Host Factors Controlling Neuroinvasive Flavivirus Pathogenesis

控制神经侵袭性黄病毒发病机制的宿主因素

• 批准号: 10677657
• 负责人: Helen Lazear
• 金额: $ 38.88万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-05 至 2026-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10677657
• 关键词: Alleles; Antiviral Response; Brain; Candidate Disease Gene; Cells; Central Nervous System; Clinical; Culicidae; Disease; Disease Outbreaks; Disease Outcome; Encephalitis; Exhibits; Fever; Flavivirus; Flavivirus Infections; Foundations; Future; Genes; Genetic; Genetic Polymorphism; Genetic Variation; Human; Immune; Immunologic Factors; Immunologics; Inbred Mouse; Incidence; Infection; Inflammatory; Inflammatory Response; Integration Host Factors; Interferons; Investigation; Ixodes; Japanese encephalitis virus; Leucocytic infiltrate; Lyme Disease; Maps; Measures; Mediating; Meningitis; Mus; Neurons; North America; Outcome; Paralysed; Pathogenesis; Pathogenicity; Pathology; Persons; Phenotype; Population; Powassan virus; Predisposition; Quantitative Trait Loci; Recombinants; Reproducibility; Resistance; Serum; Severity of illness; Stimulus; Symptoms; System; Tick-Borne Diseases; Ticks; Tissues; United States; Viral; Viral Load result; Viral Pathogenesis; Viral Physiology; Viremia; Virus; Virus Diseases; Virus Replication; West Nile virus; Work; blood-brain barrier permeabilization; insight; mosquito-borne; nervous system disorder; novel; response; tick transmission; tick-borne flavivirus; transmission process; viral resistance; viral transmission

ABSTRACT Flaviviruses such as Powassan virus (POWV), West Nile virus (WNV), and Japanese encephalitis virus (JEV) are transmitted by ticks and mosquitoes. The outcomes of flavivirus infection are heterogeneous, with only a subset progressing to neuroinvasive disease (e.g. encephalitis, meningitis, or paralysis). We hypothesize that host genetic variation, particularly in antiviral response genes, contributes to differential disease outcome following flavivirus infection. The Collaborative Cross (CC) panel of recombinant inbred mice provides an ideal system to discover novel mechanisms of immune-mediated control of flavivirus pathogenesis because these mice exhibit an expanded range of immune phenotypes on reproducible genetic backgrounds. We infected 17 CC lines with POWV and identified multiple highly susceptible lines, including CC071 and CC015, and a single resistant line, CC045. Most phenotypes were concordant among POWV, WNV, and JEV, but some lines exhibited virus-specific resistance, implying that there are both virus-specific and pan-flavivirus mechanisms that control resistance to neuroinvasive flaviviruses. We propose to use the CC to determine the viral and immunologic features of POWV pathogenesis and to identify host genes that contribute to POWV resistance. Aim 1: Define viral and immunologic features of POWV pathogenesis in CC mice. We found that CC045 mice exhibited equivalent viremia but lower brain viral loads compared to CC071 mice, suggesting that POWV resistance may result from reduced neuroinvasion. We will assess brain viral loads and infiltrating leukocytes in susceptible and resistant CC lines following POWV infection. We will assess blood-brain barrier permeability at baseline and in response to viral infection and inflammatory stimuli. We will generate primary cells from susceptible and resistant CC lines and measure replication of POWV and other flaviviruses. Aim 2: Map quantitative trait loci and evaluate antiviral activity of host factors associated with POWV resistance. To identify polymorphic host genes that determine the outcome of POWV infection, we generated two F2 crosses of susceptible and resistant lines (CC071 x CC045 and CC015 x CC045) and evaluated lethality in ~300 F2 mice per cross following POWV infection, as well as CNS viral loads in ~120 F2 mice. We will map QTL associated with POWV resistance in both crosses and investigate candidate genes under significant QTL. Aim 3: Distinguish pan-flavivirus and virus-specific restriction factors in CC mice. We will infect additional CC lines with JEV to identify lines that are differentially resistant to JEV compared to POWV or WNV. We will evaluate brain viral loads and infiltrating leukocytes following JEV infection. We will generate F2 progeny of susceptible and resistant lines and map QTL associated with JEV resistance. The proposed studies will provide insight into the pathogenic mechanisms of POWV and reveal polymorphic host immune mechanisms that impact susceptibility to flavivirus neuroinvasive disease. This work will provide the foundation for future investigations of novel immune factors that control flavivirus pathogenesis.

抽象的 黄病毒，例如波瓦桑病毒 (POWV)、西尼罗河病毒 (WNV) 和日本脑炎病毒 (JEV) 由蜱虫和蚊子传播。黄病毒感染的结果是异质的，只有 进展为神经侵袭性疾病（例如脑炎、脑膜炎或瘫痪）的子集。我们假设 宿主遗传变异，特别是抗病毒反应基因，有助于不同的疾病结果 黄病毒感染后。重组近交小鼠的协作杂交 (CC) 小组提供了理想的 系统发现免疫介导控制黄病毒发病机制的新机制，因为这些 小鼠在可重复的遗传背景上表现出更广泛的免疫表型。我们感染了17人 带有 POWV 的 CC 品系，并鉴定了多个高度易感品系，包括 CC071 和 CC015，以及一个 抵抗线，CC045。大多数 POWV、WNV 和 JEV 的表型是一致的，但有些品系 表现出病毒特异性耐药性，这意味着存在病毒特异性机制和泛黄病毒机制 控制对神经侵袭性黄病毒的抵抗力。我们建议使用 CC 来确定病毒和 POWV 发病机制的免疫学特征，并鉴定有助于 POWV 抗性的宿主基因。 目标 1：确定 CC 小鼠 POWV 发病机制的病毒和免疫学特征。我们发现CC045 与 CC071 小鼠相比，小鼠表现出相同的病毒血症，但脑部病毒载量较低，这表明 POWV 抵抗可能是由于神经侵袭减少所致。我们将评估脑病毒载量和浸润白细胞 POWV 感染后易感和抗性 CC 系。我们将评估血脑屏障的通透性 基线以及对病毒感染和炎症刺激的反应。我们将产生原代细胞 敏感和抗性 CC 系并测量 POWV 和其他黄病毒的复制。 目标 2：绘制数量性状位点图并评估与 POWV 相关的宿主因子的抗病毒活性 反抗。为了鉴定决定 POWV 感染结果的多态性宿主基因，我们生成了 敏感品系和抗性品系（CC071 x CC045 和 CC015 x CC045）的两个 F2 杂交并评估致死率 POWV 感染后每次杂交约 300 只 F2 小鼠中的病毒载量，以及约 120 只 F2 小鼠中 CNS 病毒载量。我们将绘制地图 QTL 与两个杂交中的 POWV 抗性相关，并研究显着 QTL 下的候选基因。 目标 3：区分 CC 小鼠中的泛黄病毒和病毒特异性限制因子。我们会感染 附加带有 JEV 的 CC 品系，以识别与 POWV 或 WNV 相比，对 JEV 具有差异抗性的品系。 我们将评估乙脑病毒感染后的脑病毒载量和浸润白细胞。我们将产生F2后代 敏感和抗性品系的分析，并绘制与 JEV 抗性相关的 QTL。 拟议的研究将深入了解 POWV 的致病机制并揭示多态性 影响黄病毒神经侵袭性疾病易感性的宿主免疫机制。这项工作将提供 为未来研究控制黄病毒发病机制的新型免疫因子奠定基础。