Antibodies to membrane structures that distinguish suppressor/cytotoxic and helper T lymphocyte subpopulations block the mixed leukocyte reaction in man.
Two major subsets of human T lymphocytes that are functionally analogous to the mouse Lyt-2+ and Lyt-2- subsets have been defined by their expression of two thymus-dependent membrane antigens, Leu-2 and Leu-3. Leu-2+,3- cells have suppressor/cytotoxic functions and Leu-2-,3+ cells have helper functions. These studies were designed to determine the effects of adding IgG1 monoclonal anti-Leu-2 and anti-Leu-3 antibodies to the mixed leukocyte reaction (MLR). At high concentrations, each antibody partially inhibited the proliferative response of unseparated T cells and abolished the response of the isolated subset having the appropriate phenotype. An IgG1 monoclonal antibody to HLA-A2 and an IgG2a antibody to Leu-1, a pan-T antigen, failed to inhibited the MLR. These results suggest that the Leu-2 and Leu-3 antigens may have a direct role in the mechanism whereby T cells recognize and respond to alloantigen.
D000818:Animals; D000906:Antibodies; D000911:Antibodies, Monoclonal; D001667:Binding, Competitive; D002462:Cell Membrane / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D008807:Mice, Inbred BALB C; D012397:Rosette Formation; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
D000906:Antibodies; D000911:Antibodies, Monoclonal