The role of aberrant gene expression in chlamydial persistence and reactivation

异常基因表达在衣原体持续存在和重新激活中的作用

• 批准号: 10289946
• 负责人: SCOTT S GRIESHABER
• 金额: $ 21.75万
• 依托单位: UNIVERSITY OF IDAHO
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-13 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10289946
• 关键词: Affect; Antibiotic Therapy; Antibiotics; Atherosclerosis; Bacteria; Biological Assay; Biology; Blindness; Categories; Cell division; Cells; Chlamydia; Chlamydia Infections; Chlamydia trachomatis; Chlamydiales; Chlamydophila pneumoniae; Chlamydophila psittaci; Chronic; Clinical; Collection; Data; Development; Developmental Gene; Diagnosis; Disease; Eukaryotic Cell; Excision; Eye Infections; Gene Expression; Gene Expression Profile; Growth; Hour; Human; Infection; Iron; Kinetics; Lead; Life Cycle Stages; Lifting; Link; Lung diseases; Microscopic; Modeling; Molecular; Morbidity - disease rate; Nutrient; Parasites; Pathogenesis; Pattern; Peptidoglycan; Pharmaceutical Preparations; Phenotype; Pneumonia; Polyploidy; Process; Production; Reporter; Reporter Genes; Reporting; Reproductive Health; Role; Sexually Transmitted Diseases; Starvation; Stress; System; Testing; Time; Trachoma; Treatment Failure; Tryptophan; Vertebrates; Women' s Health; Zoonoses; cell type; chronic infection; design; environmental stressor; falls; human pathogen; inhibitor/antagonist; live cell imaging; live cell microscopy; member; pathogenic bacteria; promoter; recurrent infection; response; transcriptome sequencing

Project Summary/Abstract: The bacteria in the Chlamydiales order are intracellular parasites of eukaryotic cells. They are reliant on a de- velopmental cycle consisting of three cell forms termed the reticulate body (RB), the intermediate body (IB) and the elementary body (EB). The EB is infectious but does not replicate. The RB replicates in the host cell but is non-infectious, while the IB is an intermediate form that transitions to the EB form. Completion of this develop- mental cycle is central to chlamydial pathogenesis. Within this order, the genus Chlamydia contains the causative agents of a number of important pathogens of humans. C. psittaci causes zoonotic infections result- ing in pneumonia, while C. pneumoniae is a human pathogen that causes respiratory disease and is linked to atherosclerosis. Biovars of C. trachomatis are the causative agents of trachoma, the leading cause of pre- ventable blindness worldwide, as well as the sexually transmitted disease Chlamydia. Irrespective of the result- ing disease, all chlamydial species share the same obligate intracellular life cycle and developmental cycle. The chlamydial developmental cycle reacts to environmental stresses by exiting the developmental cycle and forming “aberrant” cell forms and delaying the production of infectious EBs. These cell forms can then reenter the productive developmental cycle when the environmental stress is lifted. It is hypothesized that this re- sponse to stress conditions contributes to the clinical observation that chlamydial infections are often chronic or reoccur in a significant number of diagnosed cases. We have developed a live-cell reporter system to follow cell-type switching in real time at the single inclusion level and determined that Chlamydia’s response to stress conditions such as peptidoglycan inhibitors or nutrient stress differs between treatments and over time. Treat- ment with peptidoglycan inhibitors results in a block in RB to IB development creating aberrant polyploid RBs. These aberrant cells express the RB reporter for ~ 10 hours prior to expressing the IB reporter but never ex- press EB reporters or gain infectivity. Nutrient stress such as tryptophan and iron starvation are also reported to cause Chlamydia to exit the productive developmental cycle and form “aberrant” RBs. Our live cell data suggests that these cells do not exhibit the same phenotype as those treated with peptidoglycan inhibitors. Therefore Aim 1 will Determine the phenotype and gene expression profile of aberrant RBs that reacti- vate to produce infectious EBs. IB to EB development is a slow process taking ~10 hours until maximal EB reporter gene expression. We therefore hypothesize that the IB may respond to nutrient stress by halting de- velopment until the nutrient stress is resolved. The IB then could reenter the developmental state producing infectious progeny. Therefore Aim 2 will Determine the contribution of the IB to EB transition in persis- tence.

项目摘要/摘要： 衣原体中的细菌是真核细胞的细胞内寄生虫。他们依靠 速度周期由三种细胞形式组成，称为网状体（RB），中间体（IB）和 基本身体（EB）。 EB具有传染性，但没有复制。 RB在主机单元中重复，但 非感染者，而IB是过渡到EB形式的中间形式。完成此发展 - 心理周期是衣原体发病机理的核心。在此顺序中，衣原体包含 C. psittaci引起人畜共患感染结果 - 在肺炎中，而肺炎肺炎则是引起呼吸系统疾病的人类病原体，与 动脉粥样硬化。沙眼梭状芽孢杆菌的生物群是沙眼的致病药物，这是前预先原因的 全球通风盲人以及性传播的疾病衣原体。不论结果 - 疾病，所有衣原体物种具有相同的义务细胞内生命周期和发育周期。 衣原体发育周期通过退出发展周期和 形成“异常”细胞并延迟传染性EB的产生。这些细胞形式然后可以重新进入 消除环境应力时的生产性发育周期。假设这个重新 对压力条件的赞助者有助于临床观察，即衣原体感染通常是慢性或 在大量诊断病例中再次发生。我们已经开发了一个活细胞记者系统以遵循 单个包含水平实时实时切换细胞类型，并确定衣原体对压力的反应 辣椒抑制剂或营养应激等疾病在治疗之间和随着时间的流逝之间有所不同。对待- 用辣椒糖抑制剂进行刺激导致rb中的一个障碍，从而产生异常的多倍体RB。 这些异常细胞在表达IB记者之前表达了RB报告基因约10小时 按EB记者或获得感染。还报道了诸如色氨酸和铁饥饿之类的营养应激 使衣原体退出产品的发展周期并形成“异常” RB。我们的活细胞数据 表明这些细胞与用辣椒抑制剂治疗的细胞不存在相同的表型。 因此，AIM 1将确定异常RB的表型和基因表达谱，反应 生产传染性EB的vate。 IB到EB开发是一个缓慢的过程，需要大约10个小时直到最大EB 报告基因表达。因此，我们假设IB可能会通过停止消除来应对营养应激 速度直至养分应激。 IB然后可以重新进入发展状态 传染性后代。因此，AIM 2将确定IB对Persis中EB过渡的贡献 tence。