Effect of Quorum Sensing on N. gonorrhoeae infection of human PMN's

群体感应对人中性粒细胞淋病奈瑟菌感染的影响

• 批准号: 8621355
• 负责人: Michael A. Apicella
• 金额: $ 22.65万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-11 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8621355
• 关键词: Acetylation; Acetyltransferase; Affect; Anabolism; Antimicrobial Resistance; Apoptosis; Apoptotic; Biochemistry; Biology; Cell Degranulation; Cell division; Cell surface; Cellular biology; Cervical; DNA; DNA Binding Domain; Data; Deacetylase; Developed Countries; Environment; Enzymes; Epithelial Cells; Eukaryotic Cell; Event; Gene Expression; Gene Expression Profile; Genes; Genetic Transcription; Homologous Gene; Human; Immune; Indigent; Infection; Ingestion; Laboratories; Lactones; Lysine; MAPK14 gene; Metabolic; Microbial Biofilms; Micrococcal Nuclease; Modeling; Modification; Mutation; NADPH Oxidase; Neisseria gonorrhoeae; Operon; Pathogenesis; Pathway interactions; Peptides; Peptidoglycan; Phagocytes; Phagocytosis; Play; Population; Post-Translational Protein Processing; Protein Acetylation; Proteins; Proteomics; Regulator Genes; Relative (related person); Role; Signal Transduction; Site; Staphylococcus aureus; System; Testing; VAI-2; Virulence Factors; base; effective therapy; interest; migration; mutant; neutrophil; novel; novel strategies; nuclease; pathogen; public health relevance; quorum sensing; transcriptomics; vaccine development

DESCRIPTION (provided by applicant): Neisseria gonorrhoeae (Ng) is a prototypic stealth pathogen that uses multiple mechanisms to evade human immune defenses; consequently re-infection is a problem. This has frustrated attempts at vaccine development, while resistance to antimicrobials has made effective therapy more difficult and costly. New approaches are necessary to identify means to control this important pathogen, which causes almost 65 million cases on a worldwide basis, the majority in indigent populations and in less well-developed countries. Studies in our laboratory have demonstrated that Ng has the ability to form biofilms on the cervical epithelial cell surface. As part of these studies, we have been examining the role of gonococcal luxS in biofilm formation and have evidence that the gonococcus has a functional quorum sensing system that it uses to modify gene expression during biofilm formation. Furthermore, our studies have shown that the Ng autoinducer -2 (AI-2) interacts with the two component regulatory genes, misRS. Among the approximately 80 genes under the control of misRS are the gonococcal thermonuclease that is critical to remodeling the biofilm DNA matrix, and genes involved in peptidoglycan biosynthesis and cell division. We also observed that a homolog of a SIR-2 deacetylase and a novel acetyltransferase are also regulated by misRS, and based on these observations, we undertook proteomic studies of N-lysine acetylation and we discovered that N¿-lysine acetylation increases significantly in a Ng luxS mutant. A number of studies have shown that bacterial quorum agents can impact on signaling in eukaryotic cells. Our previous studies with Staphylococcus aureus have shown that within the confines of the phagolysome, autoinducer levels are sufficiently high to cause modifications in gene expression through the agr system and promote expression of virulence factors integral to survival in phagocytes. N. gonorrhoeae can survive within the phagolysome and induces an anti-apoptotic event in neutrophils. The gonococcus only has an AI-2 system lacking the enzymes to produce acylhomoserine lactone. Our interest is to examine whether the AI-2 produced by N. gonorrhoeae and N¿-lysine acetylation might play a role in pathogenesis after phagocytosis. The hypothesis that we will test in this proposal is that an intact Ng quorum sensing system functions within the PMN phagolysome and is necessary for survival of Ng in that environment. We will resolve this hypothesis by the following specific aims: Specific Aim 1: Determine the state of activation of the quorum sensing system of Ng ingested by human PMN and Specific Aim 2: Determine if and how mutations in the gonococcal quorum sensing system affect both the survival of Ng in PMN and the cell biology of Ng-laden PMN.

描述（由申请人提供）： 淋病奈瑟氏菌（NG）是一种原型蒸汽病原体，使用多种机制逃避人类免疫防御。因此，重新感染是一个问题。这对疫苗开发产生了沮丧的尝试，而对抗菌剂的抵抗使有效的治疗更加困难和昂贵。必须采用新的方法来确定控制这一重要病原体的手段，该病原体在全球范围内导致近6500万例病例，贫困人口的大多数和较不发达的国家。我们实验室的研究表明，NG具有在宫颈上皮细胞表面形成生物膜的能力。作为这些研究的一部分，我们一直在研究淋球菌在生物膜形成中的作用，并有证据表明淋球菌具有功能性群体敏感性系统，用于在生物膜形成过程中修改基因表达。此外，我们的研究表明，NG自动诱导剂-2（AI -2）与两个组件调节基因Misrs相互作用。在MISRS控制下的大约80个基因中，有淋球菌热酶酶对重塑生物膜DNA基质至关重要，以及参与peptidedoglyglycan的生物合成和细胞分裂的基因。我们还观察到，siR-2脱乙酰基酶和新型乙酰基转移酶的同源物也受到MISR的调节，基于这些观察结果，我们进行了N-赖氨酸乙酰化的N-赖氨酸乙酰化的蛋白质组学研究在NG luxs突变中显着增加。许多研究表明，细菌群体可能会影响真核细胞中的信号传导。我们先前对金黄色葡萄球菌的研究表明，在吞噬体的范围内，自动诱导剂水平足够高，可以通过AGR系统引起基因表达的修饰，并促进吞噬细胞中生存的病毒因子的表达。淋病链球菌可以在吞噬体中生存，并在中性粒细胞中诱导抗凋亡事件。淋球菌只有一个AI-2系统，缺乏产生酰基糖苷内酯的酶。我们的兴趣是检查淋病链球菌和雷胺乙酰化产生的AI -2是否在吞噬吞噬后的发病机理中起作用。我们将在此提案中测试的假设是，完整的NG Quorum传感系统在PMN吞噬体中起作用，对于在该环境中的NG生存是必不可少的。我们将通过以下特定目的解决这一假设： 具体目的1：确定人类PMN摄入的NG的群体灵敏度系统的激活状态和特定目标2：确定gocococococcal Quorum敏感性系统中的突变是否以及如何影响NG在PMN中的存活和NG-Laden PMN的细胞生物学的存活。