title: Inhibition of IL 2-dependent proliferation of rat T lymphoblasts by the monoclonal antibody ART62 which reacts with MHC class 1 antigens.
abstract: During the course of studies designed to obtain monoclonal antibodies (mAb) that recognize the rat interleukin 2 receptor, a mouse IgG1 mAb (ART62) was identified which inhibits the interleukin 2 (IL 2)-dependent proliferation of rat T lymphoblasts without affecting the binding of IL 2 to such cells. In order to characterize the cell surface components that react with the mAb ART62, T lymphoblasts were surface-labeled with 125I, and the radioactive molecules were immunoprecipitated by the antibody analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The mAb ART62 precipitated two major components of 48,000 m.w. and 12,000 m.w., respectively, which were different from those which react with the anti-IL 2-receptor antibody ART18, a molecule of 50,000 to 55,000 m.w. Sequential immunoprecipitation studies revealed that the mAb ART62 reacts with the MHC class 1 antigen that reacts with the classical anti-rat MHC class 1 mAb OX18, and vice versa. In contrast to the mAb ART62, OX18 that does not affect and several other mAbs known to inhibit the rat MLR failed to inhibit IL 2-dependent proliferation of rat T lymphoblasts. In contrast to the anti-IL 2 receptor antibody ART18, ART62 effectively inhibited IL 2-driven proliferation even when added to cells already committed to proliferate by IL 2-IL 2 receptor interaction. These data raise the possibility that MHC class 1 antigens could be involved in the chain of reactions mediating the signals required for cell proliferation.
authors.forename: H
authors.initials: H
authors.lastname: Osawa
authors.forename: T
authors.initials: T
authors.lastname: Herrmann
authors.forename: T
authors.initials: T
authors.lastname: Diamantstein
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000502:physiology*; D000937:Antigen-Antibody Reactions; D000954:Antigens, Surface / Q000032:analysis; D001667:Binding, Competitive; D000939:Epitopes / Q000276:immunology; D005260:Female; D006649:Histocompatibility Antigens / Q000032:analysis / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D007376:Interleukin-2 / Q000502:physiology*; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D051381:Rats; D011917:Rats, Inbred Lew; D013045:Species Specificity; D013601:T-Lymphocytes / Q000276:immunology*; D014018:Tissue Distribution
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D000939:Epitopes; D006649:Histocompatibility Antigens; D000949:Histocompatibility Antigens Class II; D007376:Interleukin-2; C038353:histocompatibility antigens RT, rat