Role of MiT Transcription Factors in Host Defense Against Bacterial Infection

MiT 转录因子在宿主防御细菌感染中的作用

• 批准号: 8610327
• 负责人: Javier Elbio Irazoqui
• 金额: $ 38.92万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-01 至 2017-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8610327
• 关键词: Address; Animal Model; Apical; Bacteria; Bacterial Infections; Binding; Biochemical; Biogenesis; Biological; Caenorhabditis elegans; Cell Line; Cell physiology; Cell surface; Cells; Chronic; Communicable Diseases; Complement Factor B; Coupled; Defect; Detection; Development; Discrimination; Disease; Enterobacteriaceae; Epithelial Cells; Exhibits; Family; Gene Expression Profiling; Gene Targeting; Genes; Genetic Models; Genetic Transcription; Goals; Homologous Gene; Host Defense; Human; Immune response; In Vitro; Infection; Infection Control; Inflammation; Inflammatory; Inflammatory disease of the intestine; Intestines; Knowledge; Ligands; Link; Lysosomes; Malignant Neoplasms; Mediating; Microbe; Mission; Modeling; Molecular; NF-kappa B; Outcome; Pathogen detection; Pathogenesis; Pathway interactions; Patients; Play; Post-Translational Protein Processing; Prevention; Prevention approach; Public Health; Publishing; Regulation; Research; Role; Sepsis; Signal Pathway; Signal Transduction; Stream; Surface; TFE3 gene; Testing; Time; Toll-like receptors; United States National Institutes of Health; Work; antimicrobial; base; chromatin immunoprecipitation; genetic analysis; in vivo; innovation; insight; intestinal epithelium; methicillin resistant Staphylococcus aureus; microbial; novel; pathogen; pathogenic bacteria; promoter; public health relevance; receptor; response; tool; transcription factor

DESCRIPTION (provided by applicant): A key function of the intestinal epithelium is to discriminate commensal from pathogenic microbes and thus avoid infectious disease and chronic inflammation; however, little is known about how intestinal epithelial cells (IECs) sense bacteria at the apical surface and transduce the signals to drive appropriate transcriptional responses. The long-term goal of this research is to elucidate relationships between IEC and microbe regulatory networks that determine the outcome of host-microbe interactions in vivo. The overall objective of this proposal is to elucidate pathways mediated by MITF-TFE (MiT) family transcription factors (TFs) that determine the host IEC response to infection. Because MiT family TFs are highly conserved, we chose to use Caenorhabditis elegans, a genetically tractable model organism, as a tool to address these questions. C. elegans exhibits pathogen-specific responses that are independent of TLR, NLR, and NF-kB, and thus represents a useful tool to study novel host defense pathways that are evolutionarily conserved, in an unbiased manner in vivo. The central hypothesis of this proposal is that unknown signaling pathways activated during pathogenic infection control MiT-mediated host defense in C. elegans and human IECs. The rationale for the proposed research is that, once it is understood how MiT TFs function in the host response and how they are regulated in vivo, their activity could likely be manipulated pharmacologically, resulting in new and innovative approaches for the prevention and treatment of a variety of infectious or inflammatory diseases. To test the central hypothesis, three specific aims are proposed: 1) Elucidate upstream regulators of HLH-30/MiT, using mosaic genetic analysis, biochemical characterization of post-translational modifications, and genetic analysis of candidate upstream pathways; 2) Elucidate downstream target pathways of HLH-30/MiT, using global gene expression profiling and chromatin immunoprecipitation approaches, and 3) Elucidate the role of MiT TFs in human IEC host defense, using human IEC lines in biochemical, molecular, and cell biological approaches cou- pled with high-throughput gene expression profiling. The contribution of the proposed research is expected to be the elucidation of novel, non-TLR/NLR/NF-¿B, HLH-30/MiT-mediated pathways regulating the host response to bacteria in C. elegans and human IECs. These contributions are significant because they are the first step in a continuum of research that will eventually allow pharmacologic manipulation of host defense via MiT signaling, either positively or negatively, to treat infection or inflammatory disease. The proposed research is conceptually innovative because it shows for the first time that MiT TFs are differentially expressed in human IECs during microbial stimulation and intestinal inflammation.Furthermore, the proposed research is innovative because it represents a departure from more directed in vitro approaches and takes advantage of the tractability of C. elegans, and thus is an unbiased and efficient in vivo approach.

描述（申请人提供）：肠上皮的一个关键功能是区分共生微生物和病原微生物，从而避免传染病和慢性炎症；然而，人们对肠上皮细胞（IEC）如何感知顶端表面的细菌并转导信号以驱动适当的转录反应知之甚少。这项研究的长期目标是阐明 IEC 和微生物调控网络之间的关系，这些网络决定体内宿主-微生物相互作用的结果。该提案的总体目标是阐明由 MITF-TFE (MiT) 家族转录因子 (TF) 介导的途径，这些转录因子决定宿主 IEC 对感染的反应。由于 MiT 家族 TF 高度保守，因此我们选择使用秀丽隐杆线虫（一种遗传上易于处理的模式生物）作为解决这些问题的工具。线虫表现出独立于 TLR、NLR 和 NF-kB 的病原体特异性反应，因此代表了一种有用的工具，可以在体内以公正的方式研究进化上保守的新型宿主防御途径。该提议的中心假设是，在秀丽隐杆线虫和人类 IEC 中，在病原感染控制 MiT 介导的宿主防御过程中，未知的信号通路被激活。这项研究的基本原理是，一旦了解 MiT 转录因子如何在宿主反应中发挥作用以及它们在体内如何受到调节，它们的活性就可能通过药理学来操纵，从而产生预防和治疗各种传染病或炎症性疾病的新方法和创新方法。为了检验中心假设，提出了三个具体目标：1）利用镶嵌遗传分析、翻译后修饰的生化表征以及候选上游途径的遗传分析来阐明HLH-30/MiT的上游调节因子； 2) 使用全局基因表达谱和染色质免疫沉淀方法阐明 HLH-30/MiT 的下游靶标通路，以及 3) 使用生化、分子和细胞生物学方法中的人 IEC 系与高通量基因表达谱相结合，阐明 MiT TF 在人类 IEC 宿主防御中的作用。拟议研究的贡献预计将是阐明新的非 TLR/NLR/NF-¿B、HLH-30/MiT 介导的途径，调节秀丽隐杆线虫和人类 IEC 中细菌的宿主反应。这些贡献意义重大，因为它们是连续研究的第一步，最终将允许通过 MiT 信号传导对宿主防御进行药理学操作，无论是积极的还是消极的，以治疗感染或炎症性疾病。该研究在概念上具有创新性，因为它首次表明 MiT TF 在微生物刺激和肠道炎症期间在人类 IEC 中差异表达。此外，该研究具有创新性，因为它代表了与更直接的体外方法的背离，并利用了秀丽隐杆线虫的易处理性，因此是一种公正且有效的体内方法。