Role of Aryl hydrocarbon receptor (AhR) and RelB during the initiation of dendrit

芳烃受体 (AhR) 和 RelB 在树突形成过程中的作用

• 批准号: 7740312
• 负责人: CHRISTOPH F A VOGEL
• 金额: $ 22万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-16 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7740312
• 关键词: ARNT protein; Affect; Agonist; Aryl Hydrocarbon Receptor; Binding; Biological; Biological Assay; Bone Marrow; Bone Marrow Cells; CD80 gene; Cell Differentiation process; Cell Line; Cell Nucleus; Cells; Complex; Confocal Microscopy; Dendritic Cells; Dioxins; EMSA; Elements; Enzymes; Family; Flow Cytometry; Gene Expression; Gene Silencing; Genetic Transcription; Goals; Health; Human; IL8 gene; Image; Immune; Immune response; Immune system; In Vitro; Interleukin-8; Investigation; Knowledge; Ligands; Luciferases; Measurement; Mediating; Modeling; Mus; Myeloid Cells; Nuclear Protein; Nuclear Proteins; Pathway interactions; Physiological; Play; Process; Receptor Signaling; Regulation; Regulator Genes; Reporter; Research; Role; Signal Pathway; Source; Spleen; Surface; System; T-Lymphocyte; TNFRSF5 gene; Testing; Tetrachlorodibenzodioxin; Time; Toxic Environmental Substances; Toxic effect; Work; Xenobiotics; aryl hydrocarbon receptor ligand; base; chemokine; cytokine; dimer; in vivo; insight; lead immunotoxic effect; mRNA Expression; member; mouse Ahr protein; novel; public health relevance; response; transcription factor

DESCRIPTION (provided by applicant): This proposal investigates a new mechanism of cross talk between the transcription factors Aryl hydrocarbon Receptor (AhR) and the NF-?B member RelB in the process of dendritic cell (DC) differentiation. The long-term objective of the project is to give insight into the missing knowledge about the endogenous role of the AhR and its role together with RelB in regulating gene transcription especially immune regulatory genes like cytokines and chemokines. The major impetus for this study has been provided by recent findings that RelB, a member of the NF-?B family, may play an important role in the classical AhR signaling pathway. In the present study, we will assess the physiological relevance of the AhR/RelB activity in human DC in vitro systems for the process of DC differentiation. We like to evaluate the established human myeloid cell lines U937 and THP-1 as a source of DC-like cells since most if not all studies with DC and dioxin have been performed in mice or cells derived from mouse. Further, we like to test the effect of TCDD (AhR agonist) and AhR antagonists on differentiation and the biological response of the DCs based on the measurement of selected activation markers such as surface expression of CD1a, CD40, CD80, CD86 and MHCII by flow cytometry and chemokines relevant for the function of DCs like DC-CK1, DC-STAMP, and IL-8 mRNA expression by real time PCR analysis. In project 2 of the current proposal we will identify the role of AhR and AhR/RelB activity in the differentiation process of bone marrow cells derived from C57BL/6 wild type and AhR null (AhR-/-) mice into DC. This study reveals a novel concept of the function of the AhR together with RelB and is critical in understanding how environmental toxicants like dioxins affect critical functions of the immune system and human health. PUBLIC HEALTH RELEVANCE: About 15 years ago Hankinson and coworkers identified the encoded protein ARNT, which is required for ligand-dependent translocation of the Aryl hydrocarbon Receptor (AhR) to the nucleus and its binding to Dioxin responsive elements (DRE) mediating induction of xenobiotic metabolizing enzymes (classical AhR/ARNT pathway), but the physiological role of the AhR remains a key question. The present study focuses on a new mechanism of cross talk between AhR and the NF- ?B member RelB (alternative AhR/RelB pathway), which suggests an example of how an activated AhR pathway may connect to the NF-?B subunit RelB in order to cooperatively regulate cytokine/chemokine expression as well as differentiation and function of dendritic cells. This work will help to understand the mechanism how environmental toxicants like dioxin or dioxin-like compounds, which activate the AhR, elicit immunotoxic effects and lead to adverse health effects.

描述（由申请人提供）：该提案研究了转录因子芳烃受体（AhR）和NF-？B成员RelB在树突状细胞（DC）分化过程中的作用。该项目的长期目标是深入了解AhR的内源性作用及其与RelB一起调节基因转录，特别是免疫调节基因（如细胞因子和趋化因子）的作用。这项研究的主要动力已提供了最近的研究结果，RelB，NF-？B家族可能在经典的AhR信号通路中起重要作用。在本研究中，我们将评估的AhR/RelB活性在人DC在体外系统的DC分化的过程中的生理相关性。我们喜欢评估已建立的人骨髓细胞系U937和THP-1作为DC样细胞的来源，因为大多数（如果不是所有）DC和二恶英的研究都是在小鼠或小鼠衍生细胞中进行的。此外，我们希望基于通过流式细胞术测量所选活化标志物如CD 1a、CD 40、CD 80、CD 86和MHCII的表面表达和通过真实的时间PCR分析测量与DC功能相关的趋化因子如DC-CK 1、DC-STAMP和IL-8 mRNA表达来测试TCDD（AhR激动剂）和AhR拮抗剂对DC的分化和生物学应答的影响。在当前提案的项目2中，我们将鉴定AhR和AhR/RelB活性在源自C57 BL/6野生型和AhR null（AhR-/-）小鼠的骨髓细胞向DC的分化过程中的作用。这项研究揭示了AhR与RelB功能的新概念，对于了解二恶英等环境毒物如何影响免疫系统和人类健康的关键功能至关重要。公共卫生相关性：大约15年前，Hankinson及其同事鉴定了编码的蛋白ARNT，其是芳烃受体（AhR）向细胞核的配体依赖性易位以及其与二恶英响应元件（DRE）的结合所必需的，介导异生物质代谢酶的诱导（经典AhR/ARNT途径），但是AhR的生理作用仍然是一个关键问题。本研究的重点是一个新的机制之间的串扰AhR和NF-？B成员RelB（替代AhR/RelB途径），这表明了一个激活的AhR途径如何连接到NF-？B亚基RelB，以协同调节细胞因子/趋化因子表达以及树突状细胞的分化和功能。这项工作将有助于了解环境毒物如二恶英或二恶英样化合物如何激活AhR，引起免疫毒性效应并导致不良健康影响的机制。