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，从而导致发病率和死亡率增加。我们实验室的最新结果表明，一种新的机制可以解释病毒引发的哮喘恶化的易感性。我们认为，通过两种异常协同增强病毒诱导的核因子-kappaB的激活，哮喘的气道处于恶化的风险中。首先，Toll样受体(TLRs)在呼吸道细胞上的表达增加转导了NF-kappaB的激活，以应对急性病毒感染。其次，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-kappaB介导的细胞因子、趋化因子和共刺激分子的炎症基因转录。我们的假设是，TLRs和GILZ表达的这些异常对核因子-kB的激活具有互补作用，共同增加了哮喘恶化的易感性。 目的1研究TLRs和GILZ在人类志愿者中的表达与病毒诱导的哮喘加重的关系。在活体内，我们将检测正常人和哮喘受试者的常驻呼吸道细胞中TLR和GILZ的表达，然后在分离的支气管上皮细胞和肺泡巨噬细胞中确定TLR介导的核因子-kappaB活性的功能后果。他们与急性哮喘恶化的关系将被前瞻性地分析。目的2分析TLRs和GILZ影响核因子-kappaB活性的机制。将在关键信号步骤的水平上分析核因子-kappaB的潜在协同激活；并评估GILZ调节呼吸道细胞中核因子-kappaB活性的能力。最终目标将使用具有靶向基因干扰的小鼠来测试TLRs和GILZ在哮喘小鼠模型中的重要性。 我们的方法将采用人体体内、体外细胞和小鼠体内模型的互补性研究。我们期望这项建议将提供有关急性哮喘恶化机制的新的和临床相关的数据。

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.