The Control of LPS Heterogeneity and Virulence by C-di-AMP Signaling in P. gingivalis

牙龈卟啉单胞菌中 C-di-AMP 信号传导对 LPS 异质性和毒力的控制

• 批准号: 10430357
• 负责人: Fata Moradali
• 金额: $ 15.64万
• 依托单位: UNIVERSITY OF LOUISVILLE
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10430357
• 关键词: Adenosine; Adenosine Monophosphate; Adult; Affect; Agonist; Anaerobic Bacteria; Anti-Inflammatory Agents; Applications Grants; Bacteria; Biological; Biological Assay; Bone Resorption; Cell Survival; Cell Wall; Cell membrane; Cell physiology; Cell surface; Cells; Chemical Structure; Communities; Data; Detection; Development; Diffusion; Disease; Disease Progression; Equilibrium; Etiology; Genes; Heterogeneity; Host Defense; Immune system; Infection; Inflammatory; Inflammatory Response; Innate Immune Response; Lead; Learning; Link; Lipopolysaccharides; Mammals; Membrane; Microbial Biofilms; Modeling; Modification; Molecular; Outcome; Pathogenesis; Pathogenicity; Pathologic; Pathway interactions; Peptide Hydrolases; Periodicity; Periodontal Pocket; Periodontitis; Physiology; Play; Population; Porphyromonas gingivalis; Post-Translational Protein Processing; Production; Property; Regulation; Role; Series; Signal Pathway; Signal Transduction; Stimulus; Stress; Structure; System; Systemic disease; TLR4 gene; Therapeutic; Tissues; Tooth Loss; Tooth structure; United States; Variant; Virulence; Virulence Factors; Virulent; alveolar bone; antagonist; cytokine; economic impact; experimental study; extracellular; gingipain; macromolecule; mutant; neutrophil; new therapeutic target; novel; pathogen; pathogenic bacteria; phosphoric diester hydrolase; receptor; response; socioeconomics

Project Summary Periodontitis is a highly prevalent infectious, inflammatory disease of the tissues supporting the teeth that can lead to tissue destruction, alveolar bone resorption, formation of the deep periodontal pocket, and tooth loss. Etiological models suggest that periodontitis is driven by a synergistic community of virulent bacteria that trigger host inflammatory responses below the gum line resulting in disease progression. Among recognized pathogens, the Gram-negative, highly proteolytic anaerobe Porphyromonas gingivalis (Pg) has been strongly implicated in periodontitis. Pg strains produce lipopolysaccharide (LPS) macromolecules as the main components of the outermost layer of the cells that have been repeatedly shown to stimulate innate immune responses. Intriguingly, Pg strains can diversify the structure of LPSs in response to biologically relevant stimuli to temporarily disguise themselves, evade the immune system, protect from stresses, and promote survival. Accordingly, at least four LPS variants have been identified in Pg strains that may act as agonists or antagonists to activate innate immune responses. A specific form of LPSs, called A-LPS, serves to anchor a series of destructive proteolytic enzymes known as gingipains on the cell surface. These virulence factors collectively play prominent roles in the pathological outcome of infection by being involved in various activities, including tissue destruction, host-defense perturbation, immune system evasion, and bone resorption. However, we do not yet know the mechanisms of the regulation of LPS heterogeneity and its biological importance during pathogenesis. We discovered that Pg strains have evolved with c-di-AMP signaling pathway in which the c-di-AMP synthase PGN_0523 (dacpg) and the c-di-AMP phosphodiesterase PGN_0521 (pdepg) control the essential turnover of c- di-AMP and, in turn, cell viability within biofilms, LPS heterogeneity, the diffusion of gingipains into the surrounding milieu, and virulence potential. We will investigate how c-di-AMP turnover regulates the heterogeneity and immunostimulatory properties of LPSs and affects gingipain-associated virulence potential. To this end, two specific aims are proposed, and each aim includes a set of separate experiments and assays: Specific Aim 1: To understand c-di-AMP-controlled heterogeneity of LPSs in Pg. Specific Aim 2: To understand the impact of c-di-AMP-dependent variation of LPS on the innate immune response and gingipains- associated virulence. Upon completion of the proposed studies, we will learn how c-di-AMP signaling controls LPS heterogeneity, impacts immunostimulatory responses, and the virulence potential of Pg. Since c- di-AMP signaling does not exist in mammals, our findings will inform about a novel druggable target.

项目摘要 牙周炎是一种高度流行的感染性，炎症性疾病，支持牙齿 导致组织破坏，牙槽骨吸收，深牙周口袋的形成和牙齿脱落。 病因模型表明，牙周炎是由触发的有毒细菌的协同社区驱动的 牙龈线以下的宿主炎症反应导致疾病进展。在公认的病原体中， 革兰氏阴性，高度蛋白水解的厌氧菌牙龈（PG）已经很强 与牙周炎有关。 PG菌株产生脂多糖（LPS）大分子作为主要 已反复证明可以刺激先天免疫的细胞最外层的成分 回答。有趣的是，PG菌株可以响应生物学相关的刺激来使LPS的结构多样化 暂时掩饰自己，逃避免疫系统，保护压力并促进生存。 因此，在PG菌株中至少发现了至少四个LPS变体，这些变体可能充当激动剂或拮抗剂 激活先天免疫反应。一种称为A-LPS的特定形式的LPS来锚定一系列 破坏性的蛋白水解酶在细胞表面被称为牙龈。这些毒力因素集体发挥 通过参与包括组织在内的各种活动，在感染的病理结局中重要作用 破坏，宿主防御扰动，免疫系统逃避和骨吸收。但是，我们还没有 了解LPS异质性调节的机制及其在发病机理期间的生物学重要性。 我们发现PG菌株已随着C-DI-AMP信号传导途径的发展而演变 PGN_0523（DACPG）和C-DI-AMP磷酸二酯酶PGN_0521（PDEPG）控制C-的必要周转率 di-amp，进而在生物膜内的细胞活力，LPS异质性，gingipains扩散到 周围环境和毒力潜力。我们将调查C-DI-AMP离职如何调节 LPSS的异质性和免疫刺激性能，并影响与牙龈蛋白酶相关的毒力潜力。 为此，提出了两个具体目标，每个目标包括一组单独的实验和测定： 具体目的1：了解PG中LPSS的C-DI-AMP控制异质性。具体目标2： 了解LPS依赖C-DI-AMP依赖性变化对先天免疫反应和gingipains的影响 - 相关的毒力。拟议的研究完成后，我们将学习C-DI-AMP信号如何传导 控制LP的异质性，影响免疫刺激反应以及PG的毒力潜力。由于c- DI-AMP信号传导不存在于哺乳动物中，我们的发现将告知新型可药物目标。