DIMETHYLNITROSAMINE EFFECTS ON CELLULAR IMMUNITY

二甲基亚硝胺对细胞免疫的影响

• 批准号: 3252460
• 负责人: LAWRENCE B SCHOOK
• 金额: $ 14.38万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 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 1992-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3252460
• 关键词: T lymphocyte; cell differentiation; cell growth regulation; centrifugation; cytotoxicity; delayed hypersensitivity; drug administration rate /duration; drug administration routes; enzyme mechanism; flow cytometry; hematopoiesis; histocompatibility antigens; immunofluorescence technique; immunosuppression; laboratory mouse; leukocyte activation /transformation; macrophage; mitogens; mixed lymphocyte reaction test; molecular site; nitrosamines; plaque assay; radionuclides; tissue /cell culture

The proposed research addresses the central immunosuppressive mechanism(s) generated by daily exposure to N-Nitroso-dimethylamine (DMN). It has been previously demonstrated that DMN is toxic and carcinogenic to a variety of animal species. The effects appear to be mediated by metabolites generated in the enzymatic oxidation of DMN by the liver resulting in the formation of alkylated nucleic acids. Other alkylating agents like cyclophosphamide have been shown to be potent immunosuppressants, few studies unfortunately have established the relationship between exposure to DMN and alterations in the immune response. Preliminary results have demonstrated a decrease in cell-mediated immunity as a result of changes in macrophage (M0) function. This proposal will determine the suppressive effects of DMN using purified immunocompetent cells in defined functional assays and identify the molecular mechanisms(s) responsible for this induced alteration. Experiments outlined will establish how daily exposure of animals to DMN compromises T-lymphocytes, or M0 populations in number, ectoenzyme profiles, expression of phenotypic markers, and function in cell-mediated responses. These studies will include reconstitution of T lymphocyte antigen and mitogen responses; induction of delayed typed hypersensitivity and mixed lymphocyte reactions, and tumorcidal assays. Bone marrow from DMN treated animals will be grown with colony stimulating factor to determine the effects on the in vitro generation of M0 populations using the above outlined functional assays. The relationship between the cellularity, DNA synthesis, cell-cycling, ectoenzyme profile and expression of Ia antigens will also be established. Although results suggest an immunosuppressive component(s) found on the serum or liver homogenates from DMN treated animals is responsible, additional experiments will establish the effects of direct DMN exposure. Another major thrust will be to identify the DMN induced mediator(s) responsible for modulation of M0 maturation. This will entail isolation from the liver homogenates and serum samples followed by biochemical analysis using established methodologies. These studies also permit delineation of the immunosuppressive nature of the hepatocarcinogen DMN at the molecular, cellular and animal level and how such toxic compounds compromise immune responsiveness.

拟议的研究涉及中枢免疫抑制机制 每天接触 N-亚硝基二甲胺 (DMN) 时产生。 它一直 先前已证明DMN对多种物质具有毒性和致癌性 动物种类。 这些影响似乎是由产生的代谢物介导的 DMN 被肝脏酶促氧化，形成 烷基化核酸。 其他烷化剂如环磷酰胺 已被证明是有效的免疫抑制剂，不幸的是很少有研究 建立了 DMN 暴露与改变之间的关系 在免疫反应中。 初步结果显示下降 巨噬细胞变化导致的细胞介导免疫 (M0) 功能。 该提案将确定 DMN 的抑制效果 在确定的功能测定中使用纯化的免疫活性细胞 确定导致这种诱导的分子机制 改造。 概述的实验将确定每日暴露于 动物 DMN 会损害 T 淋巴细胞或 M0 群体的数量， 外酶谱、表型标记的表达和功能 细胞介导的反应。 这些研究将包括 T 的重建 淋巴细胞抗原和有丝分裂原反应；延迟打字的诱导 超敏反应和混合淋巴细胞反应以及杀肿瘤试验。 来自 DMN 治疗动物的骨髓将通过集落刺激进行生长 确定对 M0 体外生成影响的因素 使用上述功能测定的人群。 关系 细胞结构、DNA 合成、细胞周期、胞外酶谱之间 Ia 抗原的表达也将被确定。 虽然结果 表明在血清或肝脏中发现了免疫抑制成分 来自 DMN 处理动物的匀浆是负责的，额外的实验 将确定直接 DMN 暴露的影响。 又一重大推力 将识别负责调节的 DMN 诱导介体 M0 成熟期。 这将需要与肝脏匀浆分离 和血清样本，然后使用已建立的生化分析 方法论。 这些研究还允许描绘 肝癌DMN在分子水平上的免疫抑制性质， 细胞和动物水平以及这些有毒化合物如何损害免疫 反应能力。