ROLE OF INTERLEUKIN 8 IN AIRWAY EPITHELIUM

气道上皮细胞存在于与外界 环境，因此上皮细胞在战略上处于有利地位， 环境刺激物（例如，细菌，病毒，污染物， 香烟烟雾）。 Neutrophil产品涉及各种 气道炎症反应，以及D-3项目支持的工作， 最近表明中性粒细胞蛋白酶是有效的腺体促分泌素。 气道细胞（包括上皮细胞）产生细胞因子， 白细胞介素-8（IL-8），其是有效的中性粒细胞化学引诱物。 D-3项目支持的研究提供了IL-8存在的证据 在囊性纤维化（CF）患者痰中的高浓度中， 支气管扩张症，慢性支气管炎，和亚组的患者， 哮喘，这表明气道细胞诱导IL-8参与了 中性粒细胞募集 这个项目将利用分子，细胞， 研究气道上皮细胞作用的生物化学和生理学工具 细胞IL-8在气道炎症反应中的作用。 因为CF患者 经常感染铜绿假单胞菌（PA）， 因为最近D-3项目的研究表明， 诱导IL-8的表达和分泌，研究建议检查 PA诱导气道上皮细胞和其他细胞中的IL-8。 研究 将利用从肺移植供体和受体获得的组织， 移植 对人类的研究一定是有限的，所以研究人员在 D-3项目最近克隆了狗IL-8。 这个项目的第一个目标 将重组犬IL-8进行表达，纯化重组犬IL-8， 蛋白质，并验证其活性。 犬IL-8的抗体将在 将产生中和抗体。 使用这些 材料，将开发用于狗IL-8的ELISA，因此IL-8活性可以 被衡量。 第二个目标是确定气道中的哪些细胞 表达IL-8以响应递送到气道中的PA上清液， 狗在体内和体外。当中和抗体可用时， 其对中性粒细胞募集和气道分泌抑制作用 随后检查PA上清液。 评价潜在 抑制IL-8的机制（例如，皮质类固醇）进行评价。 产物的分离、结构分析和合成 负责IL-8产生的铜绿假单胞菌 在气道上皮细胞将进行，在合作， 碳水化合物和蛋白质领域的生物有机化学专家 微生物化学 今后，研究将集中在其他领域。 细菌、病毒和污染物对气道中IL-8产生的影响。 的 研究具有重要的病理生理学和治疗意义： 他们提出了慢性炎症和气道炎症的基础机制， 呼吸道疾病中的分泌过多。 在CF和支气管扩张症中， 提出干预方法。 在哮喘中，他们提出的机制， 可以解释病理学研究中报告的粘液堵塞 死于哮喘的病人 在慢性支气管炎，他们可能会提供 解释某些症状和炎症反应的机制 呼吸道

The airway epithelium exists at the interface with the external environment, so epithelial cells are strategically positioned to respond to environmental irritants (e.g., bacteria, viruses, pollutants, cigarette smoke). Neutrophil products are implicated in various inflammatory responses in airways, and work supported by Project D-3 has recently shown that neutrophil proteases are potent gland secretagogues. Airway cells (including epithelial cells) produce a cytokine, interleukin-8 (IL-8), which is a potent neutrophil chemoattractant. Studies supported by Project D-3 have provided evidence that IL-8 exists in high concentrations in sputum of patients with cystic fibrosis (CF), bronchiectasis, chronic bronchitis, and in subsets of patients with asthma, suggesting that IL-8 induction by airway cells is implicated in neutrophil recruitment. This project will utilize molecular, cellular, biochemical and physiologic tools to study the role of airway epithelial cell IL-8 in airway inflammatory responses. Because patients with CF often become infected with Pseudomonas aeruginosa (PA) bacteria, and because recent studies in Project D-3 showed that a product from PA induces IL-8 expression and secretion, studies are proposed to examine PA induction of IL-8 in epithelial and other cells in airways. Studies in humans will utilize tissue obtained from donors and recipients of lung transplants. Studies in humans must be limited, so the investigators in Project D-3 have recently cloned dog IL-8. The first goal in the project will be to express dog recombinant IL-8, to purify the recombinant protein, and to verify its activity. Antibodies to dog IL-8 will be raised, and neutralizing antibodies will be selected. Using these materials, an ELISA for dog IL-8 will be developed, so IL-8 activity can be measured. A second goal is to determine which cells in airways express IL-8 in response to PA supernatant delivered into the airways in dogs in vivo and in vitro. When neutralizing antibodies are available, its inhibitory effect on neutrophil recruitment and on airway secretion following PA supernatant will be examined. Evaluation of potential mechanisms for inhibiting IL-8 (e.g., corticosteroids) will be evaluated. The isolation, structural analysis and synthesis of the product of Pseudomonas aeruginosa bacteria that is responsible for IL-8 production in airway epithelial cells will be undertaken, in collaboration with expert bioorganic chemists in the area of carbohydrate and protein chemistry of microbes. In the future, studies will focus on other bacteria, viruses and pollutants on IL-8 production in airways. The studies have important pathophysiologic and therapeutic implications: they suggest mechanisms that underlie chronic inflammation and airway hypersecretion in diseases of airways. In CF and bronchiectasis, they suggest methods of intervention. In asthma, they suggest mechanisms that might explain the mucous plugging that is reported in pathologic studies of patients dying of asthma. In chronic bronchitis, they may provide mechanisms to explain some of the symptoms and inflammatory effects in the airways.