Studies on the virulence of Fillifactor alocis

Fillifactor alocis的毒力研究

• 批准号: 8320703
• 负责人: Hansel M. Fletcher
• 金额: $ 23.7万
• 依托单位: LOMA LINDA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-08 至 2014-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8320703
• 关键词: Actinobacillus actinomycetemcomitans; Adherence; Animal Model; Apical; Apoptosis; Bacteria; Biological Models; Clinical; Coculture Techniques; Communities; Complex; Computer Simulation; Data; Development; Diagnostic; Disease; Endocytic Vesicle; Endodontics; Environment; Epithelial Cells; Forsythia; Fusobacterium; Genetic; Gingiva; Gingival Pocket; Goals; Growth; Health; Human; Immune response; Infection; Inflammation; Knowledge; Laboratories; Lead; Mass Spectrum Analysis; Mediating; Microbial Biofilms; Modeling; Molecular; Mono-S; Neuraminidase; Oral; Organism; Oxidative Stress; PAWR protein; Pathogenesis; Pathogenicity; Patients; Peptide Hydrolases; Periodontal Diseases; Periodontal Pocket; Periodontitis; Personal Communication; Phylogenetic Analysis; Play; Porphyromonas gingivalis; Prevention; Prevotella intermedia; Property; Proteome; Rattus; Refractory; Research; Resistance; Ribosomal RNA; Role; Structure; Structure of gingival sulcus; System; Techniques; Testing; Treponema denticola; Variant; Virulence; Virulence Factors; Work; base; design; in vivo; novel; novel therapeutic intervention; novel therapeutics; oral microbiome; pathogen; retinal rods; soft tissue; success

DESCRIPTION (provided by applicant): Bacteria in the periodontal pocket can develop complex sessile communities that play a significant role in infection-induced periodontal disease. Data emerging from the oral microbiome project is facilitating a shift in the paradigm for infection-induced periodontal diseases. Bacteria like Porphyromonas gingivalis, Prevotella intermedia, Aggregatibacter (Actinobacillus) actinomycetemcomitans, Tannerella forsythia and Treponema denticola have previously been demonstrated to be major pathogens associated with periodontal diseases. However, recent developments including novel, culture-independent techniques have allowed the identification of as-yet-culturable and fastidious organisms in patients suffering from periodontitis. Collectively, these studies have demonstrated that changes in periodontal status are associated with shifts in the composition of the bacterial community in the periodontal pocket. Filifactor alocis, a Gram-positive, asaccharolytic, obligate anaerobic rod, is one of the marker organisms that is now identified to be significant to the pathogenetic structure of biofilms associated with periodontal inflammation and should be considered an important organism for periodontal disease. Further, in comparison to the other traditional periodontal pathogens, F. alocis is present in the periodontal pocket in higher numbers and is least detected in healthy or periodontitis resistant patients. Currently, there is little or no information on the pathogenesis of F. alocis. In our laboratory, preliminary studies of F. alocis showed non-gingipain protease and sialidase activities. In silico analysis revealed molecular relatedness of several virulence factors from F. alocis and P. gingivalis. F. alocis was more resistant to oxidative stress and its growth stimulated under those condition in contrast to P. gingivalis. Biofilm formation was significantly increased in co-culture. There was an increase in adherence and invasion of epithelial cells in co-culture compared with P. gingivalis or F. alocis mono-cultures. In those epithelial cells, endocytic vesicle mediated internalization was only observed during co-culture. The F. alocis clinical isolate D-62D had an increased invasive capacity in co-culture with P. gingivalis compared to the F. alocis ATCC 35896 strain. In addition, there was variation in the proteome of the clinical isolates compared to the ATCC 35896 strain. Hypothetical proteins and those known to be important virulence factors in other bacteria were indentified. Our observations, taken together, may suggest that F. alocis has virulence properties that may enhance its ability to survive/persist in the periodontal pocket and may play an important role in infection-induced periodontal disease. It is our hypothesis that in F. alocis, similar to other periodontal pathogens, multiple coordinately regulated mechanisms are significant in the pathogenicity of the organism. We wish to gain an understanding of F. alocis potential virulence factors and evaluate whether they contribute to its pathogenicity. The primary goal of this R21 application is to develop a genetic system and an animal model to evaluate the host response to and virulence potential of F. alocis. The specific aims are: (1) To evaluate the specific role(s) of protease activity in the survival/pathogenicity of F. alocis. (2) o develop an animal model for testing the virulence potential of F. alocis. Collectively, the results from this study will establish basic information on the pathogenesis of F. alocis. It will generatea model system(s) that will yield important clues that will facilitate the development of novel therapeutic interventions to aid in the control and prevention of periodontal disease PUBLIC HEALTH RELEVANCE: The goal of this research is to establish basic information on the ability of Filifactor alocis to cause gum disease. This bacterium which was previously unrecognized is now proposed to be a diagnostic indicator of gum disease. Because of the success of this bacterium in the periodontal pocket, an understanding of components that may lead to its survival and persistence is vital. This information will lead to the identification of rime targets for the development of novel therapeutics that will have a positive impact on human health.

描述（由申请人提供）：牙周袋中的细菌可以形成复杂的固着群落，在感染引起的牙周病中发挥重要作用。口腔微生物组项目的数据正在促进范式的转变 感染引起的牙周病。牙龈卟啉单胞菌、中间普雷沃氏菌、放线菌聚集杆菌、连翘坦氏菌和齿垢密螺旋体等细菌此前已被证明是与牙周病相关的主要病原体。然而，最近的发展，包括新颖的、独立于培养的技术，已经能够在患有牙周炎的患者中鉴定出尚未培养的、挑剔的微生物。总的来说，这些研究表明牙周状态的变化与牙周袋中细菌群落组成的变化有关。 Filifactor alocis，一种革兰氏阳性、解糖、专性厌氧杆， 是目前已确定对与牙周炎症相关的生物膜的致病结构具有重要意义的标记生物之一，应被视为牙周病的重要生物。此外，与其他传统牙周病原体相比，牙周袋中存在的 F. alocis 数量较多，并且在健康或牙周炎抵抗患者中检测到最少。目前，关于 F. alocis 发病机制的信息很少或根本没有。在我们的实验室中，F. alocis 的初步研究显示出非牙龈蛋白酶和唾液酸酶活性。计算机分析揭示了 F. alocis 和 P. gingivalis 的几种毒力因子的分子相关性。与牙龈卟啉单胞菌相比，F. alocis 对氧化应激具有更强的抵抗力，并且在这些条件下其生长受到刺激。共培养中生物膜的形成显着增加。与单独培养 P. gingivalis 或 F. alocis 相比，共培养中上皮细胞的粘附和侵袭有所增加。在这些上皮细胞中，仅在共培养期间观察到内吞囊泡介导的内化。与 F. alocis ATCC 35896 菌株相比，F. alocis 临床分离株 D-62D 在与牙龈卟啉单胞菌共培养中具有增强的侵袭能力。此外，与 ATCC 35896 菌株相比，临床分离株的蛋白质组存在差异。鉴定了假设的蛋白质和已知的其他细菌中重要毒力因子的蛋白质。综合起来，我们的观察结果可能表明 F. alocis 具有毒力特性，可以增强其在牙周袋中生存/持续存在的能力，并且可能在感染诱发的牙周病中发挥重要作用。我们的假设是，在 F. alocis 中，与其他牙周病原体类似，多种协调调节机制在生物体的致病性中具有重要意义。我们希望了解 F. alocis 的潜在毒力因子并评估它们是否有助于其致病性。 R21 应用的主要目标是开发遗传系统和动物模型，以评估 F. alocis 的宿主反应和毒力潜力。具体目的是： (1) 评估蛋白酶活性在 F. alocis 存活/致病性中的具体作用。 (2) o 开发动物模型来测试 F. alocis 的毒力潜力。综合来看，结果 这项研究将确定 F. alocis 发病机制的基本信息。它将生成一个模型系统，该系统将产生重要线索，促进新型治疗干预措施的开发，以帮助控制和预防牙周病 公共健康相关性：本研究的目的是建立有关 Filifactor alocis 引起牙龈疾病的能力的基本信息。这种以前未被识别的细菌现在被认为是牙龈疾病的诊断指标。由于这种细菌在牙周袋中的成功，了解可能导致其生存和持久存在的成分至关重要。这些信息将有助于确定新疗法的开发目标，从而对人类健康产生积极影响。