The natural killer cell-like lytic activity expressed by cytolytic T lymphocytes is associated with the expression of a novel function-associated molecule.
Experiments were performed to analyse the natural killer cell (NK)-like cytotoxicity frequently expressed by human antigen-specific cytolytic T lymphocytes (CTL). To this end, several monoclonal antibodies (MoAbs) previously shown to identify a novel function-associated molecule (FAM) involved in human NK function were utilized. Flow cytometry revealed that these MoAbs reacted with the majority of human NK, but only with a subpopulation of CTL isolated from primary mixed lymphocyte cultures. Preincubation of CTL with the MoAbs inhibited the NK-like lysis of K562 targets. Experiments with anti-CD3 MoAb demonstrated that neither the NK-like cytotoxicity of CTL nor the lytic activity of NK were mediated by the CD3 complex. Expression of the novel FAM was found to develop in T-cell cultures at the time that NK-like cytotoxicity was observed. Repeated in vitro antigenic stimulation of CTL was shown to result in loss of NK-like cytotoxicity, as well as loss of the FAM on the CTL surface. Thus, NK-like cytotoxicity displayed by antigen-specific CTL appears to be mediated by a novel FAM that is identical to that structure found on NK.
Harris
D T
DT
Department of Microbiology & Immunology, University of Arizona, Tucson 85721.
Jaso-Friedmann
L
L
Devlin
R B
RB
Koren
H S
HS
Evans
D L
DL
D000293:Adolescent; D000328:Adult; D000911:Antibodies, Monoclonal / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology; D017252:CD3 Complex; D003601:Cytotoxicity Tests, Immunologic; D003602:Cytotoxicity, Immunologic; D005434:Flow Cytometry; D006801:Humans; D007694:Killer Cells, Natural / Q000737:chemistry / Q000276:immunology*; D016131:Lymphocyte Subsets; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000378:metabolism; D013997:Time Factors; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D011948:Receptors, Antigen, T-Cell