Applications of proteomic methods for CHO host cell protein characterization in biopharmaceutical manufacturing

Chinese hamster ovary (CHO) cells are the most prevalent host organism for production of recombinant therapeutic proteins, including monoclonal antibodies (mAbs). Regulatory guidance mandates control of the host cell protein (HCP) concentration in the production process, which remains a primary challenge. Although HCP concentrations are typically measured by ELISA, orthogonal proteomic methods are gaining popularity for identification and quantitation of individual HCP species. Recent applications of proteomic techniques to characterize extracellular CHO HCPs include those that have explored the effects of upstream factors (cell line, viability, process conditions), characterized specific HCPs likely to co-purify by mAb interactions, identified HCPs likely to impact drug product quality, and enabled strategies to limit HCP expression (media composition, temperature shift, genetic modification) and maximize clearance (polishing chromatography, wash additives).