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Powassan病毒（POWV），西尼罗河病毒（WNV）和日本脑炎病毒（JEV） 由壁虱和蚊子传播。黄病毒感染的结果是异质的，只有一个 子群发展为神经侵袭性疾病（例如脑炎，脑膜炎或麻痹）。我们假设这一点 宿主遗传变异，特别是在抗病毒反应基因中，有助于差异疾病结果 黄病毒感染后。重组近交小鼠的协作十字架（CC）面板提供了理想 发现免疫介导的黄病毒发病机理的新型机制，因为 小鼠在可再现的遗传背景上表现出扩展的免疫表型。我们感染了17 具有POWV的CC线，确定了多个高度易感线，包括CC071和CC015，一个 抵抗线，CC045。大多数表型在POWV，WNV和JEV中都是一致的，但是有些线条 表现出病毒特异性的抗性，这意味着既有病毒特异性和泛流行病的机制 控制对神经侵染的黄素病毒的抗性。我们建议使用CC确定病毒和 POWV发病机理的免疫学特征，并确定有助于POWV抗性的宿主基因。 AIM 1：定义CC小鼠POWV发病机理的病毒和免疫学特征。我们发现CC045 与CC071小鼠相比，小鼠表现出同等的病毒血症，但脑病毒载量较低，这表明POWV 耐药性可能是由于神经入侵的降低而导致的。我们将评估脑病毒载荷和浸润的白细胞 POWV感染后的易感和抗性CC线。我们将评估血脑屏障的渗透率 基线以及对病毒感染和炎症刺激的反应。我们将从 易感和抗性的CC线，并测量POWV和其他黄病毒的复制。 目标2：地图定量性状基因座并评估与POWV相关的宿主因素的抗病毒活性 反抗。为了识别确定POWV感染结果的多态宿主基因，我们产生了 两个F2的易感和抗性线（CC071 X CC045和CC015 X CC045）的杂交和评估的致死性 在POWV感染后，每个交叉的约300只小鼠以及〜120 F2小鼠中的CNS病毒载荷。我们将映射 QTL与两个杂交中的POWV抗性相关，并在显着QTL下研究候选基因。 AIM 3：区分CC小鼠中的泛氟病毒和病毒特异性限制因子。我们将感染 与POWV或WNV相比，具有JEV的其他CC线，以识别对JEV具有差异性的线路。 我们将评估JEV感染后的脑病毒载荷和浸润白细胞。我们将产生F2后代 易感和抗性线以及与JEV抗性相关的QTL。 拟议的研究将提供对POWV的致病机制的见解，并揭示了多态性 宿主的免疫机制会影响对黄病毒神经侵袭性疾病的易感性。这项工作将提供 未来研究控制黄素发病机理的新型免疫因子的基础。