Antibodies recognizing a carbohydrate containing epitope on CD-43 and CEA expressed on cancer cells and methods using same
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 a structure, a Le 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.
1. An isolated monoclonal antibody, which antibody specifically binds to an epitope on the extracellular domain of a human CD43 or a human carcinoembryonic antigen (CEA) expressed by a human colorectal cancer cell, or a human gastric cancer cell, but does not specifically bind to a human CD43 expressed on the cell surface of human peripheral I cells or Jurkat cells, and is capable of inducing apoptosis of the cancer cell after binding to the epitope on the cell surface of the cancer cell in vitro 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 oligosaccharides Le a , Le a -lactose, and lacto-N-difucohexaose II (LNDFH II).
2. The monoclonal antibody of claim 1 , wherein the epitope comprises a fucose.
3. The monoclonal antibody of claim 1 , wherein the binding of the antibody to the epitope is inhibited by oligosaccharide lacto-N-tetraose (LNT).
4. The monoclonal antibody of claim 1 , wherein the antibody specifically competes with an antibody comprising 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, for binding to the epitope present on the cell surface of the cancer cell.
5. The monoclonal antibody of claim 1 , wherein the antibody specifically competes with an antibody comprising 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, for binding to the epitope present on the cell surface of the cancer cell.
6. The monoclonal antibody of claim 1 , wherein the antibody specifically competes with an antibody comprising 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, for binding to the epitope present on the cell surface of the cancer cell.
7. The monoclonal antibody of claim 1 , wherein the antibody is a humanized antibody.
8. The monoclonal antibody of claim 1 , wherein the antibody is a chimeric antibody.
9. The monoclonal antibody of claim 1 , wherein the antibody is a human antibody.
10. An isolated monoclonal antibody that specifically binds to an epitope on the extracellular domain of a human CD43 expressed by a human colorectal cancer cell, wherein the antibody comprises a heavy chain variable region comprising the three complementary determining regions from the amino acid sequence of SEQ ID NO:1, and a light chain variable region comprising the three complementary determining regions from the amino acid sequence of SEQ ID NO:2.
11. The monoclonal antibody of claim 10 , wherein the 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.
12. An isolated monoclonal antibody that specifically binds to an epitope on the extracellular domain of a human CD43 expressed by a human colorectal cancer cell, wherein the antibody comprises a heavy chain variable region comprising the three complementary determining regions from the amino acid sequence of SEQ ID NO:3, and a light chain variable region comprising the three complementary determining regions from the amino acid sequence of SEQ ID NO:4.
13. The monoclonal antibody of claim 12 , wherein the 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.
14. An isolated monoclonal antibody that specifically binds to an epitope on the extracellular domain of a human CD43 expressed by a human colorectal cancer cell, wherein the antibody comprises a heavy chain variable region comprising the three complementary determining regions from the amino acid sequence of SEQ ID NO:5, and a light chain variable region comprising the three complementary determining regions from the amino acid sequence of SEQ ID NO:6.
15. The monoclonal antibody of claim 14 , wherein the 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.
16. An isolated monoclonal antibody that specifically binds to an epitope on the extracellular domain on a human CD43 expressed by a human colorectal cancer cell, wherein the 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.
17. An isolated cell that produces the monoclonal antibody of claim 1 .
18. A composition comprising the monoclonal antibody of claim 1 , and a pharmaceutically acceptable carrier.
19. A kit comprising a pharmaceutical composition comprising the monoclonal antibody of claim 1 .
20. The monoclonal antibody of claim 10 , wherein the antibody is a humanized antibody.
21. The monoclonal antibody of claim 11 , wherein the antibody is a chimeric antibody comprising the heavy chain constant region from the heavy chain constant region from a human antibody, and the light chain constant region from the light chain constant region from a human antibody.
22. The monoclonal antibody of claim 12 , wherein the antibody is a humanized antibody.
23. The monoclonal antibody of claim 13 , wherein the antibody is a chimeric antibody comprising the heavy chain constant region from the heavy chain constant region from a human antibody, and the light chain constant region from the light chain constant region from a human antibody.
24. The monoclonal antibody of claim 14 , wherein the antibody is a humanized antibody.
25. The monoclonal antibody of claim 15 , wherein the antibody is a chimeric antibody comprising the heavy chain constant region from the heavy chain constant region from a human antibody, and the light chain constant region from the light chain constant region from a human antibody.
26. A pharmaceutical composition comprising the monoclonal antibody of claim 20 .
27. A pharmaceutical composition comprising the monoclonal antibody of claim 21 .
28. A pharmaceutical composition comprising the monoclonal antibody of claim 22 .
29. A pharmaceutical composition comprising the monoclonal antibody of claim 23 .
30. A pharmaceutical composition comprising the monoclonal antibody of claim 24 .
31. A pharmaceutical composition comprising the monoclonal antibody of claim 25 .
32. A method of producing the antibody of claim 1 , comprising culturing a host cell under conditions that allow production of the antibody, wherein the host cell comprise one or more expression vectors encoding the antibody.
33. A method of producing the antibody of claim 10 , comprising culturing a host cell under conditions that allow production of the antibody, wherein the host cell comprise one or more expression vectors encoding the antibody.
34. A method of producing the antibody of claim 12 , comprising culturing a host cell under conditions that allow production of the antibody, wherein the host cell comprise one or more expression vectors encoding the antibody.
35. A method of producing the antibody of claim 14 , comprising culturing a host cell under conditions that allow production of the antibody, wherein the host cell comprise one or more expression vectors encoding the antibody.
36. A method of producing the antibody of claim 16 , comprising culturing a host cell under conditions that allow production of the antibody, wherein the host cell comprise one or more expression vectors encoding the antibody.