The Effect And Mechanism Of The Apoptotic Cell Death Of Matured T Iymphocytes Induced By Mouse Sertoli Cells In Vitro

Tissue transplantation is one of the commonly used techniques inplastic surgery. So far, autograft is most widely used in clinicalpractice, though it has several disadvantages such as shortage of anddamage to donor sites, as well as bringing more suffering to thepatients. Allograft(xenograft) is abundant in source, easy to obtain andperfect in appearance. However, its clinical application in plasticsurgery is significantly limited due to rejection as an immunologicalreaction.It is well known that one of the main barriers to the acceptance of xenogeneic and allogeneic grafts is T cell-mediated immuno-response of the host. Immunosuppressant drugs that depress T cell activity leave the host more susceptible to infection. A strategy allowing specific deletion of the T cells that recognized the graft would allow toleranc? of the graft without systemic immunosuppression. The understanding of immune privilege has highlighted this idea.For a long time, immunologists have recognized that there are sites such as eye, brain and testis in the body where immune responses do not occur. These sites have been termed as immune privileged sites. Recent achievements in understanding the phenomenon of immune privilege have shown that these tissues naturally express FasL, which. functions to induce apoptotic cell death in infiltrating lymphocytes and inflammatory cells, and thus protect tissues from immune assault. Sertoli cells of the testis can express FasL.The above results demonstrated the possibility that, by placing FasL into any tissue of choice or cotransplanting the tissue with sertoli cells, allograft (xenograft) will be protected from immune rejection. Yet there are some controversies on the effects of FasL: 1. FasL can 第H军医大学地七论义 英义皿要－6．confer immunological privilege. 2. FasL provoked a granulocytic infiltrate rather than acting as an immunosuppressant. Sertoli cells have been reported to be able to protect cotransplanted allogenic cells from rejection, but the mechanism has not been clearly defined.The objectives of the present study:1.To study the influence of sertoli cells on the apoptosis of matured T lymphocytes in vitro.2.To clarify the mechanism of apoptosis of T lymphocytes induced by sertoli cells.3.To demonstrate the effects of FasL in the process of inducing apoptosis of I lymphocytes by~sertoli cells.4.To evaluate the possibility of applying FasL or sertoli cells for preventing allografts from immune rejection. To supply experimental clues for further in vivo and clinical studies.The present study contains the following two parts:1.Effects of mouse sertoli cells on the matured T lymphocytesin vitro.Objective: To study the influence of effects induced by mouse sertoli cells on apoptosis of the matured T lymphocytes in vitro.Methods:Apoptosis and its rates of mouse matured T lymphocytes were studied using TUNEL, DNA electrophoresis, electromicrography and Flow cytometry in control group(T lymphocytes only), group A (T lymphocytes +the 24 hours cultured medium of sertoli cells), group B (T lymphocytes + sertoli cells). Results: T lymphocytes in all groups underwent apoptosis. The apoptotic rates of T lymphocytes in group A6 ＿。。dMMeqwwW,W。,＿。 一 0and B were significantly higher than that in the control group(P<0.0 I).2.The effect of FasL in the process of inducing apoptosis of the matured T lymphocytes by sertoli cells.Objective: To study the effect of FasL in the process of inducing apoptosis of the matured I lymphocytes by sertoli cells. Methods:Different primers were designed to block the express of FasL on sertoli cells. A mGuse k~ratinocyte cell line was set up with continuous express...