Anaplasma regulation of host granulocyte function

无形体对宿主粒细胞功能的调节

• 批准号: 9355565
• 负责人: JOHN STEPHEN Dumler
• 金额: $ 34.98万
• 依托单位: HENRY M. JACKSON FDN FOR THE ADV MIL/MED
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9355565
• 关键词: 3-Dimensional; Address; Anaplasma; Anaplasma phagocytophilum; Apoptosis; Apoptotic; Area; Bacteria; Binding; Binding Proteins; Bovine Anaplasmosis; Cell Culture Techniques; Cell Nucleus; Cell physiology; Cells; Chromatin; Chromatin Structure; Chromosome Territory; Custom; DNA; DNA Binding; DNA Methylation; Data; Disease; Distant; Enzymes; Epigenetic Process; Eukaryota; Event; Exclusion; Gene Silencing; Genes; Genetic Transcription; Genome; Genomics; Global Change; Goals; HDAC1 gene; Health; Histone Deacetylase; Histone Deacetylation; Histone H3; Histones; Host Defense; Human; Human Genome; Impairment; In Vitro; Infection; Inflammasome; Inflammation; Inflammatory; Injury; Innate Immune Response; Intervention; Investigation; Lead; Life; Mammals; Matrix Attachment Regions; Measures; Mediating; Medicine; Metabolism; Microbe; Mind; Modeling; Molecular; Molecular Conformation; Mutation; Natural Immunity; Neutrophil Infiltration; Nuclear Matrix; Nuclear Protein; Organism; Oxidases; Pathogenicity; Phagocytes; Play; Process; Prokaryotic Cells; Proteins; RNA Polymerase II; Recruitment Activity; Regulation; Regulator Genes; Role; Signal Transduction; Structure; System; Tick-Borne Diseases; Ticks; Tissues; Transcriptional Regulation; Whole Organism; Work; antimicrobial; bacterial fitness; epigenome; fitness; genome-wide; granulocyte; improved; in vivo; innovation; killings; microbial; mouse model; mutant; neutrophil; novel strategies; novel therapeutic intervention; pathogen; programs; promoter; public health relevance; response; scaffold; therapy design; tool; transmission process

 DESCRIPTION (provided by applicant): Human granulocytic anaplasmosis is caused by a tick-transmitted Anaplasma phagocytophilum, an obligate intracellular bacterium that is the paradigm for microbial subversion of neutrophils because it directly reprograms host cells for improved bacterial fitness, and in doing so, causes significant disease. Over 14 years we focused on neutrophil-A. phagocytophilum interactions and altered functions; we discovered AnkA, the nucleomodulin effector protein that silences the host CYBB promoter allowing intracellular survival, epigenetic changes at CYBB and other genes, and defined molecular mechanisms by which AnkA binds and modulates promoter activity via histone deacetylase-1 (HDAC1) recruitment. In fact, infection and AnkA mediate genome- wide epigenetic changes, including DNA methylation and histone deacetylation that likely belie the coordinated transcriptional reprogramming. Such extensive coordination of the host epigenome by a prokaryote is unprecedented and could explain how small genome prokaryotes subvert large genome eukaryotes for parasitic or symbiotic life. The basis of these reprogramming events is the focus of this competing renewal application in 3 specific aims: 1) the molecular basis of HDAC-1 recruitment to A. phagocytophilum AnkA will be studied with AnkA mutations that abrogate host transcription and reduce pathogen survival; 2) AnkA binds AT-rich loci throughout the genome at nuclear matrix attachment regions (MARs). We hypothesize that AnkA organizes 3 dimensional chromatin structure by bringing together function-related genes in specific chromosomal territories at large genomic distances to coordinate reprogramming. Here we will show that AnkA alters higher order granulocyte chromatin organization to influence accessibility of DNA to gene regulatory components and coordinate global transcription. AnkA mutants with defective or reduced HDAC-1 recruitment will be used to discern abrogated transcription and granulocyte functions; 3) the basis for A. phagocytophilum fitness and pathogenicity relates to its ability to alter gene programs in cells impacting tissues and whole organisms, as in infected humans. Proving the in vivo functions of AnkA and its relationship to microbial fitness and pathogenicity is not readily possible in humans. Therefore, we will demonstrate that cis- (Aim 1) and trans-transcriptional regulation mediated by AnkA also occurs in vivo and impacts infected cell function and disease manifestations by validating the results obtained in vitro or ex vivo in human cell cultures, and by measuring how changes in transcriptional programs impact pathogen propagation and disease in a mouse model. These integrated aims will extend the understanding of prokaryotes whose metabolism is shared with their host and organize cis and trans epigenetic changes for global reprogramming of host functions. The results will provide new directions for investigation in other microbes, novel approaches for disease intervention, or leverage the evolutionary adaptations of this and other organisms to create custom approaches for manipulation of eukaryotic hosts in disease and health.

 描述(申请人提供)：人类粒细胞无浆体病是由扁虱传播的吞噬无形体引起的，这是一种专有的细胞内细菌，是微生物颠覆中性粒细胞的范例，因为它直接对宿主细胞进行重新编程，以改善细菌的适应性，并在这样做的过程中，导致重大疾病。在14年的时间里，我们专注于中性粒细胞-A。吞噬细胞的相互作用和功能改变；我们发现了Anka，一种核调节蛋白效应器蛋白，它可以沉默宿主的CyBB启动子，允许细胞内存活，CYBB和其他基因的表观遗传变化，并定义了Anka通过组蛋白脱乙酰酶-1(HDAC1)募集结合和调节启动子活性的分子机制。事实上，感染和ANKA介导了全基因组的表观遗传学变化，包括DNA甲基化和组蛋白去乙酰化，这可能掩盖了协调的转录重新编程。原核生物对宿主表观基因组的如此广泛的协调是史无前例的，可以解释小基因组原核生物是如何颠覆大基因组真核生物的寄生或共生生命的。这些重新编程事件的基础是这种竞争性更新应用的重点，具体目的有3个：1)吞噬细胞型嗜血杆菌的HDAC-1募集的分子基础将通过ANKA突变进行研究，这些突变可以取消宿主转录，降低病原菌的存活率；2)ANKA在整个基因组的核基质附着区(MARS)结合富含AT的基因座。我们假设ANKA通过在大基因组距离的特定染色体区域聚集功能相关基因来协调重新编程来组织三维染色质结构。在这里，我们将展示ANKA改变高级粒细胞染色质组织，以影响DNA对基因调控组件的可及性，并协调全球转录。HDAC-1征集有缺陷或减少的ANKA突变体将被用于识别被取消的转录和粒细胞功能；3)吞噬细胞素A的适合性和致病性的基础与其改变影响组织和整个生物体的细胞中的基因程序的能力有关，例如在受感染的人类中。在人类身上证明ANKA的体内功能及其与微生物适应性和致病性的关系是不可能的。因此，我们将通过在人类细胞培养中验证体外或体外获得的结果，并通过在小鼠模型中测量转录程序的变化如何影响病原体繁殖和疾病表现，来证明由ANKA介导的顺式和反式转录调控也在体内发生，并影响感染细胞的功能和疾病表现。这些整合的目标将扩大对原核生物的理解，这些原核生物的代谢与宿主共享，并组织顺式和反式表观遗传变化以进行宿主功能的全球重新编程。这些结果将为其他微生物的研究提供新的方向，为疾病干预提供新的方法，或者利用这种生物和其他生物的进化适应来创建定制方法，用于在疾病和健康中操纵真核宿主。