title: IL-2-mediated T cell proliferation in humans is blocked by a monoclonal antibody directed against monomorphic determinants of HLA-DR antigens.
abstract: We have studied the effect on the interleukin (IL-) 2-dependent human T cell growth of two distinct monoclonal antibodies (Mab), D1-12 and 4F2, with specificity for common determinant of human Ia antigens and for a differentiation antigen expressed on all activated T cells, respectively. Strong inhibition of cell growth was found in cultures supplemented with the anti-Ia D1-12 Mab but not in cultures supplemented with 4F2 Mab. These results were obtained when either total mixed leukocyte culture (MLC) T cells or an MLC-derived T cell clone were used as indicator cell systems for IL-2 activity. The inhibition of cell growth appears to be mediated by a direct interaction of D1-12 Mab with the cells and not by a direct inactivation of the growth factor, as addition of the antibody to murine MLC T cells, which do not express the determinant defined by D1-12 Mab, resulted in no inhibition of their proliferation induced by the same source of human IL-2.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000920:Antibody-Dependent Cell Cytotoxicity; D001667:Binding, Competitive; D000939:Epitopes; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects*; D007959:Lymphocyte Culture Test, Mixed; D008222:Lymphokines / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D000949:Histocompatibility Antigens Class II; D007376:Interleukin-2; D008222:Lymphokines