Mechanism of Bach1-Mediated Transcriptional Regulation and Immune Function

描述（由申请人提供）：免疫系统的精确调节是保护免受外来入侵者和自我耐受所必需的。免疫调节功能障碍可导致对感染的免疫应答受损以及自身免疫性疾病的发展。转录因子Bach 1在调节免疫过程中的作用已经间接涉及，但尚未直接探索;因此，该项目的广泛和长期目标是确定Bach 1的功能及其在细胞和分子水平介导保护性免疫和自身免疫性疾病的机制。本文将采用以下研究设计和方法来实现这一目标。1)首先，将阐明Bach 1调节转录的机制。具体而言，染色质免疫沉淀，然后微阵列（ChIP芯片）将用于确定Bach 1是否结合启动子近端和/或远端调控元件，以直接引发转录激活和抑制。计算基序分析和荧光素酶报告分析将被用来定义那些重要的Bach 1转录调控的功能域。2)第二，Bach 1在病毒和细菌感染中的作用将被确定。在感染期间，将在巨噬细胞和小鼠中消融Bach 1，以表征Bach 1调节保护性免疫应答的分子途径。3)第三，将研究Bach 1在自身免疫中的作用。初步数据表明，Bach 1促进小鼠实验性自身免疫性脑脊髓炎（EAE）的发展，这模拟了人类多发性硬化症。因此，将使用骨髓重建和过继转移实验来鉴定其中Bach 1的内在功能调节EAE的那些免疫细胞。将在这些细胞中进行微阵列实验，以确定Bach 1调控的潜在靶点和下游信号通路。4)第四，巴赫1负责调解其在EAE的发展中的作用的目标将被确定和表征。将通过产生Bach 1和目标靶标的双敲除动物来检查Bach 1介导的EAE对消融这些靶标的影响。此外，Bach 1的功能结构域，其在体内的调节功能所必需的将被确定。总的来说，该项目将确定一种新的免疫系统调节因子（Bach 1），并揭示其在感染期间调节保护性免疫和在功能障碍期间调节自身免疫的信号级联。因此，该项目的成功完成将通过确定治疗免疫相关疾病和自身免疫疾病的新靶点而有益于公共卫生。 公共卫生相关性：该项目将阐明Bach 1在调节免疫系统中的作用，包括Bach 1如何在微生物感染期间提供保护，并确定Bach 1如何介导自身免疫性疾病，如多发性硬化症。该项目还将确定由Bach 1调控的基因，这些基因对执行这些免疫过程很重要。该项目通过确定Bach 1和其他潜在的新靶点来治疗免疫相关和自身免疫性疾病，与公共卫生相关。

DESCRIPTION (provided by applicant): Precise regulation of the immune system is required for protection from foreign invaders and tolerance of self. Dysfunctional immune regulation can lead to impaired immune responses to infections as well as development of autoimmune diseases. The role of the transcription factor Bach1 in regulating immune processes has been indirectly implicated but has not been directly explored; thus, the broad and long-term objective of this project is to determine the function of Bach1 and the mechanism by which it mediates protective immunity and autoimmune diseases at a cellular and molecular level. The following research design and methods will be employed to achieve this goal. 1) First, the mechanism by which Bach1 regulates transcription will be elucidated. Specifically, chromatin immunoprecipitation followed by microarray (ChIP-chip) will be used to determine whether Bach1 binds promoter proximal and/or distal regulatory elements to directly elicit transcriptional activation and repression. Computational motif analyses and luciferase reporter assays will be used to define those functional domains of Bach1 important for transcriptional regulation. 2) Second, the role of Bach1 during viral and bacterial infections will be determined. Bach1 will be ablated in macrophages and in mice during infection in order to characterize the molecular pathways by which Bach1 regulates protective immune responses. 3) Third, the role of Bach1 in autoimmunity will be investigated. Preliminary data demonstrated that Bach1 promotes the development of murine experimental autoimmune encephalomyelitis (EAE), which mimics human multiple sclerosis. Accordingly, bone marrow reconstitution and adoptive transfer experiments will be used to identify those immune cell(s) in which the intrinsic function of Bach1 modulates EAE. Microarray experiments will be performed in those cells to identify potential targets and downstream signaling pathways regulated by Bach1. 4) Fourth, Bach1 targets responsible for mediating its role in the development of EAE will be identified and characterized. The effect of Bach1-mediated EAE upon ablating these targets will be examined by generating double knockout animals of Bach1 and the target(s) of interest. Furthermore, functional domains of Bach1 necessary for its regulatory function in vivo will be identified. Overall, this project will identify a new regulator of the immune system (Bach1) and reveal those signaling cascades by which it modulates protective immunity during infection and autoimmunity during dysfunction. The successful completion of this project will therefore benefit public health by identifying new targets for therapy against immune-related and autoimmune diseases. PUBLIC HEALTH RELEVANCE: This project will elucidate the role of Bach1 in regulating the immune system, including how Bach1 may offer protection during microbial infections and establish how Bach1 mediates autoimmune diseases, such as multiple sclerosis. This project will also identify genes regulated by Bach1 important for carrying out these immune processes. This project is relevant to public health by identifying Bach1 and other potential new targets for therapy against immune-related and autoimmune diseases.