Improvement of growth rates through nucleoside media supplementation of CHO clones

Abstract

Chinese Hamster Ovary (CHO) cells are used for the production of therapeutic proteins. This work examines improving passaging growth rate of two CHO clones. Growth rates were significantly improved for both clones with supplementation of the nucleosides cytidine, hypoxanthine, uridine, and thymidine to the culturing media at the optimal concentration of 100 lM of each nucleoside. We investigated supplementing the same combination of nucleosides to seed bioreactors and production fed batch bioreactors. In the seed bioreactors, growth rate and harvest density were improved. However, in the production fed batch bioreactors, no improvements in growth rate or peak viable cell density were observed. Cell cycle analysis of the passaging cells provides evidence that nucleosides can affect the cell cycle. It is not clear from our work how the nucleosides impact the cell cycle regulatory pathways. Overall, nucleoside supplementation in cell culture media is an effective approach for improving growth rate in passaging and seed bioreactors of certain CHO cells.

Serum-Free Medium for Recombinant Protein Expression in Chinese Hamster Ovary Cells

“…However, for cells whose de novo synthesis pathway is blocked, such as dihydrofolate reductase-deficient cells, it is necessary to add substrates for the remedial pathway, namely hypoxanthine and thymidine ( Carvalhal et al, 2003 ). The addition of 1 mmol/L adenine (or 1 mmol/L guanine) can severely inhibit the growth of CHO cells, and 5 mmol/L uracil (or 10 mmol/L cytosine) does not affect the growth of CHO cells ( Wong et al, 2010 ; Morrison et al, 2019 ). The different effects of nucleic acids on cell growth may be attributed to the different cell lines and culture processes used.…”

“…The addition of 1 mmol/L adenine (or 1 mmol/L guanine) can severely inhibit the growth of CHO cells, and 5 mmol/L uracil (or 10 mmol/L cytosine) does not affect the growth of CHO cells (Wong et al, 2010;Morrison et al, 2019). The different effects of nucleic acids on cell growth may be attributed to the different cell lines and culture processes used.…”