Anti-interferon globulin inhibits macrophage phagocytic enhancement in vivo by tilorone or Newcastle disease virus

Administration of the interferon inducers tilorone or Newcastle disease virus to mice enhances the in vitro uptake of opsonized erythrocytes (EA) by peritoneal macrophages. To evaluate the role of induced interferon (IF) in the macrophage stimulation, sheep anti-IF, or control globulins were given to mice prior to and after the administration of the inducers. Both IF titers and uptake of EA by macrophages were reduced by anti-IF but not by control globulin. In contrast, phagocytic stimulation by a lipopolysaccharide, a weak IF inducer, was unaffected by the anti-IF globulin. The results indicate that endogenously generated type I IF may participate in the control of macrophage function in vivo.