Characterization of the precursors of the NK-like cytotoxic cells generated in the autologous mixed leukocyte reaction and by interleukin 2 activation.

In vitro stimulation of E+ cells with autologous E- cells (AMLR) for 7 days results in the generation of NK-like killer cells with the same phenotype (E+, 4F+2, OKT-8, OKM-1) as the killer cells produced by activation of E+ cells with IL-2 for 3 days in our system. IL-2 activity was also detected in the course of AMLR culture in concordance with the generation of the killer cells. These data prompted us to characterize the progenitor cells in the 2 systems by using positive (panning) or negative (complement mediated cytolysis) selection techniques. The NK-like killer cells generated from both the AMLR responder population and by activation with IL-2 are derived from the same population of cells with an E+, OKM+1 but not Leu 7+ phenotype.