Investigating the Role of ADAM8 in Allergic Airway Inflammation

描述(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，ADAMS在小鼠过敏性呼吸道炎症(AAI)中具有强大的抗炎活性。该项目的目标是研究亚当斯限制小鼠AAI和AHR的机制。从长远来看，这项研究可能为哮喘患者带来新的治疗方法。ADAMS是一种含有去整合素和金属蛋白酶结构域的跨膜蛋白。ADAMS具有调节肺部炎症过程的潜力，因为它们脱落，从而调节细胞表面的细胞因子、生长因子、凋亡配体和这些分子的受体的生物活性。ADAMS还与整合素结合来调节细胞黏附和迁移。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-/-小鼠有更多的气道巨噬细胞聚集，并增加了对乙酰甲胆碱挑战的气道高反应性(AHR)。这表明亚当斯在AAI中具有抗炎作用。我们将通过追求以下特定目标来探讨其机制：特定目标1：验证ADAMS降低纯BALB/c小鼠AAI和AHR的假设，并充分表征该品系中ADAMS-/-小鼠的表型。我们将在卵蛋白或PBS处理的BALB/c ADAMS-/-与BALB/c WT对照小鼠中进行以下比较：1)支气管肺泡灌洗液(BAL)样本和肺切片中的AAI；BAL液体样本中的Th1、Th2和抗炎细胞因子；以及气道杯状细胞化生；以及2)使用FlexiventTM分析AHR对乙酰胆碱的挑战。具体目标2：我们将验证ADAMS通过以下途径减少AAI小鼠肺内巨噬细胞聚集的假设：1)增加AAI期间气道巨噬细胞的凋亡；和/或2)减少AAI期间单核细胞的内皮迁移；和/或3)在AAI期间蛋白水解性灭活肺内单核细胞趋化因子。具体目标3：我们将验证亚当斯通过减少小鼠呼吸道巨噬细胞聚集来限制AAI小鼠AHR的假设。我们将测试在患有AAI的ADAM8-/-小鼠中耗尽巨噬细胞是否减少了这些小鼠对乙酰甲胆碱的AHR挑战。与公共卫生相关：哮喘是一种常见疾病，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副作用。因此，迫切需要新的和改进的治疗方法来限制与哮喘相关的高发病率和死亡率。

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.