Autocytotoxic activity of lymphokine-activated killer cells: characterization of effector cells and susceptible targets

The specificities and surface markers of murine autocytotoxic cells induced by in vitro culture with interleukin 2 (IL2) were studied. Culturing murine spleen cells with recombinant human IL2 resulted in the generation of cytotoxic cells which killed syngeneic lymphoblasts and syngeneic activated macrophages (M phi). Both lectins and protein antigens were capable of inducing lymphoblasts recognized by lymphokine-activated killer (LAK) cells. B-lymphoblasts as well as T-lymphoblasts were sensitive to lysis by these effector cells. In addition, peritoneal M phi activated in vivo with Bacille Calmette-Guérin (BCB), Corynebacterium parvum (C. parvum), thioglycollate (TG) or lipopolysaccharide (LPS) were shown to be susceptible to lysis by LAK cells. In contrast, neither unstimulated T cells nor resident peritoneal M phi were sensitive to lysis by LAK cells, suggesting that normal cells have to be activated in order to be sensitive to lysis by these effector cells. Surface marker analysis indicated that majority of effector cells which killed syngeneic lymphoblasts and activated M phi were Thy1+, asialo GM1+, L3T4-, Ly2-.