title: Characterization and fed-batch culture of hybridoma overexpressing apoptosis suppressing gene bcl-2.
abstract: Mouse hybridoma 2E3 transfected with human bcl-2 gene survived longer with increasing expression level of bcl-2 when cultured in DME medium supplemented with 9% serum. One of the transfectants, 2E3BCMGbcl-2, overexpressed bcl-2 and could maintain viable cell density higher than the initial density for more than four days at a low 0.5% serum concentration. In comparison a mock transfectant 2E3BCMG remained viable for only one day. However, both hybridomas died out within a day in serum-free medium. These results suggested that bcl-2 needed a small amount of some serum components to suppress apoptosis of the hybridoma. Overexpression of bcl-2 also suppressed apoptosis of the hybridoma induced by glutamine deprivation. When hybridoma 2E3BCMGbcl-2 was inoculated in DME medium supplemented with 9% serum and cultured for 10 d with additional 2% serum feed at day 4 of the culture, viable cell density increased 2-fold and antibody produced 3-fold, in comparison with mock transfected 2E3 cultured in the same manner. The mock transfectant with additional feed of serum at day 4 of the culture showed no difference in viable cell density and antibody production. These results suggested that the mock transfectant committed to apoptosis before day 4 of the culture and the additional serum at day 4 could not reverse the commitment.
authors.affiliation: Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, Hongo, Bunkyoku, Tokyo, 113, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Terada
authors.forename: Y
authors.initials: Y
authors.lastname: Itoh
authors.forename: H
authors.initials: H
authors.lastname: Ueda
authors.forename: E
authors.initials: E
authors.lastname: Suzuki