Induction Of Tolerance By Suppressive Macrophages In Rat Heart Transplantation And The Study Of Its Mechanisms

Transplantation has become an accepted treatment for organ failure for many patients. The ultimate goal of transplantation is drug-free allograft acceptance. Nonetheless, one major drawback to this treatment is the need for continous, indefinite immunosuppressive drugs to prevent acute graft rejection. With the use of cyclosporine and tacrolimos, immunosuppressive therapies have improved dramatically, but the drug are expensive and associated with undesirable side effects, including increased risks of opportunistic infection, malignancy and end-organ toxicities and what is more, they have no effect on chronic rejection. Strenuous efforts thus continue to be made to identify methods of inducing drug-free, permanent, donor-specificunresponsiveness(tolerance), which preserve overall host immunocompetence with minimal attendant side effects. Up to date, almost all the studies on specific tolerance focused on basic research including (1) the use of donor-antigen to induce specific tolerance,including transfusion of donors' blood at some time beforetransplantation,transfusion of hematopoietic stem cell or bone marrow cells,treated or untreated lymphocytes, DCs, even parenchymal cells of some organs, polypeptide (MHC-I, MHC-II antigen) before transplantation; (2) the use of certain antibodies (anti-IL-2 antibody,anti-CD3 antibody, anti-CD4 antibody etc.); (3) application of specific antibody together with donor antigen; (4)transgenic animal and so on. But little was studied about SM(ps in specific tolerance of transplantation. It has long been recognized that some inflammatory-type M(ps support T cell activation but some other M(ps suppress T cell proliferation. M