基于肠道菌群-调节性T细胞路径探讨粪菌移植联合柴苓汤诱导小鼠心脏移植免疫耐受的实验研究

课题组前期研究发现柴苓汤可诱导小鼠心脏移植免疫耐受，但其作用仅限于柴苓汤2g/kg/d，而柴苓汤0.2g/kg/d虽然能延长移植心脏存活时间却并不能诱导免疫耐受。由于肠道菌群具有促进Treg扩增的作用，预试验也发现：以接受粪菌移植小鼠作为受体，移植心脏存活时间明显延长，提示肠道菌群在小鼠心脏移植免疫排斥中可能发挥重要作用。因此本研究尝试将粪菌移植联合低剂量柴苓汤应用于小鼠心脏移植，应用宏基因组方法分析肠道菌群变化，并筛选出丰度显著升高的细菌；应用流式细胞术、免疫荧光、实时定量RT-PCR、Western Blot等技术，检测Treg、PI3K/AKT/mTOR通路分子的动态变化，观察粪菌移植联合低剂量柴苓汤能否诱导免疫耐受并探讨其机制。本项目集合成员的研究优势并在前期研究的基础之上创新性地将粪菌移植联合中药复方引入移植免疫研究，能充分发挥中西医结合的优势，为移植免疫耐受研究提供一个新的思路。

Previous studies found that Chailing decoction could induce immune tolerance in mice heart transplantation, but its effect was limited to Chailing decoction 2g/kg/d, while Chailing decoction 0.2g/kg/d could only prolong the survival time of cardiac allograft, but could not induce immune tolerance. Because gut microbiota can promote the expansion of Treg, the results of pre-tests also found that the survival time of cardiac allograft could be significantly prolonged by using the mice received fecal microbiota transplantation as recipients, which suggested that gut microbiota might play an important role in immune rejection after heart transplantation. Therefore, in this study, we attempt to apply fecal microbiota transplantation combined with low-dose Chailing decoction in mice heart transplantation. The changes of gut microbiota will be analyzed by metagenomics sequencing approach, and the bacteria with significantly increased abundance will be screened out. The dynamic changes of the Treg level and the mTOR signal pathway molecules expression will be analyzed by using the methods of FACS, immune stain, real time RT-PCR, Western blot, to observe whether fecal microbiota transplantation combined with low-dose Chailing decoction could induce immune tolerance or not and explore its mechanisms. The study brings together the advantages of the research team in related research and innovatively introduce fecal microbiota transplantation combined with traditional Chinese medicine into transplantation immunity research on the basis of previous research, which might exert the advantages of integrated Chinese and Western medicine, and provide a new way for the research of transplantation immunity.