(367f) Glycosylation: Trace Metals and Design for Robustness

Glycosylation profile may affect the efficacy of therapeutic monoclonal antibodies, and is impacted by macro and micro nutrient levels. Trace metals are known to be cofactors of glycosylation enzymes as well as inhibitors. Variability in trace metal concentrations can thus impact glycoform consistency. This may result either from a metabolic effect causing changed availability of intracellular nucleotide-sugars or a more direct effect on enzyme activity. Knowledge of these effects and their probable cause will help design robust processes targeting a specific glycoform.

In this work, we have evaluated the impact of change in concentration of several trace metals on glycosylation of IgG in CHO cells to identify trace elements which affect glycosylation in a dose dependent manner. Medium supplementation strategies are used to understand the probable causes of the observed effects. A mathematical model is used to help evaluate the hypotheses. Based on these, a medium formulation strategy to reduce the effect of variability in the concentration of such trace elements on the glycoform of recombinant IgG will be discussed. Tools developed in our group to facilitate evaluation of some feeding strategies will be discussed.