An investigation of nucleotide sugar dynamics under the galactose supplementation in CHO cell culture

Abstract

Abstract Monoclonal antibodies (mAbs) produced by Chinese hamster ovary (CHO) cells commonly generate bi-antennary N-linked glycan that is attached with none to one galactose at each antenna. This process is called galactosylation and is dependent on cell lines and cell culture processes. Intracellular uridine diphosphate galactose (UDP-Gal) is the galactosylation precursor and its abundance is modulated by cell culture feeds. This can be a possible strategy to control glycoform profiles on mAbs. However, the kinetic regulation and its rates of nucleotide sugars in cell cultures and under culture feeds is largely unknown. This study investigated the dynamic profiles of nucleotide sugars and glycoforms in batch and galactose-fed cultures. The results reveal the dynamic rate of UDP-Gal production from galactose feed(s) while showing the perturbation of nucleotide sugar metabolism by cellular physiology and feed designs. A positive correlation was noted between the accumulative UDP-Gal and the galactose increase on mAbs over the course of cell culture. Glucose was also compared with galactose as a feed to understand the different impacts amongst the isoform sugars. The study provides a dynamic linkage that was previously missing between culture supplementation, intracellular nucleotide sugars and N-linked glycan.