Role of Oxidatve Stress in Chronic Beryllium Disease

描述(由申请人提供)：本申请的总体目标是了解氧化应激在慢性铍病(CBD)中的作用。CBD是一种炎症性过敏性肺部疾病，在美国约80万暴露于铍的工人中仍有10%发生，其特征是存在非干酪性肉芽肿，并聚集巨噬细胞和铍特异的CD4+T淋巴细胞。在体外铍刺激下，这些T细胞增殖并产生异常高水平的Th1细胞因子(即肿瘤坏死因子-α、干扰素-γ和白介素2)。铍调节这些高水平细胞因子的产生的确切分子机制(S)尚不清楚。假设氧化应激增强了APC向T细胞递呈铍抗原的能力，这可能在一定程度上解释了过度的细胞因子反应和相关的肺肉芽肿形成。令人兴奋的初步研究表明，抗原提呈细胞(APC)的氧化还原状态会影响T细胞的反应，这可能有助于解释为什么只有一部分接触铍的人实际上会患上CBD。表达II类分子的APC的存在是CBD患者的CD4+T细胞在铍存在下体外增殖所必需的。本项目将使用改良的临床铍淋巴细胞增殖试验(BeLPT)来检查氧化还原平衡对铍抗原呈递的影响。这一系统将使氧化应激影响APC向T细胞呈递铍抗原的能力以及氧化应激在调节T细胞激活中的作用的假设得到验证。该假说旨在：(1)检测铍对APC和T细胞抗氧化状态和刺激反应的影响；(2)检测APC谷胱甘肽状态改变对铍抗原提呈的影响；(3)检测氧化状态改变对通过APC和T细胞激活提呈铍抗原的影响。测量的主要终点是(1)谷胱甘肽及其合成和利用所涉及的酶；(2)脂类、蛋白质和DNA氧化的标志物；(3)T细胞增殖和Th1细胞因子的释放和辅助分子的表达。有人认为，铍本身会在APC中启动氧化应激，也可以作为抗原。静态APC抗氧化剂状态或APC对铍的氧化反应的固有差异被预测为决定暴露于铍的人是否会继续发展为CBD的关键因素。这些研究有可能进一步确定CBD的病因、危险因素，并提出预防和治疗这种疾病的新方法。

DESCRIPTION (provided by applicant): The overall goal of this application is to understand the role of oxidative stress in chronic beryllium disease (CBD). CBD is an inflammatory hypersensitivity lung disease that continues to occur in 10% of the estimated 800,000 beryllium-exposed workers in the United Sates and is characterized by the presence of non-caseating granulomas with accumulation of macrophages and beryllium specific CD4+ T lymphocytes. Upon beryllium stimulation in vitro, these T cells proliferate and produce Th1 cytokines (i.e. TNF-alpha, INF-gamma, and IL-2) at unusually high levels. The precise molecular mechanism(s) by which beryllium regulates the production of these high levels of cytokines is unknown. It is hypothesized that oxidative stress enhances the APC's ability to present beryllium antigen to T cells, which may, in part, explain both the excessive cytokine response and associated lung granuloma formation. Exciting preliminary studies indicate that the redox status of the antigen presenting cell (APC) affects the T cell's response and may help explain why only a portion of the people exposed to beryllium actually develop CBD. The presence of APCs expressing class II molecules is required for CD4+ T cells from CBD patients to proliferate in the presence of beryllium in vitro. This project will use a modification of the clinical beryllium lymphocyte proliferation test (BeLPT) to examine the effect of redox balance on beryllium antigen presentation. This system will enable the testing of the hypothesis that oxidative stress affects the APC's ability to present beryllium antigen to T cells and the role of oxidative stress in modulating T cell activation. The hypothesis is addressed by the AIMS: (1) examine the effect of beryllium on APC and T cell antioxidant status and stimulation response; (2) examine the effect of altered APC glutathione status on beryllium antigen presentation; (3) examine the effect of altered oxidant status on beryllium antigen presentation by APC and T cell activation. Primary endpoints measured are (1) glutathione and enzymes involved in its synthesis and utilization; (2) markers of lipid, protein and DNA oxidation; and (3) T cell proliferation and Th1 cytokine release and accessory molecule expression. It is proposed that beryllium, itself; initiates oxidative stress in the APC and also serve as the antigen. Inherent differences in either resting APC antioxidant status or APC oxidant response to beryllium are predicted to be critical factors in determining whether people exposed to beryllium go on to develop CBD. These studies have the potential to further define the etiology of CBD, risk factors, and suggest novel approaches to prevent and treat this disease.