MECHANISMS OF HUMAN LUNG HYPERSENSITIVITY REACTIONS

人肺超敏反应的机制

• 批准号: 2003290
• 负责人: Edward Schulman
• 金额: $ 22.36万
• 依托单位: ALLEGHENY UNIVERSITY OF HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-01-01 至 1999-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2003290
• 关键词: RNase protection assay; antiinflammatory agents; cell type; cellular pathology; corticosteroids; cytokine; enzyme inhibitors; gene expression; human tissue; immunocytochemistry; immunomodulators; in situ hybridization; indomethacin; inflammation; interleukin 4; interleukin 5; lipoxygenase; low density lipoprotein; mast cell; messenger RNA; polymerase chain reaction; prostaglandin endoperoxide synthase; respiratory hypersensitivity; respiratory pharmacology; stimulant /agonist

The central role of airway inflammation in chronic asthma has received increasing attention concordant with an alarming decade-long surge in asthma morbidity and mortality especially in urban populations where sizable numbers of asthmatics have elevated levels of IgE directed against indoor inhalants. The long term objective of this project is a better understanding of the cellular and molecular mechanisms of human lung allergic disorders and asthma, and means of their control. The human lung mast cell (HLMC) by virtue of its anatomic localization, elaboration of potent chemical mediators upon stimulation, and the effects of these mediators on cell and tissue targets, triggers the pathophysiologic manifestations of the acute ("early phase," EPR) asthmatic response that results in immediate breathlessness. It is unknown what cell(s) directly produces the groundwork for chronic airway inflammatory ("late phase", LPR) responses characterized by leukocyte, especially eosinophil, infiltration of airways. The current view, principally based on cell samplings obtained well beyond the initial development of airway inflammation, is that the LPR is "driven" by Interleukin-4 and -5, the major cytokines responsible for IgE generation and eosinophilia, respectively, emanating from the "Th2" subtype of cD4+ T-lymphocytes. We hypothesize that the mast cell is the major contributor of "TH2" cytokines released within 2-4 hours following allergen challenge, and thus sets the framework for chronic inflammation. Over the past twelve years, techniques developed in our laboratory to purify HLMC have allowed for the first time, detailed studies of their biology. Also, we discovered and physically separated HLMC subpopulations distinguished by morphologies, histochemistry, and function. Recently, we have applied molecular hybridization and protein quantification techniques to identify the gene expression, protein release and temporal pattern of co-expression from purified HLMC and lung tissue, of Th2 cytokines. Moreover, we have begun to uncover pharmacologic mechanisms regulating gene expression and release of IL-5, including the annihilation of the IL-5 mRNA and protein responses by corticosteroids. Our specific aims are to define "Th2-like" cytokines in purified HLMC, HLMC subsets, and human lung tissue fragments, with respect to: identification, quantification, triggers, and their drug modulation including corticosteroids, and 13-agonists. Gene expression will be screened using reverse transcription polymerase chain reaction (RT-PCR), and RNase protection. Cellular attribution of cytokine generation will be performed by in situ hybridization and immunocytochemistry. Increased understanding of HLMC heterogeneity, Th2 cytokine generation from human lung and purified HLMC, and the capacity of specific drugs to target "inflammation" and the LPR, will broaden our understanding of human hypersensitivity, and influence the construction of therapies.

呼吸道炎症在慢性哮喘中的核心作用已被 越来越多的关注与令人震惊的长达十年的激增相一致 哮喘发病率和死亡率，特别是在城市人口中 相当数量的哮喘患者的IgE水平升高 反对室内吸入剂。这个项目的长期目标是 更好地理解人类的细胞和分子机制 肺部变态反应性疾病和哮喘及其控制方法。人类 肺肥大细胞(HLMC)凭借其解剖学定位、构筑 有效的化学介体对刺激的影响，以及这些影响 细胞和组织靶点上的介质，触发病理生理 急性(早期，EPR)哮喘反应的表现 导致立即上气不接下气。还不知道是什么细胞(S)直接 为慢性呼吸道炎症(“晚期”)奠定基础。 LPR)反应的特征是白细胞，尤其是嗜酸性粒细胞， 呼吸道渗入。当前视图，主要基于单元格 获得的样本远远超出了呼吸道的初始发育阶段 炎症，是LPR由白介素4和白介素5“驱动”， 导致IgE生成和嗜酸性粒细胞增多的主要细胞因子， 分别来自“Th2”亚型的CD4+T淋巴细胞。我们 假设主单元是“TH2”的主要贡献者 过敏原攻击后2-4小时内释放的细胞因子，以及 从而为慢性炎症奠定了基础。 在过去的12年里，我们实验室发展出的技术 Purify HLMC首次允许对其进行详细研究 生物学。此外，我们发现了HLMC亚群，并在物理上将其分开 以形态、组织化学和功能为特征的。最近， 我们应用了分子杂交和蛋白质定量 识别基因表达、蛋白质释放和时间的技术 纯化的HLMC与肺组织共表达Th2的模式 细胞因子。此外，我们已经开始揭示药理机制。 调节IL-5的基因表达和释放，包括 糖皮质激素对IL-5mRNA和蛋白反应的抑制作用。 我们的具体目标是确定纯化的HLMC中的“Th2样”细胞因子， HLMC亚群和人肺组织碎片，涉及： 识别、量化、触发因素及其药物调节 包括皮质类固醇和13种激动剂。基因表达将是 经逆转录聚合酶链式反应(RT-PCR)筛选， 和核糖核酸酶保护。细胞因子产生的细胞属性将 通过原位杂交和免疫细胞化学进行检测。增加了 对人类HLMC异质性、Th2细胞因子产生的认识 肺和纯化的HLMC，以及特定药物的靶向能力 “炎症”和LPR，将拓宽我们对人类的认识 过敏症，并影响治疗的构建。