Differential affects of low glucose on the macroheterogeneity and microheterogeneity of glycosylation in CHO-EG2 camelid monoclonal antibodies

Background The demand for high yield recombinant protein production systems has focused industry on culture media and feed strategies that optimize productivity, yet maintain product quality attributes such as glycosylation. Minimizing media components such as glucose, reduces the production of lactate, but may also affect glycosylation. The first steps in the glycosylation pathway involve the synthesis of lipid-linked oligosaccharides (LLOs). Glycan macroheterogeneity is introduced by variation in site-specific glycosylation with the transfer of the oligosaccharide to the protein. Further modification of the oligosaccharide can occur through processing reactions, where some sugars are removed and additional sugars added. This produces microheterogeneity of the glycan pool. Both macroheterogeneity and microheterogeneity may be affected by fermentation conditions. The objective of this study has been to investigate the effect of variable concentrations of glucose on the glycosylation patterns of a camelid monoclonal antibody produced in Chinese hamster ovary (CHO) cells and to further evaluate their effect on components of the N-glycosylation pathway.