Project 3 - USUHS

项目总结/摘要 致病病毒的出现和重新出现代表了对人类的持续的传染病威胁。 公共卫生其中，副粘病毒，包括许多重要的人类和动物， 病原体，还包括两个很好的例子出现，人畜共患病毒病原体的重要性： 亨德拉病毒（Hendra virus，HeV）。NiV和HeV具有独特的广泛寄主向性 能够感染6个哺乳动物目至少18种动物。NiV和HeV也会导致 在包括人类在内的11种哺乳动物物种中发生全身性且常常致命的呼吸系统和/或神经系统疾病。 这些亨尼帕病毒对澳大利亚的人类和经济上重要的牲畜仍然是重大的生物威胁 整个东南亚。此外，还没有批准用于人类的疫苗或治疗剂。 亨尼帕病毒是单链、负义、有包膜RNA病毒，具有两层膜， 参与病毒进入的锚定糖蛋白，一种介导宿主细胞受体附着（G糖蛋白） 另一种是I类融合（F）糖蛋白，其促进病毒体和宿主细胞膜融合。的 病毒G和F糖蛋白是中和抗体的主要抗原靶标， 积极的疫苗战略。我们一直在研究非致病性的亨尼帕病毒，雪松病毒， （CedPV）。使用重组病毒糖蛋白介导的细胞融合试验，我们已经确定CedPV- 介导的融合向性与NiV和HeV相似，然而，CedPV的肝配蛋白受体向性与NiV和HeV相似。 非常广泛，融合是由肝配蛋白-B1和-B2以及糖磷脂酰肌醇- 锚定A亚型肝配蛋白-A1、-A2和-A5。这些肝配蛋白中的每一种的融合向性活性也是 与CedPV G结合相关，并使用最近开发的反向遗传学系统制备 重组CedPV（rCedPV）感染研究证实了融合嗜性的发现。 rCedPV平台现在提供了一种新的病毒学系统，可用于各种应用研究 在BSL-2控制下安全的亨尼帕病毒，将被CETR研究项目广泛使用， 丹但更重要的是，它是一个真正的亨尼帕病毒系统，与 NiV和HeV，并且可以被遗传操作以用作活减毒通用亨尼帕病毒疫苗 平台，并且可能能够诱导持久和平衡的免疫反应。使用这种新 我们的目标是开发rCedPV嵌合病毒，其编码的F和G糖蛋白是： NiV或HeV，并表征和探索它们作为新型亨尼帕病毒疫苗的潜力。具体而言，我们将：1） 构建和拯救rCedPV-NiV/HeV病毒; 2）在基于细胞的感染中表征嵌合病毒 和向性研究; 3）分析免疫活性和 用rCedPV感染后的免疫缺陷小鼠; 4）通过以下方法测试rCedPV的保护能力： 在动物受试者中接种疫苗，以响应NiV和HeV攻击。

Project Summary/Abstract The emergence and reemergence of pathogenic viruses represent 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 viral pathogens of importance: the henipaviruses; Nipah virus (NiV) and Hendra virus (HeV). NiV and HeV have a uniquely broad host tropism capable of infecting at least 18 animal species across 6 orders of mammals. NiV and HeV 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. In addition, there are no vaccines or therapeutics 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 mediates host cell receptor attachment (G glycoprotein) and the other is a Class I fusion (F) glycoprotein which facilitates virion and host cell membrane fusion. The viral G and F glycoproteins are the major antigenic targets of neutralizing antibodies and are the main focus of active vaccine strategies. We have been characterizing the non-pathogenic species of henipavirus, Cedar virus (CedPV). Using recombinant viral glycoprotein mediated cell fusion assays, we have determined that CedPV- mediated fusion tropism is similar to NiV and HeV, however, the ephrin receptor tropism of CedPV is remarkably broad and fusion is triggered by ephrin-B1 and -B2 as well as the glycophosphatidylinositol- anchored A subtype ephrins-A1, -A2, and -A5. The fusion tropism activity by each of these ephrins is also correlated with CedPV G binding, and using a recently developed reverse genetics system for preparing recombinant CedPV (rCedPV) we have confirmed the fusion tropism findings with rCedPV infection studies. The rCedPV platform now offers a new virological system that can be used in a variety of applications to study henipaviruses safely under BSL-2 containment which will be broadly used by the CETR Research Projects and Cores. But of additional importance, it is an authentic henipavirus system that is attenuated in comparison to NiV and HeV, and can be genetically manipulated to serve as a live-attenuated universal henipavirus vaccine platform, and one likely capable of inducting a long-lasting and balanced immune response. Using this new system our objectives here will be to develop rCedPV chimeric viruses encoding the F and G glycoproteins of NiV or HeV and characterize and explore their potential a novel henipavirus vaccine. Specifically, we will: 1) Construct and rescue rCedPV-NiV/HeV viruses; 2) Characterize the chimeric viruses in cell-based infection and tropism studies; 3) Analyze the immune responses and outcomes in both immunocompetent and immunodeficient mice following infection with rCedPVs; 4) Test the protective abilities of rCedPVs by vaccination in animal subjects, in response to NiV and HeV challenge.