Defining the impact of host factors on the molecular architecture and bacterial physiology of Staphylococcus aureus abscesses

项目概要/摘要 金黄色葡萄球菌能够感染几乎所有脊椎动物的器官系统， 一种称为“脓肿”的特征性组织损伤了解S。金黄色葡萄球菌生存在阴道内， 这对新疗法的开发至关重要，因为这些病变代表了感染期间的病原体生态位。 在这个应用中，我们将利用一个强大的基于质谱的成像平台来识别宿主， 导致葡萄球菌病的细菌因素。通过定义组织生态位和宿主生物学如何驱动 分子异质性，我们将发现新的目标，定制的抗葡萄球菌治疗。 从历史上看，研究细菌和宿主因素导致的疾病在技术上一直具有挑战性。 脓肿生理学有两个主要原因。首先，寻求保留脓肿结构的方法 组织样品固有地局限于研究已知的微生物和宿主靶标。这适用于技术 如免疫组织化学和荧光原位杂交，它们可以确定 组织中的分析物，但依赖于预先存在的目标知识。从定义上讲，这些方法不能 用于发现未知的细菌或导致疾病的宿主因素。相反，基于发现的 RNA测序或蛋白质组学等方法可以鉴定新的疾病相关分析物，但需要 破坏性的组织处理，其消除关于微生物和宿主的空间取向的信息 分子。为了克服这些技术限制，我们创建了一个基于质谱的成像平台， 在侵入性S.金黄色葡萄球菌感染因为成像 质谱（IMS）不需要探针或检测试剂，该平台可以定义定位 以及以空间限定的方式富集与生物学相关的分析物，从而能够发现 微生物和宿主因素，有助于疾病的发病机制。当应用到一个模型的传播S。 金黄色葡萄球菌感染，这个基于IMS的平台使三维分子成像的葡萄球菌， 宿主界面，并推动了细菌蛋白质的发现，标志着病原体生态位内的细菌。 虽然个体乳腺癌通常具有相似的组织学表现，但我们基于IMS的分析表明， 揭示了S.金黄色病变。我们假设， 对组织生态位、抗菌免疫反应和共病宿主反应的分子异质性 条件为了验证这一假设，我们将IMS平台与激光捕获显微切割相结合， 葡萄球菌-宿主界面的空间分辨蛋白质组学。拟议的目标将定义分子 跨S.金黄色葡萄球菌感染的组织，并确定如何先天免疫效应细胞和 宿主共病导致细菌生理学和原位脓肿分子结构的异质性。总的来说， 这些实验将解释宿主生物学如何在侵入性感染期间驱动分子异质性。

PROJECT SUMMARY / ABSTRACT Staphylococcus aureus is capable of infecting nearly every vertebrate organ system, triggering the formation of characteristic tissue lesions known as abscesses. Understanding how S. aureus survives within abscesses is critical to the development of new therapeutics, as these lesions represent the pathogen niche during infection. In this application, we will leverage a powerful mass spectrometry-based imaging platform to identify host and bacterial factors that contribute to staphylococcal disease. By defining how tissue niche and host biology drive molecular heterogeneity in abscesses, we will uncover new targets for tailored anti-staphylococcal therapeutics. Historically, it has been technically challenging to study the bacterial and host factors that contribute to abscess physiology for two primary reasons. First, approaches that seek to preserve abscess architecture within a tissue sample are inherently limited to the study of known microbial and host targets. This applies to techniques such as immunohistochemistry and fluorescence in situ hybridization, which can define the spatial distribution of analytes in a tissue but rely on pre-existing knowledge of targets. These approaches, by definition, cannot be used to discover unknown bacterial or host factors that contribute to disease. Conversely, discovery-based methods such as RNA sequencing or proteomics can identify novel, disease-associated analytes, but require destructive tissue processing that eliminates information regarding the spatial orientation of microbial and host molecules. To overcome these technical limitations, we created a mass spectrometry-based imaging platform to identify host and microbial analytes in abscessed tissue during invasive S. aureus infection. Because imaging mass spectrometry (IMS) does not require probes or detection reagents, this platform can define the localization and abundance of abscess-associated analytes in a spatially-defined manner, thereby enabling the discovery of microbial and host factors that contribute to disease pathogenesis. When applied to a model of disseminated S. aureus infection, this IMS-based platform enabled three-dimensional molecular imaging of the staphylococcal- host interface and powered the discovery of bacterial proteins that mark the pathogen niche within abscesses. Although individual abscesses typically have a similar histologic appearance, our IMS-based analysis revealed significant molecular heterogeneity between S. aureus lesions. We hypothesize that abscesses display molecular heterogeneity in response to tissue niche, antibacterial immune responses, and comorbid host conditions. To test this hypothesis, we will couple our IMS platform with laser capture microdissection to enable spatially-resolved proteomics of the staphylococcal-host interface. The proposed Aims will define the molecular architecture of abscesses across S. aureus infected tissues and determine how innate immune effector cells and host comorbidities drive heterogeneity in bacterial physiology and abscess molecular architecture in situ. In total, these experiments will decipher how host biology drives molecular heterogeneity during invasive infection.