PROCESS FOR PRODUCING POLYPEPTIDE

• US 20090203078A1
• Filed: 02/02/2009
• Published: 08/13/2009
• Est. Priority Date: 10/19/1999
• Status: Active Grant

• Current Assignee: Kyowa Kirin Co., Ltd. (Kirin Holdings Company Limited)
• Original Assignee: Kyowa Hakko Kogyo Company Limited (Kirin Holdings Company Limited)
• Inventors: Takasugi, Hiroshi, OGAWA, Tatsuya, Konno, Yoshinobu, Akashi, Naohisa, Sugimoto, Seiji, Yano, Keiichi
• Granted Patent: US 8,945,867 B2
• Time in Patent Office: Days
• US Class Current: 435/69.600
• CPC Class Codes: C07K 16/00 Immunoglobulins [IGs], e.g. monoclonal or polyclonal antibodies antibodies with enzymatic activity, e.g. abzymes C12N9/0002

Abstract

The present invention relates to a process for producing a desired polypeptide using rat cells. Specifically, the present invention relates to a process for producing the polypeptide which comprises culturing rat cells such as YB2/3HL.P2.G11.16Ag.20 (hereinafter referred to as YB2/0), preferably rat cells to which a recombinant DNA comprising DNA encoding a desired polypeptide such as an immunologically functional molecule is introduced, in a medium which does not contain serum (hereinafter referred to as a serum-free medium). Among the desired polypeptides obtained by the process of the present invention, an antibody obtained by using a transformant of YB2/0 has a high antibody-dependent cell-mediated cytotoxic activity (hereinafter sometimes referred to as ADCC activity) and is useful as a pharmaceutical agent.

Claims

1. A process for producing a polypeptide which comprises culturing a rat cell line adapted to a medium which does not contain serum (hereinafter referred to as a serum-free medium) in a serum-free medium, and recovering the desired polypeptide from the culture.

2. The process according to claim 1, wherein the rat cell line adapted to a serum-free medium is a rat cell line which can be subcultured in a serum-free medium for two months or more.

3. The process according to claim 1, wherein the rat cell is a myeloma cell or a hybrid cell derived from a myeloma cell.

4. The process according to claim 1, wherein the rat cell is YB2/3HL.P2.G11.16Ag.20 (ATCC CRL 1662:

hereinafter referred to as YB2/0).

5. The process according to claim 1, wherein the cell is a cell to which a recombinant DNA comprising DNA encoding the desired polypeptide is introduced.

6. The process according to claim 1, wherein the culturing is carried out by batch culture, fed-batch culture or perfusion culture.

7. The process according to claim 1, comprising adding at least one member selected from the group consisting of a nutrient factor and a physiologically active substance to the medium during the culturing.

8. The process according to claim 7, wherein the nutrient factor is at least one member selected from the group consisting of glucose, an amino acid and a vitamin.

9. The process according to claim 7, wherein the physiologically active substance is at least one member selected from the group consisting of insulin, transferrin and albumin.

10. The process according to claim 1, wherein the desired polypeptide is an immunologically functional molecule.

11. The process according to claim 10, wherein the immunologically functional molecule is a protein or a peptide.

12. The process according to claim 11, wherein the protein or peptide is an antibody, an antibody fragment or a fusion protein comprising an antibody Fc region.

13. The process according to claim 12, wherein the antibody is an antibody recognizing a tumor-related antigen, an antibody recognizing an allergy- or inflammation-related antigen, an antibody recognizing a circulatory disease-related antigen, an antibody recognizing an autoimmune disease-related antigen, or an antibody recognizing a viral or bacterial infection-related antigen.

14. The process according to claim 13, wherein the antibody recognizing a tumor-related antigen is an anti-GD2 antibody, an anti-GD3 antibody, an anti-GM2 antibody, an anti-HER2 antibody, an anti-CD52 antibody, an anti-MAGE antibody, an anti-basic fibroblast growth factor antibody, an anti-basic fibroblast growth factor receptor antibody, an anti-FGF8 antibody, an anti-FGF8 receptor antibody, an anti-insulin-like growth factor antibody, an anti-PMSA antibody, an anti-vascular endothelial cell growth factor antibody, or an anti-vascular endothelial cell growth factor receptor antibody;

the antibody recognizing an allergy- or inflammation-related antigen is an anti-interleukin 6 antibody, an anti-interleukin 6 receptor antibody, an anti-interleukin 5 antibody, an anti-interleukin 5 receptor antibody, an anti-interleukin 4 antibody, an anti-interleukin 4 receptor antibody, an anti-tumor necrosis factor antibody, an anti-tumor necrosis factor receptor antibody, an anti-CCR4 antibody, an anti-chemokine antibody, or an anti-chemokine receptor antibody;

the antibody recognizing a circulatory disease related antigen is an anti-GpIIb/IIIa antibody, an anti-platelet-derived growth factor antibody, an anti-platelet-derived growth factor receptor antibody, or an anti-blood coagulation factor antibody;

the antibody recognizing an autoimmune disease-related antigen is an anti-auto-DNA antibody; and

the antibody recognizing a viral or bacterial infection-related antigen is an anti-gp120 antibody, an anti-CD4 antibody, an anti-CCR4 antibody, or an anti-verotoxin antibody.

15. The process according to claim 13, wherein the antibody is an anti-GD3 human chimeric antibody, a humanized anti-interleukin 5 receptor α

chain antibody, or an anti-GM2 human CDR-grafted antibody.

16. The process according to claim 1, wherein the rat cell is cultured while an insulin concentration in the culture kept is at 10 mg/l or above, followed by culturing while an insulin concentration in the culture is kept at 10 mg/l or below.

17. A process for adapting a rat cell to a serum-free medium, which comprises inoculating rat cells into a conditioned medium at a cell density of 1×

10⁵ to 1×

10⁶ cells/ml.

18. The process according to claim 17, wherein the rat cell is a myeloma cell or a hybrid cell derived from a myeloma cell.

19. The process according to claim 17, wherein the rat cell is YB2/0.

20. The process according to claim 17, wherein the cell carries an introduced recombinant DNA comprising DNA encoding the desired polypeptide.

21. A process for producing a rat cell line adapted to a serum-free medium, which comprises adapting rat cells to a serum-free medium by the process according to claim 17, and then cloning the cells.

22. A rat cell line adapted to a serum-free medium, which is obtained by the process according to claim 21.

23. The rat cell line adapted to a serum-free medium according to claim 22, wherein the rat cell line is a rat cell line which can be subcultured in a serum-free medium for two months or more.

24. A rat cell line adapted to a serum-free medium, 61-33γ

(FERM BP-7325).