Modulation of Antigen Bunding of Human Antibody Via Glycosylation by Hybridoma Culture with Various Carbon Sources

Abstract

The human hybridoma HB4C5 produces a lung adenocarcinoma reactive antibody (mAbC5) which possesses an unique N-linkedcarbohydrateon its light chain. We intended to design the culture environment in which the varied glycoforms on the light chain induce the alterd antigen binding affinity. HB4C5 cells were cultured in medium containing diverse carbohydrates such as monosaccharides, oligosaccharidesandpolysaccharides. Antigen bindingability ofmAbC5 significantly varied depending upon carbon sources. In particular, addition of N-acetylglucosamineandchitosan to medium led to the creation of a certain light chain glycoforms that exhibit increased antigen binding. To clarify the mechanism of carbohydratesaugement on mAbC5 light chain, the expression level of a glycogenesis-related enzyme was examined by using specific antibody. The expession level ofgalactosidasevaried depencding upon carbon sources, suggesting that the enzyme activity can be regulated by carbon sources.