Background: Recombinant monoclonal antibodies have emerged as the most successful modality of biotherapeutics. They are primarily expressed in Chinese Hamster Ovary (CHO) cells. It is well known that post-translational modifications (PTM) contribute significantly to heterogeneity with respect to charge, glycosylation, and size. These attributes in turn may impact stability, pharmacokinetics, and pharmacodynamics of the biotherapeutic product. Cell culture media components are known to significantly contribute to both cellular productivity as well as post-translational modifications. In recent times, chemically defined (CD) media are replacing complex undefined media so as to improve consistency in process performance and product quality. Thus, it is highly desirable to understand how media components affect product quality. Method and Results: This study aims to explore the impact of vitamins and metal ions on protein expression and post-translational modifications specifically charge heterogeneity. Biotin, choline chloride, D-calcium pantothenate, folic acid, pyridoxine hydrochloride, thiamine hydrochloride vitamins and Fe, Cu, Mg, Co, Zn, Mn, Ni metal ions were examined in this study. The results indicate that pyridoxine enhances productivity while Zn, Cu, Fe, Mn, and biotin impact charge heterogeneity. While, Fe, Mn and Ni enhance production of the acidic variants Cu and biotin inhibit it. Zn reduces formation of basic variants while biotin enhances them. Conclusion: The results from this investigation could be used for process control so as to get consistent charge variant profile, in particular for biosimilar products.

Effect of vitamins and metal ions on productivity and charge heterogeneity of IgG1 expressed in CHO cells

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.