Investigating the Role of ADAM8 in Allergic Airway Inflammation

描述（由申请人提供）：目前对哮喘的抗炎途径知之甚少。我们的新研究发现了ADAMS在小鼠变应性气道炎症（AAI）中的有效抗炎活性。本项目的目的是研究ADAMS限制小鼠AAI和AHR的机制。从长远来看，这项研究可能会为哮喘患者带来新的治疗方法。ADAMs是一种跨膜蛋白酶，具有分解素和金属蛋白酶结构域。ADAMs具有调节肺部炎症过程的潜力，因为它们脱落，从而调节细胞因子、生长因子和凋亡配体的生物活性，以及细胞表面这些分子的受体。ADAMs还与整合素结合，调节细胞粘附和迁移。人们对亚当斯在哮喘中的作用知之甚少。我们的初步研究表明，与患有AAI的WT小鼠相比，患有AAI的ADAMS-/-小鼠气道巨噬细胞积聚增加，气道对甲胆碱的高反应性（AHR）增加。说明ADAMS在AAI中具有抗炎作用。我们将通过以下具体目的来研究其机制：具体目的1：验证ADAMS降低纯BALB/c小鼠株AAI和AHR的假设，并充分表征该株ADAMS-/-小鼠的表型。我们将在卵清蛋白或pbs处理的BALB/c ADAMS-/-与BALB/c WT窝代对照小鼠中进行以下比较：1)支气管肺泡灌洗（BAL）样本和肺切片中的AAI；BAL液样品中Th1、Th2和抗炎细胞因子；气道杯状细胞化生；2)利用FlexiventTM分析AHR对甲胆碱挑战的影响。特异性目的2：我们将通过以下方式验证ADAMS降低AAI BALB/c小鼠肺中巨噬细胞积聚的假设：1)增加AAI期间气道巨噬细胞的凋亡；和/或2)在AAI期间减少单核细胞跨内皮迁移；和/或3)AAI期间肺中单核细胞趋化因子的蛋白水解失活。具体目的3：我们将验证ADAMS通过减少小鼠气道中巨噬细胞积聚来限制AAI BALB/c小鼠AHR的假设。我们将测试在患有AAI的ADAM8-/-小鼠中消耗巨噬细胞是否会降低这些小鼠对甲胆碱挑战的AHR。与公众健康相关：哮喘是一种常见病，2005年影响了1570万美国人。目前的治疗方法有时无效或有不良的副作用。因此，有很大的需要新的和改进的治疗方法，以高极限发病率和死亡率与哮喘有关。

DESCRIPTION (provided by applicant): Little is currently known about anti-inflammatory pathways in asthma. Our novel studies have identified potent anti-inflammatory activities for ADAMS in allergic airway inflammation (AAI) in mice. The goal of this project is investigate the mechanisms by which ADAMS limits AAI and AHR in mice. In the long term, this research may lead to novel treatments for patients with asthma. ADAMs are transmembrane proteinases with a disintegrin and a metalloproteinase domain. ADAMs have the potential to regulate inflammatory processes in the lung because they shed and thereby regulate the biologic activites of cytokines, growth factors, and apoptosis ligands, and receptors for these molecules from cell surfaces. ADAMs also bind to integrins to regulate cell adhesion and migration. Little is known about the roles of ADAMs in asthma. Our preliminary studies show that ADAMS-/- mice with AAI have increased airway macrophage accumulation and increased airway hyper-responsiveness (AHR) to methacholine challenges compared to WT mice with AAI. This indicates that ADAMS has an anti-inflammatory role in AAI. We will investigate the mechanisms involved by pursuing the following Specific Aims: Specific Aim 1: Test the hypothesis that ADAMS reduces AAI and AHR in the pure BALB/c murine strain and fully characterize the phenotype of ADAMS-/- mice in this strain. We will compare the following in ovalbumin- or PBS-treated BALB/c ADAMS-/- versus BALB/c WT littermate control mice: 1) AAI in bronchoalveolar lavage (BAL) samples and lung sections; Th1, Th2, and anti-inflammatory cytokines in BAL fluid samples; and airway goblet cell metaplasia; and 2) AHR to methacholine challenges using FlexiventTM analysis. Specific Aim 2: We will test the hypothesisthat ADAMS reduces macrophage accumulation in the lungs of BALB/c mice with AAI by: 1) increasing apoptosis of airway macrophages during AAI; and/or 2) reducing monocyte transendothelial migration during AAI; and/or 3) proteolytically inactivating monocyte chemokines in the lung during AAI. Specific Aim 3: We will test the hypothesis that ADAMS limits AHR in BALB/c mice with AAI by reducing macrophage accumulation in murine airways. We will test whether depleting macrophages in ADAM8-/- mice with AAI reduces AHR to methacholine challenges in these mice. Relevance to public health: Asthma is a common disease which affected 15.7 million Americans in 2005. Current therapies are sometimes ineffective or have undesirable side-effects. Thus, there is a great need to new and improved treatments to the high limit morbidity and mortality associated with asthma.