GILZ Controls TLR-Induced NF-kB Activity In Acute Asthma

描述（由申请人提供）： 病毒感染是哮喘急性加重的主要原因，其结果是发病率和死亡率增加。我们实验室的最新结果提示了一种新的机制来解释病毒引起的哮喘急性发作的易感性。我们认为，哮喘气道的两个异常，协同增强病毒诱导的NF-κ B活化的风险加剧。首先，气道细胞上Toll样受体（TLR）表达的增加增强了急性病毒感染时NF-κ B的活化。第二，内源性抗炎蛋白糖皮质激素诱导的亮氨酸拉链（GILZ）的表达减少增强了NF-κ B介导的细胞因子、趋化因子和共刺激分子的炎性基因转录。我们的假设是，这些异常的TLRs和GILZ的表达有互补性。 对NF-κ B活化的影响，共同增加哮喘急性发作的易感性。 目的1研究TLRs和GILZ表达与病毒诱导的哮喘急性发作的关系。 将在正常和哮喘受试者中测量常驻气道细胞中的体内TLR和GILZ表达，然后在分离的支气管上皮细胞和肺泡巨噬细胞中确定TLR介导的NF-kappaB活性的功能后果。将前瞻性分析其与急性哮喘加重的关系。目的2将分析TLR和GILZ影响NF-κ B活性的机制。将在关键信号传导步骤的水平上分析NF-κ B的潜在协同活化;并评估GILZ调节气道细胞中NF-κ B活性的能力。最终的目标是使用靶向基因破坏的小鼠来测试TLR和GILZ在哮喘小鼠模型中的重要性。 我们的方法将采用涉及人体内、体外细胞和鼠体内模型的互补研究。我们预计，这一建议将提供新的和临床相关的数据，急性哮喘加重的机制。

DESCRIPTION (provided by applicant): Viral infection is the leading cause of acute asthma exacerbations, with consequent enhanced morbidity and mortality. Recent results from our laboratories suggest a novel mechanism to explain susceptibility to viral provoked asthma exacerbations. We propose that the asthmatic airway is placed at risk for exacerbations by two abnormalities that synergistically augment viral-induced NF-kappaB activation. First, increased expression of Toll-like receptors (TLRs) on airway cells transduce enhanced NF-kappaB activation in response to acute viral infection. Second, reduced expression of the endogenous anti-inflammatory protein glucocorticoid-induced leucine zipper (GILZ) augments NF-kappaB mediated inflammatory gene transcription of cytokines, chemokines and co-stimulatory molecules. Our hypothesis is that these abnormalities in the expression of TLRs and GILZ have complementary effects on NF-kB activation that together increase susceptibility to asthma exacerbations. Aim 1 will investigate the relationships between expression of TLRs and GILZ with virus-induced asthma exacerbations in human volunteers. In vivo TLR and GILZ expression in resident airway cells will be measured in normal and asthmatic subjects, then the functional consequences on TLR-mediated NF-kappaB activity determined in isolated bronchial epithelial cells and alveolar macrophages. Their relationship to acute asthma exacerbations will be analyzed prospectively. Aim 2 will analyze the mechanisms underlying the ability of TLRs and GILZ to influence NF-kappaB activity. Potential synergistic activation of NF-kappaB will be analyzed at the level of the critical signaling steps; and the ability of GILZ to modulate NF-kappaB activity in airway cells assessed. The final aim will use mice with targeted gene disruption to test the importance of TLRs and GILZ in a murine model of asthma. Our approach will employ complementary studies involving human in vivo, in vitro cell, and murine in vivo models. We anticipate that this proposal will provide novel and clinically relevant data regarding the mechanisms of acute asthma exacerbations.