Role of disrupted ASL pH regulation in small airways in CF lung disease pathogenesis

项目总结/摘要 囊性纤维化（CF）是一种常见的遗传性疾病，由CF跨膜传导缺陷引起 调节器（CFTR）。CF肺病的发病机制尚不清楚，也存在争议，至少部分原因是 缺乏适当CF动物模型的研究。此外，大多数关于发病机制的研究依赖于 数据来自培养的人类患病的大近端气道，例如气管和支气管组织。然而，在这方面， 病理和临床数据表明，该疾病起始于直径<2 mm的小气道。 爱荷华州研究小组已经对猪进行了CFTR缺失或突变的工程改造。这些猪模仿人类CF，包括 发生自发性感染和粘液和炎性细胞阻塞气道。这 该模型为研究CF肺病的发病机制提供了前所未有的机会。我们 本研究的目的是探讨CF小气道CFTR缺失如何导致宿主防御缺陷 如果病毒载体介导的CFTR cDNA向CF小气道的递送将拯救宿主防御 缺陷我们的总体假设是，AAV 4介导的CFTR递送将纠正ASL性质并恢复CFTR。 CF小气道上皮细胞防御功能研究在目标1中，我们将使用AAV 4将CFTR cDNA递送到细胞中。 培养CF猪的小气道上皮细胞，并检查ASL特性，包括pH和粘度， 杀菌能力。在目标2中，我们将使用来自CF患者的人小气道上皮细胞来测试 假说.在目的3中，我们将检查AAV 4介导的基因递送至细胞的细胞向性和效率。 猪和人肺小气道上皮细胞。拟议的研究将导致更好的 了解CFTR介导的宿主防御机制，并说明了一个潜在的重要，但 小气道上皮细胞在CF肺疾病发病机制中的作用以前未被充分认识。

PROJECT SUMMARY / ABSTRACT Cystic fibrosis (CF) is a common genetic disease caused by a defect in the CF transmembrane conductance regulator (CFTR). The pathogenesis of CF lung disease is unclear and controversial, at least partially due to lack of studies in an appropriate CF animal model. In addition, most studies regarding the pathogenesis rely on data from cultured human diseased large proximal airways, such as tracheal and bronchial tissue. However, pathological and clinical data suggest that the disease is initiated in small airways with a diameter <2mm. Iowa group has engineered pigs with deletion or mutation of CFTR. These pigs mimic human CF, including development of spontaneous infections and obstruction of airways with mucus and inflammatory cells. This model provides an unprecedented opportunity to investigate the pathogenesis of CF lung disease. Our objective for this study is to investigate how loss of CFTR leads to host defense defects in CF small airway epithelia and if viral vector mediated delivery of CFTR cDNA to CF small airways will rescue host defense defects. Our overall hypothesis is that AAV4 mediated delivery of CFTR will correct ASL properties and restore host defense function of small airway epithelium in CF. In Aim 1, we will use AAV4 to deliver CFTR cDNA in cultured small airway epithelial cells from CF pigs and examine ASL properties including pH and viscosity and bacterial killing abilities. In Aim 2, we will use human small airway epithelia from CF patients to test the hypothesis. In Aim 3, we will examine the cellular tropism and efficiency of AAV4 mediated gene delivery to small airway epithelium in live pigs and human lung explant. The proposed studies will lead to a better understanding of the CFTR-mediated host defense mechanisms and illustrate a potentially important yet previously underappreciated role of small airway epithelial cells in pathogenesis of CF lung disease.