Expression and excretion of human fibroblast beta 1 interferon in monkey cells after transfection with a recombinant SV40 plasmid vector.

We have constructed a eukaryotic expression vector designed to express a gene under late SV40 transcriptional control. From this chimeric plasmic-SV40 vector, virtually all the sequences which code for the major capsid protein VP1 have been deleted and instead, the human fibroblast interferon beta 1 cDNA gene has been inserted. After transfection of monkey cells with this recombinant, substantial quantities of human beta 1 interferon (up to 2 x 10(-4) IU/ml) were excreted in the culture medium. Transfection of nonpermissive mouse L cells or rat cells yielded virtually undetectable quantities of human beta 1 interferon (5 x 10(3) to 10(4) times less than that in monkey cells). The recombinant SV40 vector may serve as a model vehicle for the efficient expression of other eukaryotic genes and might also be used as a direct screening vector for cloning of eukaryotic or prokaryotic cDNA genes.