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: 10849965
• 负责人: Fata Moradali
• 金额: $ 15.65万
• 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 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10849965
• 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; Cytoprotection; Data; Detection; Development; Diffusion; Disease; Disease Progression; Equilibrium; Etiology; Genes; Heterogeneity; Host Defense; Immune Evasion; Immune system; Infection; Inflammatory; Inflammatory Response; Innate Immune Response; 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， 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，牙周炎是由一个协同的有毒细菌群落驱动的， 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、高蛋白水解厌氧菌牙龈卟啉单胞菌（Pg）已被强烈地 与牙周炎有关Pg菌株主要产生脂多糖（LPS）大分子 细胞最外层的成分，已被反复证明可以刺激先天免疫 应答有趣的是，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，保护免受压力，并促进生存。 因此，在Pg菌株中已经鉴定了至少四种LPS变体，其可以作为激动剂或拮抗剂起作用 来激活先天免疫反应一种特殊形式的LPS，称为A-LPS，用于锚一系列的 破坏性的蛋白水解酶称为牙龈卟啉菌蛋白酶的细胞表面。这些毒力因子共同作用 通过参与各种活动，包括组织， 破坏、宿主防御干扰、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意义。 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-AMP的基本周转。 di-AMP和，反过来，生物膜内的细胞活力，LPS异质性，牙龈卟啉菌蛋白酶扩散到 周围环境和潜在的毒力我们将研究c-di-AMP周转如何调节 LPS的异质性和免疫刺激特性，并影响牙龈卟啉菌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依赖性变化对先天免疫应答和牙龈卟啉菌蛋白酶的影响- 相关毒力在完成拟议的研究后，我们将了解c-di-AMP信号传导 控制LPS的异质性，影响免疫刺激反应和Pg的毒力潜力。 di-AMP信号在哺乳动物中不存在，我们的研究结果将为新的药物靶点提供信息。

项目成果

Atypical cyclic di-AMP signaling is essential for Porphyromonas gingivalis growth and regulation of cell envelope homeostasis and virulence.

• DOI: 10.1038/s41522-022-00316-w
• 发表时间: 2022-07-06
• 期刊: NPJ BIOFILMS AND MICROBIOMES
• 影响因子: 9.2
• 作者: Moradali, M. Fata;Ghods, Shirin;Baehre, Heike;Lamont, Richard J.;Scott, David A.;Seifert, Roland
• 通讯作者: Seifert, Roland