牛和猪天然免疫Toll样受体8型（TLR8）细胞内信号通路机制

The family of innate immune receptors plays a key role in the recognition of pathogens and initiation of immune responses. However, the information of innate receptor function and cell signaling transduction in domestic animals is especially lacking. The research on the innate receptor Toll-like receptor 8 (TLR8) has been backward relative to others, but TLR8 attracted much attention recently. Previously, the applicant studied systematically bovine TLR8 (bTLR8) and porcine TLR8 (pTLR8) in terms of the ligand recognition, cellular localization, signaling essential sites, dimerization and the mechanism of activation. From the study, there were several important findings, for example: bTLR8 and pTLR8 can be recognized and activated by TLR7 specific agonist Imiquimod; both bTLR8 and pTLR8 ectodomain (ECD) are localized intracellularly. Current proposal will further explore the molecular basis of the above findings. Furthermore, the applicant will make TLR8 stable cells and TLR8-NF-kB stable reporter cells combined with RNA-Seq to search for the signaling molecules of the TLR8-NF-kB pathway including those of bTLR8 and pTLR8 specific. This study will shed light on the livestock TLR, broaden the knowledge of the human and mouse TLR8, and provide a template for studying other animal innate immune receptors.

天然免疫受体家族在识别病原和影响免疫应答方面起关键作用，但是家畜动物的天然免疫受体功能和信号通路研究非常缺乏。 天然免疫受体TLR8过去研究相对滞后，近年来吸引研究者注意。 申请人过去系统研究了牛和猪TLR8的配体识别特异性、细胞定位、受体活化信号位点、二聚化和活化机制。 研究发现牛和猪TLR8都能识别TLR7特异激活剂Imiquimod； 胞外区（ECD）蛋白在细胞内定位等。 针对这些发现，本项目继续研究其分子基础。 同时利用TLR8稳定细胞系和TLR8-NF-kB稳定报告细胞系结合RNA深度测序（RNA-Seq）技术，寻找并确定牛和猪TLR8细胞通路信号分子包括家畜动物特异性信号分子。 本研究将丰富对家畜动物天然免疫受体的认识，填补人和鼠天然免疫受体TLR8的认识空白，也为其它动物天然免疫受体信号机制研究提供模板。

天然免疫受体家族在识别病原和影响免疫应答方面起关键作用，但是家畜动物的天然免疫受体功能和信号通路研究非常缺乏。天然免疫受体TLR8过去研究相对滞后。申请人在过去系统研究牛和猪TLR8的配体识别特异性、细胞定位、受体活化信号位点、二聚化和活化机制的基础上，进一步研究猪和人TLR8识别咪唑喹啉小分子配体包括Imiquimod（R837）的氨基酸位点；胞外区（ECD）蛋白在细胞内定位及其调控机制；同时利用猪和人TLR8-NF-kB报告细胞系结合RNA深度测序（RNA-Seq）技术，寻找并确定猪TLR8信号特异细胞通路信号分子并研究其对TLR8信号反馈调控作用。本研究发表了7篇SCI免疫学研究论文，其它3篇论文即将发表或正在撰写，另外转让产品1项。因此我们的研究丰富了家畜动物天然免疫受体信号的认识，填补人和鼠天然免疫受体TLR8的认识空白。