IKK-NF-kB pathways in viral-induced lung inflammation

描述(申请人提供)：呼吸道合胞病毒(RSV)是每年婴儿下呼吸道感染流行的主要病原体，与儿童时期反复发作的喘息和呼吸道高反应性(AHR)的发展有关。肺部炎症与局部产生的促炎细胞因子和趋化因子有关，在呼吸道合胞病毒急性感染及其长期发病的免疫发病机制中起重要作用。在父母资助(AI 40218；PI：Allan R.Brasier；Co-I：Roberto P.Garofalo)的支持下进行的研究中，我们已经表明，在RSV感染的上皮细胞中，宿主基因的转录是通过IkB-激酶(IKK)复合体的协调激活、IkBA抑制剂的蛋白降解以及核因子(NF)kappa-kB反式激活亚基relA和p50的核移位来发生的。我们推测，RSV诱导的上皮细胞IKK-NF-kappaB通路的激活是控制呼吸道粘膜炎症和免疫调节基因关键网络表达的“总开关”，导致肺部炎症和AHR。本申请中提出的目标将应用新的试剂、分子遗传学方法和尖端基因组学技术，将我们父母拨款中提出的体外细胞研究扩展到复杂的肺部活体环境。我们将追求与这一假说相关的两个目标：1.确定选择性干扰上皮细胞中NF-kB调节的基因表达是否会影响实验性RSV感染的病毒清除、肺部炎症和临床疾病。这些研究是在我们的新型转基因小鼠中进行的，它在四环素操作者系统的控制下表达一种受调控的、组织选择性(肺上皮)显性的NF-kappaB负抑制物。2.研究阻断IKK活性的细胞通透性多肽Nemo结合域(NBD)对RSV诱导的全肺基因表达和AHR的影响。将通过基于寡核苷酸的微阵列和全身体积描记技术，对呼吸道合胞病毒感染的BALB/c小鼠进行NBD多肽鼻腔治疗，以研究全球肺基因的表达和肺功能。这些研究的结果将促进我们对体内IKK-NF-kappaB通路的有限了解，并将有助于设计新的药理策略来治疗和/或预防与病毒感染相关的呼吸道炎症。

DESCRIPTION (provided by applicant): Respiratory Syncytial Virus (RSV), the major etiologic agent of yearly epidemics of lower respiratory tract infections in infants, has been linked to recurrent episodes of wheezing and to the development of airway hyperresponsiveness (AHR) in childhood. Lung inflammation, associated with local production of proinflammatory cytokines and chemokines, plays a crucial role in the immunopathogenesis of acute RSV infection and its long-term morbidity. In studies conducted with the support of the parent grant (AI 40218; PI: Allan R. Brasier; Co-I: Roberto P. Garofalo), we have shown that host gene transcription in RSV-infected epithelial cells occurs via the coordinated activation of the IkB-kinase (IKK) complex, proteolytic degradation of the IkBa inhibitor and nuclear translocation of the nuclear factor (NF) kappa-kB transactivating subunits RelA and p50. We hypothesize that RSV-induced activation of the IKK-NF-kappaB pathway in epithelial cells is the "master switch" that controls the expression of critical networks of inflammatory and immunomodulatory genes in the airway mucosa, leading to lung inflammation and AHR. The aims proposed in this application will apply novel reagents, molecular genetic approaches, and cutting-edge genomics techniques to extend the in vitro cellular studies proposed in our parent grant to the complex in vivo environment of the lung. We will pursue two aims related to this hypothesis: 1. Determine whether selective disruption of NF-kB-regulated gene expression in epithelial cells affects viral clearance, lung inflammation and clinical illness in experimental RSV infection. These studies wall be conducted in our novel transgene mouse, which expresses a regulated, tissue-selective (lung epithelium) dominant negative inhibitor of NF-kappaB under the control of a tetracycline operator system. 2. Characterize the effect of the NEMO-binding domain (NBD), a cell-permeable peptide that blocks IKK activity, on RSV-induced global lung gene expression and AHR. Global lung gene expression, by oligonucleotide-based microarrays, and pulmonary function, by whole body plethysmography, will be studied in RSV-infected BALB/c mice treated intranasally with the NBD peptide. The results of these studies will advance our still limited understanding of the IKK-NF-kappaB pathway in vivo and will contribute to the design of novel pharmacological strategies to treat and/or prevent airway inflammation associated with viral infections.