INVITRO CYTOTOXIC EFFECT OF GUINEA-PIG NATURAL-KILLER-CELLS (KURLOFF CELLS) ON HOMOLOGOUS LEUKEMIC-CELLS (L2C)

The Kurloff cell (KC) of the guinea-pig develops natural killer cytoto xic activity in heterologous systems. We report in this paper the effe ctive in vitro cytotoxic activity of the KC in a homologous guinea-pig system, i.e. against the guinea-pig target leukemic L2C cells. A dual -color flow analysis of homologous effector-target conjugates, using c alcein-labeled KC and hydroethidine-labeled L2C shows a 40% frequency KC-L2C conjugation. The specific cytotoxicity of KC against L2C (78%) was estimated as the target-loss of green fluorescence due to hydrolys ed carboxy-fluorascein diacetate after 4 hours st 37-degrees-C. We pro pose that the Kurloff cell could be involved in surveillance against s pontaneously arising leukemic cells, and this could be an explanation for the high degree of resistance to spontaneous or experimentally-ind uced cancers, in the guinea-pig.