Improvement in the proliferative activity of human-human hybridomas at low cell density by transfection with bFGF gene.
Highly purified recombinant basic fibroblast growth factor (rbFGF) and acidic FGF (aFGF) stimulated the proliferation of human-human (h-h) hybridomas to the extent of over four-fold from a low cell density such as 1 x 10(3) cells per ml in a serum-free medium in 24-well plates. The stimulatory effect of rbFGF was also observed in various lymphoid cell lines. Expecting that FGF could be an autocrine growth factor, we introduced bFGF gene into a h-h hybridoma using an expression plasmid induced by dexamethasone. The transformed cells thus obtained, HPO-75.11 bFGF-7, were able to grow well from a low inoculum density in a serum-free medium and antibody production was also increased when bFGF gene expression was induced. The transformed cells could grow at clonal density in a serum-free medium in 96-well plates, though the original cells could not. We also obtained a more practical transfectant, HPO-75.29-H74, using a high-shear stress adapted clone as the recipient and an expression plasmid having bFGF gene under the control of metallothionein-I promoter. The HPO-75.29-H74 cells were capable of growing and producing human monoclonal antibody against hepatitis B virus surface antigen from an inoculum density of 1 x 10(3) cells per ml in an agitation vessel without addition of an inducer.
Iwamoto
K
K
Microbiology Research Laboratories, Takeda Chemical Industries, Ltd., Osaka, Japan.
Shintani
Y
Y
Sawada
H
H
Kitano
K
K
D000818:Animals; D015139:Blotting, Southern; D002417:Cattle; D002452:Cell Count; D002455:Cell Division; D003907:Dexamethasone / Q000494:pharmacology; D016222:Fibroblast Growth Factor 2 / Q000235:genetics*; D006801:Humans; D006825:Hybridomas / Q000166:cytology*; D008668:Metallothionein / Q000235:genetics; D011401:Promoter Regions, Genetic; D014162:Transfection
D016222:Fibroblast Growth Factor 2; D003907:Dexamethasone; D008668:Metallothionein