[Isolation from the human peripheral blood of a fraction of mononuclear cells with high cytotoxicity against K-562 and HeLa target cells].

Adherent cells were released from human peripheral blood mononuclears and the remaining mononuclears were separated by the density gradient centrifugation on percoll. Five fractions obtained were tested for cytotoxicity against K-562 and HeLa tumour target cells. Cell morphology and reactivity to some monoclonal antibodies were also studied. Fractions 2 and 3 were enriched by large granular lymphocytes (LGL) and BMA-070 positive cells and showed increased cytotoxicity only to K-562 target cells, while fraction 1 contained 9.5% of monocytes, but no LGL, and showed increased cytotoxicity against both K-562 and HeLa target cells.