A study of the molecular pathogenesis of Murray Valley encephalitis virus in mice using infectious clone-derived virus

这个项目的重要性主要来自澳大利亚墨累谷脑炎流行所造成的公共卫生问题，更重要的是，来自东南亚更大和更频繁的日本脑炎流行。报告的墨累谷脑炎和日本脑炎的病死率为20%至40%。神经系统后遗症（运动缺陷、智力迟钝、抽搐、记忆丧失）在幸存者中的发生率很高，给受影响的个人以及社区保健和康复服务造成了相当大的负担。目前，除了支持性措施外，还没有有效的治疗方法可用于急性黄病毒脑炎。这项研究旨在了解致病病毒与其哺乳动物宿主在分子、细胞和整个动物水平上的复杂相互作用。为了实现这一目标，我们已经开发了一个感染性的cDNA克隆墨累谷脑炎病毒，使我们能够创建基因定义的减毒病毒含有单一或有限的氨基酸差异，从有毒的野生型病毒。这项研究将使我们能够全面了解实验室来源的突变体基因组中的单个或有限核苷酸变化如何导致哺乳动物宿主中毒力的减弱。这项研究具有重要的意义，从感染性cDNA克隆基因定义的，减毒活黄病毒疫苗的发展。我们最近的研究表明，墨累谷脑炎在小鼠中的发病机制部分是由宿主的炎症反应引起的。因此，我们计划严格分析小鼠对MVE感染的炎症反应，并评估几种抗炎剂减轻小鼠急性墨累谷脑炎或其神经系统后遗症的临床表现的能力。

The significance of this project derives primarily from the public health problem posed by epidemics of Murray Valley encephalitis in Australia and, more importantly, by the very much larger and more frequent epidemics of Japanese encephalitis in southeast Asia. Reported case fatality rates of Murray Valley encephalitis and of Japanese encephalitis range from 20 to 40%. Rates of neurological sequelae (motor deficits, mental retardation, convulsions, memory loss) are high among survivors and impose a considerable burden on affected individuals and on community health and rehabilitation services. Currently there are no effective treatments, other than supportive measures, available for acute flavivirus encephalitis. The research outlined in this grant application is designed to understand the complex interaction between a pathogenic virus and it's mammalian host at the molecular, cellular and whole animal level. To achieve this aim, we have developed an infectious cDNA clone of Murray Valley encephalitis virus, allowing us to create genetically defined attenuated viruses containing single or limited amino acid differences from the virulent wild-type virus. This research will allow us to achieve a comprehensive understanding of how single or limited nucleotide changes in the genomes of laboratory-derived mutants result in attenuation of virulence in a mammalian host . This research has important implications for the development of genetically defined, live-attenuated flavivirus vaccines engineered from infectious cDNA clones. We have recently shown that the pathogenesis of Murray Valley encephalitis in mice results, in part, from host inflammatory responses. Thus, we plan to rigorously analyze the inflammatory responses to MVE infection in mice and to assess the ability of several anti-inflammatory agents to alleviate the clinical manifestations of acute Murray Valley encephalitis or it's neurological sequelae in mice.