Methods of generating and using antibody-producing cells
An objective of the present invention is to facilitate the acquisition of antibody-producing cells that are infiltrating virus-infected cells, cancer cells, abnormal cells forming a benign hyperplasia, and the like, and to improve the efficiency of the production of antibodies as well as nucleic acids encoding them from the antibody-producing cells. The present inventors discovered that, when cancer tissues comprising infiltrating lymphocytes are transplanted into highly immunodeficient animals that do not have T cells, B cells, and NK cells and further exhibit a low IFN production ability, the differentiation and proliferation of infiltrating lymphocytes are unexpectedly promoted, and the number of plasma cells that produce antibodies recognizing cancer tissues increases dramatically, plasma cells can be separated easily, and antibodies or nucleic acids encoding them can be easily prepared from the plasma cells.
1. A method of producing cells which produce an antibody or antigen-binding portion thereof, wherein the method comprises the steps of:
(a) transplanting a lesion tissue comprising infiltrating lymphocytes into a highly immunodeficient non-human animal, wherein the animal is not a severe combined immunodeficient (SCID) mouse;
(b) detecting the proliferation of plasma cells at the site of transplantation; and
(c) recovering a sample of the lesion tissue from the site of transplantation, wherein the sample comprises plasma cells.
2. The method of claim 1 , further comprising the step of:
(d) excising a plasma cell from the recovered sample of lesion tissue and fusing the plasma cell with a partner cell.
3. The method of claim 1 , wherein the transplanted lesion tissue comprises cancer cells, hyperplasia cells, or virus-infected cells.
4. The method of claim 3 , wherein the transplanted lesion tissue comprises cells of a solid cancer or a blood cancer.
5. The method of claim 4 , wherein the transplanted lesion tissue comprises cells of a solid cancer that is a prostate cancer, stomach cancer, breast cancer, lung cancer, liver cancer, colorectal cancer, or pancreatic cancer.
6. The method of claim 3 , wherein the transplanted lesion tissue comprises cells of benign prostatic hyperplasia.
7. The method of claim 1 , wherein the highly immunodeficient non-human animal lacks NK cells.
8. The method of claim 1 , wherein the highly immunodeficient non-human animal lacks T cells, B cells, and NK cells.
9. The method of claim 1 , wherein the lesion tissue is from a human subject.
10. The method of claim 1 , wherein the antibody is a human antibody.
11. The method of claim 1 , wherein step (b) comprises determining the level of human antibodies in the serum of the animal, wherein a higher level of human antibodies in the serum is indicative of a higher number of plasma cells at the site of transplantation.
12. A method of producing an antibody or antigen-binding portion thereof, wherein the antibody or antigen-binding portion thereof is isolated from the antibody-producing cells produced according to claim 1 .
13. The method of claim 12 , wherein the transplanted lesion tissue comprises cancer cells, hyperplasia cells, or virus-infected cells.
14. The method of claim 13 , wherein the transplanted lesion tissue comprises cells of a solid cancer or a blood cancer.
15. The method of claim 14 , wherein the transplanted lesion tissue comprises cells of a solid cancer that is a prostate cancer, stomach cancer, breast cancer, lung cancer, liver cancer, colorectal cancer or pancreatic cancer.
16. The method of claim 13 , wherein the transplanted lesion tissue comprises cells of a benign prostatic hyperplasia.
17. The method of claim 13 , wherein the antibody or an antigen-binding portion thereof is an IgG, an IgM, an Fab, an F(ab′)2, an Fv, or a single chain Fv.
18. The method of claim 17 , wherein the antibody is an IgG.
19. The method of claim 17 , wherein the antibody is an IgM.
20. The method of claim 17 , wherein the antibody or antigen-binding portion thereof is a single chain Fv.
21. The method of claim 12 , further comprising conjugating the antibody or antigen-binding portion to a molecule selected from the group consisting of polyethylene glycol, a radioisotope, a chemotherapeutic, a cytotoxic substance, and a labeling substance.
22. The method of claim 3 , wherein the solid cancer is a prostate cancer.
23. The method of claim 3 , wherein the solid cancer is a stomach cancer.
24. The method of claim 3 , wherein the solid cancer is a breast cancer.
25. The method of claim 3 , wherein the solid cancer is a lung cancer.
26. The method of claim 3 , wherein the solid cancer is a liver cancer.
27. The method of claim 3 , wherein the solid cancer is a colorectal cancer.
28. The method of claim 3 , wherein the solid cancer is a pancreatic cancer.
29. The method of claim 15 , wherein the solid cancer is a prostate cancer.
30. The method of claim 15 , wherein the solid cancer is a stomach cancer.
31. The method of claim 15 , wherein the solid cancer is a breast cancer.
32. The method of claim 3 , wherein the solid cancer is a lung cancer.
33. The method of claim 15 , wherein the solid cancer is a liver cancer.
34. The method of claim 15 , wherein the solid cancer is a colorectal cancer.
35. The method of claim 15 , wherein the solid cancer is a pancreatic cancer.