defective on the T cells of males with the Wiskott-Aldrich
syndrome, an X chromosome-linked recessive immunodeficiency
disorder (Remold-O'Donnell et al. (1987) Blood 70(1):104-9;
Remold-O'Donnel et al. (1984) J. Exp. Med. 159:1705-23).
[0005] Functional studies demonstrated that anti-CD43 monoclonal
antibody stimulates the proliferation of peripheral blood T
lymphocytes (Mentzer et al. (1987) J. Exp. Med. 1; 165 (5):1383-92;
Park et al. (1991) Nature, 350:706-9) and the activation of
monocytes (Nong et al. (1989) J. Exp. Med. 1:170(1):259-67). A
monoclonal anti-CD43 antibody L11 blocks T cell binding to lymph
node and Peyer's patch HEV. Antibody L11 inhibits T cell
extravasation from the blood into organized secondary lymphoid
tissues (McEvoy et al. (1997) J. Exp. Med. 185:1493-8). Monoclonal
antibody recognizing CD43 molecule induces apoptosis of lineage
marker-negative bone marrow hematopoietic progenitor cells (HPCs)
that express CD34 at a high density (Bazil et al. (1996) Blood,
87(4):1272-81) and of human T-lymphoblastoid cells (Brown et al.
(1996) J. Biol. Chem. 271:27686-95). Recent studies further
indicated that CD43 functions as a ligand for E-selectin on human T
cells (Matsumoto et al. (2005) J. Immunol. 175:8042-50; Fuhlbrigge
et al. (2006) Blood, 107:1421-6).
[0006] Interestingly, scientists have also discovered that certain
nonhematopoietic tumor cells, especially colorectal
adenocarcinomas, do express CD43 molecules on the cell surface.
Santamaria et al. (1996) Cancer Research, 56:3526-9: Baeckstrom et
al. (1995) J. Biol. Chem. 270:13688-92; Baeckstrom et al. (1997) J.
Biol. Chem. 272:11503-9; Sikut et al. (1997) Biochem. Biophy. Res.
Commun. 238:612-6. It has been shown that glycans on CD43 expressed
in a colon carcinoma cell line (COLO 205) are different from those
of leukocyte CD43 (Baeckstrom et al. (1997) J. Biol. Chem.
272:11503-9). Although it has been suggested that over-expression
of CD43 causes activation of the tumor suppressor protein p53
(Kadaja et al. (2004) Oncogene 23:2523-30) and suppresses a subset
of NF-kappaB target genes, partly via the inhibition of p65
transcriptional activity (Laos et al. (2006) Int. J. Oncol.
28:695-704), the direct evidence showing the causal role of CD43 in
colon tumorigenesis is still lacking. The use of conventional
anti-CD43 antibody as therapeutics for nonhematopoietic tumor cells
is not practical due to its strong binding to both tumor and immune
T cells. There remains a need to generate antibodies that
specifically bind to a CD43 expressed on non-hematopoietic tumor or
cancer cells, but do not bind to a CD43 expressed on leukocytes or
other cells of hematopoietic origin. These antibodies may be useful
as therapeutic agents for treating CD43 expressing nonhematopoietic
cancer.
[0007] CEA is normally expressed in a variety of glandular
epithelial tissues (such as the gastrointestinal, respiratory, and
urogenital tracts) where it appears to be localized to the apical
surface of the cells (Hammarstrom, S. (1999) Semin. Cancer Biol. 9,
67-81.). In tumors arising from these tissues, there is an
increasing level of CEA expression extending from the apical
membrane domain to the entire cell surface, together with secretion
of the protein into the blood (Hammarstrom, S. (1999) Semin. Cancer
Biol. 9, 67-81.). The excessive expression of CEA was observed in
many types of cancers, including colorectal cancer, pancreatic
cancer, lung cancer, gastric cancer, hepatocellular carcinoma,
breast cancer, and thyroid cancer. Therefore, CEA has been used as
a tumor marker and immunological assays to measure the elevated
amount of CEA in the blood of cancer patients have long been
utilized clinically in the prognosis and management of cancers
(Gold P, et al. (1965) J. Expl. Med. 122:467-81; Chevinsky, A. H.
(1991) Semin. Surg. Oncol. 7, 162-166; Shively, J. E. et al.,
(1985) Crit. Rev. Oncol. Hematol. 2, 355-399).
[0008] More importantly, CEA has become a potentially useful
tumor-associated antigen for targeted therapy (Kuroki M, et al.
(2002) Anticancer Res 22:4255-64). Two major strategies using CEA
as a target for cancer immunotherapy have been developed. One
method is the specific targeting of suicide genes (nitric oxide
synthase (iNOS) gene) (Kuroki M. et al., (2000) Anticancer Res.
20(6A):4067-71) or isotopes (Wilkinson R W. et al., (2001) PNAS USA
98, 10256-60, Goldenberg, D. M. (1991) Am. J. Gastroenterol., 86:
1392-1403, Olafsen T. et al., Protein Engineering, Design &
Selection, 17, 21-27, 2004) to CEA-expressing tumor cells by
anti-CEA antibodies. This method has also been extended to the use
of antibody or antibody fragment conjugated with therapeutic
agents, such as drugs, toxins, radionucleotides, immumodulators or
cytokines. The other method is to utilize immunological cytolytic
activities, specifically through antibody-dependent cellular
cytotoxicity (ADCC) or complement-dependent cytotoxicity (CDC) to
eliminate CEA-expressing tumor cells (Imakiire T et al., (2004)
Int. J. Cancer: 108, 564-570). These methods often give rise to
cytokine releases resulting in systemic side effects.
[0009] All references, publications, and patent applications
disclosed herein are hereby incorporated by reference in their
entirety.
BRIEF SUMMARY OF THE INVENTION
[0010] In one aspect, the present invention provides novel
antibodies that specifically bind to an epitope on CD43 and CEA
expressed by a nonhematopoietic cancer cell, but do not
specifically bind to a CD43 expressed by a leukocyte (e.g., human
peripheral T cells) or a Jurkat cell (a lymphoblastoid leukemia
cell). The epitope that the antibodies bind to comprises a
carbohydrate. These antibodies are capable of inducing cell death
in these nonhematopoietic cancer cells in the absence of cytotoxin
conjugation to the antibodies and immune effector function.
[0011] The invention provides an antibody, which antibody
specifically binds to an epitope on CD43 and/or CEA expressed by a
nonhematopoietic cancer cell, but does not specifically bind to a
CD43 expressed by a leukocyte or by a Jurkat cell, and is capable
of inducing apoptosis of the nonhematopoietic cancer cell after
binding to the epitope expressed on cell surface of the
nonhematopoietic cancer cell in the absence of cytotoxin
conjugation and immune effector function, wherein the epitope
comprises a carbohydrate, and the binding of the antibody to the
epitope is inhibited by a carbohydrate comprising a Le.sup.a
structure, a Le.sup.a-lactose structure, a LNDFH II structure, or a
LNT structure. In some embodiments, the epitope that the antibody
binds to is fucose sensitive.
[0012] The nonhematopoietic cancer cell includes, but is not
limited to, cells from colorectal cancer and gastric cancer.
[0013] In some embodiments, the antibody described herein is a
monoclonal antibody. In some embodiments, the antibody described
herein is a murine, a human, a humanized, or a chimeric
antibody.
[0014] In some embodiments, the antibody described herein, upon
binding to the epitope expressed on the cell surface of the
nonhematopoietic cancer cell, reduces the number of cancer cells,
and/or inhibits growth or proliferation of the cancer cell. For
example, the reduction in cell number or inhibition of cell growth
in the presence the antibody is by at least any of about 10%, about
20%, about 30%, about 40%, about 50%, about 65%, about 75%, or
greater as compared to cell number or cell growth in the absence of
the antibody.
[0015] In some embodiments, the antibody described herein
recognizes a conformation epitope on an extracellular domain of the
CD43 and CEA expressed by the nonhematopoietic cancer cell, wherein
the conformation epitope includes a structure having physical and
chemical characteristics equivalent to the structure formed by
tripeptide, N'-Trp-Pro-Ile-C'. In some embodiments, the antibody
described herein binds to a polypeptide comprising the amino acid
sequence of N'-Trp-Pro-Ile-C' at the N-terminus of the
polypeptide.
[0016] In some embodiments, the antibody described herein competes
with an antibody comprising a heavy chain variable region
comprising the amino acid sequence of SEQ ID NO:1, and a light
chain variable region comprising the amino acid sequence of SEQ ID
NO:2, for binding to the epitope present on the cell surface of the
nonhematopoietic cancer cell.
[0017] In some embodiments, the antibody described herein competes
with an antibody comprising a heavy chain variable region
comprising the amino acid sequence of SEQ ID NO:3, and a light
chain variable region comprising the amino acid sequence of SEQ ID
NO:4, for binding to the epitope present on the cell surface of the
nonhematopoietic cancer cell.
[0018] In some embodiments, the antibody described herein competes
with an antibody comprising a heavy chain variable region
comprising the amino acid sequence of SEQ ID NO:5, and a light
chain variable region comprising the amino acid sequence of SEQ ID
NO:6, for binding to the epitope expressed on the cell surface of
the nonhematopoietic cancer cell.
[0019] In some embodiments, the antibody comprises a heavy chain
variable region comprising three CDRs from the amino acid sequence
of SEQ ID NO:1, and a light chain variable region comprising three
CDRs from the amino acid sequence of SEQ ID NO:2. In some
embodiments, the antibody comprises a heavy chain variable region
comprising the amino acid sequence of SEQ ID NO:1, and a light
chain variable region comprising the amino acid sequence of SEQ ID
NO:2.
[0020] In some embodiments, the antibody comprises a heavy chain
variable region comprising three CDRs from the amino acid sequence
of SEQ ID NO:3, and a light chain variable region comprising three
CDRs from the amino acid sequence of SEQ ID NO:4. In some
embodiments, the antibody comprises a heavy chain variable region
comprising the amino acid sequence of SEQ ID NO:3, and a light
chain variable region comprising the amino acid sequence of SEQ ID
NO:4.
[0021] In some embodiments, the antibody comprises a heavy chain
variable region comprising three CDRs from the amino acid sequence
of SEQ ID NO:5, and a light chain variable region comprising three
CDRs from the amino acid sequence of SEQ ID NO:6. In some
embodiments, the antibody comprises a heavy chain variable region
comprising the amino acid sequence of SEQ ID NO:5, and a light
chain variable region comprising the amino acid sequence of SEQ ID
NO:6.
[0022] In some embodiments, the antibody is a humanized antibody
comprising a heavy chain variable region comprising the amino acid
sequence of SEQ ID NO:7, and a light chain variable region
comprising the amino acid sequence of SEQ ID NO:8.
[0023] In another aspect, the present invention provides
polypeptides comprising a heavy chain and/or light chain, or a
fragment of the antibody described herein. The invention also
provides polypeptides derived from any of the antibodies described
herein, wherein the polypeptides specifically bind to the epitope
on CD43 and CEA expressed by a nonhematopoietic cancer cell, but do
not specifically bind to a CD43 expressed by a leukocyte or by a
Jurkat cell, and are capable of inducing apoptosis of the
nonhematopoietic cancer cell after binding to the CD43 expressed on
cell surface of the nonhematopoietic cancer cell in the absence of
cytotoxin conjugation and immune effector function.
[0024] In another aspect, the present invention provides
polynucleotides encoding any of the antibodies or polypeptides
described herein. The invention also provides vectors (such as
expression vectors) comprising any of the polynucleotides described
herein. The invention also provides host cells comprising any of
the polynucleotides or vectors described herein.
[0025] In another aspect, the present invention provides a
composition comprising any of the antibodies or polypeptides
described herein. In certain embodiments, the antibodies or the
polypeptides are linked to an agent. In some embodiments, the agent
is a therapeutic agent (e.g., radioactive moieties, cytotoxins, and
chemotherapeutic agents). In some embodiments, the agent is a label
(e.g., enzymes, fluorescent molecules, and biotin).
[0026] The invention also provides a pharmaceutical composition
comprising an effective amount of any of the antibodies or
polypeptides described herein, or polynucleotides encoding the
antibodies or polypeptides, and a pharmaceutically acceptable
carrier. In some embodiments, the antibodies or the polypeptides
are linked to a therapeutic agent. In some embodiments, the
composition is formulated for administration by intraperitoneal,
intravenous, subcutaneous, and intramuscular injections, and other
forms of administration such as oral, mucosal, via inhalation,
sublingually, etc.
[0027] In some embodiments, the composition may comprise more than
one antibodies of the invention, or one antibody of the invention
with one or more other anti-cancer antibodies or other anti-cancer
agents.
[0028] In another aspect, the present invention provides methods
for generating an antibody or a polypeptide described herein
comprising culturing a host cell or progeny thereof under
conditions that allow production of the antibody or polypeptide,
wherein the host cell comprises an expression vector that encodes
for the antibody or the polypeptide. In some embodiments, the
method further comprises purifying the antibody or the
polypeptide.
[0029] In another aspect, the invention provides methods of
generating any of the antibodies described herein by expressing one
or more polynucleotides encoding the antibody (which may be
separately expressed as a single light or heavy chain, or both a
light and a heavy chain are expressed from one vector) in a
suitable cell, generally followed by recovering and/or isolating
the antibody or polypeptides of interest.
[0030] In another aspect, the present invention provides methods
for inducing apoptosis in a nonhematopoietic cancer cell expressing
the epitope on the cell surface, comprising contacting the cancer
cell with an antibody or a polypeptide described herein. In some
embodiments, the cancer cell is in an individual.
[0031] In another aspect, the present invention provides methods
for treating nonhematopoietic cancer in an individual comprising
administering to the individual an effective amount of a
composition comprising an antibody or a polypeptide described
herein, wherein the antibody or polypeptide bind to the cancer
cells in the individual. In some embodiments, the cancer is
colorectal, pancreatic, gastric, or lung cancer.
[0032] In another aspect, the present invention provides methods
for treating nonhematopoietic cancer in an individual comprising
administering to the individual an amount of an antibody or a
polypeptide described herein, and an amount of another anti-cancer
agent, wherein the antibody or polypeptide binds to the cancer
cells in the individual, and whereby the antibody or the
polypeptide and the anti-cancer agent in conjunction provide
effective treatment of cancer in the individual.
[0033] In another aspect, the present invention provides kits for
treating nonhematopoietic cancer in an individual comprising an
antibody or a polypeptide described herein. These kits may further
comprise instructions for administering the antibody or the
polypeptide to the individual for treating the cancer.
[0034] In another aspect, the present invention provides methods
for detecting or diagnosing of a nonhematopoietic cancer,
identifying individual having a nonhematopoietic cancer for
treatment, or monitoring progression of a nonhematopoietic cancer,
comprising contact a sample with an antibody or a polypeptide
described herein; and detecting presence or absence, or level of
binding the antibody or the polypeptide to a cell in the sample.
The presence of binding between the antibody and a cell in the
sample indicates that the sample may contain a cancer cell, and/or
the individual having cancer may be treated with an antibody
described herein. The methods may further comprises a step of
comparing the level of binding to a control.
[0035] In another aspect, the present invention provides kits for
detecting or diagnosing of nonhematopoietic cancer, identifying
individual having nonhematopoietic cancer for treatment, or
monitoring progression of nonhematopoietic cancer, comprising an
antibody or a polypeptide described herein, and reagents for
detecting binding of the antibody or the polypeptide to a cell in a
sample.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1 shows the results of identification of the target
protein of 5F1. Protein in the eluate of 5F1 immunoaffinity column
from COLO 205 lysate (lanes 1 and 3) or COLO 320 lysate (lanes 2
and 4) was immunoblotted with a commercial anti-CD43 antibody
AF2038 (lanes 1 and 2) or antibody 5F1 (lanes 3 and 4).
[0037] FIG. 2A shows the results of flow cytometric analysis of
antibody 5F1 binding to three cancer cell lines: colorectal cancer
cells (COLO 205 and DLD-1), and gastric cancer cell (NCI-N87).
[0038] FIG. 2B shows the results of flow cytometric analysis of
antibody 5F1 binding to normal endothelial cells (HUVEC), normal
(embryonic) lung cells (MRC-5), normal mammary gland epithelial
cells (MCF-10A), normal colorectal cells (CCD841-CoN), activated T
lymphocytes (activated for seven days), or normal peripheral blood
mononuclear cells (PBMC).
[0039] FIG. 3 shows mean enrichment of nucleosomes in the cytoplasm
of COLO 205 cells after incubation in the presence of antibody 5F1
or 9E10 (an anti-myc antibody), or control medium for 6, 24, and 48
hours.
[0040] FIG. 4 shows the results of cell growth of COLO 205 measured
by WST-1 assay after incubation with antibody 5F1, 9E10, or azide
in vitro for 72 hr.
[0041] FIG. 5 shows the results of cell growth measured by WST-1
assay. Colorectal carcinoma cells COLO 205 and normal colorectal
cell line CCD841-CoN, were either untreated, or incubated with
9E10, 5F1 (referred to as "m133-5F1"), or 0.5% azide.
[0042] FIG. 6 shows the results of MTT staining of COLO 205 cells
after incubation with various concentration of 5F1 (0, 2, 4, 8, 16,
32, 64 ug/ml), 9E10 (64 ug/ml) or 0.5% azide.
[0043] FIG. 7 shows in vivo effects (on tumor size) of antibody 5F1
(also referred to as "m133-5F1") on human COLO 205 tumors in SCID
mice. Antibody 5F1 (at 500 .mu.g/injection), or control antibody
9E10 (at 500 .mu.g/injection), or PBS (untreated) was injected on
days 0, 3, 5, 7, 10, 12, 14, and 17.
[0044] FIG. 8 shows in vivo effects (on tumor size) of antibody 5F1
with chemical drugs 5FU/LV on human COLO 205 tumors in SCID mice.
5FU/LV was intravenously injected every other day with four doses
of 25 mg/kg a week after the inoculation of COLO 205 cells.
Antibody 5F1 was intra-peritoneally injected at 0, 6.25 mg/kg, 12.5
mg/kg, and 25 mg/kg twice weekly for 3 weeks post 7 days of tumor
implant.
[0045] FIG. 9A shows flow cytometry results of chimeric antibody
5F1 binding to COLO 205 cell. FIG. 9B shows percentage of annexin V
and PI positive cells after incubation of COLO 205 cells with
control medium (untreated), sodium azide (0.5%), mouse antibody 5F1
(m5F1, 2-32 .mu.g/ml), or chimeric antibody 5F1 (c5F1, 2-32
.mu.g/ml).
[0046] FIGS. 10A and 10B show staining of COLO 205 and NCI-N87
cells for apoptotic cell death after incubation with various
antibodies. COLO 205 and NCI-N87 cells were incubated overnight
with control, 9E10 (30 ug/ml), m5F1 (10 ug/ml), or m5F1 (30 ug/ml).
Cells were then stained with YO-PRO.RTM.-1 (FIG. 10A) or combined
Annexin-V & PI (FIG. 10B). Staining percentage for each
condition is shown in the bar graph.
[0047] FIGS. 11A and 11B show that m5F1 binds to recombinant human
CEA (rhCEA) expressed on COLO 205 cells, but does not recognize
rhCEA expressed on COS-7 cells. In FIG. 11A, cell lysates of COLO
205 expressing flag-tagged human CEA were immunoprecipitated with
anti-Flag.RTM. antibody M2, immunoprecipitated proteins were run on
SDS-PAGE and then transferred to NC paper. NC paper was incubated
with anti-Flag M2, m5F1, 51-41, 138-10, or CEA/Ab-3 as indicated.
In FIG. 11B, cell lysates of COS-7 cells expressing flag-tagged
human CEA (+) or non-CEA expressing COS-7 cells (-) were
immunoprecipitated with anti-Flag.RTM. antibody M2,
immunoprecipitated proteins were run on SDS-PAGE and then
transferred to NC paper. NC paper was incubated with anti-Flag.RTM.
M2, m5F1, or CEA/Ab-3 as indicated.
[0048] FIGS. 12A and 12B show that m5F1 binds to recombinant CD43
(rhCD43) expressed on COLO 205 cells, but does not recognize rhCD43
expressed on COS-7 cells. In FIG. 12A, soluble CD43 expressed by
COLO 205 cells purified with protein A Sepharose.RTM. beads were
run on SDS-PAGE and transferred to NC paper, and the NC paper was
Western blotted with antibody m5F1, 51-14 or 138-10. In FIG. 12B,
cell lysates of COS-7 cells transfected with hCD43, hCD43/myc-His,
or untransfected cells were run on SDS-PAGE and transferred to NC
paper, and the NC paper was Western blotted with anti-CD43 (MEM59)
(left panel) or m5F1 (right panel).
[0049] FIG. 13 shows that m5F1 antibody recognizes a fucose
dependent glyco-epitope. rhCEA expressed by COLO 205 cells were
treated with 0, 0.01, 0.03, 0.1 mU of
.alpha.-1.fwdarw.(2,3,4)-Fucosidase. After treatment, proteins were
run on SDS-PAGE, and then Coomassie blue stained (right panel) or
Western blotted with m5F1 antibody.
[0050] FIG. 14 shows the structure of Lewis.sup.a-lactose
(Le.sup.a-lactose), Lewis.sup.b-lactose (Le.sup.b-lactose),
Lewis.sup.x-lactose (Le.sup.x-lactose), lactose, Lewis.sup.y
(Le.sup.y), Sialyl-Lewis.sup.x (Sialyl-Le.sup.x), Lewis.sup.a
(Le.sup.a), Lacto-N-tetraose (LNT), and Lecto-N-difucohexaose II
(LNDFH II).
[0051] FIG. 15 shows the results of binding inhibition assays by
adding oligosaccharides to compete m5F1, 138-10, and 51-41 binding
to COLO 205 cells. Oligosaccharides (LNDFH II, LNT, sLe(x), Le(y),
Lactose, Le(x)-lactose, Le(b)-lactose, Le(a)-lactose, or Le(a);
each at 1 mM) were added into different wells containing
2.times.10.sup.5 COLO 205 cells, followed by the addition of the
antibodies (138-10, 51-41, or m5F1) or no antibodies as control.
Binding of the antibodies to COLO 205 cells were measured by flow
cytometry analysis. Binding inhibition by the oligosaccharides for
each antibody is shown as percentage of inhibition determined by
florescence mean value in the Figure.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0052] An "antibody" is an immunoglobulin molecule capable of
specific binding to a target, such as a carbohydrate,
polynucleotide, lipid, polypeptide, etc., through at least one
antigen recognition site, located in the variable region of the
immunoglobulin molecule. As used herein, the term encompasses not
only intact polyclonal or monoclonal antibodies, but also fragments
thereof (such as Fab, Fab', F(ab').sub.2, Fv), single chain (ScFv),
mutants thereof, fusion proteins comprising an antibody portion,
and any other modified configuration of the immunoglobulin molecule
that comprises an antigen recognition site. An antibody includes an
antibody of any class, such as IgG, IgA, or IgM (or sub-class
thereof), and the antibody need not be of any particular class.
Depending on the antibody amino acid sequence of the constant
domain of its heavy chains, immunoglobulins can be assigned to
different classes. There are five major classes of immunoglobulins:
IgA, IgD, IgE, IgG, and IgM, and several of these may be further
divided into subclasses (isotypes), e.g., IgG1, IgG2, IgG3, IgG4,
IgA1 and IgA2. The heavy-chain constant domains that correspond to
the different classes of immunoglobulins are called alpha, delta,
epsilon, gamma, and mu, respectively. The subunit structures and
three-dimensional configurations of different classes of
immunoglobulins are well known.
[0053] The antibody of the present invention is further intended to
include bispecific, multispecific, single-chain, and chimeric and
humanized molecules having affinity for a polypeptide conferred by
at least one CDR region of the antibody. Antibodies of the present
invention also include single domain antibodies which are either
the variable domain of an antibody heavy chain or the variable
domain of an antibody light chain. Holt et al., Trends Biotechnol.
21:484-490, 2003. Methods of making domain antibodies comprising
either the variable domain of an antibody heavy chain or the
variable domain of an antibody light chain, containing three of the
six naturally occurring complementarity determining regions from an
antibody, are also known in the art. See, e.g., Muyldermans, Rev.
Mol. Biotechnol. 74:277-302, 2001.
[0054] As used herein, "monoclonal antibody" refers to an antibody
of substantially homogeneous antibodies, i.e., the individual
antibodies comprising the population are identical except for
possible naturally-occurring mutations that may be present in minor
amounts. Monoclonal antibodies are generally highly specific, being
directed against a single antigenic site. Furthermore, in contrast
to polyclonal antibody preparations, which typically include
different antibodies directed against different determinants
(epitopes), each monoclonal antibody is directed against a single
determinant on the antigen. The modifier "monoclonal" indicates the
character of the antibody as being obtained from a substantially
homogeneous population of antibodies, and is not to be construed as
requiring production of the antibody by any particular method. For
example, the monoclonal antibodies to be used in accordance with
the present invention may be made by the hybridoma method first
described by Kohler and Milstein, 1975, Nature, 256:495, or may be
made by recombinant DNA methods such as described in U.S. Pat. No.
4,816,567. The monoclonal antibodies may also be isolated from
phage libraries generated using the techniques described in
McCafferty et al., 1990, Nature, 348:552-554, for example.
[0055] As used herein, a "chimeric antibody" refers to an antibody
having a variable region or part of variable region from a first
species and a constant region from a second species. An intact
chimeric antibody comprises two copies of a chimeric light chain
and two copies of a chimeric heavy chain. The production of
chimeric antibodies is known in the art (Cabilly et al. (1984),
Proc. Natl. Acad. Sci. USA, 81:3273-3277; Harlow and Lane (1988),
Antibodies: a Laboratory Manual, Cold Spring Harbor Laboratory).
Typically, in these chimeric antibodies, the variable region of
both light and heavy chains mimics the variable regions of
antibodies derived from one species of mammals, while the constant
portions are homologous to the sequences in antibodies derived from
another. One clear advantage to such chimeric forms is that, for
example, the variable regions can conveniently be derived from
presently known sources using readily available hybridomas or B
cells from non human host organisms in combination with constant
regions derived from, for example, human cell preparations. While
the variable region has the advantage of ease of preparation, and
the specificity is not affected by its source, the constant region
being human is less likely to elicit an immune response from a
human subject when the antibodies are injected than would the
constant region from a non-human source. However, the definition is
not limited to this particular example.
[0056] An "isolated" antibody is one which has been identified and
separated and/or recovered from a component of its natural
environment.
[0057] As used herein, "substantially pure" refers to material
which is at least 50% pure (i.e., free from contaminants), more
preferably at least 90% pure, more preferably at least 95% pure,
more preferably at least 98% pure, more preferably at least 99%
pure.
[0058] As used herein, "humanized" antibodies refer to forms of
non-human (e.g. murine) antibodies that are specific chimeric
immunoglobulins, immunoglobulin chains, or fragments thereof (such
as Fv, Fab, Fab', F(ab').sub.2 or other antigen-binding
subsequences of antibodies) that contain minimal sequence derived
from non-human immunoglobulin. For the most part, humanized
antibodies are human immunoglobulins (recipient antibody) in which
residues from a complementary determining region (CDR) of the
recipient are replaced by residues from a CDR of a non-human
species (donor antibody) such as mouse, rat, or rabbit having the
desired specificity, affinity, and capacity. In some instances, Fv
framework region (FR) residues of the human immunoglobulin are
replaced by corresponding non-human residues. Furthermore, the
humanized antibody may comprise residues that are found neither in
the recipient antibody nor in the imported CDR or framework
sequences, but are included to further refine and optimize antibody
performance. In general, the humanized antibody will comprise
substantially all of at least one, and typically two, variable
domains, in which all or substantially all of the CDR regions
correspond to those of a non-human immunoglobulin and all or
substantially all of the FR regions are those of a human
immunoglobulin consensus sequence. The humanized antibody optimally
also will comprise at least a portion of an immunoglobulin constant
region or domain (Fc), typically that of a human immunoglobulin.
Antibodies may have Fc regions modified as described in WO
99/58572. Other forms of humanized antibodies have one or more CDRs
(one, two, three, four, five, six) which are altered with respect
to the original antibody, which are also termed one or more CDRs
"derived from" one or more CDRs from the original antibody.
[0059] As used herein, "human antibody" means an antibody having an
amino acid sequence corresponding to that of an antibody produced
by a human and/or has been made using any of the techniques for
making human antibodies known in the art or disclosed herein. This
definition of a human antibody includes antibodies comprising at
least one human heavy chain polypeptide or at least one human light
chain polypeptide. One such example is an antibody comprising
murine light chain and human heavy chain polypeptides. Human
antibodies can be produced using various techniques known in the
art. In one embodiment, the human antibody is selected from a phage
library, where that phage library expresses human antibodies
(Vaughan et al., 1996, Nature Biotechnology, 14:309-314; Sheets et
al., 1998, PNAS, (USA) 95:6157-6162; Hoogenboom and Winter, 1991,
J. Mol. Biol., 227:381; Marks et al., 1991, J. Mol. Biol.,
222:581). Human antibodies can also be made by introducing human
immunoglobulin loci into transgenic animals, e.g., mice in which
the endogenous immunoglobulin genes have been partially or
completely inactivated. This approach is described in U.S. Pat.
Nos. 5,545,807; 5,545,806; 5,569,825; 5,625,126; 5,633,425; and
5,661,016. Alternatively, the human antibody may be prepared by
immortalizing human B lymphocytes that produce an antibody directed
against a target antigen (such B lymphocytes may be recovered from
an individual or may have been immunized in vitro). See, e.g., Cole
et al., Monoclonal Antibodies and Cancer Therapy, Alan R. Liss, p.
77 (1985); Boerner et al., 1991, J. Immunol., 147 (1):86-95; and
U.S. Pat. No. 5,750,373.
[0060] A "variable region" of an antibody refers to the variable
region of the antibody light chain or the variable region of the
antibody heavy chain, either alone or in combination. The variable
regions of the heavy and light chain each consist of four framework
regions (FR) connected by three complementarity determining regions
(CDRs) also known as hypervariable regions. The CDRs in each chain
are held together in close proximity by the FRs and, with the CDRs
from the other chain, contribute to the formation of the
antigen-binding site of antibodies. There are at least two
techniques for determining CDRs: (1) an approach based on
cross-species sequence variability (i.e., Kabat et al. Sequences of
Proteins of Immunological Interest, (5th ed., 1991, National
Institutes of Health, Bethesda Md.)); and (2) an approach based on
crystallographic studies of antigen-antibody complexes (Al-lazikani
et al (1997) J. Molec. Biol. 273:927-948)). As used herein, a CDR
may refer to CDRs defined by either approach or by a combination of
both approaches.
[0061] A "constant region" of an antibody refers to the constant
region of the antibody light chain or the constant region of the
antibody heavy chain, either alone or in combination. A constant
region of an antibody generally provides structural stability and
other biological functions such as antibody chain association,
secretion, transplacental mobility, and complement binding, but is
not involved with binding to the antigen. The amino acid sequence
and corresponding exon sequences in the genes of the constant
region will be dependent upon the species from which it is derived;
however, variations in the amino acid sequence leading to allotypes
will be relatively limited for particular constant regions within a
species. The variable region of each chain is joined to the
constant region by a linking polypeptide sequence. The linkage
sequence is coded by a "J" sequence in the light chain gene, and a
combination of a "D" sequence and a "J" sequence in the heavy chain
gene.
[0062] As used herein "antibody-dependent cell-mediated
cytotoxicity" and "ADCC" refer to a cell-mediated reaction in which
nonspecific cytotoxic cells that express Fc receptors (FcRs) (e.g.
natural killer (NK) cells, neutrophils, and macrophages) recognize
bound antibody on a target cell and subsequently cause lysis of the
target cell. ADCC activity of a molecule of interest can be
assessed using an in vitro ADCC assay, such as that described in
U.S. Pat. No. 5,500,362 or 5,821,337. Useful effector cells for
such assays include peripheral blood mononuclear cells (PBMC) and
NK cells. Alternatively, or additionally, ADCC activity of the
molecule of interest may be assessed in vivo, e.g., in a animal
model such as that disclosed in Clynes et al., 1998, PNAS (USA),
95:652-656.
[0063] "Complement dependent cytotoxicity" and "CDC" refer to the
lysing of a target in the presence of complement. The complement
activation pathway is initiated by the binding of the first
component of the complement system (Clq) to a molecule (e.g. an
antibody) complexed with a cognate antigen. To assess complement
activation, a CDC assay, e.g. as described in Gazzano-Santoro et
al., J. Immunol. Methods, 202:163 (1996), may be performed.
[0064] The terms "polypeptide", "oligopeptide", "peptide" and
"protein" are used interchangeably herein to refer to polymers of
amino acids of any length. The polymer may be linear or branched,
it may comprise modified amino acids, and it may be interrupted by
non-amino acids. The terms also encompass an amino acid polymer
that has been modified naturally or by intervention; for example,
disulfide bond formation, glycosylation, lipidation, acetylation,
phosphorylation, or any other manipulation or modification, such as
conjugation with a labeling component. Also included within the
definition are, for example, polypeptides containing one or more
analogs of an amino acid (including, for example, unnatural amino
acids, etc.), as well as other modifications known in the art. It
is understood that, because the polypeptides of this invention are
based upon an antibody, the polypeptides can occur as single chains
or associated chains.
[0065] "Polynucleotide," or "nucleic acid," as used interchangeably
herein, refer to polymers of nucleotides of any length, and include
DNA and RNA. The nucleotides can be deoxyribonucleotides,
ribonucleotides, modified nucleotides or bases, and/or their
analogs, or any substrate that can be incorporated into a polymer
by DNA or RNA polymerase. A polynucleotide may comprise modified
nucleotides, such as methylated nucleotides and their analogs. If
present, modification to the nucleotide structure may be imparted
before or after assembly of the polymer. The sequence of
nucleotides may be interrupted by non-nucleotide components. A
polynucleotide may be further modified after polymerization, such
as by conjugation with a labeling component. Other types of
modifications include, for example, "caps", substitution of one or
more of the naturally occurring nucleotides with an analog,
internucleotide modifications such as, for example, those with
uncharged linkages (e.g., methyl phosphonates, phosphotriesters,
phosphoamidates, cabamates, etc.) and with charged linkages (e.g.,
phosphorothioates, phosphorodithioates, etc.), those containing
pendant moieties, such as, for example, proteins (e.g., nucleases,
toxins, antibodies, signal peptides, ply-L-lysine, etc.), those
with intercalators (e.g., acridine, psoralen, etc.), those
containing chelators (e.g., metals, radioactive metals, boron,
oxidative metals, etc.), those containing alkylators, those with
modified linkages (e.g., alpha anomeric nucleic acids, etc.), as
well as unmodified forms of the polynucleotide(s). Further, any of
the hydroxyl groups ordinarily present in the sugars may be
replaced, for example, by phosphonate groups, phosphate groups,
protected by standard protecting groups, or activated to prepare
additional linkages to additional nucleotides, or may be conjugated
to solid supports. The 5' and 3' terminal OH can be phosphorylated
or substituted with amines or organic capping group moieties of
from 1 to 20 carbon atoms. Other hydroxyls may also be derivatized
to standard protecting groups. Polynucleotides can also contain
analogous forms of ribose or deoxyribose sugars that are generally
known in the art, including, for example, 2'-O-methyl-, 2'-O-allyl,
2'-fluoro- or 2'-azido-ribose, carbocyclic sugar analogs,
.alpha.-anomeric sugars, epimeric sugars such as arabinose, xyloses
or lyxoses, pyranose sugars, furanose sugars, sedoheptuloses,
acyclic analogs and abasic nucleoside analogs such as methyl
riboside. One or more phosphodiester linkages may be replaced by
alternative linking groups. These alternative linking groups
include, but are not limited to, embodiments wherein phosphate is
replaced by P(O)S("thioate"), P(S)S ("dithioate"), "(O)NR.sub.2
("amidate"), P(O)R, P(O)OR`, CO or CH.sub.2 ("formacetal"), in
which each R or R' is independently H or substituted or
unsubstituted alkyl (1-20 C) optionally containing an ether (--O--)
linkage, aryl, alkenyl, cycloalkyl, cycloalkenyl or araldyl. Not
all linkages in a polynucleotide need be identical. The preceding
description applies to all polynucleotides referred to herein,
including RNA and DNA.
[0066] As used herein, "vector" means a construct, which is capable
of delivering, and preferably expressing, one or more gene(s) or
sequence(s) of interest in a host cell. Examples of vectors
include, but are not limited to, viral vectors, naked DNA or RNA
expression vectors, plasmid, cosmid or phage vectors, DNA or RNA
expression vectors associated with cationic condensing agents, DNA
or RNA expression vectors encapsulated in liposomes, and certain
eukaryotic cells, such as producer cells.
[0067] As used herein, "expression control sequence" means a
nucleic acid sequence that directs transcription of a nucleic acid.
An expression control sequence can be a promoter, such as a
constitutive or an inducible promoter, or an enhancer. The
expression control sequence is operably linked to the nucleic acid
sequence to be transcribed.
[0068] As used herein, an "effective dosage" or "effective amount"
of drug, compound, or pharmaceutical composition is an amount
sufficient to effect beneficial or desired results. For
prophylactic use, beneficial or desired results include results
such as eliminating or reducing the risk, lessening the severity,
or delaying the onset of the disease, including biochemical,
histological and/or behavioral symptoms of the disease, its
complications and intermediate pathological phenotypes presenting
during development of the disease. For therapeutic use, beneficial
or desired results include clinical results such as decreasing one
or more symptoms resulting from the disease, increasing the quality
of life of those suffering from the disease, decreasing the dose of
other medications required to treat the disease, enhancing effect
of another medication such as via targeting, delaying the
progression of the disease, and/or prolonging survival. In the case
of cancer or tumor, an effective amount of the drug may have the
effect in reducing the number of cancer cells; reducing the tumor
size; inhibiting (i.e., slow to some extent and preferably stop)
cancer cell infiltration into peripheral organs; inhibit (i.e.,
slow to some extent and preferably stop) tumor metastasis;
inhibiting, to some extent, tumor growth; and/or relieving to some
extent one or more of the symptoms associated with the disorder. An
effective dosage can be administered in one or more
administrations. For purposes of this invention, an effective
dosage of drug, compound, or pharmaceutical composition is an
amount sufficient to accomplish prophylactic or therapeutic
treatment either directly or indirectly. As is understood in the
clinical context, an effective dosage of a drug, compound, or
pharmaceutical composition may or may not be achieved in
conjunction with another drug, compound, or pharmaceutical
composition. Thus, an "effective dosage" may be considered in the
context of administering one or more therapeutic agents, and a
single agent may be considered to be given in an effective amount
if, in conjunction with one or more other agents, a desirable
result may be or is achieved.
[0069] As used herein, "in conjunction with" refers to
administration of one treatment modality in addition to another
treatment modality. As such, "in conjunction with" refers to
administration of one treatment modality before, during or after
administration of the other treatment modality to the
individual.
[0070] As used herein, "treatment" or "treating" is an approach for
obtaining beneficial or desired results including and preferably
clinical results. For purposes of this invention, beneficial or
desired clinical results include, but are not limited to, one or
more of the following: reducing the proliferation of (or
destroying) cancerous cells, decreasing symptoms resulting from the
disease, increasing the quality of life of those suffering from the
disease, decreasing the dose of other medications required to treat
the disease, delaying the progression of the disease, and/or
prolonging survival of individuals.
[0071] As used herein, "delaying development of a disease" means to
defer, hinder, slow, retard, stabilize, and/or postpone development
of the disease (such as cancer). This delay can be of varying
lengths of time, depending on the history of the disease and/or
individual being treated. As is evident to one skilled in the art,
a sufficient or significant delay can, in effect, encompass
prevention, in that the individual does not develop the disease.
For example, a late stage cancer, such as development of
metastasis, may be delayed.
[0072] An "individual" or a "subject" is a mammal, more preferably
a human. Mammals also include, but are not limited to, farm
animals, sport animals, pets (such as cats, dogs, horses),
primates, mice and rats.
[0073] As use herein, the term "specifically recognizes" or
"specifically binds" refers to measurable and reproducible
interactions such as attraction or binding between a target and an
antibody, that is determinative of the presence of the target in
the presence of a heterogeneous population of molecules including
biological molecules. For example, an antibody that specifically or
preferentially binds to an epitope is an antibody that binds this
epitope with greater affinity, avidity, more readily, and/or with
greater duration than it binds to other epitopes of the target or
non-target epitopes. It is also understood by reading this
definition that, for example, an antibody (or moiety or epitope)
that specifically or preferentially binds to a first target may or
may not specifically or preferentially bind to a second target. As
such, "specific binding" or "preferential binding" does not
necessarily require (although it can include) exclusive binding. An
antibody that specifically binds to a target may have an
association constant of at least about 10.sup.3 M.sup.-1 or
10.sup.4 M.sup.-1, sometimes about 10.sup.5 M.sup.-1 or 10.sup.6
M.sup.-1, in other instances about 10.sup.6 M.sup.-1 or 10.sup.7
M.sup.-1, about 10.sup.8 M.sup.-1 to 10.sup.9 M.sup.-1, or about
10.sup.10 M.sup.-1 to 10.sup.11 M.sup.-1 or higher. A variety of
immunoassay formats can be used to select antibodies specifically
immunoreactive with a particular protein. For example, solid-phase
ELISA immunoassays are routinely used to select monoclonal
antibodies specifically immunoreactive with a protein. See, e.g.,
Harlow and Lane (1988) Antibodies, A Laboratory Manual, Cold Spring
Harbor Publications, New York, for a description of immunoassay
formats and conditions that can be used to determine specific
immunoreactivity.
[0074] As used herein, the terms "cancer," "tumor," "cancerous,"
and "malignant" refer to or describe the physiological condition in
mammals that is typically characterized by unregulated cell growth.
Examples of cancer include but are not limited to, carcinoma,
including adenocarcinoma, lymphoma, blastoma, melanoma, and
sarcoma. More particular examples of such cancers include squamous
cell cancer, small-cell lung cancer, non-small cell lung cancer,
lung adenocarcinoma, lung squamous cell carcinoma, gastrointestinal
cancer, Hodgkin's and non-Hodgkin's lymphoma, pancreatic cancer,
glioblastoma, cervical cancer, glioma, ovarian cancer, liver cancer
such as hepatic carcinoma and hepatoma, bladder cancer, breast
cancer, colon cancer, colorectal cancer, endometrial or uterine
carcinoma, salivary gland carcinoma, kidney cancer such as renal
cell carcinoma and Wilms' tumors, basal cell carcinoma, melanoma,
prostate cancer, thyroid cancer, testicular cancer, esophageal
cancer, and various types of head and neck cancer.
[0075] As used herein and in the appended claims, the singular
forms "a," "an," and "the" include plural reference unless the
context clearly indicates otherwise. For example, reference to an
"antibody" is a reference to from one to many antibodies, such as
molar amounts, and includes equivalents thereof known to those
skilled in the art, and so forth.
[0076] It is understood that aspect and variations of the invention
described herein include "consisting" and/or "consisting
essentially of" aspects and variations.
Antibodies and Polypeptides that Specifically Bind to a
Carbohydrate Epitope on CD43 and CEA Expressed on Nonhematopoietic
Cancer Cells
[0077] The invention provides isolated antibodies, and polypeptides
derived from the antibodies, that specifically bind to an epitope
on CD43 and/or CEA expressed by nonhematopoietic cancer cells, but
do not specifically bind to a CD43 expressed by a leukocyte (such
as a peripheral T cell) or a Jurkat cell. The antibodies and
polypeptides of the invention may further have one or more of the
following characteristics: (a) binding of the antibody or the
polypeptide to the epitope is reduced if the molecule comprising
the epitope is treated with .alpha.-1.fwdarw.(2,3,4)-Fucosidase;
(b) binding of the antibody or the polypeptide to the epitope is
inhibited by a carbohydrate comprising a Le.sup.a structure, a
Le.sup.a-lactose structure, a LNDFH II structure, and/or a LNT
structure; (c) induce death of the nonhematopoietic cancer cell
(such as through apoptosis) after binding to the epitope expressed
on the cell surface of the cancer cell in the absence of cytotoxin
conjugation and immune effector function; (d) inhibit cell growth
or proliferation of the nonhematopoietic cancer cell after binding
to the epitope expressed on the cell surface of the cancer cell;
and (e) treat or prevent nonhematopoietic cancer expressing the
epitope on the cell surface, such as colorectal cancer and gastric
cancer, in an individual.
[0078] As used herein, the term "inhibition" includes partial and
complete inhibition. For example, binding of the antibody or the
polypeptide to the epitope on CD43 and CEA is inhibited by at least
about 20%, at least about 30%, at least about 40%, at least about
50%, at least about 60%, at least about 70%, at least about 80%, or
at least about 90% by a carbohydrate comprising a Le.sup.a
structure, a Le.sup.a-lactose structure, a LNDFH II structure, or a
LNT structure. Binding of the antibody to the epitope may be
inhibited by direct competition or by other mechanisms.
[0079] Examples of non-hematopoietic cancer cells expressing the
epitope include, but are not limited to, colorectal cancer cells
(such as COLO 205 and DLD-1) and gastric cancer cells (such as
NCI-N87).
[0080] The antibodies and polypeptides of the present invention may
recognize an extracellular domain of a CD43 present on a
nonhematopoietic cancer cell, but does not bind to an extracellular
domain of a leukocyte CD43 (e.g., a peripheral T cell), or an
extracellular domain of CD43 expressed on a Jurkat cell (a
lymphoblastoid leukemia cell). In some embodiments, the novel
antibodies or polypeptides of the invention do not specifically
bind to a CD43 expressed by a cell of hematopoietic origin.
[0081] The antibodies of the invention can encompass monoclonal
antibodies, polyclonal antibodies, antibody fragments (e.g., Fab,
Fab', F(ab').sub.2, Fv, Fc, etc.), chimeric antibodies, single
chain (ScFv), mutants thereof, fusion proteins comprising an
antibody portion, and any other modified configuration of the
immunoglobulin molecule that comprises an antigen recognition site
of the required specificity. The antibodies may be murine, rat,
camel, human, or any other origin (including humanized
antibodies).
[0082] The binding affinity of the polypeptide (including antibody)
to CD43 or CEA may be less than any of about 500 nM, about 400 nM,
about 300 nM, about 200 nM, about 100 nM, about 50 nM, about 10 nM,
about 1 nM, about 500 pM, about 100 pM, or about 50 pM. As is well
known in the art, binding affinity can be expressed as K.sub.D, or
dissociation constant, and an increased binding affinity
corresponds to a decreased K.sub.D. One way of determining binding
affinity of antibodies to CD43 or CEA is by measuring binding
affinity of monofunctional Fab fragments of the antibody. To obtain
monofunctional Fab fragments, an antibody (for example, IgG) can be
cleaved with papain or expressed recombinantly. The affinity of an
Fab fragment of an antibody can be determined by surface plasmon
resonance (BIAcore3000.TM. surface plasmon resonance (SPR) system,
BIAcore, INC, Piscaway N.J.) and ELISA. Kinetic association rates
(k.sub.on) and dissociation rates (k.sub.off) (generally measured
at 25.degree. C.) are obtained; and equilibrium dissociation
constant (K.sub.D) values are calculated as k.sub.off/k.sub.on.
[0083] In some embodiments, the antibodies and polypeptides of the
invention reduce the number of cancer cells, and/or inhibit cell
growth or proliferation of tumor or cancer cells that have the
epitope. Preferably, the reduction in cell number or inhibition of
cell growth or proliferation is by at least about 10%, about 20%,
about 30%, about 40%, about 50%, about 65%, about 75%, or greater
as compared to the cell not treated with the antibody or
polypeptides. Cancer cells include, but are not limited to,
colorectal cancer, pancreatic cancer, lung cancer, gastric
cancer.
[0084] In some embodiments, the antibodies and polypeptides of the
invention are capable of inducing cell death alone, for example
through apoptosis, after binding the epitope expressed on cell
surface of the nonhematopoietic cancer cell. The term "induce cell
death" as used herein, means that the antibodies or polypeptides of
the present invention, can directly interact with a molecule
expressed on the cell surface, and the binding/interaction alone is
sufficient to induce cell death in the cells without the help of
other factors such as cytotoxin conjugation or other immune
effector functions, i.e., complement-dependent cytotoxicity (CDC),
antibody-dependent cellular cytotoxicity (ADCC), or
phagocytosis.
[0085] As used herein, the term "apoptosis" refers to gene-directed
process of intracellular cell destruction. Apoptosis is distinct
from necrosis; it includes cytoskeletal disruption, cytoplasmic
shrinkage and condensation, expression of phosphatidylserine on the
outer surface of the cell membrane and blebbing, resulting in the
formation of cell membrane bound vesicles or apoptotic bodies. The
process is also referred to as "programmed cell death." During
apoptosis, characteristic phenomena such as curved cell surfaces,
condensation of nuclear chromatin, fragmentation of chromosomal
DNA, and loss of mitochondrial function are observed. Various known
technologies may be used to detect apoptosis, such as staining
cells with Annexin V, propidium iodide, DNA fragmentation assay and
YO-PRO.RTM.-1 (Invitrogen).
[0086] Methods of detecting cell death (such as apoptosis) include,
but are not limited to, detecting morphology, DNA fragmentation,
enzymatic activity, and polypeptide degradation, etc. See Siman et
al., U.S. Pat. No. 6,048,703; Martin and Green (1995), Cell, 82:
349-52; Thomberry and Lazebnik (1998), Science, 281:1312-6; Zou et
al., U.S. Pat. No. 6,291,643; Scovassi and Poirier (1999), Mol.
Cell Biochem., 199: 125-37; Wyllie e tal. (1980), Int. Rev. Cytol.,
68:251-306; Belhocine et al. (2004), Technol. Cancer Res. Treat.,
3(1):23-32, which are incorporated herein by reference.
[0087] In some embodiments, the antibodies and polypeptides of the
invention recognize a conformation epitope expressed on a
nonhematopoietic cancer cell, and this epitope includes a structure
having physical and chemical characteristics equivalent to the
structure formed by tripeptide, N'-Trp-Pro-Ile-C'. As used herein,
"an epitope which includes a structure having physical and chemical
characteristics equivalent to the structure formed by a peptide"
means that both structures have a similar physical and chemical
property related to antibody binding so that an antibody that
specifically binds to one structure would bind to both structures.
In some embodiments, the antibodies and polypeptides bind to a
polypeptide comprising amino acid sequence, N'-Trp-Pro-Ile-C' at
the N-terminus of the polypeptide.
[0088] In some embodiments, the antibodies and polypeptides of the
invention competes with antibody 5F1, 138-10, or 51-41, for binding
to the epitope expressed on the cell surface of the cancer cell. In
some embodiments, the antibodies or polypeptides of the invention
binding to an epitope on CD43 or CEA to which at least one of
antibodies 5F1, 138-10, and 51-41 binds.
[0089] Competition assays can be used to determine whether two
antibodies bind the same epitope by recognizing identical or
sterically overlapping epitopes or one antibody competitively
inhibits binding of another antibody to the antigen. These assays
are known in the art and are described in detail in the Examples.
Typically, antigen or antigen expressing cells is immobilized on a
multi-well plate and the ability of unlabeled antibodies to block
the binding of labeled antibodies is measured. Common labels for
such competition assays are radioactive labels or enzyme
labels.
[0090] In some embodiments, the antibody of the invention is
antibody 5F1 or an antibody derived from 5F1. The heavy chain and
light chain variable sequences of 5F1 are set forth in SEQ ID NO:1
and SEQ ID NO:2, respectively. The invention provides an antibody
or a polypeptide comprising a fragment or a region of the antibody
5F1. In one embodiment, the fragment is a light chain of the
antibody 5F1. In another embodiment, the fragment is a heavy chain
of the antibody 5F1. In yet another embodiment, the fragment
contains one or more variable regions from a light chain and/or a
heavy chain of the antibody 5F1. In yet another embodiment, the
fragment contains one, two, or three CDRs from a light chain and/or
a heavy chain of the antibody 5F1. In some embodiments, the
antibody is a humanized antibody of 5F1, such as h5F1 comprising
the heavy chain variable region shown in SEQ ID NO:7 and the light
chain variable region shown in SEQ ID NO:8. In some embodiments,
the one or more CDRs derived from antibody 5F1 are at least about
85%, at least about 86%, at least about 87%, at least about 88%, at
least about 89%, at least about 90%, at least about 91%, at least
about 92%, at least about 93%, at least about 94%, at least about
95%, at least about 96%, at least about 97%, at least about 98%, or
at least about 99% identical to at least one, at least two, at
least three, at least four, at least five, or at least six CDRs of
5F1.
[0091] In some embodiments, the antibody of the invention is
antibody 138-10 or an antibody derived from 138-10. The heavy chain
and light chain variable sequences of 138-10 are set forth in SEQ
ID NO:3 and SEQ ID NO:4, respectively. The invention provides an
antibody or a polypeptide comprising a fragment or a region of the
antibody 138-10. In one embodiment, the fragment is a light chain
of the antibody 138-10. In another embodiment, the fragment is a
heavy chain of the antibody 138-10. In yet another embodiment, the
fragment contains one or more variable regions from a light chain
and/or a heavy chain of the antibody 138-10. In yet another
embodiment, the fragment contains one, two, or three CDRs from a
light chain and/or a heavy chain of the antibody 138-10. In some
embodiments, the antibody is a humanized antibody of 138-10. In
some embodiments, the one or more CDRs derived from antibody 138-10
are at least about 85%, at least about 86%, at least about 87%, at
least about 88%, at least about 89%, at least about 90%, at least
about 91%, at least about 92%, at least about 93%, at least about
94%, at least about 95%, at least about 96%, at least about 97%, at
least about 98%, or at least about 99% identical to at least one,
at least two, at least three, at least four, at least five, or at
least six CDRs of 138-10.
[0092] In some embodiments, the antibody of the invention is
antibody 51-41 or an antibody derived from 51-41. The heavy chain
and light chain variable sequences of 51-41 are set forth in SEQ ID
NO:5 and SEQ ID NO:6, respectively. The invention provides an
antibody or a polypeptide comprising a fragment or a region of the
antibody 51-41. In one embodiment, the fragment is a light chain of
the antibody 51-41. In another embodiment, the fragment is a heavy
chain of the antibody 51-41. In yet another embodiment, the
fragment contains one or more variable regions from a light chain
and/or a heavy chain of the antibody 51-41. In yet another
embodiment, the fragment contains one, two, or three CDRs from a
light chain and/or a heavy chain of the antibody 51-41. In some
embodiments, the antibody is a humanized antibody of 51-41. In some
embodiments, the one or more CDRs derived from antibody 51-41 are
at least about 85%, at least about 86%, at least about 87%, at
least about 88%, at least about 89%, at least about 90%, at least
about 91%, at least about 92%, at least about 93%, at least about
94%, at least about 95%, at least about 96%, at least about 97%, at
least about 98%, or at least about 99% identical to at least one,
at least two, at least three, at least four, at least five, or at
least six CDRs of 51-41.
[0093] In some embodiments, the CDR is a Kabat CDR. In other
embodiments, the CDR is a Chothia CDR. In other embodiments, the
CDR is a combination of a Kabat and a Chothia CDR (also termed
"combined CDR" or "extended CDR"). In other words, for any given
embodiment containing more than one CDR, the CDRs may be any of
Kabat, Chothia, and/or combined.
[0094] Methods of making antibodies and polypeptides derived from
the antibodies are known in the art and are disclosed herein. The
monoclonal antibodies of the present invention can be prepared
using well-established methods. For example, the monoclonal
antibodies can be prepared using hybridoma technology, such as
those described by Kohler and Milstein (1975), Nature, 256:495. In
a hybridoma method, a mouse, a hamster, or other appropriate host
animal, is typically immunized with an immunizing agent (e.g., a
cancer cell expressing CD43 or CEA, CD43 or CEA (including
extracellular domain and fragments thereof expressed by the cancer
cell) which may be purified using antibodies described herein, or a
polypeptide comprising amino acid sequence N'-Trp-Pro-Ile-C' at the
N-terminus of the polypeptide) to elicit lymphocytes that produce
or are capable of producing antibodies that will specifically bind
to the immunizing agent. Alternatively, the lymphocytes may be
immunized in vitro. The lymphocytes are then fused with an
immortalized cell line using a suitable fusing agent, such as
polyethylene glycol, to form a hybridoma cell (Goding, Monoclonal
Antibodies: Principles and Practice, Academic Press, (1986) pp.
59-1031). Immortalized cell lines are usually transformed mammalian
cells, particularly myeloma cells of rodent, rabbit, bovine and
human origin. Usually, rat or mouse myeloma cell lines are
employed. The hybridoma cells may be cultured in a suitable culture
medium that preferably contains one or more substances that inhibit
the growth or survival of the unfused, immortalized cells. For
example, if the parental cells lack the enzyme hypoxanthine guanine
phosphoribosyl transferase (HGPRT or HPRT), the culture medium for
the hybridomas typically will include hypoxanthine, aminopterin,
and thymidine ("HAT medium"), which substances prevent the growth
of HGPRT-deficient cells.
[0095] Preferred immortalized cell lines are those that fuse
efficiently, support stable high level expression of antibody by
the selected antibody-producing cells, and are sensitive to a
medium such as HAT medium. More preferred immortalized cell lines
are murine myeloma lines, which can be obtained, for instance, from
the Salk Institute Cell Distribution Center, San Diego, Calif. and
the American Type Culture Collection, Manassas, Va. Human myeloma
and mouse-human heteromyeloma cell lines also have been described
for the production of human monoclonal antibodies (Kozbor, J.
Immunol. (1984), 133:3001; Brodeur et al., Monoclonal Antibody
Production Techniques and Applications, Marcel Dekker, Inc., New
York, (1987) pp. 51-63).
[0096] The culture medium in which the hybridoma cells are cultured
can then be assayed for the presence of monoclonal antibodies. The
antibody may be screened for having specific binding to the epitope
on CD-43 or CEA expressed by the nonhematopoietic cancer or tumor
cells, but no specific binding to CD43 expressing leukocyte, Jurkat
cells, and/or other CD43 expressing cells of hematopoietic origin.
Cancer cells or extracellular domain (including fragments thereof)
containing the epitope may be used for screening. For example,
CEA-N-A2 expressed by COLO 205 cells described in Example 10 may
used for screening.
[0097] Jurkat cell line is a lymphoblastoid leukemia cell, and was
established from the peripheral blood of a 14 year old boy by
Schneider et al. Schneider et al., Int. J. Cancer 19:621-626, 1977.
Various Jurkat cell lines are commercially available, for example,
from American Type Culture Collection (e.g., ATCC TIB-152, ATCC
TIB-153, ATCC CRL-2678).
[0098] Preferably, the binding specificity of monoclonal antibodies
produced by the hybridoma cells is determined by
immunoprecipitation or by an in vitro binding assay, such as
radioimmunoassay (RIA) or enzyme-linked immunoabsorbent assay
(ELISA). Such techniques and assays are known in the art. The
binding affinity of the monoclonal antibody can, for example, be
determined by the Scatchard analysis of Munson and Pollard (1980),
Anal. Biochem., 107:220.
[0099] The antibodies identified may further be tested for their
capabilities to induce cell death (e.g., apoptosis), and/or
inhibiting cell growth or proliferation using methods known in the
art and described herein.
[0100] After the desired hybridoma cells are identified, the clones
may be subcloned by limiting dilution procedures and grown by
standard methods (Goding, supra). Suitable culture media for this
purpose include, for example, Dulbecco's Modified Eagle's Medium or
RPMI-1640 medium. Alternatively, the hybridoma cells may be grown
in vivo as ascites in a mammal.
[0101] The monoclonal antibodies can be generated by culturing the
hybridoma cells, and the antibodies secreted by the hybridoma cells
may further be isolated or purified. Antibodies may be isolated or
purified from the culture medium or ascites fluid by conventional
immunoglobulin purification procedures such as, for example,
protein A-Sepharose.RTM., hydroxylapatite chromatography, gel
electrophoresis, dialysis, or affinity chromatography.
[0102] The antibodies of the invention can also be made by
recombinant DNA methods, such as those described in U.S. Pat. Nos.
4,816,567 and 6,331,415, which are hereby incorporated by
reference. for example, DNA encoding the monoclonal antibodies of
the invention can be readily isolated and sequenced using
conventional procedures (e.g., by using oligonucleotide probes that
are capable of binding specifically to genes encoding the heavy and
light chains of murine antibodies). The hybridoma cells of the
invention serve as a preferred source of such DNA. Once isolated,
the DNA can be placed into expression vectors, which are then
transfected into host cells such as simian COS cells, Chinese
hamster ovary (CHO) cells, or myeloma cells that do not otherwise
produce immunoglobulin protein, to obtain the synthesis of
monoclonal antibodies in the recombinant host cells. The DNA also
can be modified, for example, by substituting the coding sequence
for human heavy and light chain constant domains in place of the
homologous murine sequences (U.S. Pat. No. 4,816,567) or by
covalently joining to the immunoglobulin coding sequence all or
part of the coding sequence for a non-immunoglobulin polypeptide.
Such a non-immunoglobulin polypeptide can be substituted for the
constant domains of an antibody of the invention, or can be
substituted for the variable domains of one antigen-combining site
of an antibody of the invention to create a chimeric bivalent
antibody.
[0103] In some embodiment, the antibodies of the present invention
are expressed from two expression vectors. The first expression
vector encodes a heavy chain of the antibody (e.g., a humanized
antibody), comprising a first part encoding a variable region of
the heavy chain of the antibody, and a second part encoding a
constant region of the heavy chain of the antibody. In some
embodiments, the first part encodes a variable region having an
amino acid sequence represented by SEQ ID NO:7. The second
expression vector encodes a light chain of the antibody, comprising
a first part encoding a variable region of the light chain of the
antibody, and a second part encoding a constant region of the light
chain of the antibody. In some embodiments, the first part encodes
a variable region having an amino acid sequence represented by SEQ
ID NO:8.
[0104] Alternatively, the antibodies (e.g., a humanized antibody)
of the present invention are expressed from a single expression
vector. The single expression vector encodes both the heavy chain
and light chain of the antibodies of the present invention. In some
embodiments, the expression vector comprises a polynucleotide
sequence encoding a variable region of the heavy chain having an
amino acid sequence represented by SEQ ID NO:7 and a variable
region of the light chain having an amino acid sequence represented
by SEQ ID NO:8.
[0105] Normally the expression vector has transcriptional and
translational regulatory sequences which are derived from species
compatible with a host cell. In addition, the vector ordinarily
carries a specific gene(s) which is (are) capable of providing
phenotypic selection in transformed cells.
[0106] A wide variety of recombinant host-vector expression systems
for eukaryotic cells are known and can be used in the invention.
For example, Saccharomyces cerevisiae, or common baker's yeast, is
the most commonly used among eukaryotic microorganisms, although a
number of other strains, such as Pichia pastoris, are available.
Cell lines derived from multicellular organisms such as Sp2/0 or
Chinese Hamster Ovary (CHO), which are available from the ATCC, may
also be used as hosts. Typical vector plasmids suitable for
eukaryotic cell transformations are, for example, pSV2neo and
pSV2gpt (ATCC), pSVL and pSVK3 (Pharmacia), and pBPV-1/pML2d
(International Biotechnology, Inc.).
[0107] The eukaryotic host cells useful in the present invention
are, preferably, hybridoma, myeloma, plasmacytoma or lymphoma
cells. However, other eukaryotic host cells may be suitably
utilized provided the mammalian host cells are capable of
recognizing transcriptional and translational DNA sequences for
expression of the proteins; processing the leader peptide by
cleavage of the leader sequence and secretion of the proteins; and
providing post-translational modifications of the proteins, e.g.,
glycosylation.
[0108] Accordingly, the present invention provides eukaryotic host
cells which are transformed by recombinant expression vectors
comprising DNA constructs disclosed herein and which are capable of
expressing the antibodies or polypeptides of the present invention.
In some embodiments, the transformed host cells of the invention,
therefore, comprise at least one DNA construct comprising the light
and heavy chain DNA sequences described herein, and transcriptional
and translational regulatory sequences which are positioned in
relation to the light and heavy chain-encoding DNA sequences to
direct expression of antibodies or polypeptides.
[0109] The host cells used in the invention may be transformed in a
variety of ways by standard transfection procedures well known in
the art. Among the standard transfection procedures which may be
used are electroporation techniques, protoplast fusion and
calcium-phosphate precipitation techniques. Such techniques are
generally described by F. Toneguzzo et al. (1986), Mol. Cell.
Biol., 6:703-706; G. Chu et al., Nucleic Acid Res. (1987),
15:1311-1325; D. Rice et al., Proc. Natl. Acad. Sci. USA (1979),
79:7862-7865; and V. Oi et al., Proc. Natl. Acad. Sci. USA (1983),
80:825-829.
[0110] In the case of two expression vectors, the two expression
vectors can be transferred into a host cell one by one separately
or together (co-transfer or co-transfect).
[0111] The present invention also provides a method for producing
the antibodies or polypeptides, which comprises culturing a host
cell comprising an expression vector(s) encoding the antibodies or
the polypeptides, and recovering the antibodies or polypeptides
from the culture by ways well know to one skilled in the art.
[0112] Furthermore, the desired antibodies can be produced in a
transgenic animal. A suitable transgenic animal can be obtained
according to standard methods which include micro-injecting into
eggs the appropriate expression vectors, transferring the eggs into
pseudo-pregnant females and selecting a descendant expressing the
desired antibody.
[0113] The present invention also provides chimeric antibodies that
specifically recognize the epitope on CD43 and CEA expressed by a
cancer cell. For example, the variable and constant regions of the
chimeric antibody are from separate species. In some embodiments,
the variable regions of both heavy chain and light chain are from
the murine antibodies described herein. In some embodiments, the
variable regions comprise amino acid sequences shown in SEQ ID NO:1
and SEQ ID NO:2. In some embodiments, the variable regions comprise
amino acid sequences shown in SEQ ID NO:3 and SEQ ID NO:4. In some
embodiments, the variable regions comprise amino acid sequences
shown in SEQ ID NO:5 and SEQ ID NO:6. In some embodiments, the
constant regions of both the heavy chain and light chain are from
human antibodies.
[0114] The chimeric antibody of the present invention can be
prepared by techniques well-established in the art. See for
example, U.S. Pat. No. 6,808,901, U.S. Pat. No. 6,652,852, U.S.
Pat. No. 6,329,508, U.S. Pat. No. 6,120,767 and U.S. Pat. No.
5,677,427, each of which is hereby incorporated by reference. In
general, the chimeric antibody can be prepared by obtaining cDNAs
encoding the heavy and light chain variable regions of the
antibodies, inserting the cDNAs into an expression vector, which
upon being introduced into eukaryotic host cells, expresses the
chimeric antibody of the present invention. Preferably, the
expression vector carries a functionally complete constant heavy or
light chain sequence so that any variable heavy or light chain
sequence can be easily inserted into the expression vector.
[0115] The present invention provides a humanized antibody that
specifically recognizes the epitope on CD43 and CEA expressed by a
nonhematopoietic cancer cell. The humanized antibody is typically a
human antibody in which residues from CDRs are replaced with
residues from CDRs of a non-human species such as mouse, rat or
rabbit having the desired specificity, affinity and capacity. In
some instances, Fv framework residues of the human antibody are
replaced by corresponding non-human residues.
[0116] There are four general steps to humanize a monoclonal
antibody. These are: (1) determining the nucleotide and predicted
amino acid sequence of the starting antibody light and heavy
variable domains (2) designing the humanized antibody, i.e.,
deciding which antibody framework region to use during the
humanizing process (3) the actual humanizing
methodologies/techniques and (4) the transfection and expression of
the humanized antibody. See, for example, U.S. Pat. Nos. 4,816,567;
5,807,715; 5,866,692; 6,331,415; 5,530,101; 5,693,761; 5,693,762;
5,585,089; 6,180,370; and 6,548,640. For example, the constant
region may be engineered to more resemble human constant regions to
avoid immune response if the antibody is used in clinical trials
and treatments in humans. See, for example, U.S. Pat. Nos.
5,997,867 and 5,866,692.
[0117] It is important that antibodies be humanized with retention
of high affinity for the antigen and other favorable biological
properties. To achieve this goal, humanized antibodies can be
prepared by a process of analysis of the parental sequences and
various conceptual humanized products using three dimensional
models of the parental and humanized sequences. Three dimensional
immunoglobulin models are commonly available and are familiar to
those skilled in the art. Computer programs are available which
illustrate and display probable three-dimensional conformational
structures of selected candidate immunoglobulin sequences.
Inspection of these displays permits analysis of the likely role of
the residues in the functioning of the candidate immunoglobulin
sequence, i.e. the analysis of residues that influence the ability
of the candidate immunoglobulin to bind its antigen. In this way,
FR residues can be selected and combined from the consensus and
import sequence so that the desired antibody characteristic, such
as increased affinity for the target antigen(s), is achieved. In
general, the CDR residues are directly and most substantially
involved in influencing antigen binding. The humanized antibodies
may also contain modifications in the hinge region to improve one
or more characteristics of the antibody.
[0118] In another alternative, antibodies may be screened and made
recombinantly by phage display technology. See, for example, U.S.
Pat. Nos. 5,565,332; 5,580,717; 5,733,743 and 6,265,150; and Winter
et al., Annu. Rev. Immunol. 12:433-455 (1994). Alternatively, the
phage display technology (McCafferty et al., Nature 348:552-553
(1990)) can be used to produce human antibodies and antibody
fragments in vitro, from immunoglobulin variable (V) domain gene
repertoires from unimmunized donors. According to this technique,
antibody V domain genes are cloned in-frame into either a major or
minor coat protein gene of a filamentous bacteriophage, such as M13
or fd, and displayed as functional antibody fragments on the
surface of the phage particle. Because the filamentous particle
contains a single-stranded DNA copy of the phage genome, selections
based on the functional properties of the antibody also result in
selection of the gene encoding the antibody exhibiting those
properties. Thus, the phage mimics some of the properties of the B
cell. Phage display can be performed in a variety of formats; for
review see, e.g., Johnson, Kevin S. and Chiswell, David J., Current
Opinion in Structural Biology 3, 564-571 (1993). Several sources of
V-gene segments can be used for phage display. Clackson et al.,
Nature 352:624-628 (1991) isolated a diverse array of
anti-oxazolone antibodies from a small random combinatorial library
of V genes derived from the spleens of immunized mice. A repertoire
of V genes from unimmunized human donors can be constructed and
antibodies to a diverse array of antigens (including self-antigens)
can be isolated essentially following the techniques described by
Mark et al., J. Mol. Biol. 222:581-597 (1991), or Griffith et al.,
EMBO J. 12:725-734 (1993). In a natural immune response, antibody
genes accumulate mutations at a high rate (somatic hypermutation).
Some of the changes introduced will confer higher affinity, and B
cells displaying high-affinity surface immunoglobulin are
preferentially replicated and differentiated during subsequent
antigen challenge. This natural process can be mimicked by
employing the technique known as "chain shuffling." Marks, et al.,
Bio/Technol. 10:779-783 (1992)). In this method, the affinity of
"primary" human antibodies obtained by phage display can be
improved by sequentially replacing the heavy and light chain V
region genes with repertoires of naturally occurring variants
(repertoires) of V domain genes obtained from unimmunized donors.
This technique allows the production of antibodies and antibody
fragments with affinities in the pM-nM range. A strategy for making
very large phage antibody repertoires (also known as "the
mother-of-all libraries") has been described by Waterhouse et al.,
Nucl. Acids Res. 21:2265-2266 (1993). Gene shuffling can also be
used to derive human antibodies from rodent antibodies, where the
human antibody has similar affinities and specificities to the
starting rodent antibody. According to this method, which is also
referred to as "epitope imprinting", the heavy or light chain V
domain gene of rodent antibodies obtained by phage display
technique is replaced with a repertoire of human V domain genes,
creating rodent-human chimeras. Selection on antigen results in
isolation of human variable regions capable of restoring a
functional antigen-binding site, i.e., the epitope governs
(imprints) the choice of partner. When the process is repeated in
order to replace the remaining rodent V domain, a human antibody is
obtained (see PCT Publication No. WO 93/06213, published Apr. 1,
1993). Unlike traditional humanization of rodent antibodies by CDR
grafting, this technique provides completely human antibodies,
which have no framework or CDR residues of rodent origin. It is
apparent that although the above discussion pertains to humanized
antibodies, the general principles discussed are applicable to
customizing antibodies for use, for example, in dogs, cats,
primates, equines and bovines.
[0119] In certain embodiments, the antibody is a fully human
antibody. Non-human antibodies that specifically bind an antigen
can be used to produce a fully human antibody that binds to that
antigen. For example, the skilled artisan can employ a chain
swapping technique, in which the heavy chain of a non-human
antibody is co-expressed with an expression library expressing
different human light chains. The resulting hybrid antibodies,
containing one human light chain and one non-human heavy chain, are
then screened for antigen binding. The light chains that
participate in antigen binding are then co-expressed with a library
of human antibody heavy chains. The resulting human antibodies are
screened once more for antigen binding. Techniques such as this one
are further described in U.S. Pat. No. 5,565,332. In addition, an
antigen can be used to inoculate an animal that is transgenic for
human immunoglobulin genes. See, e.g., U.S. Pat. No. 5,661,016.
[0120] The antibody may be a bispecific antibody, a monoclonal
antibody that has binding specificities for at least two different
antigens, can be prepared using the antibodies disclosed herein.
Methods for making bispecific antibodies are known in the art (see,
e.g., Suresh et al., 1986, Methods in Enzymology 121:210).
Traditionally, the recombinant production of bispecific antibodies
was based on the coexpression of two immunoglobulin heavy
chain-light chain pairs, with the two heavy chains having different
specificities (Millstein and Cuello, 1983, Nature 305,
537-539).
[0121] According to one approach to making bispecific antibodies,
antibody variable domains with the desired binding specificities
(antibody-antigen combining sites) are fused to immunoglobulin
constant domain sequences. The fusion preferably is with an
immunoglobulin heavy chain constant domain, comprising at least
part of the hinge, CH2 and CH3 regions. It is preferred to have the
first heavy chain constant region (CH1), containing the site
necessary for light chain binding, present in at least one of the
fusions. DNAs encoding the immunoglobulin heavy chain fusions and,
if desired, the immunoglobulin light chain, are inserted into
separate expression vectors, and are cotransfected into a suitable
host organism. This provides for great flexibility in adjusting the
mutual proportions of the three polypeptide fragments in
embodiments when unequal ratios of the three polypeptide chains
used in the construction provide the optimum yields. It is,
however, possible to insert the coding sequences for two or all
three polypeptide chains in one expression vector when the
expression of at least two polypeptide chains in equal ratios
results in high yields or when the ratios are of no particular
significance.
[0122] In one approach, the bispecific antibodies are composed of a
hybrid immunoglobulin heavy chain with a first binding specificity
in one arm, and a hybrid immunoglobulin heavy chain-light chain
pair (providing a second binding specificity) in the other arm.
This asymmetric structure, with an immunoglobulin light chain in
only one half of the bispecific molecule, facilitates the
separation of the desired bispecific compound from unwanted
immunoglobulin chain combinations. This approach is described in
PCT Publication No. WO 94/04690, published Mar. 3, 1994.
[0123] Heteroconjugate antibodies, comprising two covalently joined
antibodies, are also within the scope of the invention. Such
antibodies have been used to target immune system cells to unwanted
cells (U.S. Pat. No. 4,676,980), and for treatment of HIV infection
(PCT Publication Nos. WO 91/00360 and WO 92/200373; and EP 03089).
Heteroconjugate antibodies may be made using any convenient
cross-linking methods. Suitable cross-linking agents and techniques
are well known in the art, and are described in U.S. Pat. No.
4,676,980.
[0124] Single chain Fv fragments may also be produced, such as
described in Iliades et al., 1997, FEBS Letters, 409:437-441.
Coupling of such single chain fragments using various linkers is
described in Kortt et al., 1997, Protein Engineering, 10:423-433. A
variety of techniques for the recombinant production and
manipulation of antibodies are well known in the art.
[0125] It is contemplated that the present invention encompasses
not only the monoclonal antibodies described above, but also any
fragments thereof containing the active binding region of the
antibodies, such as Fab, F(ab').sub.2, scFv, Fv fragments and the
like. Such fragments can be produced from the monoclonal antibodies
described herein using techniques well established in the art
(Rousseaux et al. (1986), in Methods Enzymol., 121:663-69 Academic
Press).
[0126] Methods of preparing antibody fragment are well known in the
art. For example, an antibody fragment can be produced by enzymatic
cleavage of antibodies with pepsin to provide a 100 Kd fragment
denoted F(ab').sub.2. This fragment can be further cleaved using a
thiol reducing agent, and optionally a blocking group for the
sulfhydryl groups resulting from cleavage of disulfide linkages, to
produce 50 Kd Fab' monovalent fragments. Alternatively, an
enzymatic cleavage using papain produces two monovalent Fab
fragments and an Fc fragment directly. These methods are described,
for example, by U.S. Pat. Nos. 4,036,945 and 4,331,647 and
references contained therein, which patents are incorporated herein
by reference. Also, see Nisonoff et al. (1960), Arch Biochem.
Biophys. 89: 230; Porter (1959), Biochem. J. 73: 119, Edelman et
al., in METHODS IN ENZYMOLOGY VOL. 1, page 422 (Academic Press
1967).
[0127] Alternatively, the Fab can be produced by inserting DNA
encoding Fab of the antibody into an expression vector for
prokaryote or an expression vector for eukaryote, and introducing
the vector into a prokaryote or eukaryote to express the Fab.
[0128] The invention encompasses modifications to antibodies or
polypeptide described herein, including functionally equivalent
antibodies which do not significantly affect their properties and
variants which have enhanced or decreased activity and/or affinity.
For example, amino acid sequence of antibody 5F1 or humanized
antibody, may be mutated to obtain an antibody with the desired
binding affinity to the CD43 or CEA expressed by the cancer cell.
Modification of polypeptides is routine practice in the art and
need not be described in detail herein. Examples of modified
polypeptides include polypeptides with conservative substitutions
of amino acid residues, one or more deletions or additions of amino
acids which do not significantly deleteriously change the
functional activity, or use of chemical analogs.
[0129] Amino acid sequence insertions include amino- and/or
carboxyl-terminal fusions ranging in length from one residue to
polypeptides containing a hundred or more residues, as well as
intrasequence insertions of single or multiple amino acid residues.
Examples of terminal insertions include an antibody with an
N-terminal methionyl residue or the antibody fused to an epitope
tag. Other insertional variants of the antibody molecule include
the fusion to the N- or C-terminus of the antibody of an enzyme or
a polypeptide which increases the serum half-life of the
antibody.
[0130] Substitution variants have at least one amino acid residue
in the antibody molecule removed and a different residue inserted
in its place. The sites of greatest interest for substitutional
mutagenesis include the hypervariable regions, but FR alterations
are also contemplated. Conservative substitutions are shown in the
table below under the heading of "conservative substitutions". If
such substitutions result in a change in biological activity, then
more substantial changes, denominated "exemplary substitutions" in
the table below, or as further described below in reference to
amino acid classes, may be introduced and the products
screened.
Amino Acid Substitutions
TABLE-US-00001 [0131] Conservative Original Residue Substitutions
Exemplary Substitutions Ala (A) Val Val; Leu; Ile Arg (R) Lys Lys;
Gln; Asn Asn (N) Gln Gln; His; Asp, Lys; Arg Asp (D) Glu Glu; Asn
Cys (C) Ser Ser; Ala Gln (Q) Asn Asn; Glu Glu (E) Asp Asp; Gln Gly
(G) Ala Ala His (H) Arg Asn; Gln; Lys; Arg Ile (I) Leu Leu; Val;
Met; Ala; Phe; Norleucine Leu (L) Ile Norleucine; Ile; Val; Met;
Ala; Phe Lys (K) Arg Arg; Gln; Asn Met (M) Leu Leu; Phe; Ile Phe
(F) Tyr Leu; Val; Ile; Ala; Tyr Pro (P) Ala Ala Ser (S) Thr Thr Thr
(T) Ser Ser Trp (W) Tyr Tyr; Phe Tyr (Y) Phe Tip; Phe; Thr; Ser Val
(V) Leu Ile; Leu; Met; Phe; Ala; Norleucine
[0132] Substantial modifications in the biological properties of
the antibody are accomplished by selecting substitutions that
differ significantly in their effect on maintaining (a) the
structure of the polypeptide backbone in the area of the
substitution, for example, as a sheet or helical conformation, (b)
the charge or hydrophobicity of the molecule at the target site, or
(c) the bulk of the side chain. Naturally occurring residues are
divided into groups based on common side-chain properties:
[0133] (1) Non-polar: Norleucine, Met, Ala, Val, Leu, Ile;
[0134] (2) Polar without charge: Cys, Ser, Thr, Asn, Gln;
[0135] (3) Acidic (negatively charged): Asp, Glu;
[0136] (4) Basic (positively charged): Lys, Arg;
[0137] (5) Residues that influence chain orientation: Gly, Pro;
and
[0138] (6) Aromatic: Trp, Tyr, Phe, His.
[0139] Non-conservative substitutions are made by exchanging a
member of one of these classes for another class.
[0140] Any cysteine residue not involved in maintaining the proper
conformation of the antibody also may be substituted, generally
with serine, to improve the oxidative stability of the molecule and
prevent aberrant cross-linking. Conversely, cysteine bond(s) may be
added to the antibody to improve its stability, particularly where
the antibody is an antibody fragment such as an Fv fragment.
[0141] Amino acid modifications can range from changing or
modifying one or more amino acids to complete redesign of a region,
such as the variable region. Changes in the variable region can
alter binding affinity and/or specificity. In some embodiments, no
more than one to five conservative amino acid substitutions are
made within a CDR domain. In other embodiments, no more than one to
three conservative amino acid substitutions are made within a CDR
domain. In still other embodiments, the CDR domain is CDRH3 and/or
CDR L3.
[0142] Modifications also include glycosylated and nonglycosylated
polypeptides, as well as polypeptides with other post-translational
modifications, such as, for example, glycosylation with different
sugars, acetylation, and phosphorylation. Antibodies are
glycosylated at conserved positions in their constant regions
(Jefferis and Lund, 1997, Chem. Immunol. 65:111-128; Wright and
Morrison, 1997, TibTECH 15:26-32). The oligosaccharide side chains
of the immunoglobulins affect the protein's function (Boyd et al.,
1996, Mol. Immunol. 32:1311-1318; Wittwe and Howard, 1990, Biochem.
29:4175-4180) and the intramolecular interaction between portions
of the glycoprotein, which can affect the conformation and
presented three-dimensional surface of the glycoprotein (Hefferis
and Lund, supra; Wyss and Wagner, 1996, Current Opin. Biotech.
7:409-416). Oligosaccharides may also serve to target a given
glycoprotein to certain molecules based upon specific recognition
structures. Glycosylation of antibodies has also been reported to
affect antibody-dependent cellular cytotoxicity (ADCC). In
particular, CHO cells with tetracycline-regulated expression of
.beta.(1,4)-N-acetylglucosaminyltransferase III (GnTIII), a
glycosyltransferase catalyzing formation of bisecting GlcNAc, was
reported to have improved ADCC activity (Umana et al., 1999, Mature
Biotech. 17:176-180).
[0143] Glycosylation of antibodies is typically either N-linked or
O-linked. N-linked refers to the attachment of the carbohydrate
moiety to the side chain of an asparagine residue. The tripeptide
sequences asparagine-X-serine, asparagine-X-threonine, and
asparagine-X-cysteine, where X is any amino acid except proline,
are the recognition sequences for enzymatic attachment of the
carbohydrate moiety to the asparagine side chain. Thus, the
presence of either of these tripeptide sequences in a polypeptide
creates a potential glycosylation site. O-linked glycosylation
refers to the attachment of one of the sugars
N-acetylgalactosamine, galactose, or xylose to a hydroxyamino acid,
most commonly serine or threonine, although 5-hydroxyproline or
5-hydroxylysine may also be used.
[0144] Addition of glycosylation sites to the antibody is
conveniently accomplished by altering the amino acid sequence such
that it contains one or more of the above-described tripeptide
sequences (for N-linked glycosylation sites). The alteration may
also be made by the addition of, or substitution by, one or more
serine or threonine residues to the sequence of the original
antibody (for O-linked glycosylation sites).
[0145] The glycosylation pattern of antibodies may also be altered
without altering the underlying nucleotide sequence. Glycosylation
largely depends on the host cell used to express the antibody.
Since the cell type used for expression of recombinant
glycoproteins, e.g. antibodies, as potential therapeutics is rarely
the native cell, variations in the glycosylation pattern of the
antibodies can be expected (see, e.g. Hse et al., 1997, J. Biol.
Chem. 272:9062-9070).
[0146] In addition to the choice of host cells, factors that affect
glycosylation during recombinant production of antibodies include
growth mode, media formulation, culture density, oxygenation, pH,
purification schemes and the like. Various methods have been
proposed to alter the glycosylation pattern achieved in a
particular host organism including introducing or overexpressing
certain enzymes involved in oligosaccharide production (U.S. Pat.
Nos. 5,047,335; 5,510,261 and 5,278,299). Glycosylation, or certain
types of glycosylation, can be enzymatically removed from the
glycoprotein, for example using endoglycosidase H (Endo H),
N-glycosidase F, endoglycosidase F1, endoglycosidase F2,
endoglycosidase F3. In addition, the recombinant host cell can be
genetically engineered to be defective in processing certain types
of polysaccharides. These and similar techniques are well known in
the art.
[0147] Other methods of modification include using coupling
techniques known in the art, including, but not limited to,
enzymatic means, oxidative substitution and chelation.
Modifications can be used, for example, for attachment of labels
for immunoassay. Modified polypeptides are made using established
procedures in the art and can be screened using standard assays
known in the art, some of which are described below and in the
Examples.
[0148] The antibody or polypeptide of the invention may be
conjugated (for example, linked) to an agent, such as a therapeutic
agent and a label. Examples of therapeutic agents are radioactive
moieties, cytotoxins, or chemotherapeutic molecules.
[0149] The antibody (or polypeptide) of this invention may be
linked to a label such as a fluorescent molecule, a radioactive
molecule, an enzyme, or any other labels known in the art. As used
herein, the term "label" refers to any molecule that can be
detected. In a certain embodiment, an antibody may be labeled by
incorporation of a radiolabeled amino acid. In a certain
embodiment, biotin moieties that can be detected by marked avidin
(e.g., streptavidin containing a fluorescent marker or enzymatic
activity that can be detected by optical or colorimetric methods)
may be attached to the antibody. In certain embodiments, a label
may be incorporated into or attached to another reagent which in
turn binds to the antibody of interest. For example, a label may be
incorporated into or attached to an antibody that in turn
specifically binds the antibody of interest. In certain
embodiments, the label or marker can also be therapeutic. Various
methods of labeling polypeptides and glycoproteins are known in the
art and may be used. Certain general classes of labels include, but
are not limited to, enzymatic, fluorescent, chemiluminescent, and
radioactive labels. Examples of labels for polypeptides include,
but are not limited to, the following: radioisotopes or
radionucleotides (e.g., .sup.3H, .sup.14C, .sup.15N, .sup.35S,
.sup.90Y, .sup.99Tc, .sup.111In, .sup.125I, .sup.131I), fluorescent
labels (e.g., fluorescein isothiocyanate (FITC), rhodamine,
lanthanide phosphors, phycoerythrin (PE)), enzymatic labels (e.g.,
horseradish peroxidase, .beta.-galactosidase, luciferase, alkaline
phosphatase, glucose oxidase, glucose-6-phosphate dehydrogenase,
alcohol dehyrogenase, malate dehyrogenase, penicillinase,
luciferase), chemiluminescent, biotinyl groups, predetermined
polypeptide epitopes recognized by a secondary reporter (e.g.,
leucine zipper pair sequences, binding sites for secondary
antibodies, metal binding domains, epitope tags). In certain
embodiments, labels are attached by spacer arms of various lengths
to reduce potential steric hindrance.
[0150] The invention also provides pharmaceutical compositions
comprising antibodies or polypeptides described herein, and a
pharmaceutically acceptable carrier or excipients. Pharmaceutically
acceptable excipients are known in the art, and are relatively
inert substances that facilitate administration of a
pharmacologically effective substance. For example, an excipient
can give form or consistency, or act as a diluent. Suitable
excipients include but are not limited to stabilizing agents,
wetting and emulsifying agents, salts for varying osmolarity,
encapsulating agents, buffers, and skin penetration enhancers.
Excipients as well as formulations for parenteral and nonparenteral
drug delivery are set forth in Remington, The Science and Practice
of Pharmacy 20th Ed. Mack Publishing (2000).
[0151] In some embodiments, the invention provides compositions
(described herein) for use in any of the methods described herein,
whether in the context of use as a medicament and/or use for
manufacture of a medicament.
Polynucleotides, Vectors and Host Cells
[0152] The invention also provides polynucleotides comprising a
nucleotide sequence encoding any of the monoclonal antibodies and
polypeptides described herein. In some embodiments, the
polypeptides comprise the sequences of light chain and heavy chain
variable regions.
[0153] In some embodiments, the polynucleotides comprise a nucleic
acid sequence encoding the heavy chain variable region set forth in
SEQ ID NO:1, and/or a nucleic acid sequence encoding the light
chain variable region set forth in SEQ ID NO:2. In some
embodiments, the polynucleotides comprise a nucleic acid sequence
encoding a heavy chain variable region comprising one, two, or
three CDRs from SEQ ID NO:1, and/or a nucleic acid sequence
encoding a light chain variable region comprising one, two, or
three CDRs from SEQ ID NO:2. In some embodiments, the
polynucleotides comprise a nucleic acid sequence set forth in SEQ
ID NO:9, and/or a nucleic acid sequence set forth in SEQ ID
NO:10.
[0154] In some embodiments, the polynucleotides comprise a nucleic
acid sequence encoding the heavy chain variable region set forth in
SEQ ID NO:3, and/or a nucleic acid sequence encoding the light
chain variable region set forth in SEQ ID NO:4. In some
embodiments, the polynucleotides comprise a nucleic acid sequence
encoding a heavy chain variable region comprising one, two, or
three CDRs from SEQ ID NO:3, and/or a nucleic acid sequence
encoding a light chain variable region comprising one, two, or
three CDRs from SEQ ID NO:4. In some embodiments, the
polynucleotides comprise a nucleic acid sequence set forth in SEQ
ID NO:11, and/or a nucleic acid sequence set forth in SEQ ID
NO:12.
[0155] In some embodiments, the polynucleotides comprise a nucleic
acid sequence encoding the heavy chain variable region set forth in
SEQ ID NO:5, and/or a nucleic acid sequence encoding the light
chain variable region set forth in SEQ ID NO:6. In some
embodiments, the polynucleotides comprise a nucleic acid sequence
encoding a heavy chain variable region comprising one, two, or
three CDRs from SEQ ID NO:5, and/or a nucleic acid sequence
encoding a light chain variable region comprising one, two, or
three CDRs from SEQ ID NO:6. In some embodiments, the
polynucleotides comprise a nucleic acid sequence set forth in SEQ
ID NO:13, and/or a nucleic acid sequence set forth in SEQ ID
NO:14.
[0156] In some embodiments, the polynucleotides comprise a nucleic
acid sequence encoding the heavy chain variable region set forth in
SEQ ID NO:7, and/or a nucleic acid sequence encoding the light
chain variable region set forth in SEQ ID NO:8. In some
embodiments, the polynucleotides comprise a nucleic acid sequence
set forth in SEQ ID NO:15, and/or a nucleic acid sequence set forth
in SEQ ID NO:16.
[0157] It is appreciated by those of ordinary skill in the art
that, as a result of the degeneracy of the genetic code, there are
many nucleotide sequences that encode a polypeptide as described
herein. Some of these polynucleotides bear minimal homology to the
nucleotide sequence of any native gene. Thus, polynucleotides that
vary due to differences in codon usage are specifically
contemplated by the present invention. Further, alleles of the
genes comprising the polynucleotide sequences provided herein are
within the scope of the present invention. Alleles are endogenous
genes that are altered as a result of one or more mutations, such
as deletions, additions and/or substitutions of nucleotides. The
resulting mRNA and protein can, but need not, have an altered
structure or function. Alleles can be identified using standard
techniques (such as hybridization, amplification and/or database
sequence comparison).
[0158] The polynucleotides of this invention can be obtained using
chemical synthesis, recombinant methods, or PCR. Methods of
chemical polynucleotide synthesis are well known in the art and
need not be described in detail herein. One of skill in the art can
use the sequences provided herein and a commercial DNA synthesizer
to produce a desired DNA sequence.
[0159] For preparing polynucleotides using recombinant methods, a
polynucleotide comprising a desired sequence can be inserted into a
suitable vector, and the vector in turn can be introduced into a
suitable host cell for replication and amplification, as further
discussed herein. Polynucleotides can be inserted into host cells
by any means known in the art. Cells are transformed by introducing
an exogenous polynucleotide by direct uptake, endocytosis,
transfection, F-mating or electroporation. Once introduced, the
exogenous polynucleotide can be maintained within the cell as a
non-integrated vector (such as a plasmid) or integrated into the
host cell genome. The polynucleotide so amplified can be isolated
from the host cell by methods well known within the art. See, e.g.,
Sambrook et al. (1989).
[0160] Alternatively, PCR allows reproduction of DNA sequences. PCR
technology is well known in the art and is described in U.S. Pat.
Nos. 4,683,195, 4,800,159, 4,754,065 and 4,683,202, as well as PCR:
The Polymerase Chain Reaction, Mullis et al. eds., Birkauswer
Press, Boston (1994).
[0161] The invention also provides vectors (e.g., cloning vectors,
expression vectors) comprising a nucleic acid sequence encoding any
of the polypeptides (including antibodies) described herein.
Suitable cloning vectors can be constructed according to standard
techniques, or may be selected from a large number of cloning
vectors available in the art. While the cloning vector selected may
vary according to the host cell intended to be used, useful cloning
vectors generally have the ability to self-replicate, may possess a
single target for a particular restriction endonuclease, and/or may
carry genes for a marker that can be used in selecting clones
containing the vector. Suitable examples include plasmids and
bacterial viruses, e.g., pUC18, pUC19, Bluescript.RTM. (e.g., pBS
SK+) and its derivatives, mpl8, mpl9, pBR322, pMB9, ColE1, pCR1,
RP4, phage DNAs, and shuttle vectors such as pSA3 and pAT28. These
and many other cloning vectors are available from commercial
vendors such as BioRad, Strategene, and Invitrogen.
[0162] Expression vectors generally are replicable polynucleotide
constructs that contain a polynucleotide according to the
invention. The expression vector may replicable in the host cells
either as episomes or as an integral part of the chromosomal DNA.
Suitable expression vectors include but are not limited to
plasmids, viral vectors, including adenoviruses, adeno-associated
viruses, retroviruses, cosmids, and expression vector(s) disclosed
in PCT Publication No. WO 87/04462. Vector components may generally
include, but are not limited to, one or more of the following: a
signal sequence; an origin of replication; one or more marker
genes; suitable transcriptional controlling elements (such as
promoters, enhancers and terminator). For expression (i.e.,
translation), one or more translational controlling elements are
also usually required, such as ribosome binding sites, translation
initiation sites, and stop codons.
[0163] The vectors containing the polynucleotides of interest can
be introduced into the host cell by any of a number of appropriate
means, including electroporation, transfection employing calcium
chloride, rubidium chloride, calcium phosphate, DEAE-dextran, or
other substances; microprojectile bombardment; lipofection; and
infection (e.g., where the vector is an infectious agent such as
vaccinia virus). The choice of introducing vectors or
polynucleotides will often depend on features of the host cell.
[0164] The invention also provides host cells comprising any of the
polynucleotides or vectors described herein. Any host cells capable
of over-expressing heterologous DNAs can be used for the purpose of
isolating the genes encoding the antibody, polypeptide or protein
of interest. Non-limiting examples of mammalian host cells include
but not limited to COS, HeLa, and CHO cells. See also PCT
Publication No. WO 87/04462. Suitable non-mammalian host cells
include prokaryotes (such as E. coli or B. subtillis) and yeast
(such as S. cerevisae, S. pombe; or K. lactis).
Diagnostic Uses
[0165] The present invention provides a method of using the
antibodies, polypeptides and polynucleotides of the present
invention for detection, diagnosis and monitoring of a disease,
disorder or condition associated with the epitope expression
(either increased or decreased relative to a normal sample, and/or
inappropriate expression, such as presence of expression in
tissues(s) and/or cell(s) that normally lack the epitope
expression).
[0166] In some embodiments, the method comprises detecting the
epitope expression in a sample obtained from a subject suspected of
having cancer, such colorectal, pancreatic, gastric, and lung
cancer. Preferably, the method of detection comprises contacting
the sample with an antibody, polypeptide, or polynucleotide of the
present invention and determining whether the level of binding
differs from that of a control or comparison sample. The method is
also useful to determine whether the antibodies or polypeptides
described herein are an appropriate treatment for the patient.
[0167] As used herein, the term "a sample" or "a biological sample"
refers to a whole organism or a subset of its tissues, cells or
component parts (e.g. body fluids, including but not limited to
blood, mucus, lymphatic fluid, synovial fluid, cerebrospinal fluid,
saliva, amniotic fluid, amniotic cord blood, urine, vaginal fluid
and semen). "A sample" or "a biological sample" further refers to a
homogenate, lysate or extract prepared from a whole organism or a
subset of its tissues, cells or component parts, or a fraction or
portion thereof, including but not limited to, for example, plasma,
serum, spinal fluid, lymph fluid, the external sections of the
skin, respiratory, intestinal, and genitourinary tracts, tears,
saliva, milk, blood cells, tumors, organs. Most often, the sample
has been removed from an animal, but the term "a sample" or "a
biological sample" can also refer to cells or tissue analyzed in
vivo, i.e., without removal from animal. Typically, "a sample" or
"a biological sample" will contain cells from the animal, but the
term can also refer to non-cellular biological material, such as
non-cellular fractions of blood, saliva, or urine, that can be used
to measure the cancer-associated polynucleotide or polypeptides
levels. "A sample" or "a biological sample" further refers to a
medium, such as a nutrient broth or gel in which an organism has
been propagated, which contains cellular components, such as
proteins or nucleic acid molecules.
[0168] In one embodiment, the cells or cell/tissue lysate are
contacted with an antibody and the binding between the antibody and
the cell is determined. When the test cells are shown binding
activity as compared to a control cell of the same tissue type, it
may indicate that the test cell is cancerous. In some embodiments,
the test cells are from human tissues.
[0169] Various methods known in the art for detecting specific
antibody-antigen binding can be used. Exemplary immunoassays which
can be conducted according to the invention include fluorescence
polarization immunoassay (FPIA), fluorescence immunoassay (FIA),
enzyme immunoassay (EIA), nephelometric inhibition immunoassay
(NIA), enzyme linked immunosorbent assay (ELISA), and
radioimmunoassay (MA). An indicator moiety, or label group, can be
attached to the subject antibodies and is selected so as to meet
the needs of various uses of the method which are often dictated by
the availability of assay equipment and compatible immunoassay
procedures. Appropriate labels include, without limitation,
radionuclides (e.g., .sup.125I, .sup.131I, .sup.35S, .sup.3H, or
.sup.32P), enzymes (e.g., alkaline phosphatase, horseradish
peroxidase, luciferase, or .beta.-galactosidase), fluorescent
moieties or proteins (e.g., fluorescein, rhodamine, phycoerythrin,
GFP, or BFP), or luminescent moieties (e.g., Qdot.RTM.
nanoparticles supplied by the Quantum Dot Corporation, Palo Alto,
Calif.). General techniques to be used in performing the various
immunoassays noted above are known to those of ordinary skill in
the art.
[0170] For purposes of diagnosis, the polypeptide including
antibodies can be labeled with a detectable moiety including but
not limited to radioisotopes, fluorescent labels, and various
enzyme-substrate labels know in the art. Methods of conjugating
labels to an antibody are known in the art.
[0171] In some embodiments, the polypeptides including antibodies
of the invention need not be labeled, and the presence thereof can
be detected using a labeled antibody which binds to the antibodies
of the invention.
[0172] The antibodies of the present invention can be employed in
any known assay method, such as competitive binding assays, direct
and indirect sandwich assays, and immunoprecipitation assays. Zola,
Monoclonal Antibodies: A Manual of Techniques, pp. 147-158 (CRC
Press, Inc. 1987).
[0173] The antibodies and polypeptides can also be used for in vivo
diagnostic assays, such as in vivo imaging. Generally, the antibody
or the polypeptide is labeled with a radionuclide (such as
.sup.111In, .sup.99Tc, .sup.14C, .sup.131I, .sup.125I, or .sup.3H)
so that the cells or tissue of interest can be localized using
immunoscintiography.
[0174] The antibody may also be used as staining reagent in
pathology using techniques well known in the art.
Therapeutic Uses
[0175] A striking and surprising feature of the antibodies of the
present invention relates to their ability to effectively induce
nonhematopoietic cancer cell death. Thus, the present invention
provides therapeutic uses of the antibodies and polypeptides of the
present invention in treating cancer, such as, colorectal cancer,
lung cancer, pancreatic cancer, gastric cancer, breast cancer,
hepatocellular carcinoma, and thyroid cancer. Any cancer may be
treated, such as colon cancer, colorectal cancer, lung cancer,
breast cancer, brain tumor, malignant melanoma, renal cell
carcinoma, bladder cancer, lymphomas, T cell lymphomas, multiple
myeloma, gastric cancer, pancreas cancer, cervical cancer,
endometrial carcinoma, ovarian cancer, esophageal cancer, liver
cancer, head and neck squamous cell carcinoma, cutaneous cancer,
urinary tract carcinoma, prostate cancer, choriocarcinoma,
pharyngeal cancer, laryngeal cancer, thecomatosis, androblastoma,
endometrium hyperplasy, endometriosis, embryoma, fibrosarcoma,
Kaposi's sarcoma, hemangioma, cavernous hemangioma, angioblastoma,
retinoblastoma, astrocytoma, neurofibroma, oligodendroglioma,
medulloblastoma, ganglioneuroblastoma, glioma, rhabdomyosarcoma,
hamartoblastoma, osteogenic sarcoma, leiomyosarcoma, thyroid
sarcoma and Wilms tumor, as long as the cancer cell expresses the
epitope recognized by the antibodies described herein. The method
may further comprise a step of detecting the binding between an
antibody or a polypeptide described herein and a tumor or cancer
cell in an individual to be treated.
[0176] Generally, an effective amount of a composition comprising
an antibody or a polypeptide is administered to a subject in need
of treatment, thereby inhibiting growth of the cancer cell and/or
inducing death of the cancer cell. Preferably the composition is
formulated with a pharmaceutically acceptable carrier.
[0177] In one embodiment, the composition is formulated for
administration by intraperitoneal, intravenous, subcutaneous, and
intramuscular injections, and other forms of administration such as
oral, mucosal, via inhalation, sublingually, etc.
[0178] In another embodiment, the present invention also
contemplates administration of a composition comprising the
antibodies or polypeptides of the present invention conjugated to
other molecules, such as detectable labels, or therapeutic or
cytotoxic agents. The agents may include, but are not limited to
radioisotopes, toxins, toxoids, inflammatory agents, enzymes,
antisense molecules, peptides, cytokines, or chemotherapeutic
agents. Methods of conjugating the antibodies with such molecules
are generally known to those of skilled in the art. See, e.g., PCT
publications WO 92/08495; WO 91/14438; WO 89/12624; U.S. Pat. No.
5,314,995; and EP 396,387; the disclosures of which are
incorporated herein by reference in their entireties.
[0179] In one embodiment, the composition comprises an antibody or
polypeptide conjugated to a cytotoxic agent. Cytotoxic agents can
include any agents that are detrimental to cells. A preferred class
of cytotoxic agents that can be conjugated to the antibodies or
fragments may include, but are not limited to paclitaxol,
cytochalasin B, gramicidin D, ethidium bromide, emetine, mitomycin,
etoposide, tenoposide, vincristine, vinblastine, colchicin,
doxorubicin, daunorubicin, dihydroxy anthracin dione, mitoxantrone,
mithramycin, actinomycin D, 1-dehydrotestosterone, glucocorticoids,
procaine, tetracaine, lidocaine, propranolol, and puromycin and
analogs or homologs thereof.
[0180] The dosage required for the treatment depends on the choice
of the route of administration, the nature of the formulation, the
nature of the subject's illness, the subject's size, weight,
surface area, age and sex; other drugs being administered, and the
judgment of the attending physician. Suitable dosages are in the
range of 0.01-1000.0 mg/kg.
[0181] Generally, any of the following doses may be used: a dose of
at least about 50 mg/kg body weight; at least about 10 mg/kg body
weight; at least about 3 mg/kg body weight; at least about 1 mg/kg
body weight; at least about 750 .mu.g/kg body weight; at least
about 500 .mu.g/kg body weight; at least about 250 .mu.g/kg body
weight; at least about 100 .mu.g/kg body weight; at least about 50
.mu.g/kg body weight; at least about 10 .mu.g/kg body weight; at
least about 1 .mu.g/kg body weight, or less, is administered. For
repeated administrations over several days or longer, depending on
the condition, the treatment is sustained until a desired
suppression of disease symptoms occurs. An exemplary dosing regimen
comprises administering a weekly dose of about 6 mg/kg of the
antibody. However, other dosage regimens may be useful, depending
on the pattern of pharmacokinetic decay that the practitioner
wishes to achieve. Empirical considerations, such as the half-life,
generally will contribute to determination of the dosage. The
progress of this therapy is easily monitored by conventional
techniques and assays.
[0182] In some subjects, more than one dose may be required.
Frequency of administration may be determined and adjusted over the
course of therapy. For example, frequency of administration may be
determined or adjusted based on the type and stage of the cancer to
be treated, whether the agent is administered for preventive or
therapeutic purposes, previous therapy, the patient's clinical
history and response to the agent, and the discretion of the
attending physician. Typically the clinician will administer a
therapeutic antibody (such as humanized 5F1), until a proper dosage
is reached to achieves the desired result. In some cases, sustained
continuous release formulations of antibodies may be appropriate.
Various formulations and devices for achieving sustained release
are known in the art.
[0183] In one embodiment, dosages for the antibodies or
polypeptides may be determined empirically in subjects who have
been given one or more administration(s). Subjects are given
incremental dosages of the antibodies or polypeptides. To assess
efficacy of the antibodies or polypeptides, markers of the disease
symptoms such as CD43 or CEA can be monitored. Efficacy in vivo can
also be measured by assessing tumor burden or volume, the time to
disease progression (TDP), and/or determining the response rates
(RR).
[0184] Administration of an antibody or polypeptide in accordance
with the method in the present invention can be continuous or
intermittent, depending, for example, upon the recipient's
physiological condition, whether the purpose of the administration
is therapeutic or prophylactic, and other factors known to skilled
practitioners. The administration of an antibody or a polypeptide
may be essentially continuous over a preselected period of time or
may be in a series of spaced dose.
[0185] Other formulations include suitable delivery forms known in
the art including, but not limited to, carriers such as liposomes.
See, for example, Mahato et al. (1997) Pharm. Res. 14:853-859.
Liposomal preparations include, but are not limited to,
cytofectins, multilamellar vesicles and unilamellar vesicles.
[0186] In another embodiment, the composition can comprise one or
more anti-cancer agents, one or more antibodies described herein,
or with an antibody or polypeptide that binds to a different
antigen. Such composition can contain at least one, at least two,
at least three, at least four, at least five different antibodies.
The antibodies and other anti-cancer agents may be in the same
formulation (e.g., in a mixture, as they are often denoted in the
art), or in separate formulations but are administered concurrently
or sequentially, are particularly useful in treating a broader
range of population of individuals.
[0187] A polynucleotide encoding any of the antibodies or
polypeptides of the present invention (such as antibody 5F1 or
humanized form) can also be used for delivery and expression of any
of the antibodies or polypeptides of the present invention in a
desired cell. It is apparent that an expression vector can be used
to direct expression of the antibody or polypeptide. The expression
vector can be administered by any means known in the art, such as
intraperitoneally, intravenously, intramuscularly, subcutaneously,
intrathecally, intraventricularly, orally, enterally, parenterally,
intranasally, dermally, sublingually, or by inhalation. For
example, administration of expression vectors includes local or
systemic administration, including injection, oral administration,
particle gun or catheterized administration, and topical
administration. One skilled in the art is familiar with
administration of expression vectors to obtain expression of an
exogenous protein in vivo. See, e.g., U.S. Pat. Nos. 6,436,908;
6,413,942; and 6,376,471.
[0188] Targeted delivery of therapeutic compositions comprising a
polynucleotide encoding any of the antibodies or polypeptides of
the present invention can also be used. Receptor-mediated DNA
delivery techniques are described in, for example, Findeis et al.,
Trends Biotechnol. (1993) 11:202; Chiou et al., Gene Therapeutics:
Methods And Applications Of Direct Gene Transfer (J. A. Wolff, ed.)
(1994); Wu et al., J. Biol. Chem. (1988) 263:621; Wu et al., J.
Biol. Chem. (1994) 269:542; Zenke et al. (1990), Proc. Natl. Acad.
Sci. USA, 87:3655; Wu et al. (1991), J. Biol. Chem. 266:338.
Therapeutic compositions containing a polynucleotide are
administered in a range of about 100 ng to about 200 mg of DNA for
local administration in a gene therapy protocol. Concentration
ranges of about 500 ng to about 50 mg, about 1 .mu.g to about 2 mg,
about 5 .mu.g to about 500 .mu.g, and about 20 .mu.g to about 100
.mu.g of DNA can also be used during a gene therapy protocol.
[0189] The therapeutic polynucleotides and polypeptides of the
present invention can be delivered using gene delivery vehicles.
The gene delivery vehicle can be of viral or non-viral origin (see
generally, Jolly (1994), Cancer Gene Therapy 1:51; Kimura (1994),
Human Gene Therapy 5:845; Connelly (1985), Human Gene Therapy
1:185; and Kaplitt (1994), Nature Genetics 6:148). Expression of
such coding sequences can be induced using endogenous mammalian or
heterologous promoters. Expression of the coding sequence can be
either constitutive or regulated.
[0190] Viral-based vectors for delivery of a desired polynucleotide
and expression in a desired cell are well known in the art.
Exemplary viral-based vehicles include, but are not limited to,
recombinant retroviruses, e.g., PCT Publication Nos. WO 90/07936;
WO 94/03622; WO 93/25698; WO 93/25234; WO 93/11230; WO 93/10218; WO
91/02805; U.S. Pat. Nos. 5,219,740; 4,777,127; GB Patent No.
2,200,651; and EP Patent No. 0 345 242; alphavirus-based vectors,
e.g., Sindbis virus vectors, Semliki forest virus (ATCC VR-67; ATCC
VR-1247), Ross River virus (ATCC VR-373; ATCC VR-1246) and
Venezuelan equine encephalitis virus (ATCC VR-923; ATCC VR-1250;
ATCC VR 1249; ATCC VR-532)), and adeno-associated virus (AAV)
vectors, e.g., PCT Publication Nos. WO 94/12649, WO 93/03769; WO
93/19191; WO 94/28938; WO 95/11984 and WO 95/00655. Administration
of DNA linked to killed adenovirus as described in Curiel (1992),
Hum. Gene Ther. 3:147 can also be employed.
[0191] Non-viral delivery vehicles and methods can also be
employed, including, but are not limited to, polycationic condensed
DNA linked or unlinked to killed adenovirus alone (see, e.g.,
Curiel (1992), Hum. Gene Ther. 3:147); ligand-linked DNA (see,
e.g., Wu (1989), J. Biol. Chem. 264:16985); eukaryotic cell
delivery vehicles cells (see, e.g., U.S. Pat. No. 5,814,482; PCT
Publication Nos. WO 95/07994; WO 96/17072; WO 95/30763; and WO
97/42338) and nucleic charge neutralization or fusion with cell
membranes.
[0192] Naked DNA can also be employed. Exemplary naked DNA
introduction methods are described in PCT Publication No. WO
90/11092 and U.S. Pat. No. 5,580,859. Liposomes that can act as
gene delivery vehicles are described in U.S. Pat. No. 5,422,120;
PCT Publication Nos. WO 95/13796; WO 94/23697; WO 91/14445; and EP
Patent NO. 0 524 968. Additional approaches are described in Philip
(1994), Mol. Cell Biol. 14:2411 and in Woffendin (1994), Proc.
Natl. Acad. Sci. 91:1581.
[0193] The composition comprising an antibody of the present
invention can be administered sequentially or concurrently with one
or more other therapeutic agents such as chemotherapeutic agents
(such as 5-FU, 5-FU/MTX, 5-FU/Leucovorin, Levamisole, Irinotecan,
Oxaliplatin, Capecitabin, or Uracil/Tegafur), immunoadjuvants,
growth inhibitory agents, cytotoxic agents and cytokines, etc. The
amounts of the antibody and the therapeutic agent depend on what
type of drugs are used, the pathological condition being treated,
and the scheduling and routes of administration but would generally
be less than if each were used individually.
[0194] Following administration of the composition comprising the
antibody described herein, the efficacy of the composition can be
evaluated both in vitro and in vivo by various methods well known
to one of ordinary skill in the art. Various animal models are well
known for testing anti-cancer activity of a candidate composition.
These include human tumor xenografting into athymic nude mice or
scid/scid mice, or genetic murine tumor models such as p53 knockout
mice. The in vivo nature of these animal models make them
particularly predictive of responses in human patients. Such models
can be generated by introducing cells into syngeneic mice using
standard techniques, e.g., subcutaneous injection, tail vein
injection, spleen implantation, intraperitoneal implantation and
implantation under the renal capsule, etc.
Kits
[0195] The invention also provides kits for use in the instant
methods. Kits of the invention include one or more containers
comprising a purified antibody or a polypeptide described herein
and instructions for use in accordance with any of the methods of
the invention described herein. In some embodiments, these
instructions comprise a description of administration of the
antibody to treat a nonhematopoietic cancer, such as colorectal
cancer, according to any of the methods described herein. The kit
may further comprise a description of selecting an individual
suitable for treatment based on identifying whether that individual
has the disease and the stage of the disease, or whether the
epitope is expressed on the cancer cells in the individual.
[0196] In some embodiments, the kits for detecting a cancer cell in
a sample comprise an antibody or a polypeptide described herein and
reagents for detecting binding of the antibody or the polypeptide
to a cell in the sample.
[0197] The instructions relating to the use of the antibodies or
polypeptides to treat cancer generally include information as to
dosage, dosing schedule, and route of administration for the
intended treatment. The containers may be unit doses, bulk packages
(e.g., multi-dose packages) or sub-unit doses. Instructions
supplied in the kits of the invention are typically written
instructions on a label or package insert (e.g., a paper sheet
included in the kit), but machine-readable instructions (e.g.,
instructions carried on a magnetic or optical storage disk) are
also acceptable.
[0198] The label or package insert indicates that the composition
is used for treating a cancer described herein. Instructions may be
provided for practicing any of the methods described herein.
[0199] The kits of this invention are in suitable packaging.
Suitable packaging includes, but is not limited to, vials, bottles,
jars, flexible packaging (e.g., sealed Mylar.RTM. or plastic bags),
and the like. Also contemplated are packages for use in combination
with a specific device, such as an inhaler, nasal administration
device (e.g., an atomizer) or an infusion device such as a
minipump. A kit may have a sterile access port (for example the
container may be an intravenous solution bag or a vial having a
stopper pierceable by a hypodermic injection needle). The container
may also have a sterile access port (for example the container may
be an intravenous solution bag or a vial having a stopper
pierceable by a hypodermic injection needle). At least one active
agent in the composition is an antibody described herein. The
container may further comprise a second pharmaceutically active
agent.
[0200] Kits may optionally provide additional components such as
buffers and interpretive information. Normally, the kit comprises a
container and a label or package insert(s) on or associated with
the container.
EXAMPLES
[0201] The following Examples are provided to illustrate but not to
limit the invention.
Example 1: Generation and Characterization of Monoclonal Antibodies
that Specifically Binds to CD43 Expressed on Cancer Cells
Generation of Monoclonal Antibodies
[0202] Human colorectal adenocarcinoma cell line, COLO 205 (ATCC
CCL-222), was purchased from Food Industry Research and Development
Institute (CCRC 60054), Hsin-chu, Taiwan, and grown in RPMI 1640
medium (GIBCO BRL) with 10% FBS (Hyclone), 100 units/ml of
penicillin and 100 .mu.g/ml of streptomycin (GIBCO BRL) at
37.degree. C. in a humidified atmosphere of 5% CO.sub.2. A female
8-week Balb/c mouse was immunized three times with 2.times.10.sup.7
COLO 205 cells in 500 .mu.l PBS or 10 micro-gram of partial
purified protein in CFA every two weeks and finally were given a
boost of 2.times.10.sup.6 COLO 205 cells or 10 micro-gram of
partial purified protein in 200 .mu.l PBS. Five days after the
final boost, the spleen cells were fused with X63 myeloma cells.
Hybridomas were selected with DMEM supplemented with 10% FBS
(Hyclone) and HAT (Hybri-Max.TM., Sigma H0262, at a final
concentration of 100 .mu.M hypoxanthine, 0.4 .mu.M aminopterin, 16
.mu.M thymidine). Three hybridoma cell lines m5F1, m51-41, m138-10,
which secrete the monoclonal antibody 5F1, 51-41, and 138-10, have
been generated.
Identification and Characterization of the Target Antigen for
Monoclonal Antibody 5F1
[0203] Membrane proteins from colorectal cancer tissues or COLO 205
cells were isolated with extraction buffer (50 mM Tris-HCl, pH 7.4,
150 mM NaCl, 1% Nonidet P-40) containing protease inhibitors
(Complete tabs; Roche Molecular Biochemicals). Membrane protein
lysates were first precleared on a 1-ml column containing
non-immune mouse IgG immobilized on Protein G Sepharose.RTM.
(Amersham Pharmacia Biotech Inc., N.J., U.S.A), and the
flow-through portion was directly applied onto a 1-ml column of 5F1
coupled to Protein G-Sepharose.RTM.. Column was washed and the
target protein of 5F1 was eluted. The purity of the isolated
protein was visualized by silver staining and also identified by
Western blotting after separation on 8% SDS-PAGE. The isolated
protein was also used to immunize mice to generate other 5F1-like
antibodies such as 138-10 or 51-41.
[0204] For immunoprecipitation experiments, the membrane proteins
were incubated with 5F1 or an anti-CD43 antibody (AF2038, R&D
System, Inc.) followed by incubation with protein G Sepharose.RTM.
(Amersham Pharmacia Biotech Inc., N.J., U.S.A.). The precipitates
were run on 8% SDS-PAGE and subjected to Western (or immuno) blot
analysis.
[0205] Proteins were mixed with an equal volume of sample buffer
(50 mM Tris-HCl, pH 6.8, 100 mM DTT, 2% SDS, 0.1% bromophenol blue,
10% glycerol), separated by 8% SDS-PAGE and then transferred to a
nitrocellulose membrane (Hybond.TM.-C Super, Amersham). The
nitrocellulose membrane was then blocked with 5% skimmed milk in
PBS, and incubated with 5F1 or anti-CD43 mAb (AF2038). Blot was
then treated with horseradish peroxidase-conjugated goat anti-mouse
immunoglobulin (Jackson ImmunoResearch Laboratories, West Grove,
Pa.) and developed with chemiluminescence reagents (ECL, Amersham,
UK).
[0206] To test whether 5F1 does recognize CD43, a commercially
available anti-CD43 mAb (AF2038, R&D system, Inc.) was used to
confirm the identity of 5F1 affinity-purified protein from COLO 205
lysates by Western blot analysis. The lysates from a 5F1 binding
negative cell line COLO 320 were used as control. Our results (FIG.
1) showed that both the anti-CD43 (AF2038) and 5F1 antibodies
reacted with the protein captured by 5F1 immunoaffinity column,
strongly suggesting that 5F1 does recognize CD43.
Monoclonal Antibody 5F1 Specifically Recognizes CD43 Expressed on
Cell Surface of Nonhematopoietic Cancer Cells.
[0207] 2.times.10.sup.5 COLO 205 cells were seeded in each well of
a v-bottomed 96-well plate and incubated with different
concentrations of 5F1 antibody, ranging from 0.33 to 1 .mu.g/ml, at
4.degree. C. for 1 hr. Cells were washed twice with 200 .mu.l FACS
buffer (1.times.PBS+1% FBS), stained with 10 .mu.l of 1 .mu.g/ml
(in FACS buffer) goat-anti-mouse IgG-PE (Southern Biotech.), and
then incubated at 4.degree. C. for 30 min. Cells were washed thrice
with FACS buffer and analyzed by flow cytometry (BD LSR, BD Life
Sciences).
[0208] Antibody binding results from flow cytometry are shown in
Table 1 below. Monoclonal antibody such as 5F1 (isotype: IgG3), or
138-10 (isotype IgM), or 51-41 (isotype IgM) recognizes a surface
CD43 expressed on the cytoplasmic membranes of COLO 205 colorectal
cancer cells and NCI-N87 gastric cancer cells, but not peripheral T
nor Jurkat (a lymphoblastoid leukemia cell line; ATCC TIB-152). See
Table. 1 below. Flow cytometry data (FIG. 2A and FIG. 2B) also show
5F1 binds to other types of cancer cells, such as colorectal cancer
cells (DLD-1), and gastric cancer cells (NCI-N87), but not normal
endothelial cells (HUVEC), normal lung cells (MRC-5), normal
mammary gland epithelial cells (MCF-10A), normal colorectal cells
(CCD841-CoN), activated T lymphocytes (activated for seven days),
or normal peripheral blood mononuclear cells (PBMC).
Table 1 shows antigen-binding properties of anti-CD43 antibodies
such as 5F1, 138-10, or 51-41 to colorectal cancer, gastric cancer
cells, human peripheral T cells, and Jurkat (a lymphoblastoid
leukemia cell line).
TABLE-US-00002 Jurkat NCI-N87 % of Binding/ Peripheral (Leukemia
(Gastric Abs T cells cells) COLO 205 cancer cells) 5F1 <10%
<10% >80% >80% 138-10 <10% <10% >80% >80%
51-41 <10% <10% >80% >80% Anti-CD162 >80% >80%
<10% Not tested MEM-59 (anti- >80% Not tested >70% Not
tested CD43; Biovendor, Candler, NC) Isotype control <10%
<10% <10% <10% Ab
[0209] To detect the expression of the target protein of 5F1 in
COLO 205 cells and human colorectal cancer tissues, a routine
immunohistochemical method was used. Briefly, cells or tissues were
fixed for immunostaining with 1 .mu.g/ml of 5F1, incubated with
biotin-labeled anti-mouse IgG, then incubated with avidin-biotin
peroxidase complex (Vector Laboratories, Inc. Burlingame, Calif.,
U.S.A.), and stained with the chromogen 3,3'-diaminobenzidine
tetrachloride. Immunohistochemical study showed that 52.5 percent
of the tissues from patients with colorectal cancer (31/59) stained
positive with 5F1.
Example 2. Apoptotic Activity of Antibodies that Specifically Bind
to CD43 Expressed on Cancer Cells
Detection of Apoptosis Induced by 5F1 in COLO 205 Cells by ELISA
Assay
[0210] To evaluate the type of cell death induced by 5F1,
colorectal cancer cells were grown in culture plates and incubated
with or without 5F1. The level of internucleosomal (apoptotic) DNA
fragmentation was determined by antibody-mediated capture and
detection of cytoplasmic mononucleosome- and
oligonucleosome-associated histone-DNA complexes using the Cell
Death Detection ELISA.sup.PLUS kit (Roche, Cat#1774425). The ELISA
assay was performed according to the manufacturer's instruction.
Briefly, 1.times.10.sup.4 COLO 205 cells were plated in each well
of 96-well plates and incubated with 5F1 or 9E10 (an anti-myc
antibody) at the concentration of 10 .mu.g/ml, or with medium
control. After 6, 24 or 48 hr of incubation at 37.degree. C., cells
were washed and incubated with 200 .mu.l of lysis buffer for 30
min. After pelleting nuclei (200.times.g, 10 min.), 20 .mu.l of the
supernatant (cytoplasmic fraction) containing fragmented DNA was
transferred to streptavidin-coated microtiter plates that had been
incubated with biotinylated monoclonal antihistone antibody. The
amount of fragmented DNA of nucleosomes bound to anti-histone
antibody was evaluated by peroxidase-conjugated monoclonal anti-DNA
antibody using ABTS (2,2-azino-di[3-ethylbenzthiazoline
sulfonate-6-diammonium salt]) as a substrate. Finally, absorbance
at 405 nm, upon incubating with a peroxidase substrate for 10-20
min., was determined with a microplate reader (Molecular Devices,
SpectraMax.RTM. M2). Values from wells containing lysis buffer and
substrate only were subtracted as background. The data were
analyzed as the specific enrichment of mono- and oligonucleosomes
released into the cytoplasm from the values using the following
formula:
Enrichment factor ( E . F ) = mU of the sample ( dying / dead cells
) mU of the medium control ( cells without mAb treatment )
##EQU00001## mU = absorbance [ 10 - 3 ] ##EQU00001.2##
[0211] Data shown in FIG. 3 indicate that 5F1 induced an enrichment
of nucleosomes in the cytoplasm of COLO 205 cells after 24 hr of
incubation. The detected fragmented DNA in the 5F1 treated
cytoplasm was increased more than 4-fold as compared to medium
control. Such enrichment was not observed in the cells treated with
either control antibody 9E10 (an anti-myc antibody) or medium
alone, indicating that 5F1 alone caused cancer cells to undergo
apoptosis.
Detection of Apoptosis Induced by 5F1, 138-10, and 51-41 in COLO
205 Cells Using Annexin V and PI Staining
[0212] Annexin V stains the phospholipids that flips toward the
outer side of the cytoplasmic membrane at the early stage of the
apoptosis process. Thus, staining of Annexin V, as assayed by FACS
analysis, indicates the cells undergoing apoptosis.
1.2.times.10.sup.5 COLO 205 cells were seeded to each well of a
96-well plate, and then various concentrations of 5F1 (2-16
.mu.g/ml) diluted in the medium or fresh medium (untreated control)
was added into the cells. To test whether the cross-linker (CL) is
needed for 5F1 to induce apoptosis in tumor cells, 20 .mu.g/ml of
rabbit anti-mouse IgG (Jackson ImmunoResearch, Cat#315-005-045) was
added into a set of samples for comparison. After a 6-hr incubation
at 37.degree. C., the cells were stained with 0.25 .mu.l of
FITC-conjugated Annexin V (Strong Biotech Corporation) in 100 .mu.l
Annexin V binding buffer at room temperature for 15 min. The cells
were then stained with propidium iodide (PI, a DNA staining dye)
and analyzed by flow cytometry.
[0213] Flow cytometry data showed that treatment of 5F1, in the
absence of the cross-linker, for 6 hours at concentration of 4
.mu.g/ml or higher caused significant number of colorectal cancer
cells to undergo apoptosis, suggesting that 5F1 alone could
effectively induce apoptosis in COLO 205 cells.
[0214] Effect of inducing apoptosis of COLO 205 cells by other
anti-C43 antibodies, 138-10 and 51-41, was also tested. Table 2
below shows 5F1, 138-10, or 51-41 induced apoptosis in colorectal
cancer cells. The COLO 205 cells were incubated with 32
micro-gram/ml of each antibody for 6 hours and stained with
annexin-V and then PI, followed by FACS analysis.
TABLE-US-00003 TABLE 2 Induction of apoptosis in COLO 205 cells by
5F1, 138-10, and 51-41. Control Ab 5F1 138-10 51-41 (negative
control) % Apoptosis >40% >30% >30% <15%
(annexin-V.sup.+)
[0215] The above results show that treatments with antibodies
specific for cancer expressed CD43 can induce apoptosis in a cancer
cell.
Detection of Apoptosis Induced by m5F1 in NCI-87 Cells Using
YO-PRO.RTM.-1 Staining or Annexin V and PI Staining
[0216] 4.times.10.sup.5 cells of NCI-N87 (human gastric carcinoma
cell line) or 5.times.10.sup.5 cells of COLO 205 were seeded in
12-well culture plate (Nunc Catalog #150628). After overnight
culture, medium was changed, and antibodies at concentrations as
indicated in FIG. 10 or azide were added for 6 hours incubation.
Then, the cells were trypsinized and collected for staining with
YO-PRO.RTM.-1 (Invitrogen, Catalog # Y3603) or double staining with
Annexin-V-FITC & PI (Strong Biotech, apoptosis detection kits,
Catalog # AVK250).
[0217] As shown in FIGS. 10A and 10B, antibody m5F1 induced
apoptosis in NCI-87 and COLO 205 cells as measured by YO-PRO.RTM.-1
staining (A) and by double staining with Annexin-V-FITC and PI (B).
These data indicate that m5F1 can also induce apoptosis in gastric
carcinoma cells.
Example 3. Inhibition of Cancer Cell Growth by 5F1
5F1 Alone Inhibits the Growth of Cancer Cells
[0218] Colorectal cancer cells (COLO 205), and normal endothelial
cells (HUVEC) were seeded and incubated with 5F1 or a control
antibody 9E10. Also included were untreated cells as negative
controls. Cell survival was evaluated using MTT & WST-1 assays
to detect proliferative activity as described herein.
[0219] WST-1 assay is based on the cleavage of the tetrazolium salt
WST-1 to formazan by cellular mitochondrial dehydrogenases. The
formazan produced can be quantified by spectrophotometer by
measuring absorbance at 450 nm. Proliferation of viable cells
results in an increase in the overall activity of the enzymes; and
decrease in the enzymatic activity indicates cell growth
inhibition. Thus, WST-1 assay was used to evaluate the survival
rate of tumor cells after 5F1 treatment. Briefly, 4.times.10.sup.3
COLO 205 cells in 100 .mu.l culture medium were seeded in 5
duplicates for each treatment in a 96-well culture plate. Then 10
.mu.g/ml of 5F1, control antibody 9E10 (an anti-myc antibody) or
fresh medium (untreated control) was added. The treatment of 0.5%
sodium azide (NaN.sub.3) was also included in the assay as a
cytotoxicity control. After a three-day incubation period at
37.degree. C., 20 .mu.l of WST-1 reagent (Roche, Cat#1664807) was
added to each well and the mixture was incubated at 37.degree. C.
for 30 min. Absorbance at 450 nm was obtained to reflect the
survival rate of the treated cells. The results of WST-1 assay for
COLO 205 cells are shown in FIG. 4. Data indicated that growth of
COLO 205 cells was substantially inhibited (FIG. 4) while that of
HUVEC (data not shown) was not influenced by 5F1 treatment. The
percentage of survival rate was reduced to less than 50% in the
antibody 5F1 treated as compared to isotype control antibody 9E10
treated colorectal cancer cells. The positive control group treated
with 0.5% sodium azide showed 19% survival rate.
[0220] In another experiment, cells (2.times.10.sup.3) were seeded
in each well of a 96-well culture plate and incubated with 10
micro-gram/ml of monoclonal antibody 5F1 or control antibody 9E10
(an antibody against c-myc). Untreated cells were used as negative
controls; and cells treated with 0.5% sodium azide were used as
positive controls. After a two- or three-day incubation period at
37.degree. C., 10 ul of WST-1 Reagent were added to each well and
the cells were further incubated for 30 min. WST-1 cell survival
assay was then conducted as described above. The results, shown in
FIG. 5, indicated that growth of colorectal carcinoma cells, such
as COLO 205, was substantially inhibited by antibody 5F1, but
normal colorectal cell line (such as CCD841-CoN was not
effected.
[0221] MTT is another tetrazolium-based method for the measurement
of cell viability and proliferation. The yellow tetrazolium MTT
(3-(4,5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) is
reduced by metabolically active cells, in part by the action of
dehydrogenase enzymes, to generate reducing equivalents such as
NADH and NADPH. The resulting intracellular purple formazan can be
solubilized and quantified by spectrophotometric means. Cells
(5.times.103) were seeded in each well of a 96-well culture plate
and incubated with monoclonal antibody 5F1 (concentration range
from 0-64 .mu.g/ml) or a control antibody 9E10 (64 .mu.g/ml)
against c-myc. Untreated cells were used as negative controls; and
cells treated with 0.5% sodium azide were used as positive
controls. After 72-hr incubation period at 37.degree. C., 10l of
MTT Reagent were added to each well and the cells were further
incubated for 2-4 hr until purple precipitate is visible. 100 ul
detergent reagent (DMSO) is added. Absorbance of samples at 570 nm
is recorded. Data from MTT assay demonstrated that 5F1 inhibited
cell proliferation of COLO 205 in a dose-dependent manner (from 0
to 64 .mu.g/ml) and the ED50 (effective dose for 50% inhibition)
was 8 .mu.g/ml (FIG. 6). As also indicated in the FIG. 6, a
remarkable inhibition of cell growth was found when 64 .mu.g/ml of
5F1 was used while control antibody 9E10 had no such effect at the
same concentration.
Evaluation of Anti-Tumor Effects of 5F1 In Vivo
[0222] The in vivo anti-tumor effects of 5F1 were analyzed in a
tumor xenograft mouse model. 5.times.10.sup.6 COLO 205 cells were
implanted subcutaneously into the hind flank region of SCID mice on
day 0. A week after the inoculation of cells, in one experiment,
mice were treated with 500 micro-gram of 5F1 or PBS by
intra-peritoneal injection. In another experiment, four groups of
mice (6 mice in each group) bearing established tumors were
intravenously treated every other day with four doses of 25 mg/kg
of 5-fluorouracil plus leucovorin (5 FU/LV), and with or without
various doses of 5F1 intra-peritoneal injection twice weekly.
[0223] In one experiment, tumor implantation in SCID mice were
achieved by subcutaneous injection of colorectal cancer cell COLO
205 at 1.times.10.sup.7 cells per mouse at day 0 and then treated
by intraperitoneal injection of monoclonal antibody 5F1 (at 500
.mu.g per dose) or control monoclonal antibody 9E10 (an antibody
raised against c-myc) or PBS at days 0, 3, 5, 7, 10, 12, 14, and
17. Fifteen mice were used in each group of the experiment. Tumor
size was measured starting from day 5 up to day 24 by the product
of the width, width, and length (W.times.W.times.L) and expressed
by mm.sup.3. As shown in FIG. 7, monoclonal antibody 5F1
effectively suppressed the tumor growth as compared to the control
antibody 9E10 and PBS (untreated).
[0224] To see the combined effects of 5F1 and chemo-drugs like
5FU/LV, mice were iv injected with 25 mg/kg of 5FU/LV every other
day for 4 doses and ip injected with or without various amounts of
5F1 antibodies twice weekly for 3 weeks post 7 days of tumor
implant. Tumor growth was assessed based on twice-weekly
measurement of tumor volume (mm.sup.3) by calipers and the tumor
size was calculated using the formula: .pi./6.times. larger
diameter.times.(smaller diameter).sup.2 (Kievit E, Cancer Research,
60:6649-55). As shown in FIG. 8, the combination of 5F1 antibody
and 5FU/LV treatments significantly inhibited the human colorectal
tumor growth compared to those of chemo-drug treated alone (FIG.
8).
Example 4. Three Novel Anti-CD43 Antibodies, 5F1, 138-10, and
51-41, Recognize Similar Epitope Expressed on Cancer Cells
[0225] To understand the binding property of three novel anti-CD43
antibodies (5F1, 138-10, and 51-41), FACS analysis was used. COLO
205 cells (100,000) were stained with 1 micro gram/ml of
biotinylated 5F1 at 4 degree C. for 1 hr in the presence of various
amounts of non-biotinylated antibody 5F1, 138-10, and 51-41. After
washes, the cells were further stained with streptavidin-FITC at
the same condition for 30 min. The cells were washed and analyzed
by FACS. Data shown in Table 3 below are mean Fluorescence
Intensity from one representative experiment. Both 51-41 and 138-10
antibodies were able to compete the binding of biotinylated-5F1 to
COLO 205 cells suggesting that all three antibodies bind on the
similar binding site expressed on the surface of COLO 205
cells.
TABLE-US-00004 TABLE 3 5F1, 138-10, and 51-41 recognize similar
epitopes expressed on COLO 205 cells. Competing Mean Fluorescence
antibody Intensity in the presence of unlabeled 5F1, 51-
concentration 41, or 138-10 (microgram/ml) 5F1 51-41 138-10 200
9.78 75.66 199.7 66.7 60.28 165.62 297.03 22.2 21.67 325.23 395.53
7.4 129.04 606.20 640.42 2.46 733.36 783.81 702.79 0.82 1004 789.23
724.15 0.273 1027 901.36 683.08 0.09 825 869.61 717.19 0.03 888
860.13 704.33
Example 5. Epitope Determination of Antibody 5F1
[0226] To further define the epitope structure recognized by the
monoclonal antibody 5F1, this monoclonal antibody was used to test
its specific reactivity to different polypeptide sequences. 96-well
microtiter plates were coated with antibody 5F1 with 50 .mu.l per
well at the concentration of 10 .mu.g/ml in 0.1 M NaHCO.sub.3 (pH
8.6) coating buffer over night at 4.degree. C. After wash, the
plates were blocked by incubation with blocking buffer containing
0.1 M NaHCO.sub.3 (pH 8.6), 5 mg/ml BSA, 0.02% NaN.sub.3 (150
.mu.l/well) for at least one hour at 4.degree. C. Plates were then
incubated with fusion proteins containing various fragments of
polypeptides at the various concentrations for one hour at room
temperature. After wash with 0.5% Tween.RTM. containing TBS, the
bound fusion protein-polypeptides were eluted with 1 mg/ml BSA
containing 0.2M Glycine-HCl (pH 2.2) buffer and neutralized with 1
M Tris-HCl (pH 9.1). The amino acid sequence of eluted fusion
protein-polypeptides were then determined. The polypeptides that
antibody 5F1 binds contain a tripeptide sequence of Trp-Pro-Ile
(WPI), from N-terminus to C-terminus. This tripeptide amino acid
sequence is not present in the CD43 amino acid sequence. Pallant et
al., Proc. Natl. Acad. Sci. USA 86:1328-32, 1989; Shelley et al.,
Proc. Natl. Acad. Sci. USA 86:2819-23, 1989.
[0227] To further confirm the tripeptide epitope that antibody 5F1
binds, Sandwich ELISA was performed. 96-well microtiter plates were
coated with antibody (5F1 or control antibody 9E10) with 50 .mu.l
per well at the concentration of 1 .mu.g/ml over night at 4.degree.
C. Plates were blocked by incubation with 0.25% of BSA in PBS (150
.mu.l/well) for 1 hour at 37.degree. C. Plates were then incubated
with fusion proteins containing various fragments of polypeptides
fused to a carrier protein for 2 hours at room temperature. After
washing 4 times with PBS containing 0.05% of Tween.RTM. 20, plates
were then incubated with carrier protein-specific antibody at 2
.mu.g/ml for 1.5 hours at room temperature. After incubation,
plates were washed 4 times with PBST. 50 .mu.l of 1 to 3000 diluted
Goat anti-carrier protein-specific antibody conjugated with HRP was
then added to each well and the plates were incubated for 1 hour at
37.degree. C. Enzyme reaction was carried out by adding substrate
of the HRP enzyme to determine the reactivity of the designated
polypeptide to these to these two antibodies (5F1 and 9E10). Table
4 below shows the data from ELISA assay when 5F1 or 9E10 was
immobilized on the plate. "+" indicates the designated polypeptide
binds to the monoclonal antibody; and "-" indicates the designated
polypeptide does not bind to the monoclonal antibody. Monoclonal
antibody 5F1 recognized a tripeptide WPI epitope structure. Since
the tripeptide WPI sequence is not present in CD43, these data
suggest that 5F1 recognizes a conformational epitope which includes
a structure having physical and/or chemical characteristics similar
or equivalent to the structure formed by tripeptide WPI.
TABLE-US-00005 TABLE 4 Epitope structures recognized by 5F1 Peptide
Name Amino cid sequences 5F1 9E10 5F1-01-2-21 W P I D L M S E T P I
L + - (SEQ ID NO: 17) 5F1-01-2-04 W P I A N H E N A L S A + - (SEQ
ID NO: 18) 5F1-01-2-18 W P I S G K H S F W S L + - (SEQ ID NO: 19)
5F1-01-2-17 W P I L D H A V S R P S + - (SEQ ID NO: 20) 5F1-01-2-16
W P I D I P Y A W D F S + - (SEQ ID NO: 21) 5F1-01-2-13 W P I S P Q
P G A R P V + - (SEQ ID NO: 22) 5F1-01-2-09 W P I A P N R Y L L S S
+ - (SEQ ID NO: 23) 5F1-01-2-06 W P I P P E V E P F K H + - (SEQ ID
NO: 24) 5F1-01-2-05 W P I L Q N A A G T G L + - (SEQ ID NO: 25)
5F1-01-2-23 W P I P T L M E L P S A + - (SEQ ID NO: 26) 5F1-01-2-22
W P I T N S D S R I T W + - (SEQ ID NO: 27) 5F1-01-2-14 W P I H S A
H V R Y T T + - (SEQ ID NO: 28) 9F9-01-03-24 A E T D Y D P D H F T
P - - (SEQ ID NO: 29) 9F9-01-03-18 D A R Y S H D P A W P Y - - (SEQ
ID NO: 30) 9F9-01-03-17 A G Q K W D P E W P H S - - (SEQ ID NO: 31)
9F9-01-03-21 Y D H H W T N P P T Q K - - (SEQ ID NO: 32)
9F9-01-03-25 E P N M D P N W A S P S - - (SEQ ID NO: 33)
Example 6. Cloning of the Variable Regions of Light and Heavy
Chains of 5F1, 138-10, and 51-41, and Antibody Humanization
[0228] The variable region cDNAs of 5F1 light and heavy chains were
amplified by PCR, and the synthesized cDNAs were subcloned into
pCRII (Invitrogen) for sequence determination. Nucleotide sequences
were obtained from several independent clones and analyzed.
Identical cDNA sequence from independent clones was chosen to
represent the light or heavy chain V region of each antibody. Table
5 below showed the translated amino acid sequences of and
nucleotide sequences encoding the light and heavy chain V regions
of 5F1, 138-10, 51-41, and humanized 5F1 (h5F1Vc).
TABLE-US-00006 TABLE 5 Amino acid sequences of the antibodies'
variable regions, and nucleic acid sequences encoding the
antibodies' variable regions (CDRs are underlined) 5F1 heavy chain
amino acid sequence (SEQ ID NO: 1) and nucleotide sequence (SEQ ID
NO: 9) 1 M E W S W I F L F L L S G T A G V H S E 1
ATGGAATGGAGTTGGATATTTCTCTTTCTCCTGTCAGGAACTGCAGGTGTCCACTCTGAG 21 V Q
L Q Q S G P E L V K P G A S V R M S 61
GTCCAGCTGCAGCAGTCTGGACCTGAGCTGGTAAAGCCTGGGGCTTCAGTGAGGATGTCC 41 C T
A S G Y T F T S Y V M H W I K Q K P 121
TGCACGGCTTCTGGATACACATTCACTAGCTATGTTATGCACTGGATAAAGCAGAAGCCT 61 G Q
G L D W I G Y I N P Y N G G T Q Y N 181
GGGCAGGGCCTTGACTGGATTGGATATATTAATCCTTACAATGGTGGTACTCAGTACAAT 81 E K
F K G K A T L T S D K S S S T A Y M 241
GAGAAGTTCAAAGGCAAGGCCACACTGACTTCAGACAAATCCTCCAGCACAGCCTACATG 101 E
L S S L T S E D S A V Y Y C A R R T F 301
GAGCTCAGCAGCCTGACCTCTGAGGACTCTGCGGTCTATTACTGTGCAAGACGGACCTTC 121 P
Y Y F D Y W G Q G T T L T V S S 361
CCGTACTACTTTGACTACTGGGGCCAAGGCACCACTCTCACAGTCTCCTCA 5F1 light chain
amino acid sequence (SEQ ID NO: 2) and nucleotide sequence (SEQ ID
NO: 10) 1 M K L P V R L L V L M F W I P A S S S D 1
ATGAAGTTGCCTGTTAGGCTGTTGGTGCTGATGTTCTGGATTCCTGCTTCCAGCAGTGAT 21 V L
M T Q T P L S L P V S L G D Q A S I 61
GTTTTGATGACCCAAACTCCACTCTCCCTGCCTGTCAGTCTTGGAGATCAAGCCTCCATC 41 S C
R S S Q S I L H S N G N T Y L E W Y 121
TCTTGCAGATCTAGTCAGAGCATTTTACATAGTAATGGAAACACCTATTTAGAATGGTAC 61 L Q
K P G Q S P K L L I Y K V S N R F S 181
CTGCAGAAACCAGGCCAGTCTCCAAAGCTCCTGATCTACAAAGTTTCCAACCGATTTTCT 81 G V
P D R F S G S G S G T D F T L K I S 241
GGGGTCCCAGACAGGTTCAGTGGCAGTGGATCAGGGACAGATTTCACACTCAAGATCAGC 101 R
V E A E D L G V Y Y C F Q G S H A P L 301
AGAGTGGAGGCTGAGGATCTGGGAGTTTACTACTGCTTTCAAGGTTCACATGCTCCTCTC 121 T
F G A G T K L E L K 361 ACGTTCGGTGCTGGGACCAAGCTGGAGCTGAAA 138-10
heavy chain amino acid sequence (SEQ ID NO: 3) and nucleotide
sequence (SEQ ID NO: 11) 1 M E C N W I L P F I L S V I S G V Y S E
1 ATGGAATGTAACTGGATACTTCCTTTTATTCTGTCGGTAATTTCAGGGGTCTACTCAGAG 21 V
Q L Q Q S G T V L A R P G A S V K M S 61
GTTCAGCTCCAGCAGTCTGGGACTGTGCTGGCAAGGCCTGGGGCTTCCGTGAAGATGTCC 41 C K
A S G Y S F I S Y W M H W V K Q R P 121
TGCAAGGCTTCTGGCTACAGCTTTATCAGCTACTGGATGCACTGGGTAAAACAGAGGCCT 61 G Q
G L E W I G A I S P G D S D T T Y N 181
GGACAGGGTCTAGAATGGATTGGTGCTATTTCTCCTGGAGATAGTGATACTACCTACAAC 81 Q R
F T G K A K L T A V T S A S T A Y M 241
CAGAGGTTCACGGGCAAGGCCAAACTGACTGCAGTCACATCCGCCAGCACTGCCTACATG 101 E
L S S L T N E D S A V Y Y C I R R D G 301
GAGCTCAGCAGCCTGACAAATGAGGACTCTGCGGTCTATTATTGTATAAGAAGGGATGGT 121 N
Y Q V A W F A Y W G Q G T L V T V S A 361
AACTACCAAGTTGCCTGGTTTGCTTACTGGGGCCAAGGGACTCTGGTCACTGTCTCTGCA 138-10
light chain amino acid sequence (SEQ ID NO: 4) and nucleotide
sequence (SEQ ID NO: 12) 1 M K L P V R L L V L M F W I P A S S S D
1 ATGAAGTTGCCTGTTAGGCTGTTGGTGCTGATGTTCTGGATTCCTGCTTCCAGCAGTGAT 21 V
L M T Q T P L S L P V S L G D Q A S I 61
GTTTTGATGACCCAAACTCCACTCTCCCTGCCTGTCAGTCTTGGAGATCAAGCCTCCATC 41 S C
R S S Q S I V H S N G N T Y L E W Y 121
TCTTGCAGATCTAGTCAGAGCATTGTACATAGTAATGGAAACACCTATTTAGAATGGTAC 61 L Q
K P G Q S P K L L I Y K V S N R F S 181
CTGCAGAAACCAGGCCAGTCTCCAAAGCTCCTGATCTACAAAGTTTCCAACCGATTTTCT 81 G V
P D R F S G S G S G T D F T L K I S 241
GGGGTCCCAGACAGGTTCAGTGGCAGTGGATCAGGGACAGATTTCACACTCAAGATCAGC 101 R
V E A E D L G V Y Y C F Q G S H V P F 301
AGAGTGGAGGCTGAGGATCTGGGAGTTTATTACTGCTTTCAAGGTTCACATGTTCCATTC 121 T
F G S G T K L E I K 361 ACGTTCGGCTCGGGGACAAAGTTGGAAATAAAA 51-41
heavy chain amino acid sequence (SEQ ID NO: 5) and nucleotide
sequence (SEQ ID NO: 13) 1 M E C N W I L P F L S V I I S G V Y S E
1 ATGGAATGTAACTGGATACTTCCTTTTATTCTGTCGGTAATTTCAGGGGTCTACTCAGAG 21 V
Q L Q Q S G T V L A R P G A S V K M S 61
GTTCAGCTCCAGCAGTCTGGGACTGTGCTGGCAAGGCCTGGGGCTTCCGTGAAGATGTCC 41 C K
A S G Y S F T S Y W M H W V K Q R T 121
TGCAAGGCTTCTGGCTACAGTTTTACCAGCTACTGGATGCACTGGGTAAAACAGAGGACT 61 G Q
G L E W I G A I S P G D G D T T Y N 181
GGGCAGGGTCTAGAATGGATTGGTGCTATTTCTCCTGGAGATGGTGATACTACCTACAAC 81 Q K
F T G K A K L T A V T S A S T A Y M 241
CAGAAGTTCACGGGCAAGGCCAAACTGACTGCAGTCACATCCGCCAGCACTGCCTACATG 101 E
L S S L T H E D S A V Y Y C T R R D G 301
GAGCTCAGCAGCCTGACACATGAGGACTCTGCGGTCTATTACTGTACAAGAAGAGATGGT 121 S
Y Q V A W F A Y W G R G T L V T V S A 361
AGCTACCAAGTTGCCTGGTTTGCTTACTGGGGCCGAGGGACTCTGGTCACTGTCTCTGCA 51-41
light chain amino acid sequence (SEQ ID NO: 6) and nucleotide
sequence (SEQ ID NO: 14) 1 M K L P V R L L V L M F W I P V S S S D
1 ATGAAATTGCCTGTTAGGCTGTTGGTGCTGATGTTCTGGATTCCTGTTTCCAGCAGTGAT 21 V
L M T Q T P L S L P V S L G D Q A S I 61
GTTTTGATGACCCAAACTCCACTCTCCCTGCCTGTCAGTCTTGGAGATCAAGCCTCCATC 41 S C
R S S Q S I V H S N G N T Y L E W F 121
TCTTGCAGATCTAGTCAGAGCATTGTCCATAGTAATGGAAACACCTATTTAGAATGGTTC 61 L Q
K P G Q S P K L L I Y K V S N R F S 181
CTGCAGAAACCAGGCCAGTCTCCAAAGCTCCTGATCTACAAAGTTTCCAACCGATTTTCT 81 G V
P D R F S G S G S G T D F T L K I S 241
GGGGTCCCAGACAGGTTCAGTGGCAGTGGATCAGGGACAGATTTCACACTCAAGATCAGC 101 R
V E A E D L G V Y Y C F Q G S H V P F 301
AGAGTGGAGGCTGAGGATCTGGGAGTTTATTACTGCTTTCAAGGTTCACATGTTCCATTC 121 T
F G S G T K L E I K 361 ACGTTCGGCTCGGGGACAAAGTTGGAAATAAAA h5F1Vc
heavy chain amino acid sequence (SEQ ID NO: 7) and nucleotide
sequence (SEQ ID NO: 15) 1 M G W S W I F L F L L S G T A G V H S Q
1 ATGGGATGGAGCTGGATCTTTCTCTTCCTCCTGTCAGGTACCGCGGGCGTGCACTCTCAG 21 V
Q L V Q S G A E V K K P G S S V K V S 61
GTCCAGCTTGTCCAGTCTGGGGCTGAAGTCAAGAAACCTGGCTCGAGCGTGAAGGTCTCC 41 C K
A S G Y T F T S Y V M H W V R Q A P 121
TGCAAGGCTTCTGGCTACACCTTTACTAGCTATGTTATGCACTGGGTAAGGCAGGCCCCT 61 G Q
G L E W I G Y I N P Y N G G T Q Y N 181
GGACAGGGTCTGGAATGGATTGGATATATTAATCCTTACAATGGTGGTACTCAGTACAAT 81 E K
F K G K A T I T A D E S T N T A Y M 241
GAGAAGTTCAAAGGCAAGGCCACAATTACTGCAGACGAATCCACCAATACAGCCTACATG 101 E
L S S L T S E D S A V Y Y C A R R T F 301
GAACTGAGCAGCCTGACATCTGAGGACAGCGCAGTCTATTACTGTGCAAGACGGACCTTC 121 P
Y Y F D Y W G Q G T T L T V S S 361
CCGTACTACTTTGACTACTGGGGCCAAGGAACCACGCTCACAGTCTCCTCA h5F1Vc light
chain amino acid sequence (SEQ ID NO: 8) and nucleotide sequence
(SEQ ID NO: 16) 1 M E T D T L L L W V L L L W V P G S T G 1
ATGGAGACCGATACCCTCCTGCTATGGGTCCTCCTGCTATGGGTCCCAGGATCAACCGGA 21 D I
Q M T Q S P S S L S A S V G D R V T 61
GATATTCAGATGACCCAGTCTCCATCTTCCCTCTCTGCTAGCGTCGGGGATAGGGTCACC 41 I T
C R S S Q S I L H S N G N T Y L E W 121
ATAACCTGCAGATCTAGTCAGAGCATTTTACATAGTAATGGAAACACCTATTTAGAATGG 61 Y Q
Q K P G K A P K L L I Y K V S N R F 181
TACCAGCAGAAGCCAGGCAAAGCTCCCAAGCTTCTAATCTATAAAGTTTCCAACCGATTT 81 S G
V P S R F S G S G S G T D F T L T I 241
TCTGGAGTCCCTTCACGCTTCAGTGGCAGTGGATCTGGGACCGATTTCACCCTCACAATC 101 S
S L Q P D D F A T Y Y C F Q G S H A P 301
AGCTCTCTGCAGCCAGATGATTTCGCCACTTATTACTGCTTTCAAGGTTCACATGCTCCT 121 L
T F G Q G T K V E L K 361 CTCACGTTCGGTCAGGGGACCAAGGTGGAGCTGAAA
Example 7. Production and Characterization of Chimeric 5F1 Antibody
Construction and Production of Chimeric Antibody 5F1 (c5F1)
[0229] To construct vectors for expressing chimeric antibody, the
light chain V region of 5F1 was subcloned into the plasmid pVk. pVk
contains a CMV promoter, and the human light chain constant region.
The sequence and biological information on the human light chain
constant region can be found in Hieter, P. A., et al. (1980),
Cloned human and mouse kappa immunoglobulin constant and J region
genes conserve homology in functional segments. Cell, 22(1 Pt 1):
p. 197-207.
[0230] The heavy chain V region of 5F1 was subcloned into plasmid
pVg1. pVg1 plasmid has a CMV promoter and contains the human heavy
chain constant region of IgG1. The sequence and biological
information on the human IgG1 heavy chain constant region can be
found in Ellison, J. W., B. J. Berson, and L. E. Hood (1981), The
Nucleotide sequence of a human immunoglobulin C gamma 1 gene,
Nucleic Acids Res. 10:4071.
[0231] The light and heavy chain expressing plasmids were then
co-transfected into Cos-7 cells. The supernatants containing c5F1
were collected and analyzed for the apoptosis-inducing function of
c5F1.
[0232] Functional Tests of c5F1
[0233] The supernatant containing c5F1 was then tested for its
binding to COLO 205 cells by surface staining and for its function
by Annexin V apoptosis assay as described above. For binding assay,
0.58 micro gram/ml of c5F1 was used. For apoptosis assay, 2-32
micro gram/ml of m5F1, c5F1 and 9E10 (anti-myc control antibody)
were used and the incubation was for 16 hours. The supernatant
containing c5F1 binds COLO 205 cells and induces apoptosis in COLO
205 cells, just as its mouse counterpart, demonstrating that the
cloned cDNA fragments indeed encode the V regions of 5F1 (FIG. 9A
and FIG. 9B).
Example 8. Colorectal Cancer Tissue Immunohistochemistry Study with
m5F1 Tissue Staining with m5F1
[0234] The expression of m5F1 target was investigated by
immunohistochemistry in paraffin-embedded primary tumor tissue
samples from patients with colorectal cancer (n=59). Tissue arrays
of paraffin-embedded human colon and rectum cancer tissues were
obtained from SuperBioChips Laboratories (Human tissue array, Cat
no. CD1). Standard staining procedures were used for
immunohistochemistry according to manufacturer's instruction
(VECTASTAIN.RTM. Elite ABC Kit, Vector Laboratories). All sections
were heated at 58.degree. C. for 1 hr, deparaffinized with xylene
for five times, and rehydrated in a series of ethanol with
decreasing concentration. After blocking with normal serum
(VECTASTAIN.RTM., PK6102) for 1 hr, the sections were incubated
with the m5F1 at a concentration of 1 .mu.g/ml for 1 hr at RT and
subsequently with the secondary, biotinylated anti-mouse antibody
(VECTASTAIN.RTM., PK6102). Sections were then incubated with a
streptavidin-biotin complex (VECTASTAIN.RTM., PK6102). The slides
were developed with diaminobenzidine solution. Finally the slides
were counterstained with haematoxylin, dehydrated, cleared, and
mounted in 50% glycerol in PBS.
Assessment of Grading
[0235] Antigen expression in each tissue section was evaluated by
two independent observers and the staining with 5F1 was graded
using an empirical semi-quantitative system: -, negative; +-, weak
staining; +, moderate staining; ++, strong staining.
Results
[0236] In all sections, m5F1 staining was predominantly membranous.
In total, 31 out of the 59 tumour specimens (52.5%) showed positive
staining for 5F1 target, among them, 27 (45.8%) showed strong
levels of expression. 19 samples (32.2%) showed negative staining
for m5F1 target expression. A summary of staining results across
all colorectal cancer samples tested is shown in Table 6 below.
These data indicate that antibody m5F1 may be used for diagnosing
colorectal cancer.
TABLE-US-00007 TABLE 6 Frequency of 5F1 target expression in human
colorectal cancers colorectal cancer sample/m5F1 staining result 1
++ 2 ++ 3 ++ 4 - 5 ++ 6 +- 7 ++ 8 - 9 ++ 10 ++ 11 ++ 12 - 13 ++ 14
+- 15 - 16 - 17 ++ 18 ++ 19 +- 20 ++ 21 + 22 +- 23 + 24 - 25 ++ 26
- 27 - 28 - 29 ++ 30 ++ 31 +- 32 - 33 - 34 ++ 35 ++ 36 - 37 - 38 ++
39 ++ 40 ++ 41 + 42 ++ 43 - 44 - 45 - 46 - 47 +- 48 ++ 49 - 50 + 51
++ 52 ++ 53 +- 54 ++ 55 ++ 56 ++ 57 +- 58 +- 59 - 60carbon ++:
27/59 (45.76%) +: 4/59 (6.78%) +-: 9/59 (15.25%) -: 19/59
(32.20%)
Example 9. m5F1 Binds to Recombinant Human CEA (rhCEA) and CD43
(rhCD43) Expressed by COLO 205, but does not Recognize rhCEA or
rhCD43 Expressed by COS-7 Cells
Protein Sample Preparation
[0237] Immuno-Precipitation for Recombinant Flag-Tagged CEA in COLO
205 and COS Cells:
[0238] The cDNA coding for full length CEA protein (35.about.702aa)
was cloned into plasmid pFlag-CMV-1. The engineered plasmid DNA was
introduced into COLO 205 (for stable cell line engineering) by
electroporation or COS cells (for transient expression experiment)
by Lipofectamine.TM. 2000 (Invitrogen, Catalog #11668-019). Antigen
expressing cells were collected and lysed in lysis buffer (50 mM
Tris-HCl, pH 8.5, 150 mM NaCl, 1% NP40) containing protease
inhibitors (Roche, Catalog #11836145001). The supernatant of cell
lysates were incubated with anti-Flag.RTM. (M2, Stratagene, Catalog
#200472) coupled protein G Sepharose.RTM. beads (GE Healthcare,
Catalog #17-0618-02) for 2 hours at 4.degree. C. The protein G
Sepharose.RTM. beads were then washed three times with lysis
buffer. The protein G Sepharose.RTM. beads containing IP products
were used as samples for SDS-PAGE and Western blot.
[0239] Soluble Recombinant Protein Purification for Cr1-Tagged CD43
Expressed in COLO 205 Cells:
[0240] The cDNA coding for the extracellular domain of CD43 protein
was cloned into the modified pcDNA3 plasmid which contains
N-terminal Flag and C-terminal Cr1 tags. The engineered plasmid DNA
was introduced into COLO 205 cells by electroporation for stable
cell line development. The soluble recombinant hCD4320-253
expressed by COLO 205 contains N-terminal 3.times. Flag tag and
C-terminal Cr1 tag. The soluble protein were purified with protein
A Sepharose.RTM. beads (GE Healthcare, Catalog #17-1279-02). After
eluted with glycine buffer and dialyzed against PBS, the protein
samples were stored at -20.degree. C. for future usage.
[0241] Whole Cell Lysate for CD43 Transiently Expressed in COS
Cell:
[0242] A construct containing full-length human CD43 (in
pcDNA3.1myc-His) was introduced into COS cells by Lipofectamine.TM.
2000 (Invitrogen, Catalog #11668-019). Cells were lysed with RIPA
buffer (50 mM Tris-HCl, pH 7.4, 150 mM NaCl, 1 mM EDTA, 0.25% SDS,
1% NP-40) containing protease inhibitors, and centrifuged at 21,900
g at 4.degree. C. for 10 min to collect the supernatant. After
Bio-Rad quantification, sufficient amount of protein lysates were
loaded on SDS-PAGE for Western blot analysis.
Western Blot Analysis
[0243] After adding sample buffer, the protein samples were boiled
at 95.degree. C., loaded on a SDS-PAGE mini-gel, and then
transferred to NC paper (GE Healthcare, Hybond.TM.-ECL, Catalog #
RPN303D). After blocking the membranes with 5% non-fat milk in TBS,
1st antibodies were added. The binding of 1st antibodies were
detected by HRP conjugated 2nd antibody (NEN Life Science, HRP-goat
anti-mouse IgG, Catalog # NEF822, or Southern Biotech, HRP-goat
anti-mouse Ig, Catalog #1010-05) and developed with ECL Western
blotting detection reagents (GE Healthcare, Catalog # RPN2106).
Results
[0244] In the experiment shown in FIG. 11A, cell lysates of COLO
205 cells expressing rhCEA were immunoprecipated with
anti-Flag.RTM. antibody and the immunoprecipitated proteins were
run on SDS-PAGE and transferred to NC paper. NC paper was blotted
with various antibodies: anti-Flag.RTM., m5F1, 50-14, 51-41,
138-10, 186-14, 280-6, or anti-CEA antibody (CEA/Ab-3; clone name
COL-1 from NeoMarker Cat. MS-613-P1ABX). Data in FIG. 11A showed
that m5F1, 51-41, and 138-10 recognized rhCEA expressed by COLO 205
cells.
[0245] In the experiment shown in FIG. 11B, cell lysates of COS-7
cells expressed rhCEA were immunoprecipated with anti-Flag.RTM.
antibody and the immunoprecipitated proteins were run on SDS-PAGE
and transferred to NC paper. NC paper was blotted with various
antibodies: anti-Flag.RTM., m5F1, or anti-CEA (CEA/Ab-3). Data in
FIG. 11B showed that m5F1 did not bind to rhCEA expressed by COS-7
cells.
[0246] In the experiment shown in FIG. 12A, soluble proteins
expressed by COLO 205 were purified with protein A Sepharose.RTM.
beads, and were run on SDS gel and transferred to NC paper. NC
paper was blotted with various antibodies: m5F1, 51-41, or 138-10.
Data in FIG. 12A showed m5F1, 51-41, and 138-10 recognized rhCD43
expressed by COLO 205 cells.
[0247] In the experiment shown in FIG. 12B, soluble proteins
expressed in COLO 205 were purified with protein A Sepharose.RTM.,
and were run on SDS-PAGE and transferred to NC paper. NC paper was
blotted with anti-CD43 (MEM59) (left panel) or m5F1 (right panel).
Data in FIG. 12B showed m5F1 did not recognize rhCD43 expressed by
COS-7 cells. These data indicate that the epitope recognized by
m5F1 includes a post-translational modification specific for
certain cell types.
Example 10. The Epitope Recognized by m5F1, 51-41, and 138-10
Includes a Lewis.sup.a (Le.sup.a) Structure and is Fucose
Dependent
Glycosidase Treatment
[0248] Recombinant human CEA (rhCEA) was produced by expression
human CEA protein in COLO 205 cells. The cDNA coding for the rhCEA
(CEA-N-A2), which is a fusion having amino acids 35-145 (N domain)
and amino acids 324-415 (A2 domain) of CEA, was cloned into
modified pcDNA3 plasmid which contains Flag tag. Amino acid residue
position of CEA is based on the amino acid position in the
pre-protein. The engineered plasmid DNA was introduced into COLO
205 cells for stable cell line engineering by electroporation.
Recombinant CEA protein was purified from cell culture supernatant
of the recombinant-CEA expressing stable cell lines using
anti-Flag.RTM. antibody.
[0249] For each reaction, about 1.8 .mu.g recombinant protein
(rhCEA) was incubated with different amount (0, 0.01, 0.03, or 0.1
mU) of .alpha.-1.fwdarw.(2,3,4)-Fucosidase solution from
Xanthomonas sp. (Sigma, Catalog # F1924) at 37.degree. C. for 20
hours. After treatment, the protein samples were loaded on SDS-PAGE
for Coomassie blue staining (FIG. 13 left panel) or Western blot
detection (FIG. 13 right panel) with m5F1.
[0250] As shown in FIG. 13, binding of m5F1 to the rhCEA decreased
when the antigen was treated with
.alpha.-1.fwdarw.(2,3,4)-Fucosidase, indicating m5F1 recognize a
fucose sensitive glyco-epitope.
Oligosaccharides Competition Assay
[0251] To further test the glyco-epitope recognized by m5F1,
competition assays with various oligosaccharides were conducted.
Oligosaccharides were purchased (Lewis.sup.a from Sigma Catalog
#03499, Lewis.sup.b-lactose from Sigma Catalog # L7033,
Lewis.sup.x-lactose from Sigma Catalog # L7777, Lewis.sup.y from
Sigma Catalog # L7784, Sialyl-Lewis.sup.x from Sigma Catalog #
S1782, Lacto-N-tetraose from Sigma Catalog # L6770,
Lecto-N-difucohexaose II from Sigma Catalog # L6645, Lewis.sup.a
from Calbiochem Catalog #434626, and .beta.-lactose form Sigma
Catalog # L3750) and dissolved in PBS. The structures of these
oligosaccharides are shown in FIG. 14. Oligosaccharides (at 1 mM
final concentration) were added into different wells containing
2.times.10.sup.5 COLO 205 cells, followed by the addition of
indicated antibodies (m5F1, 51-41, or 138-10; each at 0.25 ug/ml).
After one hour incubation at 4.degree. C., the supernatant was
discarded and secondary antibodies (Southern Biotech, RPE-goat
anti-mouse IgG, Catalog #1032-09, or Southern Biotech, RPE-goat
anti-mouse IgM, Catalog #1022-09) were added. And the cellular
binding signals were detected with flow cytometry analysis.
[0252] As shown in FIG. 15, LNDFH II, Le(a)-lactose, and Le(a) all
inhibited, at various levels, binding of antibodies m5F1, 51-41,
and 138-10 to COLO 205 cells; and LNT also inhibited binding of
antibodies 51-41 and 138-10, but did not significantly inhibit
binding of m5F1 to COLO 205 cells. This indicates that the epitope
recognized by these antibodies may include a Le.sup.a or similar
structure, and is fucose sensitive. In addition, m5F1 antibody has
higher dependency on fucose than antibody 51-41 and 138-10.
[0253] Although the foregoing invention has been described in some
detail by way of illustration and example for purposes of clarity
of understanding, the descriptions and examples should not be
construed as limiting the scope of the invention.
REFERENCES
[0254] Laos, S., Baeckstrom, D, and Hansson, G. C. (2006)
Inhibition of NF-kappaB activation and chemokine expression by the
leukocyte glycoprotein, CD43, in colon cancer cells. Int. J. Oncol.
28(3):695-704. [0255] Fuhlbrigge, R. C., King, S. L., Sackstein,
R., and Kupper, T S. (2006) CD43 is a ligand for E-selectin on CLA+
human T cells. Blood. 15; 107(4):1421-6. [0256] Matsumoto, M.,
Atarashi, K., Umemoto, E., Furukawa, Y., Shigeta, A., Miyasaka, M.,
and Hirata, T. (2005) CD43 functions as a ligand for E-Selectin on
activated T cells. J. Immunol. 15; 175(12):8042-50. [0257]
Pimenidou, A., Madden, L. A., Topping, K. P., Smith, K. A., Monson,
J. R., and Greenman, J. (2004) Novel CD43 specific phage antibodies
react with early stage colorectal tumours. Oncol. Rep.
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Overexpression of leukocyte marker CD43 causes activation of the
tumor suppressor proteins p53 and ARF. Oncogene. 19;
23(37):2523-2530. [0259] Fernandez-Rodriguez, J., Andersson, C. X.,
Laos, S., Baeckstrom, D., Sikut, A., Sikut, R., and Hansson, G. C.
(2002) The leukocyte antigen CD43 is expressed in different cell
lines of nonhematopoietic origin. Tumour Biol. 23(4):193-201.
[0260] Cermak, L., Simova, S., Pintzas, A., Horejsi, V., and
Andera, L. (2002) Molecular mechanisms involved in CD43-mediated
apoptosis of TF-1 cells. Roles of transcription Daxx expression,
and adhesion molecules. J Biol Chem. 8; 277(10):7955-61. [0261]
Carlow, D. A., Corbel, S. Y., and Ziltener, H. J. (2001) Absence of
CD43 fails to alter T cell development and responsiveness. J
Immunol. 166(1):256-61. [0262] Nieto, M., Rodriguez-Fernandez, J.
L., Navarro, F., Sancho, D., Frade, J. M., Mellado, M., Martinez-A,
C., Cabanas, C., and Sanchez-Madrid, F. (1999) Signaling through
CD43 induces natural killer cell activation, chemokine release, and
PYK-2 activation. Blood. 94(8):2767-77. [0263] Sikut, R.,
Andersson, C. X., Sikut, A., Fernandez-Rodriguez, J., Karlsson, N.
G., and Hansson, G. C. (1999) Detection of CD43 (leukosialin) in
colon adenoma and adenocarcinoma by novel monoclonal antibodies
against its intracellular domain. Int. J. Cancer. 82(1):52-8.
[0264] Lopez, S., Seveau, S., Lesavre, P., Robinson, M. K., and
Halbwachs-Mecarelli, L. (1998) CD43 (sialophorin, leukosialin)
shedding is an initial event during neutrophil migration, which
could be closely related to the spreading of adherent cells. Cell
Adhes. Commun. 5(2):151-60. [0265] Stockton, B. M., Cheng, G.,
Manjunath, N., Ardman, B., and von Andrian, U. H. (1998) Negative
regulation of T cell homing by CD43. Immunity. 8(3):373-81. [0266]
McEvoy, L. M., Jutila, M. A., Tsao, P. S., Cooke, J. P., and
Butcher, E. C. (1997) Anti-CD43 inhibits monocyte-endothelial
adhesion in inflammation and atherogenesis. Blood. 90(9):3587-94.
[0267] Baeckstrom, D. (1997) Post-translational fate of a
mucin-like leukocyte sialoglycoprotein (CD43) aberrantly expressed
in a colon carcinoma cell line. J Biol Chem. 272(17):11503-9.
[0268] McEvoy, L. M., Sun, H., Frelinger, J. G., and Butcher, E. C.
(1997) Anti-CD43 inhibition of T cell homing. J Exp Med.
185(8):1493-8. [0269] Brown, T. J., Shuford, W. W., Wang, W. C.,
Nadler, S. G., Bailey, T. S., Marquardt, H., and Mittler, R. S.
(1996) Characterization of a CD43/leukosialin-mediated pathway for
inducing apoptosis in human T-lymphoblastoid cells. J Biol Chem.
271(44):27686-95. [0270] Santamaria, M., Lopez-Beltran, A., Toro,
M., Pena, J., and Molina, I. J. (1996) Specific monoclonal
antibodies against leukocyte-restricted cell surface molecule CD43
react with nonhematopoietic tumor cells. Cancer Res. 56(15):3526-9.
[0271] Bazil, V., Brandt, J., Chen, S., Roeding, M., Luens, K.,
Tsukamoto, A., and Hoffman, R. (1996) A monoclonal antibody
recognizing CD43 (leukosialin) initiates apoptosis of human
hematopoietic progenitor cells but not stem cells. Blood.
87(4):1272-81. [0272] Manjunath, N., Correa, M., Ardman, M., and
Ardman, B. (1995) Negative regulation of T-cell adhesion and
activation by CD43. Nature. 377(6549):535-8 [0273] Nong, Y. H.,
Remold-O'Donnell, E., LeBien, T. W., and Remold, H. G. [0274]
(1989) A monoclonal antibody to sialophorin (CD43) induces
homotypic adhesion and activation of human monocytes. J Exp Med.
170(1):259-67. [0275] Mentzer, S. J., Remold-O'Donnell, E.,
Crimmins, M. A., Bierer, B. E., Rosen, F. S., and Burakoff, S. J.
(1987) Sialophorin, a surface sialoglycoprotein defective in the
Wiskott-Aldrich syndrome, is involved in human T lymphocyte
proliferation. J Exp Med. 165(5):1383-92. [0276] Pallant, A.,
Eskenazi, A., Mattei, M G., Fournier, R. E. K., Carlsson, S. R.,
Fukuda, M., and Frelinger, J. G. (1989) Characterization of cDNA
encoding human leukosialin and localization of the leukosialin gene
to chromosome 16. Proc. Natl. Acad. Sci. USA 86:1328-32. [0277]
Shelley, C. S., Remold-O'Donnell, E., Davis III, A. E., Bruns, G.
A. P., Rosen, F. S., Carroll, M. C., and Whitehead, A. S. (1989)
Molecular characterization of sialophorin (CD43), the lymphocyte
surface sialoglycoprotein defective in Wiskott-Aldrich syndrome.
Proc. Natl. Acad. Sci. USA 86: 2819-23.
Sequence CWU 1
1
331137PRTMurine 1Met Glu Trp Ser Trp Ile Phe Leu Phe Leu Leu Ser
Gly Thr Ala Gly 1 5 10 15 Val His Ser Glu Val Gln Leu Gln Gln Ser
Gly Pro Glu Leu Val Lys 20 25 30 Pro Gly Ala Ser Val Arg Met Ser
Cys Thr Ala Ser Gly Tyr Thr Phe 35 40 45 Thr Ser Tyr Val Met His
Trp Ile Lys Gln Lys Pro Gly Gln Gly Leu 50 55 60 Asp Trp Ile Gly
Tyr Ile Asn Pro Tyr Asn Gly Gly Thr Gln Tyr Asn65 70 75 80 Glu Lys
Phe Lys Gly Lys Ala Thr Leu Thr Ser Asp Lys Ser Ser Ser 85 90 95
Thr Ala Tyr Met Glu Leu Ser Ser Leu Thr Ser Glu Asp Ser Ala Val 100
105 110 Tyr Tyr Cys Ala Arg Arg Thr Phe Pro Tyr Tyr Phe Asp Tyr Trp
Gly 115 120 125 Gln Gly Thr Thr Leu Thr Val Ser Ser 130 135
2131PRTMurine 2Met Lys Leu Pro Val Arg Leu Leu Val Leu Met Phe Trp
Ile Pro Ala 1 5 10 15 Ser Ser Ser Asp Val Leu Met Thr Gln Thr Pro
Leu Ser Leu Pro Val 20 25 30 Ser Leu Gly Asp Gln Ala Ser Ile Ser
Cys Arg Ser Ser Gln Ser Ile 35 40 45 Leu His Ser Asn Gly Asn Thr
Tyr Leu Glu Trp Tyr Leu Gln Lys Pro 50 55 60 Gly Gln Ser Pro Lys
Leu Leu Ile Tyr Lys Val Ser Asn Arg Phe Ser65 70 75 80 Gly Val Pro
Asp Arg Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr 85 90 95 Leu
Lys Ile Ser Arg Val Glu Ala Glu Asp Leu Gly Val Tyr Tyr Cys 100 105
110 Phe Gln Gly Ser His Ala Pro Leu Thr Phe Gly Ala Gly Thr Lys Leu
115 120 125 Glu Leu Lys 130 3140PRTMurine 3Met Glu Cys Asn Trp Ile
Leu Pro Phe Ile Leu Ser Val Ile Ser Gly 1 5 10 15 Val Tyr Ser Glu
Val Gln Leu Gln Gln Ser Gly Thr Val Leu Ala Arg 20 25 30 Pro Gly
Ala Ser Val Lys Met Ser Cys Lys Ala Ser Gly Tyr Ser Phe 35 40 45
Ile Ser Tyr Trp Met His Trp Val Lys Gln Arg Pro Gly Gln Gly Leu 50
55 60 Glu Trp Ile Gly Ala Ile Ser Pro Gly Asp Ser Asp Thr Thr Tyr
Asn65 70 75 80 Gln Arg Phe Thr Gly Lys Ala Lys Leu Thr Ala Val Thr
Ser Ala Ser 85 90 95 Thr Ala Tyr Met Glu Leu Ser Ser Leu Thr Asn
Glu Asp Ser Ala Val 100 105 110 Tyr Tyr Cys Ile Arg Arg Asp Gly Asn
Tyr Gln Val Ala Trp Phe Ala 115 120 125 Tyr Trp Gly Gln Gly Thr Leu
Val Thr Val Ser Ala 130 135 140 4131PRTMurine 4Met Lys Leu Pro Val
Arg Leu Leu Val Leu Met Phe Trp Ile Pro Ala 1 5 10 15 Ser Ser Ser
Asp Val Leu Met Thr Gln Thr Pro Leu Ser Leu Pro Val 20 25 30 Ser
Leu Gly Asp Gln Ala Ser Ile Ser Cys Arg Ser Ser Gln Ser Ile 35 40
45 Val His Ser Asn Gly Asn Thr Tyr Leu Glu Trp Tyr Leu Gln Lys Pro
50 55 60 Gly Gln Ser Pro Lys Leu Leu Ile Tyr Lys Val Ser Asn Arg
Phe Ser65 70 75 80 Gly Val Pro Asp Arg Phe Ser Gly Ser Gly Ser Gly
Thr Asp Phe Thr 85 90 95 Leu Lys Ile Ser Arg Val Glu Ala Glu Asp
Leu Gly Val Tyr Tyr Cys 100 105 110 Phe Gln Gly Ser His Val Pro Phe
Thr Phe Gly Ser Gly Thr Lys Leu 115 120 125 Glu Ile Lys 130
5140PRTMurine 5Met Glu Cys Asn Trp Ile Leu Pro Phe Ile Leu Ser Val
Ile Ser Gly 1 5 10 15 Val Tyr Ser Glu Val Gln Leu Gln Gln Ser Gly
Thr Val Leu Ala Arg 20 25 30 Pro Gly Ala Ser Val Lys Met Ser Cys
Lys Ala Ser Gly Tyr Ser Phe 35 40 45 Thr Ser Tyr Trp Met His Trp
Val Lys Gln Arg Thr Gly Gln Gly Leu 50 55 60 Glu Trp Ile Gly Ala
Ile Ser Pro Gly Asp Gly Asp Thr Thr Tyr Asn65 70 75 80 Gln Lys Phe
Thr Gly Lys Ala Lys Leu Thr Ala Val Thr Ser Ala Ser 85 90 95 Thr
Ala Tyr Met Glu Leu Ser Ser Leu Thr His Glu Asp Ser Ala Val 100 105
110 Tyr Tyr Cys Thr Arg Arg Asp Gly Ser Tyr Gln Val Ala Trp Phe Ala
115 120 125 Tyr Trp Gly Arg Gly Thr Leu Val Thr Val Ser Ala 130 135
140 6131PRTMurine 6Met Lys Leu Pro Val Arg Leu Leu Val Leu Met Phe
Trp Ile Pro Val 1 5 10 15 Ser Ser Ser Asp Val Leu Met Thr Gln Thr
Pro Leu Ser Leu Pro Val 20 25 30 Ser Leu Gly Asp Gln Ala Ser Ile
Ser Cys Arg Ser Ser Gln Ser Ile 35 40 45 Val His Ser Asn Gly Asn
Thr Tyr Leu Glu Trp Phe Leu Gln Lys Pro 50 55 60 Gly Gln Ser Pro
Lys Leu Leu Ile Tyr Lys Val Ser Asn Arg Phe Ser65 70 75 80 Gly Val
Pro Asp Arg Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr 85 90 95
Leu Lys Ile Ser Arg Val Glu Ala Glu Asp Leu Gly Val Tyr Tyr Cys 100
105 110 Phe Gln Gly Ser His Val Pro Phe Thr Phe Gly Ser Gly Thr Lys
Leu 115 120 125 Glu Ile Lys 130 7137PRTArtificial Sequencesynthetic
construct 7Met Gly Trp Ser Trp Ile Phe Leu Phe Leu Leu Ser Gly Thr
Ala Gly 1 5 10 15 Val His Ser Gln Val Gln Leu Val Gln Ser Gly Ala
Glu Val Lys Lys 20 25 30 Pro Gly Ser Ser Val Lys Val Ser Cys Lys
Ala Ser Gly Tyr Thr Phe 35 40 45 Thr Ser Tyr Val Met His Trp Val
Arg Gln Ala Pro Gly Gln Gly Leu 50 55 60 Glu Trp Ile Gly Tyr Ile
Asn Pro Tyr Asn Gly Gly Thr Gln Tyr Asn65 70 75 80 Glu Lys Phe Lys
Gly Lys Ala Thr Ile Thr Ala Asp Glu Ser Thr Asn 85 90 95 Thr Ala
Tyr Met Glu Leu Ser Ser Leu Thr Ser Glu Asp Ser Ala Val 100 105 110
Tyr Tyr Cys Ala Arg Arg Thr Phe Pro Tyr Tyr Phe Asp Tyr Trp Gly 115
120 125 Gln Gly Thr Thr Leu Thr Val Ser Ser 130 135
8132PRTArtificial Sequencesynthetic construct 8Met 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 Gln Met Thr Gln Ser Pro Ser Ser Leu Ser 20 25 30 Ala
Ser Val Gly Asp Arg Val Thr Ile Thr Cys Arg Ser Ser Gln Ser 35 40
45 Ile Leu His Ser Asn Gly Asn Thr Tyr Leu Glu Trp Tyr Gln Gln Lys
50 55 60 Pro Gly Lys Ala Pro Lys Leu Leu Ile Tyr Lys Val Ser Asn
Arg Phe65 70 75 80 Ser Gly Val Pro Ser Arg Phe Ser Gly Ser Gly Ser
Gly Thr Asp Phe 85 90 95 Thr Leu Thr Ile Ser Ser Leu Gln Pro Asp
Asp Phe Ala Thr Tyr Tyr 100 105 110 Cys Phe Gln Gly Ser His Ala Pro
Leu Thr Phe Gly Gln Gly Thr Lys 115 120 125 Val Glu Leu Lys 130
9411DNAMurine 9atggaatgga gttggatatt tctctttctc ctgtcaggaa
ctgcaggtgt ccactctgag 60gtccagctgc agcagtctgg acctgagctg gtaaagcctg
gggcttcagt gaggatgtcc 120tgcacggctt ctggatacac attcactagc
tatgttatgc actggataaa gcagaagcct 180gggcagggcc ttgactggat
tggatatatt aatccttaca atggtggtac tcagtacaat 240gagaagttca
aaggcaaggc cacactgact tcagacaaat cctccagcac agcctacatg
300gagctcagca gcctgacctc tgaggactct gcggtctatt actgtgcaag
acggaccttc 360ccgtactact ttgactactg gggccaaggc accactctca
cagtctcctc a 41110393DNAMurine 10atgaagttgc ctgttaggct gttggtgctg
atgttctgga ttcctgcttc cagcagtgat 60gttttgatga cccaaactcc actctccctg
cctgtcagtc ttggagatca agcctccatc 120tcttgcagat ctagtcagag
cattttacat agtaatggaa acacctattt agaatggtac 180ctgcagaaac
caggccagtc tccaaagctc ctgatctaca aagtttccaa ccgattttct
240ggggtcccag acaggttcag tggcagtgga tcagggacag atttcacact
caagatcagc 300agagtggagg ctgaggatct gggagtttac tactgctttc
aaggttcaca tgctcctctc 360acgttcggtg ctgggaccaa gctggagctg aaa
39311420DNAMurine 11atggaatgta actggatact tccttttatt ctgtcggtaa
tttcaggggt ctactcagag 60gttcagctcc agcagtctgg gactgtgctg gcaaggcctg
gggcttccgt gaagatgtcc 120tgcaaggctt ctggctacag ctttatcagc
tactggatgc actgggtaaa acagaggcct 180ggacagggtc tagaatggat
tggtgctatt tctcctggag atagtgatac tacctacaac 240cagaggttca
cgggcaaggc caaactgact gcagtcacat ccgccagcac tgcctacatg
300gagctcagca gcctgacaaa tgaggactct gcggtctatt attgtataag
aagggatggt 360aactaccaag ttgcctggtt tgcttactgg ggccaaggga
ctctggtcac tgtctctgca 42012393DNAMurine 12atgaagttgc ctgttaggct
gttggtgctg atgttctgga ttcctgcttc cagcagtgat 60gttttgatga cccaaactcc
actctccctg cctgtcagtc ttggagatca agcctccatc 120tcttgcagat
ctagtcagag cattgtacat agtaatggaa acacctattt agaatggtac
180ctgcagaaac caggccagtc tccaaagctc ctgatctaca aagtttccaa
ccgattttct 240ggggtcccag acaggttcag tggcagtgga tcagggacag
atttcacact caagatcagc 300agagtggagg ctgaggatct gggagtttat
tactgctttc aaggttcaca tgttccattc 360acgttcggct cggggacaaa
gttggaaata aaa 39313420DNAMurine 13atggaatgta actggatact tccttttatt
ctgtcggtaa tttcaggggt ctactcagag 60gttcagctcc agcagtctgg gactgtgctg
gcaaggcctg gggcttccgt gaagatgtcc 120tgcaaggctt ctggctacag
ttttaccagc tactggatgc actgggtaaa acagaggact 180gggcagggtc
tagaatggat tggtgctatt tctcctggag atggtgatac tacctacaac
240cagaagttca cgggcaaggc caaactgact gcagtcacat ccgccagcac
tgcctacatg 300gagctcagca gcctgacaca tgaggactct gcggtctatt
actgtacaag aagagatggt 360agctaccaag ttgcctggtt tgcttactgg
ggccgaggga ctctggtcac tgtctctgca 42014393DNAMurine 14atgaaattgc
ctgttaggct gttggtgctg atgttctgga ttcctgtttc cagcagtgat 60gttttgatga
cccaaactcc actctccctg cctgtcagtc ttggagatca agcctccatc
120tcttgcagat ctagtcagag cattgtccat agtaatggaa acacctattt
agaatggttc 180ctgcagaaac caggccagtc tccaaagctc ctgatctaca
aagtttccaa ccgattttct 240ggggtcccag acaggttcag tggcagtgga
tcagggacag atttcacact caagatcagc 300agagtggagg ctgaggatct
gggagtttat tactgctttc aaggttcaca tgttccattc 360acgttcggct
cggggacaaa gttggaaata aaa 39315411DNAArtificial Sequencesynthetic
construct 15atgggatgga gctggatctt tctcttcctc ctgtcaggta ccgcgggcgt
gcactctcag 60gtccagcttg tccagtctgg ggctgaagtc aagaaacctg gctcgagcgt
gaaggtctcc 120tgcaaggctt ctggctacac ctttactagc tatgttatgc
actgggtaag gcaggcccct 180ggacagggtc tggaatggat tggatatatt
aatccttaca atggtggtac tcagtacaat 240gagaagttca aaggcaaggc
cacaattact gcagacgaat ccaccaatac agcctacatg 300gaactgagca
gcctgacatc tgaggacagc gcagtctatt actgtgcaag acggaccttc
360ccgtactact ttgactactg gggccaagga accacgctca cagtctcctc a
41116396DNAArtificial Sequencesynthetic construct 16atggagaccg
ataccctcct gctatgggtc ctcctgctat gggtcccagg atcaaccgga 60gatattcaga
tgacccagtc tccatcttcc ctctctgcta gcgtcgggga tagggtcacc
120ataacctgca gatctagtca gagcatttta catagtaatg gaaacaccta
tttagaatgg 180taccagcaga agccaggcaa agctcccaag cttctaatct
ataaagtttc caaccgattt 240tctggagtcc cttcacgctt cagtggcagt
ggatctggga ccgatttcac cctcacaatc 300agctctctgc agccagatga
tttcgccact tattactgct ttcaaggttc acatgctcct 360ctcacgttcg
gtcaggggac caaggtggag ctgaaa 3961712PRTArtificial Sequencesynthetic
construct 17Trp Pro Ile Asp Leu Met Ser Glu Thr Pro Ile Leu 1 5 10
1812PRTArtificial Sequencesynthetic construct 18Trp Pro Ile Ala Asn
His Glu Asn Ala Leu Ser Ala 1 5 10 1912PRTArtificial
Sequencesynthetic construct 19Trp Pro Ile Ser Gly Lys His Ser Phe
Trp Ser Leu 1 5 10 2012PRTArtificial Sequencesynthetic construct
20Trp Pro Ile Leu Asp His Ala Val Ser Arg Pro Ser 1 5 10
2112PRTArtificial Sequencesynthetic construct 21Trp Pro Ile Asp Ile
Pro Tyr Ala Trp Asp Phe Ser 1 5 10 2212PRTArtificial
Sequencesynthetic construct 22Trp Pro Ile Ser Pro Gln Pro Gly Ala
Arg Pro Val 1 5 10 2312PRTArtificial Sequencesynthetic construct
23Trp Pro Ile Ala Pro Asn Arg Tyr Leu Leu Ser Ser 1 5 10
2412PRTArtificial Sequencesynthetic construct 24Trp Pro Ile Pro Pro
Glu Val Glu Pro Phe Lys His 1 5 10 2512PRTArtificial
Sequencesynthetic construct 25Trp Pro Ile Leu Gln Asn Ala Ala Gly
Thr Gly Leu 1 5 10 2612PRTArtificial Sequencesynthetic construct
26Trp Pro Ile Pro Thr Leu Met Glu Leu Pro Ser Ala 1 5 10
2712PRTArtificial Sequencesynthetic construct 27Trp Pro Ile Thr Asn
Ser Asp Ser Arg Ile Thr Trp 1 5 10 2812PRTArtificial
Sequencesynthetic construct 28Trp Pro Ile His Ser Ala His Val Arg
Tyr Thr Thr 1 5 10 2912PRTArtificial Sequencesynthetic construct
29Ala Glu Thr Asp Tyr Asp Pro Asp His Phe Thr Pro 1 5 10
3012PRTArtificial Sequencesynthetic construct 30Asp Ala Arg Tyr Ser
His Asp Pro Ala Trp Pro Tyr 1 5 10 3112PRTArtificial
Sequencesynthetic construct 31Ala Gly Gln Lys Trp Asp Pro Glu Trp
Pro His Ser 1 5 10 3212PRTArtificial Sequencesynthetic construct
32Tyr Asp His His Trp Thr Asn Pro Pro Thr Gln Lys 1 5 10
3312PRTArtificial Sequencesynthetic construct 33Glu Pro Asn Met Asp
Pro Asn Trp Ala Ser Pro Ser 1 5 10
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