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

基本信息

批准号：
10630058
负责人：
Elizabeth Alexandra Kennedy
金额：
$ 0.57万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-12-01 至 2022-12-19
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10630058
关键词：
Acute Adult Age Animal Model Cell Compartmentation Cell Culture Techniques Cells Cellular Tropism Cessation of life Child Childhood Colon Core Facility DNA sequencing Data Development Ensure Enteral Exhibits Faculty Feces Gastroenteritis Hematopoietic Human Immune Immune response Immunity Immunocompetent Immunocompromised Host Immunologic Deficiency Syndromes In Situ Hybridization Individual Infection Infection Control Innate Immune Response Integration Host Factors Interferon Receptor Interferon Type I Interferon Type II 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 Productivity 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 career cell growth 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

项目摘要

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.

项目概要/摘要诺如病毒 (NoV) 是全球急性胃肠炎的主要原因，估计与 6.85 亿人相关每年都有案例。 NoV 可感染所有年龄段的个体，但 5 岁以下儿童的感染最为严重，每年导致该人群约 50,000 人死亡。年幼的孩子也会经历长时间的粪便排出的病毒载量很高，在整个人群的传播中发挥着关键作用。然而，导致 NoV 严重程度和随年龄脱落的宿主因素尚不明确。鼠NoV（MNoV）被用作模型来研究体内病毒发病机制，但几乎所有研究都已在成年小鼠中进行。这项工作的总体目标是使用新生小鼠作为模型来理解幼年动物中 NoV 的动态和免疫控制。初步研究表明，细胞和与成年小鼠相比，新生小鼠持续性 MNoV 感染的组织向性发生了改变。进一步来说，与生俱来的免疫反应对于控制新生儿病毒感染至关重要。新生 Stat1-/- 小鼠，缺乏干扰素信号传导所必需的转录因子，会释放更高水平的 MNoV 并死于感染。这致死率是幼龄动物所特有的，因为成年 Stat-/- 小鼠通常能在持续感染 MNoV 菌株后存活下来。该提案的总体假设是，IFN 反应限制了 MNoV 在新生儿中的复制和趋向性，从而控制粪便脱落和致死率。我们将使用 MNoV 新生儿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传染性病毒粒子脱落的动力学，并定义 MNoV 在野生型和 Stat1-/- 新生儿中的细胞向性。在目标 2 中，我们将描述时间、定位、个体 IFN 反应的功能以及 IFN 反应是否控制病毒突变和/或肠外传播。这些研究将有助于解释导致病毒发病机制变异的宿主因素和随着年龄的增长而持续脱落，这将代表着理解差异的重大进步成人和儿童之间的肠道病毒动态。这项工作将在圣路易斯华盛顿大学进行，该大学提供了接触完成这些研究所需的资源和培训。使用中心等尖端设施细胞成像和 DNA 测序创新实验室，以及充足的培训机会校内核心设施使这些实验在技术上成为可能。分子微生物学的支持微生物发病机制计划以及赞助商和校园其他教员的指导将确保成功完成拟议的研究。