Wang Hongmei, Zhang Xusheng, Zheng Xiufen, Lan Zhu, Shi Jun, Jiang Jifu, Zwiep Terry, Li Qing, Quan Douglas, Zhang Zhu-Xu, Min Weiping
Institute of Immunotherapy and Medical College of Nanchang University, and Jiangxi Academy of Medical Sciences, Nanchang, China.
Department of Surgery, Pathology, and Oncology, University of Western Ontario, London, Canada.
Sci Rep. 2016 Sep 23;6:33869. doi: 10.1038/srep33869.
Toll-like receptors (TLRs) act as initiators and conductors responsible for both innate and adaptive immune responses in organ transplantation. The mammalian target of rapamycin (mTOR) is one of the most critical signaling kinases that affects broad aspects of cellular functions including metabolism, growth, and survival. Recipients (BALB/c) were treated with MyD88, TRIF and mTOR siRNA vectors, 3 and 7 days prior to heart transplantation and 7, 14 and 21 days after transplantation. After siRNA treatment, recipients received a fully MHC-mismatched C57BL/6 heart. Treatment with mTOR siRNA significantly prolonged allograft survival in heart transplantation. Moreover, the combination of mTOR siRNA with MyD88 and TRIF siRNA further extended the allograft survival; Flow cytometric analysis showed an upregulation of FoxP3 expression in spleen lymphocytes and a concurrent downregulation of CD40, CD86 expression, upregulation of PD-L1 expression in splenic dendritic cells in MyD88, TRIF and mTOR treated mice. There is significantly upregulated T cell exhaustion in T cells isolated from tolerant recipients. This study is the first demonstration of preventing immune rejection of allogeneic heart grafts through concurrent gene silencing of TLR and kinase signaling pathways, highlighting the therapeutic potential of siRNA in clinical transplantation.
Toll样受体（TLRs）在器官移植中作为先天免疫和适应性免疫反应的启动者和传导者。雷帕霉素哺乳动物靶点（mTOR）是影响细胞功能广泛方面（包括代谢、生长和存活）的最关键信号激酶之一。受体（BALB/c）在心脏移植前3天和7天以及移植后7天、14天和21天用MyD88、TRIF和mTOR siRNA载体进行处理。siRNA处理后，受体接受完全MHC不匹配的C57BL/6心脏。mTOR siRNA处理显著延长了心脏移植中同种异体移植物的存活时间。此外，mTOR siRNA与MyD88和TRIF siRNA联合使用进一步延长了同种异体移植物的存活时间；流式细胞术分析显示，在MyD88、TRIF和mTOR处理的小鼠中，脾淋巴细胞中FoxP3表达上调，同时CD40、CD86表达下调，脾树突状细胞中PD-L1表达上调。从耐受受体分离的T细胞中T细胞耗竭明显上调。本研究首次证明通过同时沉默TLR和激酶信号通路来预防同种异体心脏移植物的免疫排斥，突出了siRNA在临床移植中的治疗潜力。
