ROLE OF INTERLEUKIN 8 IN AIRWAY EPITHELIUM

呼吸道上皮存在于与外部的交界处。 环境，因此上皮细胞处于战略地位，以响应 对环境刺激物(例如，细菌、病毒、污染物、 香烟烟雾)。中性粒细胞产物与多种疾病有关 呼吸道中的炎症反应，以及由D-3项目支持的工作 最近发现，中性粒细胞蛋白水解酶是一种强有力的腺体促分泌物。 呼吸道细胞(包括上皮细胞)产生一种细胞因子， 白介素8(IL-8)，这是一种强大的中性粒细胞趋化剂。 由D-3项目支持的研究提供了IL-8存在的证据 囊性纤维化患者痰中高浓度， 支气管扩张症、慢性支气管炎，以及 哮喘，提示由呼吸道细胞诱导的IL-8参与了 中性粒细胞募集。该项目将利用分子、细胞、 生化和生理学手段研究呼吸道上皮细胞的作用 细胞IL-8在呼吸道炎症反应中的作用因为慢性萎缩性胃炎患者 经常感染铜绿假单胞菌(PA)，以及 因为项目D-3的最新研究表明，PA的一种产品 诱导IL-8的表达和分泌，建议进行研究 PA诱导呼吸道上皮细胞和其他细胞产生IL-8。研究 人类将利用从肺的捐赠者和接受者那里获得的组织 移植。在人体上的研究必须是有限的，所以研究人员在 D-3项目最近克隆了狗IL-8。该项目的第一个目标 将表达的犬重组IL-8、纯化的重组 蛋白质，并验证其活性。针对狗IL-8的抗体将是 提出，将选择中和抗体。使用这些 材料，将建立犬IL-8的ELISA，使IL-8的活性可以 被测量。第二个目标是确定呼吸道中的哪些细胞 PA上清液进入呼吸道后表达IL-8的研究 狗在体内和体外。当中和抗体可用时， 对中性粒细胞募集和呼吸道分泌的抑制作用 随后将检查PA上清液。潜力评估 将评估抑制IL-8(例如，皮质类固醇)的机制。 产物的分离、结构分析和合成 产生IL-8的铜绿假单胞菌 将在呼吸道上皮细胞中进行，与 碳水化合物和蛋白质领域的专业生物有机化学家 微生物化学。在未来，研究将集中在其他方面 细菌、病毒和污染物对呼吸道产生IL-8的影响。这个 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呼吸道基础的机制。 呼吸道疾病中的高分泌。在慢性支气管炎和支气管扩张症中， 建议干预方法。对于哮喘，他们提出了一种机制， 可能解释了病理研究中所报道的粘液堵塞 死于哮喘的病人。在慢性支气管炎中，它们可能会提供 解释一些症状和炎症效应的机制 航空公司。

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.