DIMETHYLNITROSAMINE EFFECTS ON CELLULAR IMMUNITY

二甲基亚硝胺对细胞免疫的影响

• 批准号: 2153664
• 负责人: LAWRENCE B SCHOOK
• 金额: $ 20.8万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-08-01 至 1997-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2153664
• 关键词: T lymphocyte; acute phase protein; cell adhesion molecules; cellular immunity; cytokine; enzyme linked immunosorbent assay; flow cytometry; gene expression; hepatotoxin; immunofluorescence technique; immunosuppression; in situ hybridization; inflammation; laboratory mouse; macrophage; nitrosamines; polymerase chain reaction; radionuclides; solution hybridization; tissue /cell culture; transforming growth factors

Experiments outlined in this competitive renewal are aimed at determining how the tissue response to dimethylnitrosamine (DMN)-induced hepatotoxicity leads to immune dysfunction. Our previous work demonstrated that DMN exposure resulted in altered bone marrow differentiation, induction of serum borne cytokines, and tissue macrophages with increased prostaglandin synthesis, and enhanced respiratory burst activity and tumor necrosis factor alpha gene expression. Studies outlined in this proposal will continue to focus on the role of the macrophage since this cell is involved in both the inflammatory response to tissue injury as well as regulating cell- mediated immunity (CMI). Molecular methodologies developed in prior studies will be utilized to elucidate the mechanism(s) by which DMN exposure affects the immune system. The hypothesis to be addressed in this proposal is that the lack of adequate down-regulation of the chemically-induced inflammatory response results in inappropriate cytokine expression, thus, affecting the regulation of the immune response. Consequently, the overproduction of specific cytokines leads to immune dysfunction. To address this hypothesis we will perform qualitative and quantitative studies to characterize the induction and resolution of the DMN-induced inflammatory response. These studies will monitor the cellular influx, induction of acute phase proteins and adhesion molecules, and changes in cytokine expression by utilizing immunodetection, in situ hybridization, enzyme-linked immunosorbent- and bio-assays as well as solution hybridization and polymerase chain reaction (PCR) gene amplification. Secondly, experiments will determine the mechanisms responsible for elevated serum cytokine activity and the induction of "primed" macrophage populations, and altered immune responses (in vitro). These efforts will utilize the "molecular phenotyping" and quantitative PCR procedures which we have developed to focus on our continued interest in the generation of macrophage heterogeneity and why DMN-induced changes in differentiation results in macrophages with altered responses to regulatory signals. Specific questions which will be addresses include: Are specific "molecular phenotypes" associated with tissue and inflammatory macrophages following DMN exposure? What is the correlation between changes in macrophage markers with functions? Are T cell regulatory signals absent in DMN-induced inflammation? Answers to these questions will be used in our third objective to determine whether the cytokine profiles (biomarkers) associated with DMN exposure are directly responsible for immunotoxicity and can be used to predict altered host resistance (in vivo). Hence, these studies will determine the cause and effect relationships between identified biomarkers and DMN-induced immunotoxicity. The objectives of these efforts are to determine whether administration of cytokines can reverse DMN-induced immunotoxicity or that monitoring of cytokine expression can be used to predict altered immune responses in vivo. Thus, this approach will permit us to establish a model for making risk assessments following DMN exposure. Finally, experiments will be conducted to determine whether there is a genetic component to DMN-induced changes.

本次竞争性更新中概述的实验旨在 确定组织对二甲基亚硝胺 (DMN) 诱导的反应如何 肝毒性导致免疫功能障碍。我们之前的工作 证明 DMN 暴露导致骨髓改变 分化、诱导血清中的细胞因子和组织 巨噬细胞前列腺素合成增加，并增强 呼吸爆发活性和肿瘤坏死因子α基因 表达。本提案中概述的研究将继续关注 巨噬细胞的作用，因为该细胞参与 对组织损伤的炎症反应以及调节细胞 介导免疫（CMI）。先前开发的分子方法学 研究将用于阐明 DMN 的机制 暴露会影响免疫系统。要解决的假设 该提议的主要内容是缺乏充分的下调 化学物质引起的炎症反应导致不适当的 细胞因子的表达，从而影响免疫调节 回复。因此，特定细胞因子的过量产生导致 导致免疫功能失调。为了解决这个假设，我们将执行 定性和定量研究来表征归纳和 DMN 诱导的炎症反应的解决。这些研究将 监测细胞流入、急性期蛋白的诱导和 粘附分子，以及利用细胞因子表达的变化 免疫检测、原位杂交、酶联免疫吸附和 生物测定以及溶液杂交和聚合酶链 反应（PCR）基因扩增。其次，实验将确定 血清细胞因子活性升高的机制和 诱导“引发”巨噬细胞群，并改变免疫 反应（体外）。这些努力将利用“分子 我们开发的“表型分析”和定量 PCR 程序 关注我们对巨噬细胞生成的持续兴趣 异质性以及为什么 DMN 诱导的分化变化会导致 巨噬细胞对调节信号的反应发生改变。具体的 将要解决的问题包括：特定的“分子 与组织和炎症巨噬细胞相关的表型” 暴露于 DMN 后？变化之间有何相关性 巨噬细胞标记物具有哪些功能？ T细胞调节信号是否缺失 DMN 诱发的炎症？这些问题的答案将用于 我们的第三个目标是确定细胞因子谱是否 与 DMN 暴露相关的（生物标志物）直接负责 免疫毒性，可用于预测改变的宿主抵抗力（在 体内）。因此，这些研究将确定因果关系 已识别的生物标志物与 DMN 诱导之间的关系 免疫毒性。这些努力的目标是确定是否 施用细胞因子可以逆转 DMN 诱导的免疫毒性或 细胞因子表达的监测可用于预测改变 体内的免疫反应。因此，这种方法将使我们能够 建立 DMN 暴露后进行风险评估的模型。 最后，将进行实验以确定是否存在 DMN 引起的变化的遗传因素。