Differential polyamine metabolism in CHO cell lines: Insights into cell growth and antibody quality

Chinese hamster ovary (CHO) cell lines are widely utilized host cell lines in cell culture bioprocessing. Although they originated from a common ancestor, accumulated genetic mutations have led to significant heterogeneity in their behavior under specific conditions. This study investigates the cell line-specific impact of polyamine (PUT; putrescine) withdrawal on the growth, metabolism, and antibody production among three CHO clones derived from different parental cell lines: CHO-K1, CHO-S, and CHO-DG44. CHO-K1 cells strongly depended on external polyamines, showing a 77 % reduction in viable cell density and an 88 % decrease in growth rate under PUT depletion, although their culture longevity was extended. In contrast, CHO-S and CHO-DG44 cells demonstrated greater resilience, with CHO-DG44 experiencing only a 25 % reduction in cell density. PUT deprivation also impacted antibody production across all cell lines, with CHO-K1 displaying the lowest yield, antibody purity and altered charge heterogeneity. Notably, PUT depletion led to increased galactosylation of antibodies, suggesting that modulating PUT levels in the media could be used as a strategy to tailor the quality of therapeutic antibodies. These findings, together, provide valuable insights in the design of cell line-specific media, thereby optimizing both bioprocess efficiency and product quality in biopharmaceutical production.