Abstract: A recombinant DNA expression vector comprising an Epstein-Barr virus origin of replication, an EBNA-1 gene, a selectable marker expression cassette and a human gamma interferon expression cassette comprising a promoter region, an open reading frame encoding human gamma interferon and a polyadenylation region; a mammalian host cell transformed by said vector; and a process for producing human gamma interferon using said transformed mammalian host cell.

Abstract: A novel method and composition are provided for the replication and expression of exogenous genes in eukaryotic cells. A segment of a papilloma virus genome capable of extrachromosomal replication is linked to the foreign gene(s) using recombinant DNA techniques to provide a biologically functional replicon with a desired phenotypical property. The replicon is inserted into a eukaryotic cell by transformation, and the isolation of transformant provides cells for replication and expression of the DNA molecules present in the modified plasmid. The transforming region of the bovine papilloma virus provides a unique vector in that it provides both the capability of autonomous extrachromosomal replication but also the malignant transformed phenotype. Thus, genes which of themselves provide no selectable phenotypical property can be conveniently and efficiently introduced into eukaryotic cells and the transformants selected.