EV71病毒调控DNA损伤反应标志蛋白γ-H2AX 表达、定位及包装进病毒的机制研究

Hand, foot, and mouth disease (HFMD) is generally a febrile exanthematous disease prevalent in children younger than 5 years of age. The main symptoms of HFMD are vesicles on the palmar and plantar surfaces of the hands and feet, buccal mucosa, tongue, and buttocks, sometimes accompanied by death in young children. Many large outbreaks of HFMD have been reported in China. Although the vaccine with protective effect has been available to prevent HFMD in China as of December 2015, the scope of vaccination is limited to some of children and targeting virus is limited to human enterovirus 71 (EV71), and that, drugs for HFMD treatment are not available, largely because the pathogenic mechanism of HFMD has not been elucidated. . EV71 is a primary causative agent for HFMD, our previous study shows that EV71 replication induces cell cycle arrest in S phase to produce favorable conditions for viral production, but about the detailed mechanism of cell cycle arrest induced by EV71 infection is still not clear. It is reported that DNA damage response (DDR) is related to cell cycle arrest. Numerous viruses introduce DNA damage and genetic instability in host cells during their lifecycles and lead to cell cycle arrest. Activation and manipulation of the DDR by DNA viruses and retrovirus has been extensively studied, for example, small DNA virus adenovirus and retrovirus HIV induce DDR to arrest cell cycle. It is apparent, however, that many RNA viruses can also induce significant DNA damage and cell cycle arrest, even in cases where viral replication takes place exclusively in the cytoplasm. Basing on the regulation of EV71 in cell cycle we investigate the effect of EV71 on DDR, and we show that EV71 replication promotes γ-H2AX expression and induces DDR. Though γ-H2AX is canonically localized to the nuclei, EV71 induces the location in the cytoplasm, where it becomes packaged into virions and binds to the EV71 genome, but the mechanism underlying the phenomena is not clear.. In this study, we will investigate the detailed mechanism of EV71 regulating γ-H2AX expression, γ-H2AX cytoplasmic location, γ-H2AX package into virions and the effect of γ-H2AX on viral proliferation. And this study will further deep our understanding of the pathogenic mechanisms of EV71 and provide a potential target for the treatment and prevention of HMDF disease...

手足口病是一种全球流行性婴幼儿传染病，临床症状为手、足、口腔等部位的疱疹，少数患儿因并发神经系统症状而死亡。近年来在中国频频大规模爆发，目前尚无全面的预防接种及有效的治疗措施。人肠道病毒71型(EV71)是引起手足口病的主要病原之一，其利用宿主大量复制扩增是其致病的直接原因，所以从多角度阐明EV71致病机制十分紧迫。在完成国家自然基金青年项目后，我们对EV71诱导的DNA损伤反应(DDR)进行了初步研究，发现了病毒上调DDR标志蛋白γ-H2AX表达，定位γ-H2AX于细胞质，以及包装γ-H2AX进病毒等现象。但到目前为止，关于EV71病毒如何调控γ-H2AX表达，如何定位γ-H2AX于细胞质，如何包装γ-H2AX进病毒，以及γ-H2AX如何影响病毒扩增这些问题仍是未知。本课题将通过分子生物学手段对以上四个问题一一阐述。这将进一步完善EV71病毒致病机制，为药物研发和临床治疗提供理论依据。

手足口病是一种全球流行性婴幼儿传染病，临床症状为手、足、口腔等部位的疱疹，少数患儿因并发神经系统症状而死亡。近年来在中国频频大规模爆发，目前尚无全面的预防接种及有效的治疗措施。人肠道病毒71型(EV71)是引起手足口病的主要病原之一，其在患儿体内大量复制扩增是患儿出现各种临床症状的直接原因，所以从多角度阐明EV71病毒复制机制十分紧迫。在完成国家自然基金青年项目后，我们对EV71诱导的DNA损伤反应(DDR)进行了初步研究，发现了病毒上调DDR标志蛋白γ-H2AX表达，定位γ-H2AX于细胞质，以及包装γ-H2AX进病毒等现象。在本课题中，我们发现EV71激活ATR通路来上调γ-H2AX水平，说明EV71促进γ-H2AX的产生；定位γ-H2AX于细胞质，主要涉及其核质穿梭，抑制核质穿梭γ-H2AX定位于细胞质的能力降低；包装γ-H2AX进病毒，可能与其结合病毒蛋白3D和VP3相关。本课题从最初的现象观察到如今的机制分析，深入地阐述了EV71对宿主的调控机制，完善了EV71致病机制，揭示了EV71与DDR的相互作用关系，为药物研发和临床治疗提供理论依据。