(52e) Effect of Media Supplements on the Glycosylation Profile in MAbs
Monoclonal antibodies (MAbs), a commercially important class of biopharmaceuticals used as therapeutics for a variety of conditions including psoriasis and cancer, are typically expressed in mammalian cell lines such as Chinese Hamster Ovary (CHO) cells. These mammalian host cell lines ensure proper post-translational modifications in the MAb being expressed, thus generating appropriate human-like protein structures. One such post-translational modification which results in structural and pharmacological changes in the antibody is glycosylation – an enzymatic, non-template driven addition of a sugar moiety (glycan) to the protein backbone, followed by subsequent modification within the cell. Of particular interest is N-linked glycosylation, a post-translational modification, involving the addition of the glycan to an Asn-X-Ser/Thr sequon in the MAb. The modification of this glycan by the different glycosyltransferase enzymes in the cell results in a heterogeneous distribution of glycans attached to the MAb. The heterogeneity in the glycosylation profile of the MAb influences its immunogenicity, in vivohalf-life and efficacy, thus affecting the final drug product quality. Therefore to maintain product quality and a consistent glycosylation profile for the MAb, it is important to identify factors that can influence glycosylation and subsequently design effective control strategies using these factors.
Recent studies have attempted to identify different media components and media supplements that affect the glycosylation profile, specifically noting that the addition of MnCl2 can alter mannosylated and fucosylated species. However, these studies have not examined the effect of dynamic supplementation of MnCl2. Furthermore, the effect of introducing a chelating agent in media supplemented with MnCl2 and the subsequent effects on the glycosylation profile have not been characterized systematically. In this presentation, we discuss results from a design of experiments (DOE) study highlighting the changes in the glycosylation profile effected by supplementing the media with MnCl2 and a chelating agent at different points during cell growth. Our experiments demonstrate that introducing trace media supplements at different time points can influence the glycosylation profile in MAbs and that a rational approach to media supplementation can be used to attain a desired glycosylation profile.