Pathogenic T Cells in Chronic Beryllium Disease

项目总结/摘要 慢性铍病（CBD）是一种肉芽肿性肺病， 其特征在于铍特异性CD 4 + T细胞在肺中的积累。由于其 铍具有独特的化学和物理性质，继续用于高科技工业。因此，在本发明中， CBD仍然是一个重要的公共卫生问题，超过1，000，000名美国工人接触过CBD 铍和疾病发展的风险。在已知抗原的存在下， 靶器官，CBD是免疫介导的器官破坏的重要模型。我们和其他人已经证明 铍递呈最重要的HLA分子是HLA-DP。使用表达 突变的HLA-DP 2分子，铍识别依赖于69位的谷氨酸残基 （<$Glu69）的HLA-DP <$-链。此外，T细胞对铍的识别发生在无抗原的情况下 处理和核磁共振明确表明，可溶性HLA-DP 2直接结合 铍。本申请中的研究的目标是阐明通过其实现以下目的的机制： 铍特异性CD 4 + T细胞在HLA-DP 2的背景下识别铍，并证明其稳定性 铍特异性记忆T细胞库。Glu 69如何影响铍的最可能的可能性 铍直接与HLA-DP 2分子中Glu 69的羧酸盐结合， 仅完成<$$> TCR配体所需的肽或2）<$Glu 69对铍呈递的影响 是间接的，通过其对可与DP 2结合的肽库的影响，其中包括肽 能呈现铍元素我们的初步数据支持第一个假设，并建议我们可以研究 铍结合HLA-DP 2之前，知道哪些肽是重要的T细胞识别的DP 2- 肽/Be ~（2+）复合物。第一个具体目标将提供铍与x射线结合的明确证据 含和不含铍的HLA-DP 2晶体学。第二个目标中HLA-DP 2突变体的产生 将作为目标1中结构研究的功能相关性。第三个目标将描述 肽是完成TCR配体所必需的，而最终的特异性目标将决定 从铍致敏到疾病的进展与铍的频率增加有关， 血液中的特异性CD 4 + T细胞。总之，这些研究将加强我们对抗原 引起肉芽肿性炎症，特别是金属抗原如何引发免疫反应。在 此外，它们还可能使生物标志物的开发能够预测高危人群的疾病进展。 科目

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.