CHEMILUMINESCENCE OF MONONUCLEAR-CELLS IS ENHANCED DURING ANTIGEN RECOGNITION

Stimulation of phagocytes by several cytokines causes superoxide gener ation and consequently chemiluminescence. Since antigen-activated lymp hocytes generate cytokines, we investigated whether antigen recognitio n by mononuclear cells, which contain both lymphocytes and monocytes, is accompanied by changes in lucigenin-dependent chemiluminescence. Mo nonulcear cells which underwent antigen-induced proliferation showed a delayed rise in lucigenin-dependent chemiluminescence in the absence of other stimuli. The common recall antigen Candida albicans increased spontaneous chemiluminescence of mononuclear cells from unselected do nors up to 20-fold over control values after 48-72 h of culture. With Rabies virus vaccine as specific antigenic stimulus, only mononuclear cells from rabies immunized individuals responded with enhanced delaye d chemiluminescence. In contrast to opsonized zymosan and phorbol myri state acetate, antigens induced no oxidative burst within one hour aft er addition. Delayed mononuclear cell chemiluminescence was inhibited by the superoxide scavenger superoxide dismutase and by di-phenylene i odonium, a selective inhibitor of the phagocyte NADPH oxidase. A neutr alizing monoclonal antibody against interferon-gamma completely abroga ted antigen-induced chemiluminescence. Recombinant interferon-gamma by itself induced delayed mononuclear cell chemiluminescence. Thus, anti gen-induced delayed mononuclear cell chemiluminescence represents acti vation of phagocyte NADPH oxidase by interferon-gamma generated by act ivated lymphocytes.