Structural, mechanistic, and antigenic insights into the human astrovirus capsid

项目摘要 人类星状病毒（HAstV）是儿童病毒性腹泻的主要原因。不同的HAstV毒株是 与致命的人类脑炎有关目前，没有针对HAstV的疫苗或抗病毒疗法 感染.我们的目标是确定HAstV表面上的脆弱部位（阿基里斯之踵）， 用于开发针对HAstV的预防和治疗策略。HAstV病毒粒子是一种 一种由RNA基因组和衣壳蛋白组成的小的二十面体病毒。尽管重要的 HAstV衣壳蛋白在病毒进入宿主细胞中的作用，抗体表位的定位和 病毒中和抗体的机制是未知的。我们的中心假设是HAstV衣壳 刺突结构域在病毒进入中起关键作用，并且是HAstV中和抗体的靶标。使用不同的 工具箱的结构，生物化学，免疫学和病毒学的方法，我们将追求三个具体的 目的是（1）使用结构和生物物理学研究来定义HAstV衣壳表位和HAstV的表型反应性。 一组六种中和性单克隆抗体，（2）确定一组 靶向HAstV衣壳刺突的中和单克隆抗体，并定义HAstV衣壳的作用 细胞进入中的尖峰，和（3）确定趋异的、嗜神经性HAstV-VA 1衣壳核心的结构， 刺突，测试它们引发中和抗体的能力，并确定HAstV-VA 1中和表位。这项工作 代表HAstV中和表位的第一个分子研究。通过这项工作获得的结果将阐明 HAstV进入和中和的机制，并为疫苗的设计提供基础， 预防和治疗HAstV感染的治疗剂。

PROJECT SUMMARY Human astroviruses (HAstV) are a leading cause of viral diarrhea in children. Divergent HAstV strains are associated with fatal human encephalitis. Currently, no vaccines or antiviral therapies exist for HAstV infections. Our goal is to identify sites of vulnerability (Achilles' heels) on the HAstV surface that can be exploited for the development of preventative and therapeutic strategies against HAstV. The HAstV virion is a small, icosahedral virus composed of an RNA genome surrounded by capsid protein. Despite the important role of the HAstV capsid protein in virus entry into host cells, the location of antibody epitopes and the mechanisms of virus-neutralizing antibodies are unknown. Our central hypothesis is that the HAstV capsid spike domain plays a key role in virus entry and is a target of HAstV-neutralizing antibodies. Using a diverse toolbox of structural, biochemical, immunological, and virological approaches, we will pursue three specific aims to (1) use structural and biophysical studies to define HAstV capsid epitopes and serotype-reactivity of a panel of six neutralizing monoclonal antibodies, (2) determine neutralizing mechanisms of a panel of neutralizing monoclonal antibodies targeting the HAstV capsid spike, and define the role of the HAstV capsid spike in cell entry, and (3) determine the structures of the divergent, neurotropic HAstV-VA1 capsid core and spike, test their abilities to elicit neutralizing antibodies, and define HAstV-VA1 neutralizing epitopes. This work represents the first molecular study of HAstV neutralizing epitopes. Results obtained by this work will elucidate mechanisms of HAstV entry and neutralization and provide a foundation for the design of vaccines and therapeutics to prevent and treat HAstV infections.