Dynamics and immune control of norovirus infection in neonatal mice

新生小鼠诺如病毒感染动态及免疫调控

• 批准号: 10386562
• 负责人: Elizabeth Alexandra Kennedy
• 金额: $ 3.27万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-12-01 至 2023-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10386562
• 关键词: Acute; Adult; Age; Animal Model; Cell Compartmentation; Cell Culture Techniques; Cells; Cellular Tropism; Cessation of life; Child; Childhood; Core Facility; DNA sequencing; Data; Development; Ensure; Enteral; Exhibits; Faculty; Feces; Gastroenteritis; Hematopoietic; Human; Immune; Immune response; Immunity; Immunocompetent; Immunocompromised Host; In Situ Hybridization; Individual; Infection; Infection Control; Innate Immune Response; Integration Host Factors; Interferon Receptor; Interferons; Intestines; Kinetics; Knowledge; Label; Large Intestine; Mentorship; Microbiology; Modeling; Molecular; Morbidity - disease rate; Mus; Mutation; Neonatal; Neutral Red; Norovirus; Pathogenesis; Pathogenicity; Plaque Assay; Play; Population; RNA; Research; Research Personnel; Resources; Role; STAT1 gene; Severities; Signal Transduction; Small Intestines; Symptoms; Testing; Tissue imaging; Tissues; Training; Tropism; Universities; Variant; Viral; Viral Load result; Viral Pathogenesis; Virion; Virus; Virus Diseases; Virus Replication; Virus Shedding; Washington; Work; acute infection; base; career; cell type; cellular imaging; chronic infection; enteric infection; experience; experimental study; host-microbe interactions; in vivo; innovation; insight; intestinal epithelium; juvenile animal; microbial; mortality; mouse model; neonatal infection; neonatal mice; neonate; postnatal; programs; pup; response; skills; stool sample; therapeutic development; tissue preparation; tissue tropism; training opportunity; transcription factor; transmission process; viral RNA; viral genomics; viral transmission

Project Summary/Abstract Norovirus (NoV) is the leading global cause of acute gastroenteritis, associated with an estimated 685 million cases annually. NoV infects individuals of all ages but infection is most severe in children under the age of 5, causing approximately 50,000 deaths in this population each year. Young children also experience prolonged fecal shedding with high viral loads, playing a key role in transmission throughout the entire population. However, the host factors which contribute to variability in NoV severity and shedding by age are not well-defined. Murine NoV (MNoV) is used as a model to study viral pathogenesis in vivo, but almost all studies have been conducted in adult mice. The overarching objective of this work is to use neonatal mice as a model to understand the dynamics and immune control of NoV in young animals. Preliminary studies suggest that the cellular and tissue tropism of persistent MNoV infection is altered in neonatal mice compared to adult mice. Further, innate immune responses are central to controlling viral infection in neonates. Neonatal Stat1-/- mice, which lack a transcription factor necessary for interferon signaling, shed higher levels of MNoV and succumb to infection. This lethality is unique to young animals, as adult Stat-/- mice typically survive infection with persistent strains of MNoV. The overall hypothesis of this proposal is that IFN responses limit MNoV replication and tropism in neonates, thereby controlling fecal shedding and lethality. We will test this hypothesis using our neonatal model of MNoV infection. In Aim 1, we will define the kinetics of viral replication and shedding of infectious virions and define the cellular tropism of MNoV in wild-type and Stat1-/- neonates. In Aim 2, we will characterize the timing, localization, and function of individual IFN responses and whether IFN responses control viral mutation and/or extraintestinal dissemination. These studies will help explain host factors which contribute to variation in viral pathogenesis and persistent shedding by age and will represent a significant advancement into understanding the differences in enteric virus dynamics between adults and children. This work will take place at Washington University in St. Louis, which provides exceptional access to the resources and training necessary to complete these studies. Access to cutting-edge facilities such as the Center for Cellular Imaging and DNA Sequencing Innovation lab, as well as ample training opportunities available from on-campus core facilities, make these experiments technically possible. Support from the Molecular Microbiology and Microbial Pathogenesis program and mentorship from sponsors and other faculty on campus will ensure the successful completion of the proposed research.

项目摘要/摘要 诺沃克病毒(Nov)是全球引起急性胃肠炎的主要原因，估计与6.85亿人有关。 每年都有病例。新城疫感染所有年龄段的人，但感染最严重的是5岁以下的儿童， 每年在这个人口中造成大约5万人死亡。年幼的儿童也会经历长时间的 排泄物的病毒载量很高，在整个人群的传播中发挥着关键作用。然而， 导致NOV严重程度和脱落随年龄变化的宿主因素还没有明确定义。 小鼠新城疫病毒(MNov)是研究病毒体内致病机制的一种模型，但几乎所有的研究都是 在成年小鼠身上进行。这项工作的首要目标是使用新生小鼠作为模型来理解 幼年动物新城疫的动态和免疫控制。初步研究表明，细胞和 与成年小鼠相比，新生小鼠持续MNOV感染的组织嗜性发生了改变。更进一步，与生俱来 免疫反应是控制新生儿病毒感染的核心。新生STAT1-/-小鼠，缺乏一种 干扰素信号转导所必需的转录因子，释放较高水平的MNoV并屈服于感染。这 致命性是幼年动物独有的，因为成年Stat/-小鼠通常会在感染MNOV持续毒株的情况下存活下来。 这一建议的总体假设是，干扰素应答限制了MNOV在新生儿中的复制和趋向性， 从而控制粪便脱落和致命性。我们将使用我们的新生儿MNOV模型来检验这一假设 感染。在目标1中，我们将定义病毒复制和感染性病毒粒子脱落的动力学，并定义 野生型和STAT1/-新生儿MNOV的细胞嗜性。在目标2中，我们将描述时间、本地化、 个体干扰素应答的功能以及干扰素应答是否控制病毒变异和/或肠外 传播。这些研究将有助于解释宿主因素，这些因素有助于病毒发病机制和 随着年龄的增长而持续脱落，这将代表着在理解 成人和儿童之间的肠道病毒动态。 这项工作将在圣路易斯的华盛顿大学进行，该大学提供了进入 完成这些研究所需的资源和培训。接近尖端设施，如中心 用于细胞成像和DNA测序创新实验室，以及来自 校园核心设施，使这些实验在技术上成为可能。来自分子微生物学的支持 微生物致病计划和来自赞助商和校园其他教员的指导将确保 圆满完成了拟议的研究。