柯萨奇病毒A组16型引起的线粒体自噬对炎性小体的调节作用研究

Coxsackievirus A16 (CA16) infection, responsible for hand, foot, and mouth disease (HFMD), has become a common health problem due to the prevalence of the virus, the lack of specific vaccine or drugs, and the incomplete understanding of its pathogenic mechanism. As the target of the virus, mitochondrial dysfunction, in one hand activates the inflammasome and promote inflammation, on the other hand, triggers mitophagy, and inhibit the activation of inflammasome, thus maintaining mitochondrial balance is particularly important for host antiviral responses. This project aims to explore the molecular mechanism of CA16 induced mitophagy, and further identify its influence on the activation of inflammasome on basis of previous research findings. To verify that the host cells eliminate damaged mitochondria by mitophagy in the early stage of CA16 infection, as the infection time increases, the decompensation of mitophagy occurs, the number of damaged mitochondria increases, and the inflammasome is activated, leading to the responses of inflammation. And to explore the regulatory proteins of CA16 in mitophagy induced inflammatory activation. This project analyses the possibility of the regulation of mitophagy in the treatment of inflammatory diseases caused by CA16 and provide theoretical and experimental basis for the prevention and treatment of CA16-induced HFMD.

柯萨奇病毒A组16型(Coxsackievirus A16，CA16)为手足口病的主要病原体之一，其致病机制尚未阐明，且缺乏针对该病毒特异性治疗手段和有效疫苗。线粒体作为病毒作用的靶器官，在损伤时一方面可激活炎性小体促进炎症反应，另一方面则引起线粒体自噬，抑制炎性小体的激活作用，由此可见维持线粒体的平衡对于宿主抗病毒反应显得尤为重要。依据前期研究的发现，本项目拟探究CA16引发线粒体自噬的分子机制，进一步确认所引发的线粒体自噬对炎性小体的影响，以验证在CA16感染早期，细胞能通过线粒体自噬消除受损线粒体，随着感染时间增长，当线粒体自噬失代偿时，受损线粒体将增多，炎性小体被激活，促进炎症反应发生发展。并探讨CA16通过哪些自身调节蛋白引起线粒体自噬影响炎性小体的产生，分析调节线粒体自噬治疗CA16引发的炎性疾病的可能性，为防治此类疾病提供理论和实验依据。

柯萨奇病毒A组16型（Coxsackievirus A 16，CVA16）是手足口病的主要病原体，儿童普遍易感。CVA16是单股正链RNA病毒，已有的流行病学数据显示，由CVA16引发的手足口病是一个严重的世界性公共卫生问题。目前，尚无有效的CVA16疫苗或有效的抗CVA16药物，研究CVA16的致病机制迫在眉睫。病毒感染宿主细胞后会引发自噬。通常宿主细胞可以通过自噬降解病毒。然而，病毒的某些组分也可调控自噬途径以促进复制。线粒体是细胞重要的能量供给体，也是多种病毒作用的细胞器之一。消除病毒对线粒体的影响，保持宿主细胞内线粒体平衡对于抗病毒至关重要。目前，发现多种病毒能够破坏胞内线粒体平衡引发炎症反应。胞内的线粒体的数量和功能的平衡依赖于一种选择性的自噬——线粒体自噬。炎性小体是控制炎症的多蛋白信号传导平台，能够感应和协调抗微生物宿主防御。受损的线粒体可以通过释放线粒体信号激活炎性小体，而线粒体自噬可以清除受损线粒体限制炎性小体的激活。. 我们的研究发现，CVA16损伤线粒体，导致线粒体DNA、线粒体活性氧和细胞色素C的释放；CVA16通过线粒体DNA、线粒体活性氧、细胞色素C及其病毒RNA激活NLRP3炎性体，并导致IL-1β的产生；CVA16损伤的线粒体通过Parkin依赖的途径与泛素结合，并被自噬受体p62/SQSTM1特异性识别，从而诱发线粒体自噬。Parkin表达受抑制时促进了NLRP3炎症体的活化和IL-1β的产生；对受损线粒体信号（包括mtDNA、mtROS和细胞色素C/caspase-9途径）的抑制限制了NLRP3炎性体的激活并促进了CVA16的复制；其中细胞色素C/caspase-9是病毒促进NLRP3炎症体活化的新发现的途径。