特异性磷酸受体-1调节剂抑制高危角膜移植免疫排斥的机制研究

Sphingosine 1-phosphate receptor 1 (S1P1) belongs to the family of g-protein coupled receptors, decrease in peripheral blood lymphocytes, inhibiting their access to target organ Allograft transplantation, blocking immune rejection rejection role, but its ability to curb occurrence of complex immunological rejection after corneal transplantation there is no research。Our preliminary research suggests that selective S1P1 receptor modulators can significantly extend the corneal Allograft transplant graft survival time in mice, play a strong inhibition of repulsion, and can significantly increase the number of CD4+ local draining lymph node cells。For this reason, this study will further Verify protein (Profile-3D) program to filter and a target protein structure prediction, observation S1P1 modulators on complex after high-risk cornea graft rejection of corneal transplant in rats, explore S1P1 regulatory Treg and Th17 immune cell distribution and circulation, promoting lymphocytes "homing", inhibiting their access to transplantation immune tolerance induced by mechanism of action。And lymphocyte immune factor expression after in vitro S1P1 changes to illustrate S1P1 regulating lymphocyte cyclic signaling mechanism to provide theoretical and practical basis of science, discovery and access of new type high effect and low toxicity immunosuppressant is of great scientific significance and value.

鞘氨醇1-磷酸受体1（S1P1）属于G蛋白偶联受体家族，具有减少外周血淋巴细胞，抑制其进入同种异体移植靶器官，阻断免疫排斥发生的独特抗排斥作用，但其能否抑制复杂角膜移植术后免疫排斥的发生尚无研究。我们前期研究表明，选择性S1P1受体调节剂能明显延长小鼠同种异体角膜移植植片的存活时间，发挥强力的抑制排斥作用，并且能显著增加局部引流淋巴结中CD4+细胞数量。基于此，本研究将进一步通过Profile-3D程序对目标蛋白结构进行筛选和评估，观察S1P1受体调节剂对大鼠复杂角膜移植植片免疫排斥的抑制作用，深入探讨 S1P1调控Treg/Th17免疫细胞的分布和循环，促进淋巴细胞“归巢”，抑制其进入移植植片诱导免疫耐受的作用机制；并通过体外观察S1P1作用淋巴细胞后免疫因子表达变化，为阐明S1P1调控淋巴细胞循环信号机制提供科学理论和实践依据，对发现和获得新型高效低毒的免疫抑制剂具有重大的研究价值。

S1P1为G蛋白偶联受体家族成员，在各种淋巴细胞表面表达广泛，有非常重要的免疫调节功能。S1P1调节剂为本研究团队自主研发的小分子化合物，具有诱导免疫排斥赦免的作用。本研究针对S1P1小分子化合物的抗排斥作用，通过profile-3D程序筛选出的优质目标化合物，用procheck评估了模建的蛋白三维结构的合理性。完成了同种异基因大鼠角膜移植模型中S1P1受体调节剂抑制植片免疫排斥的药效学观察及与其他药物的对比，结果提示S1P1用药组植片存活时间明显延长于阴性对照组，环孢霉素组和雷帕霉素组。进一步体外试验表明通过磁珠分选后的淋巴细胞DC细胞，给予S1P1 siRNA转染后能诱导成熟的淋巴细胞出现抗免疫排斥的效果。S1P1组大鼠外周血中CD4+CD25+FoxP3，Treg细胞明显增多，在外周血、脾脏、局部引流淋巴结中Th17细胞表达明显减少。S1P1实验组中细胞表面分子CD80表达水平的变化，较对照组均具有统计学意义。