Regulated expression of human interferon beta 1 gene after transduction into cultured mouse and rabbit cells

The human interferon beta 1 gene has been inserted into simian virus 40 hybrid plasmid vectors carrying the bacterial phosphotransferase gene (neo), and introduced into cultured mammalian cells by DNA transfection. A majority of the transformants resistant to the antibiotic G418 were capable of synthesizing and secreting biologically active human interferon. The neo/interferon transformants contain several copies of the transfecting DNA integrated into cellular DNA sequences. In most transformants the production of human interferon and its mRNA is induced by the addition of poly(rI) X poly(rC); by contrast, the level of neo mRNA is not increased under the same conditions. The 5' end of the human interferon mRNA produced after induction was indistinguishable from the interferon mRNA induced in human fibroblasts. This indicates that information enabling human beta 1 interferon gene to be induced by poly(rI) X poly(rC) is localized to sequences within, or 5'-proximal to, the coding sequence.