title: Alloantigen-induced human lymphocytes rendered nonresponsive by a combination of anti-CD80 monoclonal antibodies and cyclosporin-A suppress mixed lymphocyte reaction in vitro.
abstract: Induction of a state of long-term, alloantigen-specific T cell nonresponsiveness has significant implications for human transplantation. It has been previously described that alloantigen-specific anergy may be induced by addition of cyclosporin-A together with anti-CD80(B7-1) mAb to a MLR. In this study we endeavored to verify whether alloantigen-induced PBL rendered anergic by the addition of a combination of anti-B7 mAb and cyclosporin-A during a MLR had a suppressive effect when added to autologous lymphocytes activated in MLR. We found that: 1) the addition of cells rendered anergic by this procedure to a MLR suppress both proliferative and cytotoxic response of autologous responsive PBL to either the same or third-party stimulator cells; 2) the suppressive effect is limited to alloantigen-induced T cell activation, as addition of anergic cells does not influence mitogen- or antigen-induced proliferation of autologous responsive T cells; 3) nonresponsiveness of suppressed cells cannot be reversed by either subsequent restimulation with allogeneic cells or addition of exogenous IL-2 to the cultures; 4) the suppressive effect is apparently not due to secretion of anergic cell-derived soluble factors, but it seems to be dependent on cell-cell contact between anergic, responsive, and stimulator cells. These data suggest that: 1) the delivery of a direct signal mediated by anergic lymphocytes through a cell-cell contact is likely to be the mechanism responsible for the suppressive effect here described; 2) anergic cells may propagate alloantigen-specific tolerance to potentially responsive autologous lymphocytes. Preliminary experiments indicate that anti-CD86(B7-2) mAb may play a similar role in the generation of alloantigen-induced nonresponsiveness.
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology*; D018122:B7-1 Antigen / Q000276:immunology; D002448:Cell Adhesion / Q000502:physiology; D002478:Cells, Cultured; D017635:Clonal Anergy / Q000276:immunology; D016572:Cyclosporine / Q000494:pharmacology*; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D006801:Humans; D007108:Immune Tolerance / Q000276:immunology*; D007376:Interleukin-2 / Q000096:biosynthesis; D007519:Isoantigens / Q000276:immunology*; D008213:Lymphocyte Activation / Q000187:drug effects; D007959:Lymphocyte Culture Test, Mixed; D008934:Mitogens / Q000494:pharmacology; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D018122:B7-1 Antigen; D007376:Interleukin-2; D007519:Isoantigens; D008934:Mitogens; D016572:Cyclosporine