title: A model for the differentiation of human natural killer cells. Studies on the in vitro activation of Leu-11+ granular lymphocytes with a natural killer-sensitive tumor cell, K562.
abstract: A subpopulation of low density granular lymphocytes that express the natural killer (NK) cell-associated Leu-11 antigen (IgG Fc receptor) were stimulated directly by coculture with an NK-sensitive tumor cell, K562. T lymphocytes (Leu-11-) responded only weakly when cocultured with K562. The response of Leu-11+ cells apparently did not require exogeneous factors or accessory cells. The K562-activated cells retained expression of Leu-11 antigen, acquired activation antigens, and were highly cytotoxic against NK-sensitive and -insensitive tumor cells. Anti-IL-2 receptor monoclonal antibody minimally inhibited the activation of Leu-11+ cells by K562, but completely inhibited the phytohemagglutinin-induced activation of the Leu-11- cells from the same individual. Leu-11+ cells can be divided into Leu-7-11+ and Leu-7+11+ subpopulations using anti-Leu-7 antibody. These subsets were separated by two-color fluorescence-activated cell sorting and cocultured with K562. Proliferation by Leu-7-11+ cells was significantly greater than by Leu-11+7+ cells. Leu-7+11- granular lymphocytes and T lymphocytes (Leu-7-11-) typically proliferated only weakly when cocultured with K562. A proportion of the Leu-7-11+ cells acquired Leu-7 antigen after stimulation with K562, whereas the phenotype of Leu-7+11+, Leu-7+11-, and Leu-7-11- subsets was unaffected. These results demonstrate a developmental relationship between the Leu-7-11+ and Leu-7+11+ lymphocytes and suggest that Leu-7 antigen may be expressed late in the differentiation pathway of NK cells. The direct activation of highly purified Leu-11+ cells by coculture with K562 provides an in vitro model with which to study the activation and maturation of human NK cells.
authors.forename: J H
authors.initials: JH
authors.lastname: Phillips
authors.forename: L L
authors.initials: LL
authors.lastname: Lanier
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000276:immunology; D002454:Cell Differentiation; D002460:Cell Line; D006801:Humans; D066298:In Vitro Techniques; D007694:Killer Cells, Natural / Q000145:classification / Q000166:cytology / Q000276:immunology*; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D009369:Neoplasms / Q000276:immunology*; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface