Cell culture medium

Abstract

The present application describes an optimized medium for growth of mammalian cells as well as polypeptide production. The cell culture medium is characterized by a Sow ratio of sodium to potassium ions, it further relates to the method of producing polypeptides using such cell culture media. Sn another aspect, the method of polypeptide production can also comprise a temperature shift and/or a pH-shift to further optimize growth and product yield.

The invention claimed is: 
     
       1. A serum-free and protein-free cell culture medium for expressing recombinant polypeptides from Chinese Hamster Ovary, Human Embryonic Kidney or SP2/0 myeloma cells having a molar ratio of sodium to potassium ions of between 8 to 1 and 6 to 1, and wherein the sodium ions have a concentration of between 50 and 90 mM. 
     
     
       2. The cell culture medium of  claim 1  wherein the potassium ions have a concentration of between 8 and 12 mM. 
     
     
       3. The cell culture medium of  claim 1  comprising a total amino acid concentration between 40 and 100 mM. 
     
     
       4. The cell culture medium of  claim 3  wherein the molar ratio between the total ion concentration to the total amino acid concentration is between 1.9 and 4. 
     
     
       5. A process for the production of a recombinant polypeptide comprising culturing mammalian cells comprising a recombinant nucleic acid encoding the recombinant polypeptide in the medium of  claim 1  and expressing the recombinant polypeptide, wherein the mammalian cells are selected from the group consisting of Chinese Hamster Ovary (CHO) cells, Human Embryonic Kidney (HEK) cells, and SP2/0 cells. 
     
     
       6. The process according to  claim 5  wherein culturing conditions comprise at least one temperature shift and/or at least one pH shift. 
     
     
       7. The process according to  claim 5 , wherein culturing is done by a fed batch process. 
     
     
       8. The process according to  claim 5  wherein the expressed recombinant polypeptide is glycosylated. 
     
     
       9. The process according to  claim 5 , wherein the expressed polypeptide is an antibody or antibody fragment. 
     
     
       10. A process for the production of a cell culture medium according to  claim 1  wherein the medium's components are admixed with each other. 
     
     
       11. The process according to  claim 10  wherein sodium chloride is added at a concentration between 7 and 15 mM. 
     
     
       12. The process according to  claim 10  wherein potassium chloride is added at a concentration between 8 and 12 mM. 
     
     
       13. A serum-free and protein-free cell culture medium for expressing recombinant polypeptides from Chinese Hamster Ovary, Human Embryonic Kidney or SP2/0 myeloma cells having a molar ratio of sodium to potassium ions of between 9 to 1 and 5 to 1.  
     
     
       14. A serum-free and protein-free cell culture medium for expressing recombinant polypeptides from Chinese Hamster Ovary, Human Embryonic Kidney or SP2/0 myeloma cells, having sodium ions at a concentration of between 50 and 90 mM and potassium ions at a concentration of between 8 and 12 mM.  
     
     
       15. The cell culture medium of claim 13, wherein the sodium ions have a concentration of between 50 and 90 mM.  
     
     
       16. The cell culture medium of claim 13 or 14, wherein the sodium ions have a concentration of between 65 and 85 mM.  
     
     
       17. The cell culture medium of claim 13, wherein the potassium ions have a concentration of between 8 and 12 mM.  
     
     
       18. The cell culture medium of claim 14, wherein the molar ratio of sodium to potassium ions is between 9 to 1 and 5 to 1.  
     
     
       19. The cell culture medium of claim 13 or 14 comprising a total amino acid concentration between 40 and 100 mM.  
     
     
       20. The cell culture medium of claim 13 or 14, wherein the molar ratio between the total ion concentration to the total amino acid concentration is between 1.9 and 4.  
     
     
       21. A process for the production of a recombinant polypeptide comprising culturing mammalian cells comprising a recombinant nucleic acid encoding the recombinant polypeptide in the medium of claim 13 or 14 and expressing the recombinant polypeptide, wherein the mammalian cells are selected from the group consisting of Chinese Hamster Ovary (CHO) cells, Human Embryonic Kidney (HEK) cells, and SP2/0 cells.  
     
     
       22. A process for the production of a recombinant polypeptide comprising:
 (a) culturing mammalian cells comprising a recombinant nucleic acid encoding the recombinant polypeptide in a serum-free and protein-free cell culture medium having a molar ratio of sodium to potassium ions of between 9 to 1 and 5 to 1; and   (b) expressing the recombinant polypeptide,   
       wherein the mammalian cells are selected from the group consisting of Chinese Hamster Ovary (CHO) cells, Human Embryonic Kidney (HEK) cells, and SP2/0 cells.  
     
     
       23. A process for the production of a recombinant polypeptide comprising:
 (a) culturing mammalian cells comprising a recombinant nucleic acid encoding the recombinant polypeptide in a serum-free and protein-free cell culture medium having sodium ions at a concentration of between 50 and 90 mM and potassium ions at a concentration of between 8 and 12 mM; and   (b) expressing the recombinant polypeptide,   
       wherein the mammalian cells are selected from the group consisting of Chinese Hamster Ovary (CHO) cells, Human Embryonic Kidney (HEK) cells, and SP2/0 cells.  
     
     
       24. The process of claim 22, wherein the sodium ions have a concentration of between 50 and 90 mM.  
     
     
       25. The process of claim 22 or 23, wherein the sodium ions have a concentration of between 65 and 85 mM.  
     
     
       26. The process of claim 22, wherein the potassium ions have a concentration of between 8 and 12 mM.  
     
     
       27. The process of claim 23, wherein the molar ratio of sodium to potassium ions is between 9 to 1 and 5 to 1.  
     
     
       28. The process of claim 22 or 23, wherein the cultivation of the cells is carried out in adherent culture.  
     
     
       29. The process of claim 22 or 23, wherein the cultivation of the cells is carried out in suspension culture.  
     
     
       30. The process according to claim 22 or 23, wherein culturing conditions comprise at least one temperature shift and/or at least one pH shift.  
     
     
       31. The process according to claim 22 or 23 wherein culturing is done by a fed batch process.  
     
     
       32. The process according to claim 22 or 23, wherein the expressed recombinant polypeptide is glycosylated.  
     
     
       33. The process according to claim 22 or 23, wherein the expressed polypeptide is an antibody or antibody fragment.  
     
     
       34. A process for the production of a cell culture medium according to claim 13 or 14, wherein the medium's components are admixed with each other.  
     
     
       35. The process according to claim 22 or 23, wherein sodium chloride is added at a concentration of between 7 and 15 mM.  
     
     
       36. The process according to claim 22, wherein the sodium ions are added at a concentration of between 50 and 90 mM.  
     
     
       37. The process according to claim 22, wherein the potassium ions are added at a concentration of between 8 and 12 mM.  
     
     
       38. The process according to claim 22 or 23, wherein the cell culture medium comprises a total amino acid concentration between 40 and 100 mM.  
     
     
       39. The process according to claim 22 or 23, wherein the molar ratio between the total ion concentration to the total amino acid concentration is between 1.9 and 4.