癌细胞上皮-间质细胞转化（EMT）是肿瘤侵袭转移的核心环节，肿瘤免疫也是重要的影响因素。申请者前期研究发现aPKC-ι调控胆管癌EMT并诱导CD4+CD25-Foxp3+T细胞数目的增加；并利用Raybio芯片技术，发现aPKC-ι促进胆管癌细胞分泌趋化因子CCL5，以及CD4+CD25-Foxp3+T细胞诱导胆管癌间质表型标志物N-cadherin表达。申请者据此推测：aPKC-ι介导的胆管癌间质表型细胞通过趋化因子CCL5与CD4+CD25-Foxp3+T细胞形成正反馈环路，进而影响胆管癌侵袭转移。本项目拟阐明aPKC-ι促进胆管癌细胞分泌CCL5的分子机制；构建aPKC-ι基因敲除和转基因小鼠，利用分子干预策略及共培养体系，探讨aPKC-ι介导的胆管癌间质表型细胞与CD4+CD25-Foxp3+ T细胞之间的正反馈环路形成机制。本项目可望从新的角度为胆管癌治疗的新策略提供依据。

Epithelial-Mesenchymal Transition is a core aspect of the invasion and metastasis in tumor initiation stage, meanwhile the tumor immunity is also an important factor. In the previous studies, the applicant firstly found that aPKC-ι could regulate the epithelial-mesenchymal transition in Cholangiocarcinoma, and the number of CD4+CD25-Foxp3+T cells was increased in vitro. Then antibody array showed that the level of CCL5 was higher in the culture supernatant for the cells with highly expressed aPKC-ι. Furthermore, the applicant also find that CD4+CD25-Foxp3+T cells could promote the expression of N-cadherin in cholangiocarcinoma, a mesenchymal marker. Based on the above statements, we infer that there is a positive feedback loop between the mesenchymal cells mediated by aPKC-ι and CD4+CD25-Foxp3+T cells formed by the messenger of CCL5, then it can promote the invasion and metastasis in cholangiocarcinoma. Our project intends to demonstrate the molecular mechanism of aPKC-ι regulating the secretion of CCL5 in cholangiocarcinoma cells, construct the knockout and transgenic mouse targeted at aPKC-ι, using molecular intervention strategies and co-culture system to demonstrate the mechanism of positive feedback loop between the mesenchymal cells mediated by aPKC-ι and CD4+CD25-Foxp3+T cells. This project aims to provide new clues for the therapy in cholangiocarcinoma.