Studies on the virulence of Fillifactor alocis

Fillifactor alocis的毒力研究

• 批准号: 8467702
• 负责人: Hansel M. Fletcher
• 金额: $ 18.96万
• 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 2015-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8467702
• 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

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，在感染诱导的牙周病中发挥重要作用。来自口腔微生物组项目的数据正在促进 感染引起的牙周病。牙龈卟啉单胞菌、中间普雷沃特氏菌、伴生放线杆菌、连翘单胞菌和齿密螺旋体等细菌是牙周病的主要病原菌。然而，最近的发展，包括新的，培养独立的技术，使鉴定牙周炎患者的尚可培养和挑剔的微生物成为可能。总而言之，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。Filifactoralocis，一种革兰氏阳性，无糖分解，专性厌氧菌， 是目前被认为对牙周炎相关生物膜的致病结构具有重要意义的标志性微生物之一，应被认为是牙周病的重要微生物。此外，与其他传统的牙周病原体相比，白色念珠菌在牙周袋中的存在数量更多，而在健康或牙周炎抵抗患者中检测到的最少。目前，很少或根本没有关于阿洛克斯病发病机制的信息。在我们的实验室，初步的研究表明，华南星具有非牙龈痛蛋白酶和唾液酸酶活性。在计算机分析中，揭示了阿洛克氏假丝酵母菌和牙龈假单胞菌的几个毒力因子之间的分子相关性。与牙龈假单胞菌相比，无齿假单胞菌对氧化应激具有更强的抵抗力，在此条件下其生长受到刺激。在共培养条件下，生物膜的形成显著增加。共培养组上皮细胞的黏附率和侵袭力均高于单独培养的牙龈假单胞菌和无牙根霉菌。在这些上皮细胞中，只有在共培养过程中才能观察到内吞小泡介导的内化。与阿洛克斯菌ATCC 35896株相比，阿洛克斯菌临床分离株D-62d与牙龈假单胞菌共培养时具有更强的侵袭能力。此外，与ATCC 35896株相比，临床分离株的蛋白质组也存在变异。假想的蛋白质和那些已知在其他细菌中是重要毒力因子的蛋白质被识别出来。综上所述，我们的观察结果可能表明，阿洛克氏杆菌具有毒力特性，可以增强其在牙周袋中的生存/存活能力，并可能在感染性牙周病中发挥重要作用。我们的假设是，与其他牙周病原体一样，在牙周炎中，多种协同调节机制在生物体的致病性中具有重要意义。我们希望了解福尔马氏菌潜在的毒力因子，并评估它们是否与其致病性有关。这个R21应用的主要目标是建立一个遗传系统和一个动物模型来评估寄主对阿洛克斯菌的反应和毒力潜力。本研究的具体目的是：(1)评价水解酶活性在白粉菌存活/致病中的特殊作用(S)。(2)建立检测白粉菌毒力的动物模型。总而言之，结果 从这项研究将建立基础资料的发病机制。它将产生一个模型系统(S)，将产生重要的线索，将促进开发新的治疗干预措施，以帮助控制和预防牙周病