A cell surface monoclonal antibody (H366) helps to discriminate human cytotoxic from suppressor T cells

A study has been undertaken to differentiate T cytotoxic (Tc) and T suppressor (Ts) cell subsets using a monoclonal antibody termed H366 (mouse IgG2b) previously reported to phenotype natural killer and killer (NK/K) cells. Mononuclear cell suspensions from 14 normal subjects were depleted of H366+ cells by means of complement dependent cytotoxicity and the remaining cells were phenotyped with CD8 and CD4 monoclonal antibodies. The effects of depletion with H366 plus complement (C1) on the induction and activity of suppressor and cytotoxic T cells was also examined. The results indicate that H366 antibody recognizes in addition to NK/K cells, a population of Tc but not Ts or helper cells. Therefore, H366 antibody can be useful for obtaining Ts enriched lymphocyte subpopulations and this property may also be used for the enumeration of suppressor cells in the peripheral blood in disease states.