Role of vimentin in influenza A-induced acute lung injury

描述(申请人提供)：甲型流感病毒是一种高度传染性的病毒，在美国每年会导致上呼吸道和下呼吸道感染，导致20万人住院和3.6万人死亡，新的流感病毒株会导致反复出现的流行病和大流行，具有显著的可归因性发病率和死亡率。与甲型流感感染有关的大部分死亡可归因于急性呼吸窘迫综合征(ARDS)的发展。急性肺损伤(ALI)和ARDS的定义是肺泡上皮和内皮的损伤，这允许富含蛋白质的液体渗入肺泡腔。在我们的初步数据中，我们发现Vimentin是一种III型中间丝蛋白，是激活NLRP3炎症体所必需的。我们提供的初步数据表明，波形蛋白-/-小鼠在感染甲型流感病毒(IAV)后可免受肺病毒性肺炎的影响。来自我们团队和其他人的越来越多的证据表明，这些丝状细胞骨架结构在信号转导途径中发挥关键作用，并为蛋白质复合体的形成和激活提供了支架，如NRLP3炎症体。我们发现NLRP3与Vimentin相互作用，这种蛋白质-蛋白质相互作用是前IL-1加工和成熟为生物活性IL所必需的 1？此外，我们还提供了初步数据，表明这种相互作用需要波形蛋白 NOD2转位到线粒体膜外膜，导致NOD2介导的IRF3激活和干扰素-α从IAV感染细胞释放。基于这些初步数据，我们假设波形蛋白作为NLRP3炎症体组装和激活的支架，而NOD2蛋白与波形蛋白的相互作用是激活IRF3信号所必需的。我们制定了三个相互关联的特异性目标，以研究在体内和体外甲型流感病毒诱导的肺损伤模型中波形蛋白中间丝的调节：特异性目标1：确定波形蛋白在甲型流感病毒诱导的急性肺损伤过程中促进NLR蛋白激活的机制。具体目的2：确定波形蛋白中与NLRP3炎性小体相互作用和激活所需的蛋白结构域(S)。具体目的3：确定波形蛋白和NOD2之间的相互作用是否是激活IRF3和从IAV感染的细胞释放干扰素所必需的。

DESCRIPTION (provided by applicant): Influenza A virus is a highly contagious virus that causes upper and lower respiratory tract infections resulting in 200,000 hospitalizations and 36,000 deaths in the United States annually, and new influenza strains generate recurring epidemics and pandemics with significant attributable morbidity and mortality. Most of the mortality associated with influenza A infection is attributable to development of the acute respiratory distress syndrome (ARDS). Acute lung injury (ALI) and ARDS are defined by damage to the alveolar epithelium and endothelium, which allows the exudation of protein-rich fluid into the alveolar space. In our preliminary data, we show that vimentin, a type III intermediate filament protein, is required for the activation of the NLRP3 inflammasome. We provide preliminary data that vimentin-/- mice are protected from lung viral pneumonia following infection with influenza A virus (IAV). Increasing evidence from our group and others suggests that these filamentous cytoskeleton structures play key roles in signal transduction pathways and provide a scaffold for the formation and activation of protein complexes, such as the NRLP3 inflammasome. We show that NLRP3 interacts with vimentin and that this protein-protein interaction is required for the processing and maturation of pro-IL- 1¿ into biologically active IL 1¿. Additionally, we provide preliminary data showing that vimentin is required for the interaction and translocation of NOD2 to the outer mitochondrial membrane, which results in the NOD2-mediated activation of IRF3 and release of interferon- from the IAV- infected cells. Based on these preliminary data, we hypothesize that vimentin acts as scaffold for the assembly and activation of the NLRP3 inflammasome and that NOD2 protein interaction with vimentin is required for the activation of IRF3 signaling. We have formulated three interrelated specific aims to study the regulation of vimentin intermediate filaments in both in vivo and in vitro models of influenza A-induced lung injury: Specific Aim 1: To determine the mechanism by which vimentin contributes to activation of NLR proteins during influenza A virus-induced acute lung injury. Specific Aim 2: To define the protein domain(s) in vimentin required for interaction with and activation of the NLRP3 inflammasome. Specific Aim 3: To determine whether the interaction between vimentin and NOD2 is required for the activation of IRF3 and the release of interferon from the IAV-infected cells.