Defining the molecular inventory of staphylococcal tissue abscesses and its effects on the host-pathogen interface

定义葡萄球菌组织脓肿的分子库存及其对宿主-病原体界面的影响

• 批准号: 10390885
• 负责人: Andy Weiss
• 金额: $ 0.25万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-01 至 2022-12-02
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10390885
• 关键词: Abscess; Address; Affect; Architecture; Bacteria; Bacterial Endocarditis; Cells; Chronology; Cues; Development; Elements; Environment; Equipment and supply inventories; Event; Functional disorder; Genus staphylococcus; Heterogeneity; Hospitalization; Immune; Immune system; In Vitro; Infection; Integration Host Factors; Invaded; Investigation; Knowledge; Lesion; Liquid substance; Metals; Micronutrients; Modeling; Molecular; Multimodal Imaging; Mus; Organ; Phenotype; Plant Roots; Process; Proteome; Proteomics; Reporter; Resolution; Role; Sepsis; Shapes; Site; Staphylococcus aureus; Starvation; Surface; System; Technology; Testing; Time; Tissues; Transition Elements; base; design; experimental study; imaging platform; in vivo; molecular marker; molecular shape; mutant; novel; pathogen; prevent; response; spatiotemporal; transcriptomics

Summary: Multidrug-resistant bacterial infections, particularly those caused by Staphylococcus aureus, are recognized as one of the greatest threats of the 21st century. Bloodstream infections are the most severe staphylococcal disease manifestation and are often fatal despite our best and most current therapies. Organ abscesses are primary contributors to S. aureus systemic infections and serve as initial reservoirs for the invading pathogen. Abscess formation itself follows distinct developmental stages, is actively facilitated by host and bacterium, and ultimately creates an advantageous niche for S. aureus. While past studies have generated an overview of abscess architecture, we lack information on the molecular composition of abscesses, particularly in the context of different abscess stages. This limited knowledge of the molecular events during abscess formation is especially alarming, for it hinders meaningful attempts at targeted design of anti-staphylococcal strategies. Our preliminary data show that abscess formation is characterized by the host's extensive relocation of transition metals in proximity to the abscess in a process known as nutritional immunity. Consequently, in vivo imaging reveals that bacteria within the abscess are starved for zinc and iron. Since available metal levels can serve as biomarkers for invading pathogens, we hypothesize that fluctuating elemental distributions orchestrate bacterial activities associated with abscess formation. Along these lines, we showed that zinc starvation primes S. aureus for subsequent contact with different immune cell populations. Beyond these findings, however, the chronology and factors involved in metal relocation, detection of these stimuli by S. aureus, and corresponding bacterial responses are entirely unexplored. We thus plan to address these questions in this proposal. One current barrier to the design of meaningful investigations into the development of staphylococcal tissue abscesses is a significant degree of abscess heterogeneity, likely a result of different developmental stages of individual lesions in the same organ. To account for the non-synchronous nature of tissue abscesses, we have identified a group of potential proteinaceous markers for different abscess stages. These proteins will serve as molecular clocks so we can follow the progression of individual abscesses through the developmental process. Based on these markers, we will create in vivo reporters and characterize the molecular inventory of developing abscesses, focusing on changes in elemental and proteinaceous compositions. Here, we will correlate various in vivo imaging modalities, including 3D-bioluminiscent imaging, MRI, and imaging mass spectrometry, with advanced proteomics via micro Liquid Extraction Surface Analysis. Once we have established how the abscess microenvironment changes during different phases of abscess formation, we will perform transcriptome analysis of bacterial subpopulations to assess how environmental stimuli affect staphylococcal pathophysiology and, in turn, abscess development. Combined, the proposed experiments will examine the events at the host-pathogen interface and pave the way for novel and targeted treatment strategies to combat staphylococcal infections.

概括： 多药的细菌感染，尤其是金黄色葡萄球菌引起的细菌感染，被认为是21世纪最大的威胁之一。血液感染是最严重的葡萄球菌疾病表现，尽管我们目前最好和大多数疗法，但通常还是致命的。器官脓肿是金黄色葡萄球菌全身感染的主要因素，并作为入侵病原体的初始储藏。脓肿的形成本身遵循不同的发育阶段，由宿主和细菌积极促进，并最终为金黄色葡萄球菌创造了有利的利基市场。尽管过去的研究产生了脓肿结构的概述，但我们缺乏有关脓肿的分子组成的信息，尤其是在不同的脓肿阶段。对脓肿形成过程中分子事件的这种有限的知识尤其令人震惊，因为它阻碍了有意义的反掌球策略的有意义的尝试。 我们的初步数据表明，脓肿的形成的特征在于宿主在称为营养免疫的过程中邻近脓肿的过渡金属的广泛迁移。因此，体内成像表明脓肿内的细菌对锌和铁饿了。由于可用的金属水平可以用作入侵病原体的生物标志物，因此我们假设这种波动的元素分布会协调与脓肿形成相关的细菌活性。沿着这些线路，我们表明锌饥饿素金黄色葡萄球菌用于随后与不同的免疫细胞群体接触。但是，除了这些发现之外，完全未探索了金属迁移，金黄色葡萄球菌对这些刺激的年代和因子的检测以及相应的细菌反应。因此，我们计划在此提案中解决这些问题。 当前对葡萄球菌组织脓肿发展的有意义研究设计的障碍是极大程度的脓肿异质性，这可能是同一器官中各个病变的不同发育阶段的不同结果。为了说明组织脓肿的非同步性质，我们已经确定了一组不同的脓肿阶段的潜在蛋白质标记。这些蛋白质将用作分子时钟，因此我们可以通过发育过程遵循单个脓肿的进展。基于这些标记，我们将创建体内记者并表征发展脓肿的分子清单，重点关注元素和蛋白质成分的变化。在这里，我们将通过微液体萃取表面分析将各种体内成像方式与包括3D生物淡化成像，MRI和成像质谱法与晚期蛋白质组学相关联。一旦我们确定了脓肿的微环境如何在脓肿形成的不同阶段发生变化，我们将对细菌亚群进行转录组分析，以评估环境刺激如何影响葡萄球菌病理生理学和脓肿发育。合并后，提出的实验将检查宿主病原体界面处的事件，并为新颖和有针对性的治疗策略铺平道路，以打击葡萄球菌感染。