Interactions of the oral pathogen, A. actinomycetemcomitans, with collagen

口腔病原体 A. actinomycetemcomitans 与胶原蛋白的相互作用

• 批准号: 8884581
• 负责人: KEITH Peter MINTZ
• 金额: $ 72.86万
• 依托单位: UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8884581
• 关键词: Actinobacillus actinomycetemcomitans; Adhesions; Adhesives; Amino Acids; Anabolism; Bacteria; Bacterial Adhesins; Bacterial Adhesion; Bacterial Proteins; Binding; Biochemical; Cardiovascular Diseases; Cell surface; Chemosensitization; Chimeric Proteins; Chronic; Clinical; Collagen; Complex; Comprehension; Development; Disease; Disease Progression; Dissection; Distal; Distant; Enzymes; Event; Evolution; Extracellular Matrix; Extracellular Matrix Proteins; Future; Genes; Genetic Techniques; Genotype; Gingiva; Goals; Gram-Negative Bacteria; Health; Heart Valves; Heterogeneity; Human; Immune response; Infection; Infective endocarditis; Inflammatory; Investigation; Kinetics; Knowledge; Laboratories; Lead; Light; Lipopolysaccharides; Location; Membrane; Modeling; Modification; Molecular; Mouth Diseases; N-terminal; Nature; Oral; Oral cavity; Pathogenesis; Periodontal Diseases; Periodontal Pocket; Periodontium; Phase; Play; Polysaccharides; Population; Post-Translational Protein Processing; Process; Protein Binding; Proteins; Public Health; Reagent; Resolution; Role; Sequence Deletion; Serotyping; Site; Source; Structure of gingival sulcus; Surface; Systemic disease; Systemic infection; Testing; Tissues; Tropism; Virulence; antimicrobial; antimicrobial drug; appendage; base; biophysical techniques; combat; electron tomography; glycosylation; improved; insight; monomer; mutant; novel; novel therapeutics; oral pathogen; oral tissue; pathogen; polypeptide; prevent; resistant strain; single molecule; sugar; three dimensional structure

DESCRIPTION (provided by applicant): Periodontal disease represents a group of inflammatory diseases, which lead to the destruction of the gingiva and the supporting structures of the teeth. The loss of tissue results from an imbalance of the host immune response induced by the colonization of specific sub-gingival bacteria. This microflora is also considered the source for extra-oral diseases. Aggregatibacter actinomycetemcomitans is a Gram-negative periodontal pathogen associated with both the chronic and localized aggressive forms of the disease. Multiple disseminated extra-oral diseases are attributed to this pathogen including infective endocarditis and the potentiation of cardiovascular disease. However, the tropism used by A. actinomycetemcomitans to colonize the oral cavity or infiltrate and disseminate to distant tissues has remained elusive. These tissues share common extracellular matrix (ECM) proteins including collagen. Our group has identified a novel protein, extracellular matrix protein adhesin A (EmaA), which is critical for the interaction of the bacterium with collagens and is a proven virulence determinant for the initiation of infective endocarditis. In summary, A. actinomycetemcomitans expresses a cell surface adhesin that binds collagen, the most abundant ECM protein, for establishing infectious foci. Therefore, we posit that ECM colonization acts as a reservoir for re-infection of the gingival sulcus and dissemination to extra oral sites. The EmaA adhesin is composed of three identical monomers unique to A. actinomycetemcomitans that intercalate in the outer membrane to assemble unique antenna-like surface appendages essential for collagen binding. However, the protein size and sequence of the monomers is serotype specific. Furthermore, EmaA is posttranslationally modified with O-polysaccharide (O-PS) sugars that are crucial for binding to collagen. Interestingly, this EmaA modification shares the same enzymes required for O-PS biosynthesis. The specific role of the glycan moieties in the interaction with collagen remains undefined. The goal of this application is to elucidate the mechanism(s) utilized by this pathogen for colonizing the oral cavity and disseminating to other tissues. To achieve this goal we propose the following specific aims: 1) determine the localization and composition of the glycan moiety of EmaA from serotype b bacteria; 2) determine the role of EmaA genotype and bacterial serotype in collagen binding; and 3) biochemical and biophysical determination of the EmaA/collagen interaction. Defining the nature of the active binding moiety of EmaA will aid in understanding the role of this protein in the pathogenesis of A. actinomycetemcomitans. The new insights gained from this study into the molecular mechanism of this adhesin will lead to the development of molecules to disrupt and/or diminish tissue colonization by this pathogen.

描述（由申请人提供）：牙周疾病代表一组炎症性疾病，导致牙龈的破坏和牙齿的支撑结构。组织丧失是由于特定亚生物细菌的定殖引起的宿主免疫反应的失衡而导致的。该菌群也被认为是口外疾病的来源。聚集的放线菌ceTemcitans是一种与慢性和局部侵袭性形式相关的革兰氏阴性牙周病原体。多种传播的异常疾病归因于这种病原体，包括感染性心内膜炎和心血管疾病的增强。然而，曲霉曲霉使用的疗法将口腔或浸润性定居并渗透到遥远的组织仍然难以捉摸。这些组织具有包括胶原蛋白在内的常见细胞外基质（ECM）蛋白。我们的小组已经确定了一种新型蛋白质，细胞外基质蛋白粘附素A（EMAA），这对于细菌与胶原蛋白的相互作用至关重要，并且是启动感染性心内膜炎的证明毒力决定因素。总而言之，A。放线菌coSTEMCOMITAN表示结合胶原蛋白（最丰富的ECM蛋白）的细胞表面粘附，用于建立感染灶。因此，我们认为ECM定植是重新感染牙龈沟并传播到额外的储层 口头站点。 EMAA粘附蛋白由三个相同的单体组成，其在外膜中插入叶片的放线菌的独特，以组装独特的天线样表面，对胶原蛋白结合必不可少。但是，单体的蛋白质大小和序列是血清型的。此外，EMAA是用O-丙糖糖（O-PS）糖进行翻译后修饰的，对于与胶原蛋白结合至关重要。有趣的是，该EMAA修饰具有与O-PS生物合成所需的相同酶。聚糖部分在与胶原蛋白相互作用中的具体作用仍然不确定。该应用的目的是 为了阐明该病原体用于定植口腔并传播到其他组织的机制。为了实现这一目标，我们提出以下特定目的：1）确定来自血清型B细菌的EMAA聚糖部分的定位和组成； 2）确定EMAA基因型和细菌血清型在胶原蛋白结合中的作用； 3）EMAA/胶原蛋白相互作用的生化和生物物理测定。定义EMAA的主动结合部分的性质将有助于理解该蛋白在放线杆菌的发病机理中的作用。从这项研究中获得的新见解将导致该病原体破坏和/或减少组织定植的分子的发展。