Anti-apoptotic CHO dhfr(-) host cell line

Abstract

Chinese Hamster Ovary (CHO) dhfr(-) cell line overexpressing anti-apoptotic protein Bcl-2, CHO dhfr(-) Bcl2. was developed for the establishment of recombinant CHO cells producing humanized antibody. CHO dhfr(-) Bcl2 stably overexpressed Bcl-2 protein without selection pressure and exhibited delay of apoptotic cell death in serum-free suspension culture. Established recombinant cell lines producing humanized antibody using CHO dhfr(-) Bcl2, CHO Bcl2-19-008 and CHO Bcl2-24-008, exhibited extended culture longevity in batch culture of serum-free suspension than control cell lines, CHO neo-04-008 and CHO neo-24-008. In stressful condition induced by 5mM NaBu addition, final MAb titers of CHO Bcl2-19-008 and CHO Bcl2-24-008 increased to $50㎍/mL^{-1}$, $11 ㎍/mL^{-1}$, which were five fold, three fold of final MAb titers in serum-free suspension culture, respectively. Compared with cell lines developed from CHO dhfr(-) Bcl2, CHO neo-04-008 and CHO neo-24-008 showed no significant increase of final MAb titer because rapid decline fo cell viablility after NaBa addition