Anaplasma regulation of host granulocyte function

无形体对宿主粒细胞功能的调节

基本信息

批准号：
8279490
负责人：
JOHN STEPHEN Dumler
金额：
$ 32.47万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-09-01 至 2015-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8279490
关键词：
17q23.1 6p21.3 ABI1 gene Acetylation Adhesions Affect Affinity Anaplasma Anaplasma phagocytophilum Ankyrins Antibodies Apoptosis Architecture Bacteria Binding Binding Proteins Binding Sites Biology Blood Circulation Bovine Anaplasmosis Cell Nucleus Cell Survival Cell physiology Cells ChIP-on-chip Chromatin Chromatin Loop Chromatin Remodeling Factor Chromosome Territory Chromosomes Co-Immunoprecipitations Complex Cytosol DNA DNA Binding DNA-Binding Proteins Data Deacetylase Disease Docking EMSA Elements Endothelium Engineering Enzymes Epigenetic Process Eukaryota Fostering Gene Activation Gene Expression Profile Gene Silencing Gene-Modified Genes Genetic Transcription Genome Genomics Goals Health Histone Deacetylation Histones Host Defense Human Individual Infection Inflammation Inflammatory Injury Integrins Investigation Kinetics Learning Length Life Lysine MHC Class I Genes Mass Spectrum Analysis Matrix Attachment Regions Medicine Messenger RNA Metalloproteases Methylation Methyltransferase Mutate Mutation Neoplasms Normal Cell Nuclear Nuclear Matrix Nuclear Protein Nuclear Proteins Organism Oxidases Pathogenesis Peroxidases Phagocytes Phagocytosis Pharmaceutical Preparations Prevention approach Prevention therapy Process Production Property Protein Binding Proteins Recruitment Activity Regulation Reporter Resources Respiratory Burst Rickettsiales Role Signal Pathway Signal Transduction Site Small Interfering RNA Structure Testing Therapeutic Agents Tick-Borne Diseases Ticks Tissues Transcriptional Regulation antimicrobial base cell motility chemokine chromatin remodeling eosinophil peroxidase genome-wide granulocyte killings microbicide mutant neutrophil novel pathogen promoter public health relevance response tool transcription factor

项目摘要

DESCRIPTION (provided by applicant): Human granulocytic anaplasmosis (HGA) is an emerging tick-borne disease caused by Anaplasma phagocytophilum, an obligate intracellular bacterium of neutrophils. A. phagocytophilum infection impairs neutrophil function by transcriptional reprogramming, where the reprogrammed neutrophil promotes inflammatory recruitment of new neutrophils, tissue injury, ineffective regulation of inflammation, and poor antimicrobial responses. We studied altered neutrophil function with A. phagocytophilum infection and focused on how the nuclear effector protein AnkA, when delivered into the host cell where it binds to promoters of genes regulated with infection, induces epigenetic chromatin remodeling and transcriptional reprogramming. The granulocyte transcriptome with A. phagocytophilum infection shows a number of differentially transcribed genes that promote infection [3-6]. Given the meager genomic resources of A. phagocytophilum, it is difficult to explain the extent of host transcriptional change and functional reprogramming by individual translocated effector proteins. This implies that the bacterium exerts influence over global gene transcription, including chromatin and histone remodeling, perhaps by targeting conserved mechanisms of transcriptional regulation such as in cellular differentiation and neoplasia. AnkA has properties that suggest function as a matrix attachment region-binding protein that could regulate access of chromosomal territories to transcriptional modifiers, a new paradigm in bacteria-host interactions. We hypothesize that AnkA binds to promoters of some transcriptionally regulated genes and modifies or recruits modifiers of epigenetic chromatin marks or transcription factors. In addition, we hypothesize that A. phagocytophilum reprograms the global neutrophil transcriptome by altering the epigenome through AnkA"s action on nuclear matrix, chromatin, and transcriptional apparatus recruitment. We propose the following aims: 1. To identify AnkA binding sites in the CYBB promoter and to define AnkA domains or motifs involved in CYBB promoter binding and transcriptional activity. 2. To determine whether AnkA affects host gene transcription through direct action at the CYBB promoter or through recruitment of chromatin remodeling or transcription factors. 3. To determine whether AnkA functions as a matrix attachment region-binding protein that tethers DNA to nuclear matrix, regulates DNA loopscape, and permits docking of other chromatin modifiers in global transcriptional regulation. The effects that bacteria have over cellular transcription are increasingly recognized. Testing these hypotheses will provide evidence of a potentially powerful mechanism for prokaryotic control over eukaryotes. The long- term goals are to develop a mechanistic understanding of how bacteria with intimate host cell associations circumvent host functions. This information could allow rational preventions and therapies for HGA, but could also span biology and medicine, since such molecules could be engineered as epigenetic tools or therapies. PUBLIC HEALTH RELEVANCE: Human granulocytic anaplasmosis (HGA) is a tick-borne disease caused by an intracellular bacterium, Anaplasma phagocytophilum that must live within neutrophils and similar cells. Interestingly, neutrophils are the major early host defense cells, and A. phagocytophilum alters their function to benefit survival of the bacteria. The altered function occurs mostly because the mRNA-producing machinery of the cell is altered by infection with this bacterium. We learned that one protein made by the bacterium, AnkA, is transported to the neutrophil's nucleus where mRNA is made, and its presence there changes how mRNA is made. In fact, the magnitude of changes in mRNA made by the cell are very difficult to explain based on AnkA altering mRNA made from individual genes. We propose to study the exact way that AnkA changes mRNA production from single genes, and to study whether it also affects the structure and function of chromosomes in a way that mRNA production is drastically altered. This information could provide evidence of an entirely new way for bacteria to control host cells, could define some aspects of normal cell function, and might provide new tools, even new drugs, for studying cells and their function in health and disease.

描述（由申请人提供）：人类粒细胞杂质病（HGA）是一种由Anaplasma phocytophilum引起的新兴tick传播疾病，是一种强性的嗜中性粒细胞内细菌。 A.吞噬细胞感染通过转录重编程损害了中性粒细胞的功能，重编程的中性粒细胞促进了新的中性粒细胞的炎症募集，组织损伤，炎症的无效调节和抗菌反应不良。我们研究了用吞噬细胞藻感染改变中性粒细胞功能的改变，并着重于核效应蛋白ANKA如何递送到宿主细胞中，并与受感染调节的基因启动子结合，诱导表观遗传染色质重塑和反转录。带有吞噬细胞的粒细胞转录组具有促吞噬细胞的感染，显示了许多差异转录的基因，这些基因促进了感染[3-6]。鉴于吞噬曲霉的基因组资源微薄，很难解释宿主转录变化的程度和通过个体易位效应子蛋白进行重编程的功能重编程。这意味着细菌对全球基因转录的影响，包括染色质和组蛋白重塑，也许是通过靶向转录调节的保守机制，例如细胞分化和肿瘤。 ANKA具有表明矩阵附着区域结合蛋白的功能，该蛋白可以调节染色体区域对转录修饰剂的访问，这是细菌 - 宿主相互作用的新范式。我们假设ANKA与某些转录调控基因的启动子结合，并修改或招募表观遗传染色质标记或转录因子的修饰符。 In addition, we hypothesize that A. phagocytophilum reprograms the global neutrophil transcriptome by altering the epigenome through AnkA"s action on nuclear matrix, chromatin, and transcriptional apparatus recruitment. We propose the following aims: 1. To identify AnkA binding sites in the CYBB promoter and to define AnkA domains or motifs involved in CYBB promoter binding and transcriptional 2。对这些假设进行测试越来越多的细胞转录将提供对真核生物的潜在强大机制。疗法。公共卫生相关性：人类粒细胞肿瘤病（HGA）是一种由细胞内细菌引起的tick传播疾病，必须生活在中性粒细胞和类似细胞内的细胞内吞噬细胞。有趣的是，嗜中性粒细胞是主要的早期宿主防御细胞，而吞噬细胞嗜性杆菌会改变其功能以使细菌的存活率受益。变化的功能主要是因为该细菌感染细胞的产生mRNA产生机械。我们了解到，一种由Anka细菌生成的蛋白质被转运到制作mRNA的中性粒细胞核上，其存在的存在会改变mRNA的方式。实际上，基于单个基因制成的mRNA，很难解释细胞产生的mRNA变化的大小。我们建议研究ANKA从单个基因改变mRNA产生的确切方式，并研究它是否也以巨大改变mRNA的产生方式影响染色体的结构和功能。这些信息可以为细菌控制宿主细胞的全新方法提供证据，可以定义正常细胞功能的某些方面，并可能提供新的工具，甚至是新药，用于研究细胞及其在健康和疾病中的功能。