IMMUNOBIOLOGY OF PANCREATIC ISLET XENOGRAFTING

描述：(改编自申请者的摘要) 建议的研究是研究T细胞介导的免疫的基础 以朗格汉斯胰岛为靶点的异种细胞移植物识别 相关模型体系。在资助期内获得的数据强劲 提示异种胰岛识别的流行模式是通过 受体CD4+T细胞识别抗原的间接途径 淋巴细胞。 在特定的目标i a中，将使用几只免疫缺陷小鼠来确定 CD_4~+T淋巴细胞对大鼠的异种反应性机制 小岛。胰岛异种移植在裸体和SCID中存活的概念 受体强烈表明，至少在小鼠受体中，排斥 这种移植物的数量依赖于T细胞。此外，还获得了证据 在第一个资助期内，这种细胞反应是CD4+T细胞 活体内依赖细胞。这项建议的第一个目标是分析 靶细胞破坏分子在异种移植排斥反应中的作用 通过直接裂解(穿孔素)、通过诱导细胞凋亡(Fas L)和通过 炎症介质(干扰素-g)。穿孔素缺陷小鼠，Fas L 缺陷小鼠(GLD/GLD)和干扰素-g缺陷小鼠将作为供体 CD4+T细胞，这些细胞将被转移到RAG1-/-受体。RAG 1-/- (T和B细胞缺陷，不像SCID小鼠那样渗漏)受者将 之前移植了大鼠胰岛。以此来检验的假设 系列实验是CD4T细胞介导的异种排斥反应 胰岛需要触发炎症，但它不需要 存在完整的细胞毒性调节分子。因此， 预期结果(得到初步发现的支持)是PKO CD4细胞 将诱导大鼠胰岛排斥反应的时间与WT CD4细胞相似， 而缺乏干扰素-g的CD4细胞在 调解移植物排斥反应。 而CD4+T细胞在异种胰岛排斥反应中的关键作用 已经确定，不能正式排除非T细胞介导的 效应器机制可能(部分或全部)对观察到的事物做出贡献 现象。因此，制定了具体的目标i b来探索这项工作 假设。特定目标Ic将检验CD4+T细胞 细胞介导的异种移植排斥反应可能不需要T细胞 受体介导的与移植靶细胞的相互作用。具体目标一 D着重分析非协调性胰岛移植物排斥反应的原因。 猪对鼠的模型系统。在具体目标二中，P.I.提议 研究诱导长期存活的中介机制 在小鼠体内移植异种胰岛的情况 抗LFA-1抗体。

DESCRIPTION: (Adapted from the applicant's abstract) The goal of the proposed research is to study the basis of T cell-mediated immune recognition of xenogeneic cellular grafts, using islets of Langerhans as a relevant model system. Data obtained during the funding period strongly suggests that the prevalent mode of xenogenic islet recognition is through the indirect pathway of antigen recognition by recipient's CD4+ T lymphocytes. In Specific Aim I a, several immunodeficient mice will be used to determine the mechanisms of CD4+ T lymphocyte-dependent xenoreactivity towards rat islets. The notion that islet xenografts survive in nude and SCID recipients strongly suggests that, it least in murine recipients, rejection of such grafts is dependent on T cells. Furthermore, evidence was obtained during the first funding period that such cellular response is CD4+ T cell-dependent in vivo. The first goal of this proposal is to analyze the role of molecules involved in target cell destruction in xenograft rejection via direct lysis (perforin), via induction of apoptosis (Fas L) and by mediation of inflammation (IFN-g). Perforin deficient mice (PKO), Fas L deficient mice (gld/gld) and IFN-g deficient mice will be used as donors of CD4+ T cells, which will be transferred into RAG1-/- recipients. RAG 1-/- (T and B cell deficient, not as leaky as SCID mice) recipients will be previously transplanted with rat islets. The hypothesis tested by this series of experiments is that CD4 T cell-mediated rejection of xenogeneic islets requires triggering of inflammation, but it does not require the presence of intact cell-cytotoxicity mediating molecules. Therefore the expected results (supported by preliminary findings) are that PKO CD4 cells will induce rat islet rejection in times similar to those of WT CD4 cells, while IFN-g-deficient CD4 cells will be significantly less efficient in mediating graft rejection. While the pivotal role of CD4+ T cells in xenogeneic islet rejection has been established, it can not be formally ruled out that non T cell-mediated effector mechanisms might contribute (partially or entirely) to the observed phenomena. Specific Aim I b is therefore set forth to explore this working hypothesis. Specific Aim I c will test the hypothesis that CD4+ T cell-mediated rejection of xenogeneic grafts might not require T cell receptor-mediated interaction with the grafted target cells. Specific Aim I d is focused on the analysis of rejection of discordant islet grafts in the pig to mouse model system. In Specific Aim II, the P.I. proposes to investigate the mechanisms that mediate the induction of long term survival of xenogeneic islets grafted in mice treated with a short course of anti-LFA-1 antibodies.