Methods of decreasing the galactose content of a recombinant glycoprotein expressed in CHO cells
In accordance with the present invention, CHO cells expressing a recombinant polypeptide of interest are grown in media where the amino acids, vitamins, phosphate, lipids and/or antioxidant optimization is utilized to manipulate and/or control the protein quality attributes of the polypeptides. Polypeptides expressed in accordance with the present invention may be advantageously used in the preparation of pharmaceutical compositions.
1. A method of decreasing galactose content of a recombinant glycoprotein comprising:
culturing a Chinese Hamster Ovary (CHO) host cell in a suitable cell culture medium, wherein the CHO host cell comprises an expression vector encoding a glycoprotein;
adding at least about 2 g/L asparagine and less than about 0.01 mg/L zinc to the cell culture medium,
wherein the cell culture medium is maintained under following conditions:
a) pH between 6.5-7.5;
b) dissolved oxygen between 5% and 90% of air saturation;
c) carbon dioxide between 10 mmHg and 150 mmHg; and
d) temperature between 30° C. and 37° C.; and
wherein the galactose content of the expressed glycoprotein is decreased.
2. The method of claim 1 , wherein the cell culture medium is chemically defined.
3. The method of claim 2 , wherein the chemically defined cell culture medium is basal medium.
4. The method of claim 3 , wherein the chemically defined basal medium does not contain added serum or hydrolysates.
5. The method of claim 3 , wherein the chemically defined basal medium is protein-free.
6. The process according to claim 1 , wherein the glycoprotein is a recombinant antibody, antibody fragment or fusion protein.