title: Phenotypes of human natural killer cell populations detected with monoclonal antibodies.
abstract: In our recent studies, human natural killer (NK) cell activity was found to be decreased 2- to 4-fold after treatment of monocyte-depleted peripheral mononuclear cells with monoclonal antibody OKM1 and complement (C). The present study was undertaken to determine whether there is an additional population of NK cells that is OKM1-, since treatment with OKM1 and C decreased, but did not eradicate, NK cell activity. Treatment of lymphocytes with monoclonal antibody OKT11A, which reacts with all sheep red blood cell rosetting lymphocytes, and C also decreased NK cell activity. Although approximately 90% of OKT11A+ cells are OKT3+, NK cell activity resides within the OKT11A+ cell population, which is OKT3- since OKT3-cell depletion fails to decrease NK cell activity. Double fluorescence analysis of OKT3-depleted lymphocytes revealed that 54% of the OKM1+ cells are OKT11A- and 45% of the OKT11A+ cells are OKM1-, thus demonstrating that within the OKT3-depleted population, approximately one-half the OKM1+ cells are OKT11A- and vice versa. Treatment of lymphocytes with OKM1 together with OKT11A and C decreased NK cell activity against 3 NK-sensitive leukemia lines--K562, MOLT-4, and HSB-2--more than did treatment with either antibody alone; virtually no lytic activity was retained after elimination of OKM1+ and OKT11A+ cells. The results thus provide strong evidence that there is at least 2 populations of human NK cells; one is OKM1+ and the other is OKT11A+
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000941:Antigens / Q000145:classification; D002469:Cell Separation; D003165:Complement System Proteins; D003602:Cytotoxicity, Immunologic; D006801:Humans; D007942:Leukemia, Experimental / Q000276:immunology; D051379:Mice; D008815:Mice, Inbred Strains; D010586:Phagocytes / Q000145:classification*; D010641:Phenotype; D012756:Sheep
chemical_list: D000911:Antibodies, Monoclonal; D000941:Antigens; D003165:Complement System Proteins