To Improve Skin Graft Survival Rate By Pretreatment Of New Immunosuppressant

It is an essential therapy for skin over-injured sufferers to proceed skin allografttransplant to get repaired and it must lead to graft rejection because of differentindividuals’ histocompatibility antigen existed otherness. To keep survival of the graft invivo, hosts usually have to take usage of immunosuppressant for a long time, which willresult in hypoimmunity and increase the risk of cancer and infections. Therefore, theinduction of′transplant immunological tolerance′for host toward donor allograft antigenspecially is the key to solve this problem. A large number of research, in recent years,have showed that CD4~+CD25~+Foxp3~+regulatory T cells (Foxp3~+Treg) can suppressimmune reject reaction specially and played very important role in modulating responsereaction as well as in inducing and maintaining periphery immune tolerance.Because allogeneic skin transplant is provided with characteristics, therefore, it canbe said that this work is to improve survival rate in a reactive system in which active skingraft was used as a biological dressing material through certain experimental method. Theexperimental animals model of mice skin allograft transplant can be looked upon as thereactive system and is pretreated by a new immunosuppressant before transplant. The newimmunosuppressant applied to this work is benzothiophene analogues (BP).This work mainly contains cell experiments in vitro and animal experiments in vivo.（1）In the first stage, the experiment detection of Foxp3~+Treg cells showed thatCD4~+Foxp3~+regulatory T cells were induced by BP. Then, proliferation experimentshowed that CD4~+Foxp3~+regulatory T cells were induced by BP. Last, apoptosisexperiment showed that BP suppressed cells’ proliferation through promoting apoptosis,meanwhile, BP also has certain toxic side effects. In brief, the cell experiments in vitroshowed that BP induced CD4~+Foxp3~+regulatory T cells in certain conditions and thoseinduced Foxp3~+Treg cells can promote the apoptosis of lymphocytes to suppress itsproliferation.（2）In the next stage, animal experiments in vivo showed that the mean survivaltime (MST) of the skin allograft was prolonged for hosts mice through pretreatment withBP and the mean survival time of allograft of experimental groups was prolonged fromthe9th day to the21th day, therefore improved the survival rate.To sum up, the experimental results showed that the allograft mice skin graft inexperimental animals model (male BALB/C (H-2d) and female C57BL/6(H-2b) micewere used as donor and recipient, respectively) transplantation, through application of new immunosuppressant (benzothiophene analogues, BP) to recipients mice pretreatment, canimprove the skin graft allograft survival ratio.