Human IgG Fc Production Through Methanol-Free Pichia pastoris Fermentation

By Ying Yang, Knut Madden, and Ma Sha
Volume 21, Open Access (November 2022)


Nowadays, therapeutic monoclonal antibodies (mAbs) are predominantly produced with mammalian cell culture systems such as those using Chinese hamster ovary (CHO) cells. Efforts are underway to reduce the costs of this process to meet the increasing global demand in biopharmaceuticals; meanwhile, cheaper and faster expression systems are being investigated as alternatives. The yeast, Pichia pastoris, has become a substantial workhorse for recombinant protein production. However, the N-linked glycosylation in P. pastoris, namely high mannose glycosylation, is significantly different from that in CHO or other mammalian cells, including human cells. In this study, a SuperMan5 strain of P. pastoris was constructed using Pichia GlycoSwitch¬ģ technology to successfully produce a more mammalian-like immunoglobulin¬†G (IgG) fragment crystallizable (Fc), which showcases the potential of P. pastoris as a next-generation mAb production platform. Importantly, in this study, a strong methanol-independent promoter, PUPP, was applied, which only requires glycerol feeding for protein production. Most P. pastoris promoters used for protein expression are derived from genes in the methanol metabolism pathway, creating safety concerns due to the flammable nature of methanol, especially at large scale. Here, a fed-batch SuperMan5 P. pastoris fermentation was carried out in which methanol induction, as well as its affiliated safety risks, were eliminated. Overall, this study provides insights into the development of safe and cost-effective industrial mAb production approaches independent of mammalian cell culture.

Citation:
Yang Y, Madden K, Sha M. Human IgG Fc production through methanol-free Pichia pastoris fermentation. BioProcess J, 2022; 21.
https://doi.org/10.12665/J21OA.Yang

Posted online November 21, 2022.