title: A Thy-1.1-specific monoclonal alloantibody activates both mouse and rat T cells.
abstract: In an attempt to further evaluate the role of Thy-1 in the antigen-independent triggering of mouse T cells, we have examined the activating properties of two Thy-1.1-specific mouse monoclonal antibodies (mAb). These reagents were established from an (A.TH X A.TL)F1 hybrid mouse (Thy-1b) immunized with IL-2 producing (BALB/c (Thy-1b) X BW5147 (Thy-1a)) T hybridoma cells. Although both mAb recognized the same Thy-1.1 determinant, one mAb of the gamma 3,kappa class (H171-146) was found to induce several T hybridoma cells to produce IL-2, and AKR thymocytes or cloned helper T cells to proliferate, whereas another mAb of the gamma 1,kappa class (H171-112) failed to do so even in the presence of phorbol myristic acetate (PMA). Increased IL-2 responses of T hybridoma cells were observed when the cell bound Thy-1.1-specific mAb were crosslinked by goat anti-mouse Ig (GaMIg) antibodies. Both a T-cell activating rat anti-Thy-1.2 mAb and the anti-Thy-1.1 mAb H171-146, although directed at distinct cell surface molecules, synergistically stimulated IL-2 production by T hybridoma cells. In addition, the mouse mAb H171-146 was found to stimulate LOU/M rat thymocytes to proliferate in the presence of exogenous IL-2. These data demonstrate that T cells can use Thy-1 as a signal-transducing molecule in both mouse and rat species, and support the notion that the activating properties of Thy-1.1-specific mAb are influenced by their heavy chain isotypes.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D000954:Antigens, Surface / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology; D007132:Immunoglobulin Isotypes / Q000276:immunology; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation; D051379:Mice; D051381:Rats; D013045:Species Specificity; D013601:T-Lymphocytes / Q000276:immunology*; D018800:Thy-1 Antigens
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D007376:Interleukin-2; D018800:Thy-1 Antigens