移植肾基质微环境调控致耐受性DC功能的机制及其在免疫耐受诱导与维持中的作用

Dendritic cells (DC) are the key cells in the renal mediated immune response. Tolerogenic dendritic cells (tol DC) play a key role in the induction and maintenance of immune tolerance, but the mechanism of their differentiation and function remains unclear. Previous studies confirmed the spleen/liver stromal microenvironment were involved in the regulation of the differentiation of their DC, but there is no similar research in the kidney. Our previous findings of the National Natural Science Foundation showed that ischemia-reperfusion injury can change the kidney stromal microenvironment, and the phenotype of renal DC varies. We suspect the special change of the stromal microenvironment of the transplanted kidney takes part in the regulation of DC the immunological characteristics differentiation, thereby influencing the proportion and function of tol DC, mediating the induction and maintenance of immune tolerance. Based on this hypothesis, the project intends to analyze the changes in renal stromal microenvironment after kidney transplantation and the effect of the changes in the immunological characteristics of tol DC with flow cytometry, laser scanning confocal microscopy and two-photon microscope technology in the mouse kidney transplantation models divided into immune rejection, immunosuppression and immune tolerance experimental groups in vivo and vitro respectively; to interfere kidney stromal microenvironment to induce tol DC differentiation in vitro and then reinfuse them back into the mice with no kidney transplantation history, exploring the role of tol DC in immune tolerance induction and maintenance of kidney transplantation, hopefully providing new theoretical evidence for clinical anti-rejection therapy.

树突状细胞（DC）是介导肾脏免疫反应的关键细胞。致耐受性DC（tolDC）在免疫耐受的诱导与维持中发挥重要作用，但其分化及功能的调控机制尚不明确。前期研究已证实脾脏/肝脏基质微环境参与调控其DC的分化，但在肾脏尚无相关研究。我们在前一个国家自然科学基金的研究发现，缺血再灌注损伤可致肾脏基质微环境改变，并使肾脏固有DC表型随之变化。我们推测，移植肾基质微环境所经历的特有变化参与调控DC的免疫学特性变化，进而影响tolDC的比例及功能，介导免疫耐受的诱导与维持。在此基础上，本项目拟采用小鼠肾移植模型，构建排斥、免疫抑制和免疫耐受实验组，采用流式细胞分选、激光扫描共聚焦显微镜及双光子显微镜等技术，分别在活体内外分析肾基质微环境在移植后的改变及其对tolDC免疫学特性的影响；体外干预肾基质微环境，诱导tolDC并过继回输，探究其在肾移植免疫耐受诱导与维持中的作用，为临床抗排斥治疗提供新的理论依据。

树突状细胞(DC)是介导肾脏免疫反应的关键细胞。致耐受性DC(tolDC)在免疫耐受的诱导与维持中发挥重要作用。我们前期研究发现，缺血再灌注损伤可致肾脏基质微环境改变，并使肾脏固有DC表型随之变化。我们推测，移植肾基质微环境的变化可以调控DC的免疫学特性变化，进而影响tolDC的比例及功能，介导免疫耐受的诱导与维持。在此背景上，我们利用小鼠肾移植模型，构建排斥、免疫抑制和免疫耐受模型，发现肾基质微环境在移植后Vimentin、Desmin、α-SMA、TIMP-1/-2的表达均发生了变化，同时，受者小鼠DC的表型、功能也发生了显著的不同。体外验证上述实验，观察LPS刺激对DC的表型和功能的影响，发现小鼠肾脏基质细胞可以通过IL-10介导负向免疫而调控DC的分化和表型。最后，体外干预肾基质微环境，诱导tolDC并过继回输TRDC和SRDC，发现均能显著延长受者小鼠的存活时间，并且预防移植肾损伤。探究其在肾移植免疫耐受诱导与维持中的作用，为临床抗排斥治疗提供新的理论依据。