ATG16L1 AND MOLECULAR REGULATION OF BACTERIAL PERSISTENCE

ATG16L1 和细菌持久性的分子调控

• 批准号: 8917946
• 负责人: Indira U Mysorekar
• 金额: $ 33.06万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-20 至 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8917946
• 关键词: Affect; Animals; Antibiotic Resistance; Antibiotic Therapy; Apical; Architecture; Automobile Driving; Autophagocytosis; Autophagosome; Bacteria; Binding; Biopsy; Bladder; Cell Culture Techniques; Cell membrane; Cells; Chronic; Clinical; Communicable Diseases; Complex; Crohn' s disease; Defect; Degradation Pathway; Development; Diagnosis; Disease; Economic Burden; Epithelial Cells; Event; Exhibits; Gastrointestinal Diseases; Gene Proteins; Genes; Genetic Models; Genetic Polymorphism; Goals; Health; Homeostasis; Host Defense; Human; Immune response; Immune system; Infection; Infection Control; Invaded; Knowledge; Lead; Lysosomes; Maintenance; Membrane; Membrane Protein Traffic; Modeling; Molecular; Molecular Genetics; Multivesicular Body; Mus; Mutation; Nature; Nutrient; Pathogenesis; Pathway interactions; Patients; Play; Prevalence; Process; Proteins; Publishing; Recruitment Activity; Recurrence; Recycling; Refractory; Regulation; Resistance; Resistance to infection; Role; Route; Seeds; Site; Societies; Source; Starvation; Stress; System; Testing; Therapeutic Intervention; Treatment Protocols; Urinary tract; Urinary tract infection; Uropathogenic E. coli; Urothelial Cell; Urothelium; Vesicle; Woman; Work; cell type; cellular targeting; clinically relevant; combat; in vivo; interest; loss of function; mouse model; novel; overexpression; pathogen; prevent; receptor; targeted treatment; trafficking

DESCRIPTION (provided by applicant): Pathogens have evolved a number of ways to subvert host defense arsenals to persist long term and induce recurrent infections. We have previously shown that uropathogenic E. coli (UPEC) persists as quiescent reservoirs in membrane-bound compartments within the bladder wall and causes frequent and recurrent urinary tract infections (UTIs). How these reservoirs form and persist is not known; this lack of knowledge impedes our ability to develop treatments to prevent recurrent UTIs. One mechanism used by animals to control infection by intracellular pathogens is autophagy, an evolutionarily conserved process that is activated under starvation or stress to recycle nutrients and damaged membranes by delivering them to the lysosome for degradation. We recently showed that an autophagy gene, Atg16L1, plays a key role in UTI pathogenesis: a mutation in the Atg16L1 gene limits the ability of UPEC to persist and cause recurrent UTIs and is associated with urothelial architectural defects. These defects lead to alterations in complex membrane recycling events in superficial urothelial cells required for both the normal function of the bladder and UPEC pathogenesis. The objective of this application is to determine the mechanisms by which UPEC hijack the normal vesicle trafficking of the bladder epithelial cells to form persistent reservoirs. The centrl hypothesis tested is that UPEC avoid destruction by lysosomes in urothelial cells by appropriating the autophagy pathway, and that Atg16L1 deficiency re-routes bacteria to an intracellular compartment where they cannot persist. We propose to test this hypothesis as follows: in Aim 1, we will systematically disrupt urothelial cell architecture by using newly established urothelial-specific cre mice driving loss of function of Atg16L1 and other autophagy pathway proteins to determine both the nature of the intracellular UPEC niche in vivo and the role of autophagy in UPEC persistence. In Aim 2, we will use a urothelial cell culture model to elucidate how modulation of Atg16L1 alters the process of UPEC invasion, intracellular survival into urothelial cells, and egress out of cells. We anticipate that our work will provide new insighs into the genetic and molecular interplay between the autophagy pathway and UPEC during a UTI and will provide cellular targets for development of therapeutic interventions to combat recurrent infections. Given that urinary tract infections are common and costly and that antibiotic-resistant pathogens are becoming increasingly prevalent, the potential of this knowledge to contribute to development of new treatment regimens to limit or eradicate sources of recurrent UTI could be vital.

描述（由申请人提供）：病原体已经进化出多种方式来破坏宿主的防御武库，使其长期存在并诱导反复感染。我们之前已经表明，尿路致病性大肠杆菌 (UPEC) 在膀胱壁内的膜结合区室中作为静态储存库持续存在，并导致频繁和复发性尿路感染 (UTI)。这些水库如何形成和持续存在尚不清楚；这种知识的缺乏阻碍了我们开发预防复发性尿路感染治疗方法的能力。动物用来控制细胞内病原体感染的一种机制是自噬，这是一种进化上保守的过程，在饥饿或压力下被激活，通过将营养物质和受损的细胞膜输送到溶酶体进行降解来回收它们。我们最近表明，自噬基因 Atg16L1 在 UTI 发病机制中发挥着关键作用：Atg16L1 基因的突变限制了 UPEC 持续存在并导致复发性 UTI 的能力，并且与尿路上皮结构缺陷相关。这些缺陷导致膀胱正常功能和 UPEC 发病机制所需的浅表尿路上皮细胞中复杂的膜回收事件发生改变。本申请的目的是确定 UPEC 劫持膀胱上皮细胞正常囊泡运输以形成持久性储存库的机制。测试的中心假设是 UPEC 通过利用自噬途径避免尿路上皮细胞中溶酶体的破坏，并且 Atg16L1 缺陷将细菌重新路由到它们无法持续存在的细胞内区室。我们建议按如下方式测试这一假设：在目标 1 中，我们将通过使用新建立的尿路上皮特异性 cre 小鼠驱动 Atg16L1 和其他自噬途径蛋白功能丧失，系统地破坏尿路上皮细胞结构，以确定体内细胞内 UPEC 生态位的性质以及自噬在 UPEC 持久性中的作用。在目标 2 中，我们将使用尿路上皮细胞培养模型来阐明 Atg16L1 的调节如何改变 UPEC 侵袭、尿路上皮细胞的细胞内存活以及细胞排出的过程。我们预计我们的工作将为 UTI 期间自噬途径与 UPEC 之间的遗传和分子相互作用提供新的见解，并将为开发治疗干预措施以对抗复发性感染提供细胞靶点。鉴于尿路感染常见且成本高昂，并且抗生素耐药性病原体变得越来越普遍，这些知识对于开发新的治疗方案以限制或根除复发性尿路感染的来源可能至关重要。