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.

项目概要 牙周炎是一种非常普遍的感染性炎症，发生在支持牙齿的组织中， 导致组织破坏、牙槽骨吸收、深牙周袋形成和牙齿脱落。 病因学模型表明，牙周炎是由有毒细菌的协同群落驱动的，这些细菌会引发牙周炎。 牙龈线以下发生炎症反应，导致疾病进展。在公认的病原体中， 革兰氏阴性、高度蛋白水解厌氧菌牙龈卟啉单胞菌 (Pg) 已被强烈 与牙周炎有关。 Pg菌株以产生脂多糖（LPS）大分子为主要 细胞最外层的成分已被反复证明可以刺激先天免疫 回应。有趣的是，Pg 菌株可以使 LPS 的结构多样化，以响应生物学相关的刺激 暂时伪装自己、逃避免疫系统、免受压力并促进生存。 因此，在 Pg 菌株中至少鉴定出四种 LPS 变体，它们可以充当激动剂或拮抗剂 激活先天免疫反应。 LPS 的一种特殊形式，称为 A-LPS，用于锚定一系列 细胞表面具有破坏性的蛋白水解酶，称为牙龈蛋白酶。这些毒力因素共同发挥作用 通过参与各种活动，包括组织，在感染的病理结果中发挥重要作用 破坏、宿主防御扰动、免疫系统逃避和骨吸收。然而，我们还没有 了解 LPS 异质性的调节机制及其在发病过程中的生物学重要性。 我们发现Pg菌株已经进化出c-di-AMP信号通路，其中c-di-AMP合酶 PGN_0523 (dacpg) 和 c-di-AMP 磷酸二酯酶 PGN_0521 (pdepg) 控制 c- 的基本周转 di-AMP 以及生物膜内的细胞活力、LPS 异质性、牙龈蛋白酶扩散到 周围环境和潜在的毒力。我们将研究 c-di-AMP 周转率如何调节 LPS 的异质性和免疫刺激特性并影响牙龈蛋白酶相关的毒力潜力。 为此，提出了两个具体目标，每个目标都包括一组单独的实验和分析： 具体目标 1：了解 Pg 中 c-di-AMP 控制的 LPS 异质性。具体目标 2： 了解 LPS 的 c-di-AMP 依赖性变异对先天免疫反应和牙龈蛋白酶的影响- 相关毒力。完成拟议的研究后，我们将了解 c-di-AMP 信号传导如何 控制 LPS 异质性，影响免疫刺激反应以及 Pg 的毒力潜力。由于c- di-AMP 信号传导在哺乳动物中不存在，我们的发现将为新的药物靶标提供信息。