Pathogenic T Cells in Chronic Beryllium Disease

项目摘要/摘要 慢性铍病(CBD)是一种由接触铍引起的肺部肉芽肿性疾病。 在工作场所，其特征是在肺中积累铍特异性的CD4+T细胞。由于其 铍具有独特的化学和物理特性，在高科技行业中继续得到利用。因此， CBD仍是一个重要的公共卫生问题，已有100多万美国工人接触到CBD 到铍，并面临疾病发展的风险。存在一个已知的抗原和一个可访问的 靶器官CBD是一种重要的免疫介导的器官破坏模型。我们和其他人已经展示了 与铍呈递有关的最重要的人类白细胞抗原分子是人类白细胞抗原-DP。利用成纤维细胞表达 突变的HLA-DP2分子，铍的识别依赖于第69位的谷氨酸残基 (Glu69)。此外，T细胞对铍的识别是在没有抗原的情况下发生的 处理，和核磁共振明确地表明，可溶性的人类白细胞抗原-DP2直接结合 铍。目前应用中的研究的目标是阐明 铍特异的CD4+T细胞在人类白细胞抗原DP2的背景下识别铍并证明其稳定性 铍特有的记忆T细胞池。Glu69最有可能影响铍的可能性 识别是：1)铍直接与人类白细胞抗原-DP2分子中Glu69的羧酸盐结合， 只需完成TCR配体的多肽(S)或2)Glu69对铍提呈的影响 是间接的，因为它影响了能与DP2结合的多肽库，其中包括多肽 可以提供铍的物质。我们的初步数据支持第一个假设，并表明我们可以研究 在知道哪些多肽对T细胞识别DP2很重要之前，铍与人类白细胞抗原DP2结合 多肽/Be2+络合物。第一个具体目标将提供铍与x射线结合的确凿证据。 含铍和不含铍的人类白细胞抗原-DP2的结晶学研究第二个目的：人类白细胞抗原-DP2突变体的产生 将作为目标1中的结构研究的功能关联。第三个目标将描述 需要多肽来完成TCR配体，而最终的特定目标将决定是否 从铍敏化到疾病的进展与铍的频率增加有关- 血液中特定的CD4+T细胞。总之，这些研究将加强我们对抗原如何 引起肉芽肿炎症，特别是金属抗原如何触发免疫反应。在……里面 此外，它们可能会使生物标志物的开发能够预测高危人群的疾病进展。 研究对象。

Project Summary/Abstract Chronic beryllium disease (CBD) is a granulomatous lung disorder caused by beryllium exposure in the workplace and is characterized by the accumulation of beryllium-specific CD4+ T cells in the lung. Due to its unique chemical and physical properties, beryllium continues to be utilized in high-technology industries. Thus, CBD remains an important public health concern with more than 1,000,000 US workers having been exposed to beryllium and at risk for disease development. With the presence of a known antigen and an accessible target organ, CBD is an important model of immune-mediated, organ destruction. We and others have shown that the most important HLA molecule for beryllium presentation is HLA-DP. Using fibroblasts expressing mutated HLA-DP2 molecules, beryllium recognition was dependent on the glutamic acid residue at position 69 (¿Glu69) of the HLA-DP ¿-chain. In addition, T cell recognition of beryllium occurred in the absence of antigen processing, and nuclear magnetic resonance definitively showed that soluble HLA-DP2 directly bound beryllium. The goals of the studies in the current application are to elucidate the mechanism by which beryllium-specific CD4+ T cells recognize beryllium in the context of HLA-DP2 and to demonstrate the stability of the beryllium-specific memory T cell pool. The most likely possibilities of how ¿Glu69 influences beryllium recognition are that 1) beryllium directly binds to the carboxylate of ¿Glu69 in HLA-DP2 molecules, with peptide(s) only required to complete the ¿¿TCR ligand or that 2) the effect of ¿Glu69 on beryllium presentation is indirect through its influence on the repertoire of peptides that can bind to DP2, among which are peptides that can present beryllium. Our preliminary data favor the first hypothesis and suggest that we can study beryllium binding to HLA-DP2 prior to knowing which peptides are important for T cell recognition of the DP2- peptide/Be2+ complex. The first specific aim will provide definitive proof of beryllium binding with x-ray crystallography of HLA-DP2 with and without beryllium. The generation of HLA-DP2 mutants in the second aim will serve as a functional correlate to the structural studies in Aim #1. The third aim will delineate which peptides are required to complete the ¿¿TCR ligand while the final specific aim will determine whether progression from beryllium sensitization to disease is associated with an increased frequency of beryllium- specific CD4+ T cells in blood. Together, these studies will strengthen our understanding of how antigens cause granulomatous inflammation and specifically how metal antigens trigger an immune response. In addition, they will potentially allow the development of biomarkers to predict disease progression in high-risk subjects.