Abstract
Monoclonal antibodies with specificities for subsets of human leukocytes have been used for the characterization of interferon (IFN)γ-producing cells. The production of IFNγ was demonstrated to be a function of OKT3+ T lymphocytes. The capacity to secrete IFNγ was not restricted to the OKT4+ or the OKT8+ T-cell subset. BA-1+ B lymphocytes and Leu7+ natural killer cells did not contribute to the production of IFNγ. Ia+, OKM1+ monocytes served an auxiliary function in the production of IFNγ. The requirement for accessory monocytes, however, was not absolute, because monocyte-free preparations of long-term cultured IL2-dependent T lymphocytes retained the capacity to secrete IFNγ.