Constitutive production of human interferons by mouse cells with bovine papillomavirus as a vector.
Mouse C127I cells were transformed with a chimeric plasmid consisting of bovine papillomavirus and human interferon (HuIFN) gene (either IFN-gamma or IFN-alpha 5) placed under the control of simian virus 40 early promoter. The transformed cells retained 30-50 copies each of the hybrid plasmid extrachromosomally and secreted a high level of HuIFNs constitutively up to 3-4 X 10(5) international units/ml. The secreted HuIFN-gamma had no detectable activity on mouse cells, whereas HuIFN-alpha 5 was slightly active on mouse cells. Each IFN was neutralized either by anti-HuIFN-gamma or anti-HuIFN-alpha antiserum. The partially purified 35S-labeled HuIFN-gamma produced by the transformed cells showed heterogeneous bands with apparent Mrs of 22,000-25,000 on NaDodSO4/polyacrylamide gel electrophoresis. This value is similar to that of natural IFN-gamma and larger than the molecular weight calculated from the amino acid sequence, which suggests that HuIFN-gamma secreted by transformed mouse cells was glycosylated. The 35S-labeled IFN-alpha 5, immunoprecipitated with anti-HuIFN-alpha antiserum from the supernatant of the transformed cells, had a molecular weight of mature protein. These results suggest that the bovine papillomavirus vector can be used to produce a large quantity of foreign proteins in mammalian cells.
D000818:Animals; D052688:Bovine papillomavirus 1 / Q000235:genetics*; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D006801:Humans; D007370:Interferon Type I / Q000235:genetics* / Q000302:isolation & purification; D007371:Interferon-gamma / Q000235:genetics* / Q000302:isolation & purification; D007700:Kinetics; D051379:Mice; D008970:Molecular Weight; D009693:Nucleic Acid Hybridization; D027383:Papillomaviridae / Q000235:genetics*; D010957:Plasmids; D013539:Simian virus 40 / Q000235:genetics
D007370:Interferon Type I; D007371:Interferon-gamma