Host defense against respiratory virus infections

宿主防御呼吸道病毒感染

• 批准号: 8473154
• 负责人: Santanu Bose
• 金额: $ 24.38万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-06-01 至 2014-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8473154
• 关键词: A549; Adaptor Signaling Protein; Address; Antiviral Agents; Antiviral Response; Antiviral Therapy; Baltimore; Binding; Bronchiolitis; Cell Nucleus; Cells; Child; Cytoplasmic Protein; Cytoplasmic Receptors; Development; Disease; Elderly; Epithelial; Epithelial Cells; Family; Genes; Genome; Host Defense; Host Defense Mechanism; Human; Human respiratory syncytial virus; Immune; Immune response; Immunity; Infant; Infection; Inflammation; Interferon Type I; Interferons; Invaded; Knockout Mice; Knowledge; Leucine; Ligands; Lung; Lung Inflammation; Lung diseases; MAP Kinase Gene; Measles; Mediating; Mitochondria; Molecular; Morbidity - disease rate; Natural Immunity; Nucleotides; Outer Mitochondrial Membrane; Paramyxoviridae; Paramyxovirus; Pathway interactions; Pattern; Pattern Recognition; Pattern recognition receptor; Phosphorylation; Physiological; Play; Pneumonia; Production; Proteins; RNA; Reporting; Research; Respiratory Syncytial Virus Infections; Respiratory System; Respiratory syncytial virus; Respiratory tract structure; Role; Satellite Viruses; Severity of illness; Signal Transduction; TLR10 gene; TLR3 gene; Testing; Therapeutic; Toll-like receptors; Transcription Factor AP-1; Tretinoin; Vaccine Therapy; Viral; Viral Load result; Viral Pathogenesis; Virus; Virus Diseases; cytokine; helicase; human IRF3 protein; human TLR8 protein; in vivo; induced pluripotent stem cell; interferon regulatory factor-3; lung development; lung injury; melanoma; member; mortality; parainfluenza virus; pathogen; protein function; public health relevance; receptor; respiratory infection virus; response; transcription factor; viral RNA; virus pathogenesis

DESCRIPTION (provided by applicant): Innate antiviral immunity comprises a host defense mechanism for restricting virus spread. The host cells recognizes invading viruses by specialized receptors known as pattern recognition receptors (PRRs) that can specifically identify pathogen associated molecular patterns (PAMPs). Toll-like receptors (TLRs) and RIG like helicase (RLH) receptors (e.g. RIGI and Mda5) are known to recognize virus specific PAMPs for induction of antiviral response mediated by activation of the transcription factors interferon regulatory factor-3 (IRF3). IRF3 activation results in production of antiviral cytokine interferon-a/¿ (IFN). Recently we identified nucleotide- binding oligomerization domain-2 (NOD2) protein, belonging to the nucleotide binding domain (NBD) and leucine-rich-region (LRR) containing family (known as NLRs) of cytoplasmic receptors as a viral PRR. Our preliminary studies have demonstrated that NOD2 can trigger an antiviral response (via activation of IRF3/IFN) following infection with human respiratory syncytial virus (RSV possess single stranded RNA or ssRNA as its genome), the major etiological viral agent causing worldwide pulmonary infections among infants, children and elderly. Therefore the current proposal is aimed at - a) establishing NOD2 as a new viral PRR, b) studying the mechanism of NOD2 activation, c) identifying and characterizing the molecules that act downstream of activated NOD2, and d) investigating the in vivo role of NOD2 during RSV pathogenesis, RSV induced lung inflammation and development of lung disease. Our preliminary studies demonstrated that expression of NOD2 in RSV infected cells results in activation of IRF3/IFN. Further studies revealed that - a) NOD2 can recognize ssRNA to activate IRF3/IFN, and b) mitochondrial outer membrane residing protein IPS-1 (MAVS) may act downstream of NOD2 for activation of IRF3/IFN . Thus, we hypothesize that NOD2 is a new member of viral PRR that can recognize viral ssRNA genome to launch an antiviral response following activation of mitochondrial IPS-1 protein. The hypothesis will be tested by focusing on the following specific aims: Aim # 1. Study the role of NOD2 during antiviral response against RSV - The major question of this aim is - Does NOD2 constitute a viral PRR that can activate IRF3/IFN in infected cells? We will investigate whether NOD2 is involved in IRF3/IFN activation during RSV infection of normal primary human bronchial epithelial (NHBE) cells. The physiological relevance of NOD2 during host defense against RSV pathogenesis and RSV mediated lung inflammation/disease will also be established by using NOD2 knock-out (KO) mice. Aim # 2. Study the mechanism of NOD2 activation - The major question of this aim is - a) Does NOD2 recognizes ssRNA and interacts with mitochondrial localized IPS-1 to activate IRF3/IFN? This question will be addressed by - a) studying association of NOD2 with ssRNA (RSV genome and synthetic ssRNA) and IPS-1, b) examining NOD2 mediated IRF3/IFN activation in cells lacking IPS-1, and c) identifying the specific NOD2 domain(s) involved in ssRNA recognition and IPS-1 interaction.

描述（由申请人提供）：先天抗病毒免疫包括限制病毒传播的宿主防御机制。宿主细胞通过称为模式识别受体（PRR）的特殊受体来识别入侵的病毒，这种受体可以特异性识别病原体相关分子模式（PAMP）。 Toll 样受体 (TLR) 和 RIG 样解旋酶 (RLH) 受体（例如 RIGI 和 Mda5）已知可识别病毒特异性 PAMP，从而诱导由转录因子干扰素调节因子 3 (IRF3) 激活介导的抗病毒反应。 IRF3 激活导致抗病毒细胞因子干扰素-a/¿ (IFN) 的产生。最近，我们鉴定了核苷酸结合寡聚化结构域 2 (NOD2) 蛋白，属于包含细胞质受体家族（称为 NLR）的核苷酸结合结构域 (NBD) 和富含亮氨酸区 (LRR) 的病毒 PRR。我们的初步研究表明，NOD2 可以在感染人呼吸道合胞病毒（RSV 具有单链 RNA 或 ssRNA 作为其基因组）后引发抗病毒反应（通过激活 IRF3/IFN），人呼吸道合胞病毒是导致全球婴儿、儿童和老年人肺部感染的主要病原病毒。因此，当前提案的目的是：a) 将 NOD2 建立为新的病毒 PRR，b) 研究 NOD2 激活机制，c) 识别和表征在激活的 NOD2 下游起作用的分子，以及 d) 研究 NOD2 在 RSV 发病机制、RSV 诱导的肺部炎症和肺部疾病发展过程中的体内作用。我们的初步研究表明，RSV 感染细胞中 NOD2 的表达导致 IRF3/IFN 的激活。进一步的研究表明：a) NOD2 可以识别 ssRNA 来激活 IRF3/IFN，b) 线粒体外膜驻留蛋白 IPS-1 (MAVS) 可能作用于 NOD2 下游，激活 IRF3/IFN。因此，我们假设NOD2是病毒PRR的新成员，它可以识别病毒ssRNA基因组，在线粒体IPS-1蛋白激活后启动抗病毒反应。该假设将通过关注以下具体目标进行检验： 目标#1. 研究 NOD2 在针对 RSV 的抗病毒反应过程中的作用 - 该目标的主要问题是 - NOD2 是否构成可以激活受感染细胞中的 IRF3/IFN 的病毒 PRR？我们将研究在RSV感染正常原代人支气管上皮（NHBE）细胞期间NOD2是否参与IRF3/IFN激活。 NOD2 在宿主针对 RSV 发病机制和 RSV 介导的肺部炎症/疾病的防御过程中的生理相关性也将通过使用 NOD2 敲除 (KO) 小鼠来确定。目标 # 2. 研究 NOD2 激活机制 - 该目标的主要问题是 - a) NOD2 是否识别 ssRNA 并与线粒体定位的 IPS-1 相互作用以激活 IRF3/IFN？这个问题将通过以下方式解决：a) 研究 NOD2 与 ssRNA（RSV 基因组和合成 ssRNA）和 IPS-1 的关联，b) 检查缺乏 IPS-1 的细胞中 NOD2 介导的 IRF3/IFN 激活，以及 c) 识别参与 ssRNA 识别和 IPS-1 相互作用的特定 NOD2 结构域。