Role of the Respiratory Syncytial Virus Fusion Protein in Airway Mucus Induction

呼吸道合胞病毒融合蛋白在气道粘液诱导中的作用

• 批准号: 8068877
• 负责人: Martin Lawrence Moore
• 金额: $ 38.67万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-15 至 2015-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8068877
• 关键词: Amino Acids; Automobile Driving; Basophils; Biological Assay; Bronchiolitis; Cell Line; Cells; Cessation of life; Chimeric Proteins; Data; Epithelial; Epithelial Cells; Functional disorder; Genes; Giant Cells; Goals; Hospitalization; Human; Hypoxia; Immune response; In Vitro; Inbred BALB C Mice; Infant; Infection; Inflammatory; Interleukin-13; Interleukin-4; Laboratories; Lead; Lower respiratory tract structure; Lung; Measures; Mechanical ventilation; Mediating; Modeling; Molecular Models; Mucins; Mucous body substance; Mus; Mutagenesis; Neutrophilia; Pathogenesis; Play; Production; Proteins; Respiratory Syncytial Virus Infections; Respiratory syncytial virus; Role; System; T-Lymphocyte; Transfection; Viral; Viral Bronchiolitis; Viral Fusion Proteins; Viral Load result; Virulence; Virulent; Virus; Virus Diseases; airway hyperresponsiveness; airway obstruction; base; cell injury; cell type; cytokine; in vivo; innovation; molecular modeling; mutant; neutrophil; positional cloning; public health relevance; research study; response; virus pathogenesis

DESCRIPTION (provided by applicant): Our long term goal is to elucidate mechanisms by which respiratory syncytial virus (RSV) causes lung dysfunction. In the USA, RSV hospitalizes >100K infants/year. Pulmonary mucus is a hallmark of RSV disease. Mucus mixed with epithelial cell debris blocks the airways. Mechanisms by which RSV infection induces airway mucus are not known. Goals of this proposal are to define the role of the viral fusion (F) proteins of mucus-inducing RSV strains in pathogenesis and to define the roles of neutrophils and basophils in RSV-induced mucus. In contrast to laboratory RSV strains, RSV strains line 19 and 2-20 induce mucus and bronchiolitis in mice. Using a RSV reverse genetics system, we showed that the F protein of line 19 plays a role in mucus induction. We identified five amino acids in the line 19 F protein as candidates for involvement in mucus induction. We will use F mutant viruses to define line 19 F residues that are important for mucus expression in vivo. RSV 2- 20 is virulent in mice. We hypothesize that RSV 2-20 F contributes to airway mucus and virulence. We will define the role of 2-20 F in pathogenesis using 2-20F-chimeric RSV. Line 19 and 2-20 cause greater epithelial cell cytopathic effect (CPE) and desquamation in vivo than lab RSV strains. We will use F mutants to define effects of RSV line 19 F and 2-20 F on epithelial cell CPE, syncytia, and desquamation in vivo and in vitro. We will define the fusogenicity of RSV line 19, 2-20, and lab strain F proteins in epithelial cells in vitro using a fusion assay. We hypothesize that line 19 F and 2-20 F induce greater syncytia and fusion in vivo and in vitro. The study will also determine the roles of neutrophils and basophils in RSV bronchiolitis. Concurrently wih epithelial cell damage, RSV line 19 and 2-20 induce neutrophilia in the lungs of mice. We hypothesize that neutrophils contribute to viral clearance and mucus expression in line 19 and 2-20 pathogenesis. Line 19- induced mucus is dependent on IL-13, a TH2 cytokine. IL 4 is the primary TH2-driving cytokine. We showed that basophils are the major IL 4-expressing cell type in RSV-infection. We hypothesize that basophils contribute to RSV line 19- and 2-20-induced IL-13 and mucus expression. These RSV bronchiolitis models will advance our understanding of RSV strain-dependent pathogenesis and may lead to much-needed therapies. PUBLIC HEALTH RELEVANCE: RSV causes >100,000 infant hospitalizations in the US each year and is the leading cause of bronchiolitis and viral death in infants. Mucus production is a hallmark feature of RSV disease, leading to airway obstruction, hypoxia, and mechanical ventilation. Mechanisms of RSV-induced mucus are unknown and the focus of this proposal. Elucidation of these mechanisms will identify targets for therapies

描述（由申请人提供）：我们的长期目标是阐明呼吸道合胞病毒（RSV）导致肺功能障碍的机制。在美国，每年有超过 10 万婴儿因 RSV 住院。肺部粘液是 RSV 疾病的标志。粘液与上皮细胞碎片混合会阻塞气道。 RSV 感染引起气道粘液的机制尚不清楚。该提案的目标是确定粘液诱导 RSV 菌株的病毒融合 (F) 蛋白在发病机制中的作用，并确定中性粒细胞和嗜碱性粒细胞在 RSV 诱导粘液中的作用。 与实验室RSV毒株相反，RSV毒株19和2-20在小鼠中诱导粘液和细支气管炎。使用 RSV 反向遗传学系统，我们证明了 19 系的 F 蛋白在粘液诱导中发挥作用。我们确定了 19 F 蛋白系中的 5 个氨基酸作为参与粘液诱导的候选氨基酸。我们将使用 F 突变病毒来定义对体内粘液表达很重要的 19 系 F 残基。 RSV 2-20 对小鼠具有毒性。我们假设 RSV 2-20 F 有助于产生气道粘液和毒力。我们将使用 2-20F 嵌合 RSV 定义 2-20F 在发病机制中的作用。与实验室 RSV 菌株相比，19 系和 2-20 系在体内引起更大的上皮细胞病变效应 (CPE) 和脱屑。我们将使用 F 突变体来定义 RSV 系 19 F 和 2-20 F 对体内和体外上皮细胞 CPE、合胞体和脱屑的影响。我们将使用融合测定在体外定义 RSV 19、2-20 系和实验室毒株 F 蛋白在体外上皮细胞中的融合性。我们假设 19 F 和 2-20 F 系在体内和体外诱导更大的合胞体和融合。 该研究还将确定中性粒细胞和嗜碱性粒细胞在 RSV 细支气管炎中的作用。在上皮细胞损伤的同时，RSV 19 和 2-20 系诱导小鼠肺部中性粒细胞增多。我们假设中性粒细胞有助于 19 系和 2-20 系发病机制中的病毒清除和粘液表达。 19 系诱导的粘液依赖于 IL-13（一种 TH2 细胞因子）。 IL 4 是主要的 TH2 驱动细胞因子。我们发现嗜碱性粒细胞是 RSV 感染中主要表达 IL 4 的细胞类型。我们假设嗜碱性粒细胞有助于 RSV 19 系和 2-20 系诱导的 IL-13 和粘液表达。这些 RSV 细支气管炎模型将增进我们对 RSV 毒株依赖性发病机制的理解，并可能带来急需的治疗方法。 公共卫生相关性：RSV 在美国每年导致超过 100,000 名婴儿住院，是婴儿细支气管炎和病毒性死亡的主要原因。粘液产生是 RSV 疾病的标志性特征，导致气道阻塞、缺氧和机械通气。 RSV 诱导粘液的机制尚不清楚，也是本提案的重点。阐明这些机制将确定治疗靶点