title: Building high affinity human antibodies by altering the glycosylation on the light chain variable region in N-acetylglucosamine-supplemented hybridoma cultures.
abstract: We attempted to improve antibody affinity by varying glycosylation on the light chain variable region. The human hybridoma line HB4C5 produces an antibody reactive to lung adenocarcinoma, which possess a N-glycosylated carbohydrate chain on the light chain hypervariable region. It has been shown that altering this carbohydrate structure can be accomplished by varying the level of N-acetylglucosamine in glucose free medium, a change in the carbohydrate chain could be induced which resulted in modifying antigen binding. By culturing the cells in media containing more than 20 mM N-acetylglucosamine, cells produced antibody with 10 fold improved affinity as compared with antibody produced in 20 mM glucose-containing medium. A newly induced light chain glycoform produced in the N-acetylglucosamine-containing medium was shown to be responsible for this antigen binding enhancement. Addition of glucose in the N-acetylglucosamine-containing media led to decreased antibody affinity and slightly inhibited production of a new light chain in a dose-dependent manner. Combination of 20 mM N-acetylglucosamine and 0.5 mM glucose gave a higher antibody production without the decrease of the antigen binding. These results indicate that optimization of N-glycosylation on the light chain, which leads to higher antigen binding, can be accomplished by adjusting a ratio of glucose and N-acetylglucosamine in the culture medium.
authors.affiliation: Graduate School of Genetic Resources Technology, Kyushu University, Hakozaki, Higashi-ku, Fukuoka, 812, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Tachibana
authors.forename: J Y
authors.initials: JY
authors.lastname: Kim
authors.forename: S
authors.initials: S
authors.lastname: Shirahata