IMMUNOTOXICOLOGY OF BENZENE DERIVATIVES

苯衍生物的免疫毒理学

• 批准号: 2757880
• 负责人: BRIAN M FREED
• 金额: $ 19.88万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-04-01 至 2002-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2757880
• 关键词: T lymphocyte; catechols; cell line; chemical stability; clone cells; electron spin resonance spectroscopy; environmental toxicology; genetic translation; human subject; hydroquinones; immunotoxicity; interferon gamma; interleukin 2; leukocyte activation /transformation; lymphocyte proliferation; messenger RNA; northern blottings; phenols; phlebotomy; ribonucleotide reductase; tobacco; transferrin receptor

Pyrolysis of tobacco flavinoids deposits 7-280 micrograms per cigarette of the each of the benzene derivatives phenol, hydroquinone (HQ) and catechol into the smoker's lungs. A fourth derivative, p-benzoquinone (p-BQ), is spontaneously produced by oxidation of hydroquinone. The long-term objective of this research project is to determine the mechanisms by which these benzene derivatives block T cell responses in order to gain a better understanding of how cigarette smoke suppresses T cell function in the lungs and promotes respiratory tract infections and cancer. We have found that three biologically active derivatives of benzene function at different stages in T cell activation; p-BQ blocks IL-2 and IFN-gamma production, HQ blocks transferrin-receptor expression and DNA synthesis, and catechol chelates iron needed to T cell proliferation. The inhibitory effects of these benzene derivatives occur in the absence of cytotoxicity. We hypothesize that p-BQ, HQ and catechol inhibit discrete events in early and late T cell activation that are critical for normal immune function. In order to determine the mechanism of action of these benzene metabolites, the following specific aims will be undertaken: (1) To determine if the inhibitory effect of p-BQ on IL-2 and IFN-gamma production is due to effects on mRNA stability and/or translation; (2) To determine by electron paramagnetic resonance if HQ and catechol quench the tyrosyl radical in the M2 subunit of ribonucleotide reductase; (3) To elucidate, at the subcellular level, the mechanism by which HQ down- regulates transferrin receptors on human T lymphoblasts; and (4) To determine if the anti-proliferative effect of ion-chelation by catechol is limited to inhibition of the iron-dependent enzyme, ribonucleotide reductase. Human peripheral blood T cells (resting) and human T lymphoblasts (proliferating) and a Jurkat T cell line will be used. The effect of p-BQ on IL-2 on IL-2 mRNA stability will be determined by Northern analysis at different times after stimulation of normal T cells with alphaCD3+ PMA, and by measuring its effect on the expression of a fluorescent reporter gene product containing the 3'-untranslated instability region cloned from the IL-2 and IFN-gamma genes. The ability of HQ and catechol to reduce the tyrosyl radical in the M2 subunit of ribonucleotide reductase will be measured by EPR spectroscopy.

烟草类黄素的热解沉积7-280微克每烟 每种苯衍生物苯酚，羟基酮（HQ）和儿茶酚 进入吸烟者的肺部。第四个导数P-苯醌（P-BQ）为 通过羟基酮氧化自发产生。长期 该研究项目的目的是确定 这些苯衍生物阻止了T细胞反应，以获得 更好地了解香烟如何抑制T细胞功能 肺并促进呼吸道感染和癌症。我们有 发现苯在 T细胞激活的不同阶段； P-BQ阻止IL-2和IFN-gamma 产生，总部阻断转铁蛋白受体表达和DNA合成， Catechol螯合了T细胞增殖所需的铁。抑制性 这些苯衍生物的作用发生在没有细胞毒性的情况下。 我们假设P-BQ，总部和儿茶酚抑制早期的离散事件 对于正常免疫功能至关重要的T细胞激活。 为了确定这些苯的作用机理 代谢物，将实现以下特定目标：（1） 确定P-BQ对IL-2和IFN-gamma的抑制作用是否 生产是由于对mRNA稳定性和/或翻译的影响。 （2）至 通过电子顺磁共振确定，如果HQ和Catechol淬灭 核糖核苷酸还原酶的M2亚基中的酪酶自由基； （3）到 在亚细胞水平上阐明总部下降的机制 调节人类T淋巴细胞上的转铁蛋白受体； （4）到 确定儿茶酚离子螯合的抗增殖作用是否为 仅限于抑制铁依赖性酶，核糖核苷酸 还原酶。人外周血T细胞（静止）和人类T 将使用淋巴细胞（增殖）和Jurkat T细胞系。这 P-BQ对IL-2对IL-2 mRNA稳定性的影响将由 刺激正常T细胞后在不同时间的北部分析 使用AlphACD3+ PMA，并通过测量其对A表达的影响 荧光报告基因产物包含3'-非翻译 从IL-2和IFN-GAMMA基因克隆的不稳定性区域。能力 总部和儿茶酚以减少M2亚基中的酪酶自由基 核糖核苷酸还原酶将通过EPR光谱法测量。