近年来肠病毒71亚型（EV71）的大规模流行已成为全世界特别是亚太地区的一个严重的公共卫生问题。EV71感染可以引起腹泻，皮疹，手足口病等等一些自愈性疾病。然而在部分儿童患者中，EV71可能导致严重的神经性疾病。目前，关于EV71感染后宿主细胞的反应机制的报导比较少。在本次研究中，我们运用蛋白组学方法对EV71感染后的人横纹肌瘤细胞的蛋白表达情况进行了分析，最终发现了42个差异表达的蛋白（>2倍的变化，P <0.05），其中21个下调， 21个上调。进一步分析表明，这些蛋白主要参与了细胞内代谢，生物学调控，细胞构建，信息传递和细胞死亡的调控。 接下来我们选择了其中一个变化比较大的蛋白：HSP27，对其功能进行了深入分析。我们的研究结果显示：EV71感染的早期阶段，HSP27在转录和翻译水平上都有明显上调。降低HSP27表达可以减少EV71的复制，过表达HSP27则可以提高病毒复制。通过使用特异的磷酸化蛋白抗体，我们发现HSP27第15位以及78位的丝氨酸有明显的磷酸化修饰，而82位的丝氨酸则没有发生改变。使用p38激酶抑制剂预先处理细胞可以降低HSP27的磷酸化修饰，从而抑制EV71的复制。进一步分析表明，HSP27可以帮助EV71蛋白酶2A对真核翻译起始因子eIF4G的剪切，从而加强病毒自身蛋白的翻译，最终促进了病毒的感染。这项研究结果阐明了宿主细胞EV71的反应机制，有利于我们对病毒致病机制的研究，并为EV71的抗病毒研究提供了一个新的药物靶标。 / The outbreaks of enterovirus 71 (EV71) infections have become a major public health issue worldwide, especially in the Asia-Pacific region. EV71 infection can be asymptomatic or cause diarrhea, rashes, and hand, foot, and mouth disease (HFMD). However, EV71 can also cause severe neurological disease even death. To date, little is known about the molecular mechanisms of the host response to EV71 infection. In this study, the expression patterns of host genes in EV71 infected human rhabdomyosarcoma cells were analyzed by using two-dimensional proteomics assays. In total, 42 protein spots were found to be differentially expressed (>2 fold changes, p<0.05) in three pairs of gels, of which 21 proteins were found to be down-regulated while 21 were up-regulated. Data analysis suggested that proteins associated with metabolic process, biological regulation, cellular component organization, cell communication and death were most modified. HSP27, one of the most altered proteins during EV71 infection, was selected to determine its fundamental roles upon EV71 infection. We show that HSP27 is rapidly up-regulated both at the transcriptional and the translational levels at the early stage of EV71 infection. Depleting cellular HSP27 expression reduced EV71 replication, while over-expression of HSP27 greatly enhanced viral infection. By using the phosphorylated specific antibodies, serine residues 15, 78, but not the 82 were found to be phosphorylated during EV71 infection. The phosphorylation depended on the activation of the mitogen-activated protein kinase p38 signaling pathway. After treating with p38 kinase inhibitors, EV71 replication was coordinately decreased. Further analysis showed that HSP27 affected the protease 2A mediated eIF4G cleavage and assisted the IRES driven translation, thus facilitated the EV71 replication. The findings in this work not only provided a global view of the host responses to EV71 infection, but demonstrated HSP27 to be a valid target for anti-EV71 drug development. / Detailed summary in vernacular field only. / Yi, Lina. / "September 2012." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 94-103). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese. / Abstract --- p.i / 摘要 --- p.iii / Acknowledgement --- p.iv / Publications --- p.v / Table of Contents --- p.vii / List of Tables and Figures --- p.x / List of Abbreviation --- p.xii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Enterovirus 71 --- p.2 / Chapter 1.1.1 --- Clinical features --- p.2 / Chapter 1.1.2 --- Molecular epidemiology of EV71 --- p.5 / Chapter 1.1.3 --- The virology of EV71 --- p.8 / Chapter 1.1.4 --- Pathogenesis --- p.18 / Chapter 1.1.5 --- Treatment of EV71 infection --- p.20 / Chapter 1.2 --- The heat shock protein 27 --- p.23 / Chapter 1.2.1 --- Properties of HSP27 --- p.23 / Chapter 1.2.2 --- Functions of Hsp27 --- p.26 / Chapter 1.2.5 --- Phosphorylation of Hsp27 --- p.28 / Chapter 1.2.6 --- Hsp27 and Viral infection --- p.31 / Chapter 1.3 --- Thesis hypothesis and objective --- p.33 / Chapter Chapter 2 --- Materials and Methods --- p.34 / Chapter 2.1 --- Cells and Virus propagation --- p.35 / Chapter 2.2 --- Viral infection --- p.35 / Chapter 2.3 --- 2-DE and image analysis --- p.36 / Chapter 2.4 --- MALDI-TOF-MS --- p.37 / Chapter 2.5 --- Database analysis --- p.38 / Chapter 2.6 --- Bioinformatic analysis --- p.38 / Chapter 2.7 --- Plasmids --- p.39 / Chapter 2.8 --- siRNA synthesis --- p.41 / Chapter 2.9 --- Transfection and cell treatment --- p.41 / Chapter 2.10 --- RNA extraction and cDNA synthesis --- p.41 / Chapter 2.11 --- Real-Time Quantitative PCR --- p.42 / Chapter 2.12 --- Western Blotting analysis --- p.44 / Chapter 2.13 --- Luciferase assays --- p.44 / Chapter 2.14 --- Statistical Analysis --- p.45 / Chapter Chapter 3 --- Proteomic analysis of cellular protein alterations in response to EV71 infection --- p.46 / Chapter 3.1 --- Introduction --- p.47 / Chapter 3.2 --- Results --- p.48 / Chapter 3.2.1 --- EV71 infection of the RD cells --- p.48 / Chapter 3.2.2 --- 2-DE profiling of EV71 infected and non-infected RD cells --- p.49 / Chapter 3.2.3 --- Identification of differentially expressed proteins --- p.50 / Chapter 3.2.4 --- Functional classification --- p.52 / Chapter 3.2.5 --- GO enrichment analysis --- p.54 / Chapter 3.2.6 --- Protein validation by Western blot --- p.56 / Chapter 3.3 --- Discussion --- p.57 / Chapter Chapter 4 --- HSP27 effects on EV71 infection --- p.62 / Chapter 4.1 --- Introduction --- p.63 / Chapter 4.2 --- Results --- p.64 / Chapter 4.2.1 --- Increased Hsp27 expression in EV71 infected cells --- p.64 / Chapter 4.2.2 --- Suppression of Hsp27 inhibits EV71 replication --- p.65 / Chapter 4.2.3 --- Over-expression of Hsp27 increases EV71 replication --- p.66 / Chapter 4.2.4 --- Hsp27 is rapidly phosphorylated during EV71 infection --- p.67 / Chapter 4.2.5 --- Pathways involved in Hsp27 phosphorylation --- p.68 / Chapter 4.2.6 --- Role of Hsp27 phosphorylation during EV71 infection --- p.68 / Chapter 4.3 --- Discussion --- p.70 / Chapter Chapter 5 --- HSP27 facilitate EV71 IRES driven translation --- p.75 / Chapter 5.1 --- Introduction --- p.76 / Chapter 5.2 --- Results --- p.79 / Chapter 5.2.1 --- Hsp27 increase viral IRES activity --- p.79 / Chapter 5.2.2 --- Hsp27 affects EV71 2A mediated eIF4G cleavage --- p.80 / Chapter 5.3 --- Discussion --- p.82 / Chapter Chapter 6 --- Summary and Perspectives --- p.87 / Chapter 6.1 --- Summary --- p.88 / Chapter 6.2 --- Perspectives --- p.89 / Reference --- p.93

Lu, Jing. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 119-138). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.