IMMUNE INTERFERON INDUCTION BY A MONOCLONAL-ANTIBODY SPECIFIC FOR HUMAN T-CELLS

OKT3, a monoclonal antibody reactive with a surface antigen shared by all human T lymphocytes, was found to act as a potent interferon (IFN) inducer in cultures of human mononuclear white blood cells. Two other monoclonal antibodies reactive with T cell subpopulations failed to induce IFN. IFN-inducing activity of OKT3 was similar to that of phytohemagglutinin (PHA). The phorbor ester, 12-O-tetradecanoylphorbol-13-acetate, had a strong potentiating effect on IFN production stimulated with OKT3 or PHA. IFN produced after stimulation with OKT3, like PHA-induced IFN, had properties characteristic for immune IFN (IFN-.gamma.).