Metabolic compartmentalization in 13C metabolic flux analysis of Chinese hamster ovary cells

Abstract

Chinese hamster ovary cells is currently a prime focus in mAb production, comprising over 70% of the total approved biologics. The coming patent expiration of blockbuster drugs triggers new market competition for alternative biosimilars. These alternatives create price competition, hence, biosimilar development has been driven by the need to reduce the manufacturing cost. Reducing the manufacturing cost could be achieved by the optimization of the cell lines or cell culture media. For this purpose, OMICS plays an important role, especially to understand cellular metabolism. OMICS technologies provide insights into the cellular capabilities (blueprint) to the actual activities (metabolome/fluxome). This thesis utilized flux analysis to study the metabolism of CHO cells, especially with the use of Carbon-13 (13C Metabolic Flux Analysis). The combination of isotopic non-stationary 13C MFA, compartmented metabolic model, and the sub-cellular metabolome profile allow the quantification of the in vivo mitochondrial shuttles and identification of the sub-cellular fluxes (e.g. isoenzymes). The latter was identified as the bottleneck for improving IgG1 production.