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: 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
• 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

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 诺如病毒（NOV）是急性胃肠炎的全球主要原因，估计为6.85亿 每年案件。 11月感染了所有年龄段的人，但感染在5岁以下的儿童中最严重， 每年在该人群中造成约50,000人死亡。幼儿也经历了长时间的 粪便散发出高病毒载荷，在整个人群的传播中发挥关键作用。然而， 宿主因素导致NOV严重性和按年龄脱落的变异性的因素没有明确的定义。 Murine Nov（MNOV）被用作研究体内病毒发病机理的模型，但几乎所有研究都是 在成年小鼠中进行。这项工作的总体目的是将新生儿小鼠作为一种模型来了解 幼小动物对11月的动力和免疫控制。初步研究表明细胞和 与成年小鼠相比，新生小鼠的持续性MNOV感染的组织向向趋势改变了。此外，先天 免疫反应对于控制新生儿的病毒感染至关重要。新生儿Stat1 - / - 小鼠，缺乏 干扰素信号所必需的转录因子，使较高水平的MNOV和屈服于感染。这 致死性是年轻动物独有的，因为成年统计 - / - 小鼠通常会在MNOV持续菌株中幸存下来。 该提案的总体假设是IFN响应限制了新生儿的MNOV复制和向Tropism， 从而控制粪便脱落和致死性。我们将使用MNOV的新生儿模型检验这一假设 感染。在AIM 1中，我们将定义病毒复制和脱落感染性病毒体的动力学，并定义 MNOV在野生型和STAT1 - / - 新生儿中的细胞向热。在AIM 2中，我们将表征时间，本地化， IFN反应的功能以及IFN响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宿主因素，这些因素有助于病毒发病机理的变化和 按年龄持续脱落，将代表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的华盛顿大学举行，该大学为 完成这些研究所需的资源和培训。进入中心等尖端设施 用于蜂窝成像和DNA测序创新实验室，以及可提供的充足培训机会 校园内核心设施，使这些实验在技术上成为可能。分子微生物学的支持 以及赞助商和校园其他教职员工的微生物发病机理计划和指导将确保 成功完成拟议的研究。