Project 1 - Beryllium Antigen: HLA Peptide, Metal Interactions

有了已知的抗原和可接近的靶器官，慢性铍病(CBD)就像一个 重要的器官特异性、免疫介导性疾病。慢性阻塞性肺疾病是由铍暴露引起的，与 随着铍特异的、分泌THI型细胞因子的CD4*T细胞在肺内积累。上一首 研究有助于确定T细胞抗原受体(TCR)的遗传和功能重要性，并 HLA-DP2在CBD免疫发病机制中的作用尽管我们对这一问题的理解有所进步 铍诱导疾病的免疫发病机制，铍如何与主要组织相容性结合 复合体11(MHCII)分子，随后被铍特异的004*T细胞识别 仍然不为人知。最近，我们课题组对人类白细胞抗原-DP2的结晶发现了一个潜在的铍 与P链和肽骨架上氨基酸位置上的谷氨酸残基结合的位置。数据 提示铍直接与人类白细胞抗原DP2结合，需要特定的多肽才能完成 ApTCR配体。项目1修订的中心目标是确定铍抗原的特征 负责CD4*T细胞的激活。已经设计了一系列实验来识别人类白细胞抗原DP2 完成apTCR配体和激活铍特异的CD4*T细胞所需的多肽表位。vbl.使用 已建立的方法和细胞模型系统，具体的实验将：1)确定序列和基序 与人类白细胞抗原-DP2结合并确定这些多肽的结合亲和力的多肽，2)描绘以下哪些 所鉴定的在铍盐存在下的人类白细胞抗原-DP2结合肽允许通过 抗原特异性TCR，3)识别和表征由在T细胞亚群中发现的 CBD患者的支气管肺泡灌洗(BAL)对所识别的不同肽集的反应，以及 4)确定是否可以使用人类白细胞抗原-DP2/肽/铍复合体来鉴定和表征 慢性阻塞性肺疾病患者血和BAL中铍反应性CD4+T细胞作为疾病潜在生物标志物的研究 和疾病的进展。这项转化性研究是多学科的，汇集了免疫学家， 生物化学家，人类白细胞抗原结构生物学家和内科科学家，以定义准确的性质 MHCII/铍/肽/TCR在CBD中的关系项目1与项目2集成，通过提供功能 遗传流行病学发现的基础，以及项目3通过测试免疫生物标记物的结果 措施并行不悖。这些结果将加深对金属抗原结构/功能的理解，并将有助于提高对金属抗原结构/功能的认识 结果数据支持将多肽四聚体用作临床生物标记物。

With a known antigen and an accessible target organ, chronic beryllium disease (CBD) serves as an important organ-specific, immune-mediated disease. CBD results from beryllium exposure and is associated with the accumulation of beryllium-specific, Thi-type cytokine-secreting CD4* T cells in the lung. Previous studies have helped identify the genetic and functional importance of the T cell antigen receptor (TCR) and HLA-DP2 in CBD immunopathogenesis. Despite the advances in our understanding of the immunopathogenesis of beryllium-induced disease, how beryllium binds to the major histocompatibility complex class 11 (MHCII) molecule and is subsequently recognized by beryllium-specific 004* T cells remains unknown. Recently, the crystallization of HLA-DP2 by our group has revealed a potential beryllium binding site to glutamic acid residues at amino acid positions in the p-chain and the peptide backbone. Data suggest that beryllium directly binds to HLA-DP2 and that particular peptides are required to complete the apTCR ligand. The central goal of this revision of Project 1 is to characterize the beryllium antigen responsible for CD4* T cell activation. A series of experiments has been designed to identify the HLA-DP2 peptide epitopes required to complete the apTCR ligand and activate beryllium-specific CD4* T cells. Using established methods and cell model systems, specific experiments will: 1) Define the sequence and motif of peptides that bind to HLA-DP2 and determine the binding affinities of those peptides, 2) Delineate which of the identified HLA-DP2 binding peptides in the presence of beryllium salt allow recognition of beryllium by antigen-specific TCRs, 3) Identify and characterize the TCRs expressed by the subset of T cells found in the bronchoalveolar lavage (BAL) of patients with CBD that respond to the different peptide sets identified, and 4) Determine whether HLA-DP2/peptide/beryllium complexes can be used to identify and characterize beryllium-reactive CD4+T cells in the blood and BAL of CBD patients, as a potential biomarker of disease and disease progression. This translational study is multidisciplinary, assembling immunologists, biochemists, HLA structural biologists, and physician-scientists to define the precise nature of the MHCII/Beryllium/Peptide/TCR relationship in CBD. Project 1 integrates with Project 2 by providing functional basis for genetic epidemiologic discoveries, and with Project 3 by testing immune biomarker outcome measures in parallel. The results will improve the understanding of metal antigen structure/function and result in data to support the use of peptide tetramers as clinical biomarkers.