Identification and Characterization of Entry Factors Critical for Rift Valley Fever Virus Infection and Pathogenesis

项目概要/摘要 裂谷热病毒 (RVFV) 是一种静脉病毒，属于 Phenuiviridae（以前称为 Bunyaviridae）家族 负义RNA病毒。作为一种新兴的蚊媒病毒，RVFV的重要性凸显 其被指定为 NIAID A 类病原体并被列入 WHO 优先疾病蓝图。 最近，流行病防范创新联盟 (CEPI) 也将 RVFV 作为其战略的一部分 新发传染病疫苗计划，进一步强调裂谷热病毒对全球的潜在影响 健康和经济。虽然裂谷热病毒在撒哈拉以南非洲地区流行，但有效的蚊媒 在北美发现了一些物种，凸显了裂谷热病毒在非流行国家出现的可能性， 包括美国。在暴发期间，裂谷热病毒会导致牲畜（包括绵羊和 牛，这极大地影响了资源有限环境中的社会经济框架。人类是溢出的—— 在宿主身上，感染可能导致严重后果，包括肝坏死、出血热、 脑炎、视网膜血管炎。尽管它对人类健康具有重要意义并可能产生负面影响 病毒流行的资源有限国家的社会经济结构，缺乏安全和 有效的预防性和治疗性治疗方案。造成这种差距的部分原因是我们缺乏相关知识 导致 RVFV 感染的宿主因素。为了满足这一需求，我们进行了基因组筛选，定义了 几个关键因素，包括潜在的进入因素，我们将其描述为多学科的 方法。作为支持，我们提供了令人信服的初步数据，包括宿主因素的体外验证 和缺陷细胞、反式补体研究、RVFV 糖蛋白 Gn 与宿主之间的直接相互作用 体外蛋白质，在多种细胞系中通过内源配体体外抑制进入因子 进化上不同的宿主，以及两种条件敲除中对 RVFV 感染的保护作用的初步结果 出鼠标模型。重要的是，我们已经生成了许多关键试剂，包括大多数细胞系和蛋白质， 和敲除小鼠支持了可行性。重要的是，这项工作将由高生产力和 在拟议研究的各个方面具有专业知识的合作研究人员，包括生物化学、RVFV 发病机制、免疫学、蛋白质组学、结构生物学和病毒学。完成拟议的研究将 定义具有组织特异性相关性的靶细胞中 RVFV 的新宿主或进入因子。作为特异性受体 由于 RVFV 以前未被识别，这些研究将为设计提供重要信息 预防 RVFV 感染和疾病的治疗干预措施。完成后，我们预计将填补一个关键空白 并为治疗开发提供新靶点。

Project Summary/Abstract Rift Valley fever virus (RVFV) is a phlebovirus that belongs to the Phenuiviridae (formerly Bunyaviridae) family of negative-sense RNA viruses. As an emerging mosquito-borne virus, the significance of RVFV is highlighted by its designation as a NIAID Category A pathogen and its inclusion on the WHO's Blueprint of Priority Diseases. Recently, the Coalition for Epidemic Preparedness Innovations (CEPI) has also included RVFV as a part of their emerging infectious diseases vaccine program, further emphasizing the potential impact of RVFV on the global health and economy. While RVFV is endemic throughout sub-Saharan Africa, competent mosquito vector species are found in North America, highlighting the potential for emergence of RVFV in non-endemic countries, including the United States. During outbreaks, RVFV causes severe disease in livestock, including sheep and cattle, which dramatically impact the socioeconomic framework in resource limited settings. Humans are spill- over hosts, where infections can result in severe consequences, including hepatic necrosis, hemorrhagic fever, encephalitis, and retinal vasculitis. Despite its significance to human health and the potential to negatively impact the socioeconomic fabric of resource-limited countries where the virus is endemic, there is a lack of safe and efficacious prophylactic and therapeutic treatment options. This gap is in part due to our lack of knowledge on host factors that contribute to RVFV infection. To address this need, we conducted a genomic screen that defined several critical factors, including a potential entry factor, which we will characterize by a multidisciplinary approach. In support, we provide compelling preliminary data, including in vitro validation in host factor sufficient and deficient cells, transcomplementation studies, direct interaction between RVFV glycoprotein Gn and the host proteins in vitro, inhibition of the entry factor by endogenous ligands in vitro in multiple cell lines from evolutionarily distinct hosts, and preliminary results of protection from RVFV infection in two conditional knock out mouse models. Importantly, we have generated many key reagents, including most cell lines and proteins, and knock-out mice supporting the feasibility. Importantly, this work will be performed by highly productive and collaborative investigators with expertise in every aspect of the proposed studies, including biochemistry, RVFV pathogenesis, immunology, proteomics, structural biology, and virology. Completion of the proposed studies will define novel host or entry factors for RVFV in target cells with tissue-specific relevance. As a specific receptor for RVFV has not previously been identified, these studies will provide important information for design of therapeutic interventions to prevent RVFV infection and disease. At the completion, we expect to fill a key gap in the field and to provide novel targets for therapeutic development.