Isocyanate Antigens and T-cells that Cause Asthma

二异氰酸酯是一组高反应性、广泛使用的低分子量化学品，是发达国家最常见的职业性哮喘原因。 然而，二异氰酸酯诱发哮喘和高危人群的机制。理论上，反应性二异氰酸酯作为低分子量半抗原，触发人类T细胞反应。然而，关于体内二异氰酸酯的天然“载体”蛋白和暴露后引发哮喘相关气道炎症的假定T细胞存在相当大的不确定性。我们假设，二异氰酸酯结合到特定的蛋白质在人体气道，包括白蛋白和角蛋白-18，这些二异氰酸酯哮喘和暴露的非哮喘工人表现出不同的T细胞反应二异氰酸酯共轭蛋白抗原，这将有助于了解二异氰酸酯哮喘的发病机制，并确定这些主题。为了检验这些假设，我们将：（AIM 1）进一步表征暴露于正常人气道组织和蛋白质后产生的生物学相关二异氰酸酯-蛋白质复合物（AIM 2）。根据特异性二异氰酸酯-蛋白质结合物的体外反应，评价T细胞的二异氰酸酯抗原性，并（目的3）确定不同T细胞亚群的作用（即CD 4+、CD 8+、α/β、γ/β）在对二异氰酸酯缀合蛋白的致病性免疫应答中的作用，通过对来自二异氰酸酯哮喘和暴露对照受试者的气道活检和外周血的T细胞进行体外研究。这些研究建立在我们以前的工作，已经确定了新的二异氰酸酯-蛋白质共轭物，发生在体内，并产生了抗原特异性T细胞系从人气道支气管活检样本。这些实验将利用外周血、支气管灌洗和气道活检样本，这些样本来自耶鲁医学院正在进行的研究中招募的明确定义的二异氰酸酯哮喘和对照受试者人群。这些结果将为二异氰酸酯哮喘的发病机制提供重要的见解。

Diisocyanates are a group of highly reactive, widely used low molecular weight chemicals, and are the most commonly reported cause of occupational asthma in developed countries. Yet, the mechanisms by which diisocyanate-induced asthma and those at risk. It has been theorized that reactive diisocyanates act as low-molecular weight haptens that trigger human T-cell responses. However, considerable uncertainty exists regarding the natural "carrier" proteins for diisocyanate in vivo and the putative T-cells central to eliciting asthma- related airway inflammation following exposure. We hypothesize that diisocyanates bind to specific proteins in human airways including, albumin and keratin-18, and that these diisocyanate asthmatics and exposed non-asthmatic workers manifest distinct T-cell responses to diisocyanate-conjugated protein antigens that will aid in understanding the pathogenesis of diisocyanate asthma and identifying these subjects. To test these hypotheses we will: (AIM 1) Further characterize biologically relevant diisocyanate-protein complexes that result following the exposure of normal human airway tissues and proteins, (AIM 2). Evaluate diisocyanate antigenicity at the T-cell based on in vitro responses t specific diisocyanate-protein conjugates, and (AIM 3) Determine the roles of different T cell subsets (i.e. CD4+, CD8+, alpha/beta, gamma/beta) in the pathogenetic immune response to diisocyanate-conjugated proteins, through in vitro studies with T cells derived from airway biopsies and peripheral blood of diisocyanate asthmatic and exposed control subjects. These studies build upon our previous work that has identified novel diisocyanate-protein conjugates that occur in vivo and has generated antigen-specific T-cell lines from human airway endobronchial biopsy samples. The experiments will utilize peripheral blood; bronchial lavage and airway biopsy samples from a well-defined population of diisocyanate asthmatic and control subjects enrolled in ongoing studies at the Yale School of Medicine. Together the results should provide significant insights into the pathogenesis of diisocyanate asthma.