Modified antigen-binding of human antibodies with glycosylation variations of the light chains produced in sugar-limited human hybridoma cultures.

We have characterized the effects of serum and N-acetylglucosamine in a glucose-deprived condition on the glycosylation of antibody light chains, as well as the resulting biological properties of those antibodies. We have chosen for our investigation the human hybridoma lines producing monoclonal antibodies reactive to lung adenocarcinoma. Each antibody possess a N-glycosylated carbohydrate chain in the hypervariable region of the light chains. When the cell lines were grown in the absence of glucose, variant light chains with varying molecular masses were found to be secreted. Analysis of these light chains produced in a glucose-deprived condition revealed that the changed molecular-mass of the variant light chains is due to different glycosylation. Addition of N-acetylglucosamine or fetal calf serum to the glucose-free medium led to the creation of other light chains that exhibit increased antigen binding activity.