ABSTRACT
The cytotoxic cells generated from human thymocytes resemble natural killer (NK) and NK-derived Lymphokine-activated killer (LAK) cells both phenotypically and functionally. The culture conditions and other functional characteristics suggest that thymocyte-derived LAK is extremely similar to NK-derived LAK. The kinetics of thymocyte LAK developments are slightly delayed when compared to peripheral blood lymphocytes -LAK cell development. LAK activity can develop from PBL depleted of NK cells by treatment with the toxic lysosomotropic drug L-leucine-O-methyl ester. Depletion of cells bearing NK-associated markers and K562 target binding cells does not completely abrogate LAK precursors. One advantage of using thymocyte-derived LAK as a model system is that thymocytes are phenotypically well characterized. One of the most important antigens expressed by thymocytes during differentiation is the CD3 antigen. In a number of characteristics, thymic effectors also resemble NK cells. For these comparisons, the authors examines surface phenotype, cellular granularity, and target specificity.
