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

项目总结 人类星状病毒(HAstV)是儿童病毒性腹泻的主要原因。不同的HAstV毒株有 与致命的人类脑炎有关。目前，还没有针对HAstV的疫苗或抗病毒疗法 感染。我们的目标是确定HAstV表面的脆弱部位(阿喀琉斯的脚后跟)，这些部位可能是 用于制定预防和治疗甲型HAstV病毒的战略。HAstV病毒粒子是一种 二十面体小病毒，由被衣壳蛋白包围的核糖核酸基因组组成。尽管重要的是 HAstV衣壳蛋白在病毒进入宿主细胞、抗体表位定位和病毒感染中的作用 病毒中和抗体的机制尚不清楚。我们的中心假设是HAstV衣壳 刺突结构域在病毒入侵过程中起着关键作用，是HAstV中和抗体的靶标。使用多样化的 结构、生化、免疫学和病毒学方法的工具箱，我们将追求三个特定的 目的：(1)利用结构和生物物理研究来确定HAstV衣壳表位和AAstV的血清型反应性 由六个中和性单抗组成的小组，(2)确定一组 针对HAstV衣壳尖峰的中和性单抗，并确定HAstV衣壳的作用 以及(3)确定发散的、嗜神经性的HAstV-VA1衣壳核心的结构和 检测它们诱导中和抗体的能力，并确定HAstV-VA1的中和表位。这部作品 代表了HAstV中和表位的第一个分子研究。这项工作所获得的结果将阐明 HAstV进入和中和机制，为疫苗和疫苗的设计提供了基础 预防和治疗HAstV感染的治疗学。

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.