Fusagene vectors: a novel strategy for the expression of multiple genes from a single cistron

Transduction of cells with multiple genes, allowing their stable and co-ord inated expression, is difficult with the available methodologies. A method has been developed for expression of multiple gene products, as fusion prot eins, from a single cistron. The encoded proteins are post-synthetically cl eaved and processed into each of their constituent proteins as individual, biologically active factors. Specifically, linkers encoding cleavage sites for the Golgi expressed endoprotease, furin, have been incorporated between in-frame cDNA sequences encoding different secreted or membrane bound prot eins. With this strategy we have developed expression vectors encoding mult iple proteins (IL-2 and B7.1, IL-4 and B7.1 , IL-4 and IL-2, IL-12 p40 and p35, and IL-12 p40, p35 and IL-2). Transduction and analysis of over 100 in dividual clones, derived from murine and human tumour cell lines, demonstra te the efficient expression and biological activity of each of the encoded proteins. Fusagene Vectors enable the co-ordinated expression of multiple g ene products from a single, monocistronic, expression cassette.