经CRISPR/Cas9敲入CCR7基因的iPS细胞分化的调节性DC的体内迁移及其诱导免疫耐受的研究

调节性树突状细胞(Regulatory Dendritic Cell, DCreg)因在维持免疫耐受方面的重要作用，被认为可以用来治疗自身免疫性疾病及移植免疫排斥。然而体外培养的DCreg，包括我们前一课题中成功诱导的iPS细胞由来的DCreg都极少表达CCR7分子，同时其在生体内的迁移受阻，很难迁至外周淋巴组织发挥作用，严重限制了体外培养DCreg的临床应用。因此，本项目设想结合iPS细胞可编辑的特性，利用目前最新发展的基因编辑技术CRISPR/Cas9将CCR7基因敲入小鼠iPS细胞，构建CCR7特异性iPS细胞（CCR7-iPS）。探索诱导CCR7-iPS细胞向DCreg分化，实现CCR7-iPS细胞由来的DCreg稳定表达CCR7，迁移能力提高，并发挥诱导免疫耐受的作用。本项目从实际问题出发，从诱导的源细胞入手解决DCreg的体内迁移问题，成果将为DCreg的临床应用建立重要基础。

Regulatory dendritic cell (DCreg) have an important role in maintaining immune tolerance, are believed to be used to treat autoimmune diseases and allografts rejection. However, in vitro generated DCregs, including the induced DCreg from iPS cells in our previous study rarely expressed CCR7 molecule, and their migration in vivo was inhibited. They were not easy to move into peripheral lymphoid tissues to regulate the immune reaction effectively. This shortage of in vitro generated DCregs limited their in vivo clinical application severely. Therefore, in this project, we are going to take the advantage of the editable property of iPS cells, use the latest development gene editing technology- CRISPR / Cas9 to knock-in the CCR7 gene into the mouse iPS cells to make the CCR7-specific iPS cells (CCR7-iPS). Then，we will explore the way to induce the CCR7-iPS cells into DCregs, to achieve the CCR7-iPS cells derived DCregs with CCR7 expressing stably, improve their migration to peripheral lymphoid tissues and make them play a role in the induction of immune tolerance. This project is starting from the practical problem using the derived source cells of DCreg to resolve the migrating difficulty. The results of this project will establish an important basis for clinical application of in vitro generated DCregs.