A Recombinant Cedar Virus-based Henipavirus Replication Platform for High-throughput Inhibitor Screening

项目总结/摘要 致病性病毒的出现代表了对公共卫生的持续的传染病威胁。 其中，包括许多重要的人类和动物病原体的副粘病毒还包括 新出现的重要的人畜共患病病原体的两个极好的例子：亨德拉病毒;亨德拉病毒（HeV） 尼帕病毒（Nipah virus，NiV）HeV和NiV具有独特广泛宿主嗜性，能够感染至少18种动物 6种哺乳动物。HeV和NiV还可引起全身性且通常致命的呼吸道感染。 包括人类在内的11种哺乳动物的神经系统疾病。这些亨尼帕病毒 对澳大利亚和整个东南部的人类和经济上重要的牲畜造成重大的生物威胁 在亚洲，没有疫苗或抗病毒药物被批准用于人类。亨尼帕病毒是单链的， 负义、有包膜RNA病毒，并具有两个与病毒相关的膜锚定糖蛋白 一种用于宿主细胞受体附着（G糖蛋白），另一种是融合（F）糖蛋白， 促进病毒体和宿主细胞膜融合。G和F糖蛋白是大肠杆菌的主要抗原靶点。 中和抗体，也是几种疫苗策略的重点。相反，抗病毒药物 由于生物安全等级4的要求，HeV和NiV的发现受到了极大的阻碍 （BSL-4）的遏制，目前完全缺乏任何有效的抗病毒治疗， 用于人类的亨尼帕病毒。我们一直在广泛地描述最近发现的非致病性 亨尼帕病毒属（Henipavirus）种，雪松病毒（CedPV）。利用重组病毒糖蛋白介导的细胞-细胞融合 通过检测，我们发现CedPV介导的膜融合与HeV和NiV相似，然而， 发现CedPV的ephrin受体趋向性非常广泛， B1和-B2以及糖磷脂酰肌醇锚定的A亚型肝配蛋白-A1、-A2和-A5。牢房- 这些肝配蛋白受体支持的细胞融合活性也与CedPV G结合能力相关， 通过表面等离子体共振测量。此外，我们最近拯救了重组CedPV编码， eGFP（rCedPV-GFP）。我们的rCedPV平台代表了新的病毒学 该系统可用于各种应用中以研究亨尼帕病毒细胞生物学的各个方面， 在BSL-2控制下安全地进行宿主细胞相互作用。但更重要的是，它也是一个真正的 henipavirus感染和复制报告系统现在适用于高通量筛选（HTS）， 发现潜在的泛抗亨尼帕病毒分子。使用这个新的活亨尼帕病毒平台，我们的 本文的目标是开发和优化rCedPV报告系统，并将其用于HTS测定， 发现能够抑制亨尼帕病毒感染的抗病毒分子。具体而言，我们将：1）适应 2）优化重组病毒的HTS参数 感染和报道活性;和3）使用Prestwick化学文库试验HTS测定。

Project Summary/Abstract The emergence of pathogenic viruses represents continuous infectious disease threats to public health. Among these, the paramyxoviruses, which include many important human and animal pathogens, also include two excellent examples of emerged, zoonotic pathogens of importance: the henipaviruses; Hendra virus (HeV) and Nipah virus (NiV). HeV and NiV have a uniquely broad host tropism capable of infecting at least 18 animal species across 6 orders of mammals. HeV and NiV can also cause a systemic and often fatal respiratory and/or neurological disease in 11 mammalian species including humans. These henipaviruses remain significant biothreats to humans and economically important livestock in Australia and throughout South East Asia, and there are no vaccines or antivirals approved for human use. The henipaviruses are single-stranded, negative sense, enveloped RNA viruses and possess two membrane anchored glycoproteins involved in virus entry, one for host cell receptor attachment (G glycoprotein) and the other a fusion (F) glycoprotein which facilitates virion and host cell membrane fusion. The G and F glycoproteins are the major antigenic targets of neutralizing antibodies and also the focus of several vaccine strategies. In contrast however, antiviral drug discovery for HeV and NiV has been significantly hampered because of the requirements of biosafety level-4 (BSL-4) containment, and presently there is a complete lack of any effective antiviral therapeutics against henipaviruses for human use. We have been extensively characterizing the recently identified non-pathogenic species of henipavirus, Cedar virus (CedPV). Using recombinant viral glycoprotein mediated cell-cell fusion assays, we have discovered that CedPV-mediated membrane fusion is similar to HeV and NiV, however, the ephrin receptor tropism of CedPV was found to be remarkably broad and fusion could be triggered by ephrin- B1 and -B2 as well as the glycophosphatidylinositol-anchored A subtype ephrins-A1, -A2, and -A5. The cell- cell fusion activity supported by each of these ephrin receptors also correlated with CedPV G binding ability as measured by surface plasmon resonance. Further, we have recently rescued recombinant CedPV encoding eGFP (rCedPV-GFP) using a reverse genetics approach. Our rCedPV platform represents a new virological system that can be used in a variety of applications to study various aspects of henipavirus cell biology and host cell interactions safely under BSL-2 containment. But of further importance, it is also an authentic henipavirus infection and replication reporter system now suitable for high-throughput screening (HTS) for the discovery of potentially pan-anti-henipavirus molecules. Using this new live-henipavirus platform, our objectives here will be to develop and optimize a rCedPV reporter system and utilize it in an HTS assay to discover antiviral molecules capable of inhibiting the infection of henipaviruses. Specifically, we will: 1) Adapt and develop CedPV reporters for the HTS assay; 2) Optimize the HTS parameters of recombinant virus infection and reporter activities; and 3) Pilot a HTS assay using the Prestwick Chemical Library.