(75c) Investigation of Process Parameters and Their Effect On Cell Metabolism and N-Linked Glycosylation

The efficacy of monoclonal antibodies arises from their specificity to the target antigen and their ability to trigger immune responses by activating effector functions. This is critically dependent on appropriate posttranslational modification of the antibodies, e.g. glycosylation. It has been shown that glycosylation can dramatically influence the efficacy of mAbs by either reducing the serum half-life or by altering the triggered effector mechanism.

In this study we systematically investigate operating conditions in bioreactor systems (pH, osmolarity, dissolved gases, hydrodynamic forces) in a range that covers the heterogeneous conditions observed in large-scale reactors. By performing parameter shifting experiments we investigated the effect of those external variables on cell metabolism and the glycosylation profile of the mAb. Our goal is to further understand the intracellular trigger of such alternations in order to be able to predict metabolic switches during cultivation as well as changes in product quality. In particular, we observe altered lactate and amino acid metabolism induced by process operating conditions. To further understand the effect of external factors on product quality we investigate the glycosylation profile of our model antibody at various cultivation conditions. Especially for pH and osmolarity changes, an influence on glycosylation towards less sialylated forms could be observed.

Finally, the knowledge gained will be used to develop a multi-scale model that is able to describe the effect of operating parameters on metabolism and glycosylation. On the way to targeted glycosylation such a model will help to better understand the connection of product quality attributes to process parameters.