In Vitro Study On T Cell Proliferation Inhibited By TGF-β1 And Its Mechanism

Specific immune tolerance induction is an ideal pathway to prevent allograft rejection. It remains a hotspot in the field of immunology. A new developed immunesuppressive agents associated with anti-CD3, anti-CD4 monoclone antibody have reached greatly reducing pathological damage. However side effects and toxicities such as infection and tumor greatly limited their practice in clinical. On the other hand, application of cytokines and their monoclone antibody emerged in the recent years, could result in reverse effects such as allograft rejection. Among them, TGF- β has been payed more attention. TGF- β is a multifunctional cytokine and display comprehensive suppression to immune system, microamount of it could result in strong immunosuppression. A series in vitro and in vivo experiment on animal have proved that TGF- β can inhibit T cell proliferation and induce specific immune tolerance. Our study try to evaluate the effect of TGF- β on human peripheral T cell and provide experimental proofs for the possibility of clinical application.Objective The purpose of this study is to examine the effect of TGF- β on mixed lymphocyte culture(MLC) and its possible mechanism.Methods To monitor primary and secondary MLC, lymphocytes taking from different healthy adults were isolated as responder and stimulator cells, and TGF- β was added to the experiment groups. The lymphocyte proliferation rates were detected by MTT on different times. Lactate dehydrogenase release method was used to examine the cytotoxic activity. The supernatant were assayed for IFN- γ and IL-2 with ELISA, The expression of CD4CD25 and CTLA4 were assessed with flow cytometry.Results TGF- 3 can distinctively inhibit the proliferation of T cell in primary and secondary MLC. In primary MLC, the levels of IFN- Y and IL-2 in supernatants...