TRPV2通道在树突状细胞中的表达及其在抗病毒免疫反应过程中的功能与机制研究

The various diseases caused by virus infection pose a great threat to people’s health and life safety. The human immune system protects us from virus infection by resisting the invasion of the virus, removing the virus and infected cells, and inducing tissue repair. Recent advances have shown that ion channels play an important role in immune cells and immune responses. The nociceptive receptor TRPV2 channel is widely distributed in nerves and non-nerve tissues and plays a wide variety of functions in different tissues. Previous researches had suggested TRPV2 was involved in sensing physical stresses, such as changes in pressure and temperature, as well as in detecting immune challenges and activating the immune system's T cells. Dendritic cells (DCs) are the most potent professional antigen presenting cells, which are specialized for the capture, processing and presentation of antigens in the context of either major histocompatibility complex (MHC) class I or II molecules to T cells, and they also play an important role in innate immune functions. Our preliminary data demonstrate that TRPV2 channels expressed not only in nerve cells such as dorsal root ganglion (DRG) neurons but also in innate immune cells such as DCs, and the expression level was regulated by virus infection. In DCs, activation of TRPV2 channels by 2-APB could significantly promote the replication of VSV or HSV-1 viruses, while inhibition of TRPV2 by Ruthenium Red (RR) or the selective inhibitor SKF96365 could remarkably depress virus replication, suggesting that TRPV2 channels play a key role in the process of antiviral immune responses. In this project, we aim to explore the functional role of TRPV2 in the process of antiviral immune responses in DCs, and to elucidate the mechanisms how TRPV2 regulate the virus infection and the following immune reaction during virus infection by employing a wide variety of techniques and means including TRPV2 knock out mice. The results from our study will not only expand our understanding of the functional roles of TRPV2 channel in inflammatory and immune cell function, but also provide potential targets for drug development and theoretical basis for clinical diagnosis and treatment of viral disease.

免疫系统通过抵御病毒入侵、清除病毒和感染的细胞并诱导组织修复而维护机体健康，研究表明离子通道在免疫细胞和免疫反应中发挥重要作用。TRPV2广泛分布于神经与非神经组织中，在不同组织中起着多样化功能。树突状细胞（dendritic cells, DCs）能高效地摄取、加工和递呈抗原，在机体免疫系统中发挥重要作用。我们前期发现：1）具有良好离子通道活性的TRPV2在DCs中高表达，且其表达水平受病毒感染调控；2）激活或抑制TRPV2显著促进或抑制VSV与HSV-1病毒在DCs中的复制，暗示TRPV2在抗病毒免疫反应中发挥作用。本项目旨在明确TRPV2在DCs中的表达及其在DCs分化中的功能，进而探讨TRPV2在DCs抗病毒天然免疫反应过程中的功能与机制，并阐明病毒感染调控TRPV2活性的机制。研究结果将能促进人们对TRPV2通道功能的了解，而且还为治疗病毒性疾病的药物开发提供分子靶标与理论基础。

研究背景：免疫系统通过抵御病毒入侵、清除病毒和感染的细胞并诱导组织修复而维护机体健康，研究表明离子通道在免疫细胞和免疫反应中发挥重要作用。TRPV2通道分布广泛且在不同组织中起着多样化功能。树突状细胞能高效地摄取、加工和递呈抗原，在机体免疫系统中发挥重要作用。申请人在预实验研究中发现TRPV2在树突状细胞中高表达并具有良好的离子通道活性，激活或抑制TRPV2能够显著促进或抑制VSV与HSV-1等病毒在DCs中的复制，暗示TRPV2在抗病毒感染中发挥作用。此外，与TRPV2同处相同亚家族的TRPV1和TRPV3在温度感知和痛痒觉传导上亦具有重要作用，对它们的功能调节进行研究亦具有重要意义。..主要研究内容：1）阐明TRPV2通道在抗病毒感染免疫反应中的作用及机制；2）发现并解析热敏TRPV1-3通道功能的调控新机制；3）探究TRP通道的新功能。..重要结果：1）发现并阐明了TRPV2通道通过Ca2+ -LRMDA 信号轴在树突状细胞和巨噬细胞的抗病毒感染中的作用机制；2）解析了Kv1.3通道通过调节内吞体及溶酶体等酸性细胞器的pH而阻抑病毒对宿主细胞感染的作用机理；3）综述了离子通道在免疫细胞和免疫应答反应中的功能研究进展；4）阐明了JAK1和PTPN1通过动态化修饰TRPV2通道进而调控通道活性的分子机制，及其对巨噬细胞吞噬作用的影响。5）克隆了首个蝎TRP基因（strp1），并对其所编码的sTRP1通道的功能进行了解析，揭示了瞬时受体势通道sTRP1/dTRPγ作为天然驱虫剂的分子靶标，参与介导节肢动物对环境的适应性调节，扩展了对TRP通道在跨物种尺度上的功能性理解；6）构建了TRPV1-pHluorin荧光探针，实现了活细胞中对TRPV1功能及通道蛋白循环转运的并行检测，阐明了TRPV1通道Ca2+依赖的“记忆性”脱敏机制;7）发现并阐释了Flotillin-1和Kvβ1分别通过与TRPV2和TRPV1通道蛋白直接互作而调控通道活性的机理；8）阐明1,4-dioxane和dyclonine等药物分子对TRPV1和TRPV3通道功能的调控作用机制。 ..关键数据及其科学意义：揭示了TRPV2等离子通道在抗病毒感染中的作用和分子机制，为抗病毒诊疗提供了新靶点与新思路；发现了多种调控离子通道功能的药物、互作蛋白以及信号通路，为实现靶向离子通道的功能干预提供了新策略。