Probing Respiration and Metabolism of a Periodontal Pathogen

探索牙周病原体的呼吸和代谢

基本信息

批准号：
10024222
负责人：
Alexander Klementiev
金额：
$ 4.68万
依托单位：
GEORGIA INSTITUTE OF TECHNOLOGY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-01-01 至 2022-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10024222
关键词：
Acids Actinobacillus actinomycetemcomitans Adult Affect American Amino Acids Animal Model Bacteria Biological Models Bone Tissue Carbon Chemicals Coculture Techniques Communities Complement Complex Consumption Cues Data Disease Drug Metabolic Detoxication Environment Feeds Fellowship Fermentation Genomics Goals Hydrogen Peroxide Image In Vitro Infection Inflammation Left Liquid Chromatography Maps Mass Spectrum Analysis Mediating Metabolic Metabolism Microbe Microbial Biofilms Microscopy Modeling Nature Nitrates Oral cavity Oxidants Oxygen Periodontal Pocket Periodontitis Process Production Proteins Resolution Respiration Scanning Shapes Source Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization Streptococcus Streptococcus gordonii Structure Testing Time Vitamins Work base bone loss catalase co-infection experimental study fitness in vivo insight oral bacteria oral commensal oral pathogen periodontopathogen respiratory response social sugar tandem mass spectrometry

项目摘要

Project Summary Periodontitis is a highly prevalent disease affecting nearly half of all American adults, and if left untreated leads to bone loss and tissue damage [1]. Multiple microbes are associated with this disease [2, 3] and through chemically-mediated interactions form complex interspecies communities within the periodontal crevice. Due to the complexity of these chemically-mediated interactions, periodontitis remains a difficult disease to treat. Efforts using polymicrobial communities [4, 5] and animal models [5, 6] have explored possible chemical interactions and have greatly advanced our understanding of the chemical interactions occurring during periodontitis. In the Whiteley lab we use a two-species model system composed of Streptococci gordonii (Sg), a representative Gram-positive streptococcal species capable of consuming sugars and producing acids such as L-lactate as well as producing hydrogen peroxide (H2O2), and Aggregatibacter actinomycetemcommitans (Aa), a Gram-negative oral pathogen associated with aggressive periodontitis. Previously, we have shown that when grown in co- culture, Sg cross-feeds Aa its preferred carbon source, L-lactate, while additionally providing the social cue H2O2 thereby enhancing the fitness of Aa [7-9]. By being cross-fed L-lactate, the slow-growing Aa is able to better compete within a polymicrobial environment. Furthermore, H2O2 serves as a cue by stimulating the production of the complement factor ApiA that protects Aa from complement killing [4], and induces the production of the protein Dispersin B that allows Aa to control its spatial localization [9]. In addition to these fitness benefits, we also hypothesize based on previous data that Sg-produced H2O2 also serves as a direct source of O2 for Aa through catalase mediated detoxification [8]. While L-lactate and H2O2 have been shown to provide important metabolic cues for Aa, recent genomic work indicates that there are likely additional chemical interactions occurring between these bacteria during co-infection [8, 10]. Our hypothesis is that Aa displays defined responses to Sg that are critical to establishing precise spatially structured biofilms at the micron scale. The first objective of the project is to test the hypothesis that Aa can use O2 derived from H2O2 detoxification as evidenced by a shift in respiration when Aa is grown in co-culture with Sg, and how H2O2 impacts spatial structure. In the second objective we will use mass spectrometry to develop a comprehensive understanding of the chemical interactions occurring between Aa and Sg. The results from these studies will provide direct insight into the processes underlying the additional benefits Aa receives through H2O2 detoxification. By identifying the unknown chemical interactions between Aa and Sg, we can better understand the complex interspecies interactions involved in periodontitis.

项目概要牙周炎是一种非常普遍的疾病，影响着近一半的美国成年人，如果不及时治疗会导致导致骨质流失和组织损伤[1]。多种微生物与这种疾病有关 [2, 3] 化学介导的相互作用在牙周缝隙内形成复杂的种间群落。由于由于这些化学介导的相互作用的复杂性，牙周炎仍然是一种难以治疗的疾病。努力使用多种微生物群落 [4, 5] 和动物模型 [5, 6] 探索了可能的化学相互作用并极大地增进了我们对牙周炎期间发生的化学相互作用的理解。在 Whiteley实验室我们使用由Streptococci gordonii (Sg)组成的两个物种模型系统，其代表革兰氏阳性链球菌能够消耗糖并产生 L-乳酸等酸产生过氧化氢 (H2O2) 和聚合放线菌 (Aa)（一种革兰氏阴性菌）与侵袭性牙周炎相关的口腔病原体。之前，我们已经证明，当在共同生长时文化中，Sg 交叉供给 Aa 其首选碳源 L-乳酸，同时另外提供社交信号 H2O2 从而增强Aa的适应度[7-9]。通过交叉喂养 L-乳酸，生长缓慢的 Aa 能够更好地在多种微生物环境中竞争。此外，H2O2 通过刺激生产来充当提示。补体因子 ApiA 保护 Aa 免受补体杀伤 [4]，并诱导产生蛋白质分散蛋白 B 允许 Aa 控制其空间定位 [9]。除了这些健身益处之外，我们还根据之前的数据假设 Sg 产生的 H2O2 也可以作为 Aa 的 O2 的直接来源通过过氧化氢酶介导的解毒作用[8]。虽然 L-乳酸和 H2O2 已被证明可以提供重要的 Aa 的代谢线索，最近的基因组工作表明可能存在额外的化学相互作用这些细菌在共同感染期间发生这种情况[8, 10]。我们的假设是 Aa 显示定义的对 Sg 的响应对于建立微米级精确的空间结构生物膜至关重要。该项目的第一个目标是检验 Aa 可以使用 H2O2 解毒产生的 O2 的假设通过 Aa 与 Sg 共培养时呼吸的变化以及 H2O2 如何影响空间来证明结构。在第二个目标中，我们将使用质谱法来全面了解 Aa 和 Sg 之间发生的化学相互作用。这些研究的结果将提供直接的见解进入 Aa 通过 H2O2 解毒获得的额外好处的潜在过程。通过识别 Aa 和 Sg 之间未知的化学相互作用，我们可以更好地理解复杂的种间关系牙周炎中涉及的相互作用。