IMMUNOTOXICOLOGY OF BENZENE METABOLITES

苯代谢物的免疫毒理学

• 批准号: 2154439
• 负责人: BRIAN M FREED
• 金额: $ 7.2万
• 依托单位: ALBANY MEDICAL COLLEGE
• 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 1996-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2154439
• 关键词: SDS polyacrylamide gel electrophoresis; T lymphocyte; affinity chromatography; benzene; biological signal transduction; calmodulin dependent protein kinase; cytotoxicity; density gradient ultracentrifugation; enzyme activity; flow cytometry; gel mobility shift assay; gene expression; immunotoxicity; interleukin 2; leukocyte activation /transformation; macrophage; neutrophil; northern blottings; nucleic acid probes; phosphorylation; polymerase chain reaction; protein kinase C; quinones; tissue /cell culture; toxicant interaction; transcription factor; western blottings

Studies performed over the last decade suggest that the immunotoxicity of benzene depends on its metabolism to thiol-reactive quinones. The long-term objective of the proposed research is to identify the molecular mechanisms underlying the immunosuppressive effects of the benzene metabolite, p-benzoquinone (p-BQ). We have demonstrated that p-BQ suppresses the production of the T cell growth factor, interleukin-2 (IL- 2), and inhibits the formation of macrophage/T cell aggregates (agglutination). At the molecular level, we noted that P-BQ inhibits the expression of the IL-2 gene and c-fos genes. We hypothesize that p-BQ inhibits a signal transduction pathway that regulates both the expression of these genes and the phosphorylation of LFA-1Beta (CD11a), which mediates agglutination of T cells via an interaction with ICAM-1 molecules on macrophages. We propose a series of experiments using human mononuclear cells and the Jurkat T cell line to address the following specific aims: (1) To assess the role of macrophages and peroxidases in the immunosuppressive effects of the benzene metabolites, phenol, hydroquinol (HQ), and p-BQ; (2) To measure the effects of benzene metabolites on the expression of genes encoding interleukins and other cytokines; (3) To measure the effects of benzene metabolites on the induction of transcription factors (NF-AT, NFkappaB, AP-1, and Oct-1) that regulate IL-2 gene expression; (4) To determine if the inhibition of agglutination by p-BQ is due to inhibition of LFA-1Beta phosphorylation and/or inhibition of ICAM-1 (CD54) expression; (5) To measure the effects of the benzene metabolites on the activity of two critical PMA-inducible protein kinases, protein kinase C and calmodulin- dependent protein kinase; and (6) To determine if the effects of P-BQ on c-fos expression correlate with inhibition of induction of one of its 5' transcription factors or a factor that binds to and stabilizes the c-fos MRNA transcript. These experiments will provide evidence for the molecular targets of benzene immunotoxicity.

过去十年进行的研究表明免疫毒性 苯的代谢取决于硫醇反应性奎因酮。 这 拟议的研究的长期目标是确定分子 苯免疫抑制作用的基础机制 代谢产物，P-苯喹酮（P-BQ）。 我们已经证明了P-BQ 抑制T细胞生长因子的产生，白细胞介素2（IL- 2），并抑制巨噬细胞/T细胞骨料的形成 （凝集）。 在分子水平上，我们注意到P-BQ抑制了 IL-2基因和C-FOS基因的表达。 我们假设P-BQ 抑制一个信号转导途径，以调节这两个表达 这些基因和LFA-1Beta（CD11a）的磷酸化 通过与ICAM-1的相互作用介导T细胞的凝集 巨噬细胞上的分子。 我们建议使用人类的一系列实验 单核细胞和Jurkat T细胞系以解决以下 具体目的：（1）评估巨噬细胞和过氧化物酶在 苯代谢产物，苯酚， 羟基醇（HQ）和P-BQ； （2）测量苯的影响 关于编码白细胞介素和其他基因表达的代谢产物 细胞因子； （3）测量苯代谢物对 转录因子的诱导（NF-AT，NFKAPPAB，AP-1和OCT-1） 调节IL-2基因表达； （4）确定抑制是否 P-BQ的凝集是由于LFA-1Beta的抑制作用 ICAM-1（CD54）表达的磷酸化和/或抑制作用； （5）到 测量苯代谢产物对两个活性的影响 临界PMA诱导蛋白激酶，蛋白激酶C和钙调蛋白 - 依赖性蛋白激酶； （6）确定p-bq的影响是否 C-FOS表达与抑制其5'之一的抑制相关 转录因子或结合并稳定C-FOS的因子 mRNA转录本。 这些实验将为 苯免疫毒性的分子靶标。