A rat anti-mouse T4 monoclonal antibody (H129.19) inhibits the proliferation of Ia-reactive T cell clones and delineates two phenotypically distinct (T4+, Lyt-2,3-, and T4-, Lyt-2,3+) subsets among anti-Ia cytolytic T cell clones.
Hybridoma H129 .19 was derived by fusion between spleen cells of a Lou / Ws1 rat immunized with an Lyt-1+,2- anti-I-Ak cytolytic T lymphocyte (CTL) clone and the nonsecreting myeloma X63-Ag8.653. The monoclonal antibody (mAb) H129 .19 (IgG2a, kappa) was selected for its capacity to inhibit the lytic potential of the immunizing clone. H129 .19 identified a monomorphic determinant on a 55 m.w. murine T cell differentiation antigen, which appeared to be homologous to the human T4 molecule in that: 1) H129 .19 reacted with 80% adult thymocytes, with a subset of splenic T cells, and with the interleukin 2 (IL 2)-producing EL4 thymoma; 2) The mAb bound to and inhibited the IL 2 production and the proliferation of various allo- or soluble antigen-reactive T cell clones that recognized restriction or activating determinants on the I-A or I-E molecules, respectively; 3) H129 .19 did not inhibit the proliferation and/or cytolysis of Lyt-2,3+ T cells specific for class I MHC antigen; and 4) Among six anti-Iak CTL clones examined in this study, the mAb H129 .19 reacted with two I-Ak-specific, Lyt-2,3- clones on which it exerted strong cytolysis inhibiting effect at the effector cell level. By contrast, two other anti-I-Ak and two anti-I-Ek CTL clones were found to express the Lyt-2,3+,T4- cell surface phenotype. The cytolytic potential of the latter clones was not inhibited by anti-Lyt-2,3 mAb. These studies strongly suggest that the mouse T4 molecule facilitates the recognition of class II MHC antigen by most but not all T cells.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000502:physiology*; D000945:Antigens, Differentiation, T-Lymphocyte; D000950:Antigens, Ly / Q000235:genetics; D000954:Antigens, Surface / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D001667:Binding, Competitive; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D000939:Epitopes / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000276:immunology*; D006801:Humans; D006825:Hybridomas / Q000276:immunology; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation; D051379:Mice; D008806:Mice, Inbred AKR; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008811:Mice, Inbred DBA; D009928:Organ Specificity; D010455:Peptides / Q000276:immunology; D010641:Phenotype; D011108:Polymers; D051381:Rats; D011919:Rats, Inbred Strains; D013045:Species Specificity; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology / Q000378:metabolism*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000950:Antigens, Ly; D000954:Antigens, Surface; D000939:Epitopes; D000949:Histocompatibility Antigens Class II; D007376:Interleukin-2; D010455:Peptides; D011108:Polymers; C020749:GAT