Monoclonal antibody to murine gamma interferon inhibits lymphokine- induced antiviral and macrophage tumoricidal activities

Fusion of rat immune spleen cells with mouse myeloma cells resulted in the formation of a stable hybridoma that secretes monoclonal antibody (MAb) directed against murine gamma interferon ( MuIFN -gamma). This MAb specifically neutralized the antiviral activity of a variety of MuIFN -gamma preparations, including a sample produced by recombinant DNA technologies. In contrast, the antiviral activities of a mixture of MuIFN -alpha plus MuIFN -beta, as well as those of rat or human IFN- gamma, were not neutralized by this antibody. The ability of the MAb to inhibit lymphokine-induced macrophage activation was also tested. It was found that in relation to the quantity of antibody needed to completely neutralize antiviral activity, much higher concentrations of MAb were required to abolish the capacity of lymphokine preparations to induce macrophage tumoricidal activity in vitro. The MAb was also coupled to cyanogen bromide-activated Sepharose beads and used as an immunoadsorbent. By reacting lymphokines with MAb coupled to an insoluble matrix, it was possible to show that this immobilized antibody completely and specifically removed from the lymphokine preparations the ability both to invoke macrophage tumoricidal activity and to mediate antiviral activity.