title: Functional role of HLA class I cell-surface molecules in human T-lymphocyte activation and proliferation.
abstract: This investigation addressed the role of major histocompatibility complex-encoded class I molecules in the activation and proliferation of human lymphocytes. We studied the effect of antibodies specific for HLA-A and HLA-B locus gene products on mitogen-stimulated peripheral blood mononuclear cell (PBMC) subpopulations. Three individually derived, well-characterized anti-HLA class I monoclonal antibodies were demonstrated to inhibit the proliferation of human PBMC stimulated by either OKT3 or the calcium ionophore ionomycin. The antibody directed against HLA-A, -B, and -C locus gene products (W6/32) and the antibody directed against HLA-B locus gene products (4E) inhibited proliferation induced by either mitogen by 70-90%. The HLA-A locus-specific antibody (131), though inhibiting ionomycin-induced proliferation by 80-90%, was much less effective when OKT3 was the stimulus. The inhibition affected T4+ and T8+ cells and was not mediated by DR+ accessory cells. The inhibitory effect of these antibodies was associated with a decrease in the level of interleukin 2 activity present in culture supernatants, decreased interleukin 2 receptor expression, and decreased transferrin receptor expression and was not overcome by the addition of exogenous interleukin 2. Our results suggest that HLA class I molecules are directly involved in the early critical events of human lymphocyte activation and proliferation.
mesh_terms: D000911:Antibodies, Monoclonal; D000938:Antigen-Presenting Cells / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000276:immunology; D004987:Ethers / Q000494:pharmacology; D006680:HLA Antigens / Q000276:immunology*; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism; D015759:Ionomycin; D007518:Isoantibodies / Q000276:immunology; D008213:Lymphocyte Activation; D011956:Receptors, Cell Surface / Q000378:metabolism; D011971:Receptors, Immunologic / Q000378:metabolism; D015375:Receptors, Interleukin-2; D011990:Receptors, Transferrin; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D004987:Ethers; D006680:HLA Antigens; D007376:Interleukin-2; D007518:Isoantibodies; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D011990:Receptors, Transferrin; D015759:Ionomycin