The function of CRAC channels in airway inflammation

 描述(申请人提供)：这项建议的目标是通过利用最近在钙信号领域的突破来解决哮喘患者的迫切需求，以利于哮喘治疗。多条证据表明CRAC(钙释放激活的钙通道)在哮喘中起重要作用。通过CRAC通道进入细胞内是T细胞和肥大细胞内钙升高的主要机制，而T细胞和肥大细胞是呼吸道变态反应性炎症的重要参与者。最近，我们和其他人确定Orai1(CRACM1，TMEM142)是CRAC通道中一个长期寻找的孔隙成分。CRAC通道成分的发现为通过靶向CRAC通道抑制TH2细胞的功能来治疗哮喘提供了新的机会。在这项建议中，我们将使用两个新的和强大的实验工具来测试这种可能性-Orai1条件基因敲除小鼠T细胞特异性Orai1的缺失，以及我们最近从高通量化学文库筛选中发现的Orai1的小分子阻滞剂。我们的研究将首先利用条件靶向Orai1基因敲除小鼠来研究Orai1在TH2细胞分化和哮喘中的作用(目标1)。我们将检查Orai1的缺失如何影响TH2分化的转录程序。我们还将使用哮喘动物模型，通过测量肺功能(例如，肺阻力和动态顺应性)来确定Orai1的作用。然后，我们将获得的基本知识与识别使用Orai1小分子阻滞剂治疗哮喘的新治疗方法相关联(目标2)。利用特定的阻滞剂，我们还计划确定Orai1在B细胞和肥大细胞功能中的作用 细胞。拟议的研究在概念和技术上都是新颖和创新的，因为我们将第一个使用我们建立的独特工具测试在哮喘疾病环境中阻断Orai1的治疗潜力。因此，我们的研究将广泛影响对过敏T细胞中钙信号功能的基本了解，它在其他过敏细胞功能(如B细胞、肥大细胞、2型天然免疫细胞)中的作用，以及治疗严重形式的过敏性和特应性炎症性疾病的新疗法的开发。

 DESCRIPTION (provided by applicant): The goal of this proposal is to address the urgent need for asthma patients by taking advantage of the recent breakthroughs in the field of Ca2+ signaling to benefit asthma therapy. Multiple lines of evidence suggest an important role for CRAC (Ca2+-release-activated Ca2+) channels in asthma. Ca2+ entry via CRAC channels is a predominant mechanism of intracellular Ca2+ elevation in T cells and mast cells that are important players in airway allergic inflammation. Recently, we and others identified Orai1 (CRACM1, TMEM142) as a long-sought pore component of CRAC channels. Discovery of CRAC channel components provides a new opportunity to develop asthma therapy by targeting CRAC channels to suppress the functions of TH2 cells. In this proposal, we will test this possibility using two novel and strong experimental tools- Orai1 conditional knockout mice with T cell- specific deletion of Orai1, and small molecule blockers of Orai1 that we have recently identified from high throughput chemical library screenings. Our studies will first examine the function of Orai1 in differentiation of TH2 cells and in asthma using conditionally targeted Orai1 knockout mice (Aim 1). We will check how the deficiency of Orai1 will influence the transcriptional programs for TH2 differentiation. We will also determine the role of Orai1 using an animal model of asthma by measuring lung functions (e.g. lung resistance and dynamic compliance). We then correlate the obtained basic knowledge with identification of novel therapeutic methods to treat asthma using small molecule blockers of Orai1 (Aim 2). Using specific blockers, we also plan to determine the role of Orai1 in the functions of B cells and mast cells. The proposed studies are conceptually and technically novel and innovative because we will be the first to test the therapeutic potential of blocking Orai1 in the disease settings of asthma using unique tools we have established. Thus, our studies will have a broad impact on basic understanding of the function of Ca2+ signaling in allergic T cells, its role in other allergc cell functions (e.g. B cells, mast cells, type 2 innate immune cells), and development of novel therapy to treat severe forms of allergic and atopic inflammatory diseases.