RECOMBINANT BIFUNCTIONAL MOLECULE FV IFN-GAMMA POSSESSES THE ANTITUMOR FV AS WELL AS THE GAMMA-INTERFERON ACTIVITIES/

Recombinant DNA techniques were used to clone, construct and express t he bifunctional molecule FV/IFN-gamma. The FV/IFN-gamma is a single-ch ain 42KD fusion protein expressed in E. coli under control of the stro ng T7 bacteriophage promoter in the expression vector pT7-7-FV-IFN-gam ma. The fused gene fragment FV-IFN-gamma containing a single-chain ant i-TAG72 FV gene fragment as well as the human recombinant cDNA fragmen t of IFN-gamma molecule. The renatured soluble form of FV/IFN-gamma wa s purified from E. coli inclusion bodies using HTPT chromatography. Th e yield of this fusion protein was estimated at 10mg/L. Our data showe d that the FV/IFN-gamma molecule retained the TAG72 antigen-binding sp ecificity and the IFN-gamma activity as measured in ELISA, Western blo tting and up-regulation of CEA expression by IFN-gamma. Therefore, it may prove to be useful in targeting the biological effect of IFN-gamma to tumor cells and stimulating its immune destruction.