Spontaneous and antibody-dependent cell-mediated cytotoxicity by human T cell subpopulations.

Abstract

Human peripheral blood non-T [thymus derived] cells, T cells and their subpopulations (T.mu., T.gamma., T.vphi., T.gamma.-depleted cells and T.mu.-depleted cells) were assayed for their capacity to mediate spontaneous lymphocyte-mediated cytotoxicity (SLMC) or natural killer activity against K562 [human myeloid leukemia] tumor cell line and antibody-dependent cellular cytotoxicity (ADCC) against chicken erythrocytes coated with antibody. Non-T cells, unseparated T cells, T.gamma. cells and T.mu.-depleted (T.gamma.-enriched) cells had SLMC (NK activity) and ADCC. T.mu., T.vphi. and T.gamma.-depleted cells had minimal or no SLMC and ADCC activity. Thus SLMC and ADCC activity in T cells is mediated by T.gamma. cell subpopulations. These two cytotoxic reactions were mediated by 2 distinct subsets of T.gamma. cells or by a single effector cell using 2 different mechanisms.