Characterization of monoclonal antibodies to human interferon-gamma and their application to enzyme-linked immunosorbent assay (ELISA)

The authors obtained two mouse monoclonal antibodies, G-208 and G-166, to recombinant human interferon-gamma (rH-IFN-gamma). Immunologically, they were classified as IgG1-K subclass. G-208 neutralized the antiviral activity of natural and recombinant human IFN-gamma, but did not bind to heat-denatured rH-IFN-gamma. G-166 was able to bind to rH-IFN-gamma as well as to heat-denatured rH-IFN-gamma, but it did not bind to natural human IFN-gamma (nH-IFN-gamma). A sandwich enzyme immunoassay specific to H-IFN-gamma molecule was developed using polyclonal rabbit anti-nH-IFN-gamma antibody and G-208. This assay monitors only biologically active H-IFN-gamma molecule. Thus, this method may be used for the direct determination of H-IFN-gamma instead of determination of antiviral activity of H-IFN-gamma.