Regulation of Macrophage Inflammatory Genes by CpG DNA

CpG DNA 对巨噬细胞炎症基因的调节

• 批准号: 6876170
• 负责人: Nilofer Qureshi
• 金额: $ 21.75万
• 依托单位: UNIVERSITY OF MISSOURI KANSAS CITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6876170
• 关键词: CpG islands; DNA methylation; bacteria infection mechanism; bacterial DNA; enhancer binding protein; genetic regulatory element; immunogenetics; inflammation; leukocyte activation /transformation; macrophage; methyltransferase; nitric oxide synthase; northern blottings; polymerase chain reaction; tissue /cell culture; transcription factor; transfection; tumor necrosis factor alpha

DESCRIPTION (provided by applicant): Bacterial DNA containing unmethylated CpG dinucleotides (CpG DNA) has recently been recognized as an important immune-activating agent and holds strong promise for therapeutic treatment of cancer, allergy, and infection. Although it is known now that CpG DNA functions through a signaling cascade involving Toll-like receptor 9 and associated proteins, culminating in activation of transcription factors NF-kappaB and AP-1, as well as subsequent induction of various immune-regulatory genes, studies on how host cells differentiate CpG DNA from non-CpG DNA or methylated CpG DNA have been relatively limited. My long-term goal is to contribute fundamental knowledge in molecular mechanisms of host immune responses and their role in treatment of disease. The objective of this project is to define mechanism(s) by which CpG DNA induces expression of inflammatory mediators in mouse macrophages. The central hypothesis of this research project is that the capacity of being methylated enables CpG DNA to compete with host cell genomic DNA as a substrate for DNA methyltransferase I and causes reduced methylation of genomic DNA, which leads to elevated gene expression (possibly through enhancing accessibility of upstream regulatory regions of these genes to activated transcription factors). Since our preliminary data indicate CpG DNA induces rapid expression of transcription factor C/EBPdelta, which has binding sites in the promoters of a number of proinflammatory genes, we also hypothesize that C/EBPdelta mediates inflammatory gene induction in response to CpG DNA. To test these hypotheses, the following specific aims are proposed: 1. To define the role of CpG DNA in regulation of mouse macrophage inflammatory gene expression within the framework of intracellular methylation events. 2. To determine the extent to which treatment of macrophages with CpG DNA results in reduced methylation of 5' regulatory regions of specific inflammatory genes and, as a result, causes increased expression of these genes. 3. To determine the role of transcription factor C/EBPdelta in induction of inflammatory genes in response to CpG DNA. The successful completion of this research will contribute to the development of CpG DNA as a novel therapeutic agent against cancer, allergy, and infection.

描述（由申请人提供）：含有未甲基化的CpG二核苷酸（CPG DNA）的细菌DNA最近被认为是一种重要的免疫激活剂，并且对癌症，过敏和感染的治疗治疗具有很大的希望。尽管现在已经知道CpG DNA通过涉及TOLL样受体9和相关蛋白的信号级联的功能，最终导致转录因子NF-KAPPAB和AP-1的激活以及随后诱导各种免疫调节基因的诱导，对宿主细胞的研究如何使CPG DNA与非cpG DNA的限制性DNA分化为限制性DNA或甲基甲基化的CPG。我的长期目标是在宿主免疫反应的分子机制及其在疾病治疗中的作用方面提供基本知识。该项目的目的是定义机制，CpG DNA诱导小鼠巨噬细胞中炎症介质的表达。该研究项目的核心假设是，被甲基化的能力使CpG DNA能够与宿主细胞基因组DNA作为DNA甲基转移酶I的底物竞争，并导致基因组DNA的甲基化降低，从而导致基因表达升高（通过增强了这些基因的上游调节型的访问性，这些基因的转录率升高了这些基因的转录率。由于我们的初步数据表明CpG DNA诱导转录因子C/EBPDELTA的快速表达，该转录因子C/EBPDELTA在许多促炎基因的启动子中具有结合位点，因此我们还假设C/EBPDELTA介导炎症基因诱导对CPG DNA的响应。为了检验这些假设，提出了以下特定目的：1。定义CpG DNA在调节小鼠巨噬细胞炎症基因表达中的作用。 2。确定用CpG DNA处理巨噬细胞的程度，导致5'特定炎症基因的5'调节区域的甲基化降低，从而导致这些基因的表达增加。 3。确定转录因子C/EBPDELTA在响应CpG DNA诱导炎症基因中的作用。这项研究的成功完成将有助于开发CpG DNA作为针对癌症，过敏和感染的新型治疗剂。