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

项目摘要/摘要 裂谷热病毒(RVFV)是属于现病毒科(原布尼亚病毒科)的一种细小病毒 负义RNA病毒。作为一种新兴的蚊媒病毒，RVFV的重要性凸显出来 它被指定为NIAID A类病原体，并被列入世卫组织的优先疾病蓝图。 最近，防疫创新联盟(CEPI)也将RVFV作为其 新发传染病疫苗计划，进一步强调RVFV对全球 健康和经济。虽然RVFV在撒哈拉以南非洲是地方病，但有能力的蚊子媒介 在北美发现的物种，突显了在非地方性国家出现RVFV的可能性， 包括美国在内。在暴发期间，RVFV会在牲畜中引起严重疾病，包括绵羊和 在资源有限的情况下，这极大地影响了社会经济框架。人类正在溢出- 感染可导致严重后果，包括肝坏死、出血热、 脑炎和视网膜血管炎。尽管它对人类健康具有重要意义，并有可能对 在病毒流行的资源有限国家的社会经济结构中，缺乏安全和 有效的预防和治疗方案。造成这种差距的部分原因是我们对 引起RVFV感染的宿主因素。为了解决这一需求，我们进行了一项基因组筛查，定义了 几个关键因素，包括潜在的进入因素，我们将用多学科来描述 接近。作为支持，我们提供了令人信服的初步数据，包括在宿主因素方面的体外验证 和缺陷细胞，反互补研究，RVFV糖蛋白Gn与宿主之间的直接相互作用 蛋白质在体外，内源性配体在体外抑制进入因子在多个细胞系从 进化上不同的宿主，以及在两次条件敲击中预防RVFV感染的初步结果 把老鼠模型拿出来。重要的是，我们已经产生了许多关键试剂，包括大多数细胞系和蛋白质， 而基因敲除小鼠则支持了这一可行性。重要的是，这项工作将由高生产率和 在拟议研究的各个方面拥有专业知识的合作调查人员，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。建议的研究完成后， 确定RVFV在靶细胞中的新宿主或进入因子，并与组织特异性相关。作为一种特殊的受体 由于以前未发现RVFV，这些研究将为设计RVFV提供重要信息 预防RVFV感染和疾病的治疗干预措施。在完成时，我们希望填补一个关键的空白 并为治疗开发提供新的靶点。

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.