Prolonged autophagy induction correlates with host cell protein reduction in CHO cell culture

Autophagy, a cellular recycling process regulated by the CLEAR signaling pathway, plays a pivotal role in maintaining cellular homeostasis. We hypothesize that this process may regulate and reduce high-risk host cell proteins (HCPs) levels by targeting intracellular proteins and organelles for degradation. This study investigates the relationship between autophagy induction and the reduction of HCPs, including polysorbate-degrading enzymes (PSDEs), to enhance the stability of therapeutic biologics such as monoclonal antibodies (mAbs). Using clonal analysis, we identified upregulation of the CLEAR pathway in one clone, correlating with a significant reduction in lipase activity and PSDE abundance. Furthermore, autophagy modulators, such as 3-methyladenine (3-MA), selectively decreased PSDE levels in both glucose-supplemented batch culture and fed-batch cultures. This resulted in a 62% reduction in lipase activity that corresponded to a 22% improvement in polysorbate-80 stability. Additionally, 3-MA treatment increased mAb specific productivity and altered glycosylation profiles, increasing afucosylation and galactosylation levels. These findings highlight autophagy induction as a promising strategy to modulate product quality profiles and reduce high-risk HCPs in biologics production.