Delivering antiproteases to the bronchiectatic airway

描述(由申请人提供)：在许多化脓性呼吸道疾病中，如原发纤毛运动障碍和囊性纤维化，上皮防御系统被破坏。慢性呼吸道细菌感染会刺激强烈的炎症反应，导致进行性呼吸道阻塞和支气管扩张。中性粒细胞迁移到呼吸道，一旦进入呼吸道，就会在吞噬上皮细胞表面的过程中释放出高浓度的中性丝氨酸蛋白酶，如中性粒细胞弹性蛋白酶。中性粒细胞弹性蛋白酶和其他蛋白酶通过刺激呼吸道上皮释放趋化因子并干扰细菌清除，使支气管扩张的气道炎症反应持续存在。已经提出了几种策略来阻止蛋白酶的有害影响，尤其是在呼吸道中，但成效有限。我们已经开发出一种新的方法，通过聚合免疫球蛋白受体靶向呼吸道上皮，将一种有效的抗蛋白水解酶-α1-抗胰蛋白酶输送到相对难以进入的呼吸道，该受体将药物集中在顶端表面，在那里它可能对支气管内感染和炎症产生最大的影响。在这项提案中，我们将在已建立的细胞和小鼠模型中测试这样一种假设，即呼吸道特异性递送α1抗胰蛋白酶更有效地阻止中性粒细胞衍生的丝氨酸蛋白酶在直接上皮表面，从而增强细菌的清除并减少肺部炎症反应。我们计划在上皮细胞模型和小鼠中鉴定抗分泌成分-人α1-抗胰蛋白酶的双功能特性，这些细胞模型和小鼠在呼吸道中特异性表达人多聚体免疫球蛋白受体。我们还将确定转基因肌肉是否可以产生和分泌“靶向”的人α1-抗胰蛋白酶，以达到持续的、循环的抗蛋白酶水平。最后，我们将证实，在假单胞菌支气管内感染的小鼠模型中，抑制蛋白酶可以提供更好的保护，防止细胞外丝氨酸蛋白酶的破坏作用，减少细菌负担，防止炎症反应的升级。使用这种方法，我们将确定中性粒细胞衍生的丝氨酸蛋白酶在呼吸道炎症和感染发病机制中的作用，并确定这种“靶向”抗蛋白水解酶是否可以用于治疗支气管扩张和其他呼吸道疾病。

DESCRIPTION (provided by applicant): Epithelial defenses are breached in many, suppurative airway diseases, such as primary ciliary dyskinesia and cystic fibrosis. Chronic, airway infection with bacteria stimulates an intense, inflammatory response that leads to progressive airway obstruction and bronchiectasis. Neutrophils migrate into the airway, and once there, release high concentrations of neutral serine proteases, like neutrophil elastase, during phagocytosis at the immediate epithelial surface. Neutrophil elastase and other proteases perpetuate the inflammatory response in the bronchiectatic airway by stimulating release of chemokines from the respiratory epithelium and interfering with bacterial clearance. Several strategies have been proposed to block the deleterious effects of proteases specifically in the airway, which have had limited success. We have developed a novel approach that permits the delivery of a potent antiprotease, alpha1-antitrypsin, to relatively inaccessible airways by targeting the respiratory epithelium via the polymeric immunoglobulin receptor, which concentrates the drug at the apical surface where it potentially could have the greatest impact on endobronchial infection and inflammation. In this proposal, we will test the hypothesis that airway-specific delivery of alpha1-antitrypsin more effectively blocks neutrophil-derived serine proteases at the immediate epithelial surface, thus enhancing clearance of bacteria and reducing the pulmonary inflammatory response in well-established cell and mouse models. We plan to characterize the bifunctional properties of anti-secretory component-human alpha1-antitrypsin in epithelial cell models and mice that specifically express the human polymeric immunoglobulin receptor in the airway. We will also determine whether transfected muscle can produce and secrete "targeted" human alpha1-antitrypsin to achieve a sustained, circulating level of the antiprotease. Finally, we will establish that protease inhibition affords greater protection against the damaging effects of the extracellular serine proteases, and reduce bacterial burden and prevent the escalation of the inflammatory response in murine models of Pseudomonas endobronchial infection. Using this approach, we will define the effects of neutrophil-derived serine proteases in the pathogenesis of airway inflammation and infection, and determine whether such "targeted" antiproteases could be used for therapeutic purposes in bronchiectasis and other airway diseases.