Tissue Transglutaminase Domains that Complex with Bacteria

与细菌复合的组织转谷氨酰胺酶结构域

• 批准号: 8426740
• 负责人: Heike Boisvert
• 金额: $ 14.4万
• 依托单位: ADA FORSYTH INSTITUTE, INC.
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-12-01 至 2014-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8426740
• 关键词: ATP phosphohydrolase; Adherence; Adhesives; Adult; Affect; Amines; Anaerobic Bacteria; Animals; Apoptotic; Autoimmune Diseases; Bacteria; Bacterial Infections; Binding; Biological Assay; Cell Line; Cell Surface Receptors; Cell Survival; Cell surface; Cells; Clathrin; Complex; Confocal Microscopy; Cytoplasm; Data; Defect; Development; Endocytosis Pathway; Enzymes; Epithelial; Epithelial Cells; Eukaryotic Cell; Extracellular Matrix Proteins; Fibronectins; Fluorescence Microscopy; Future; Gingiva; Glutamine; Goals; Guanosine Triphosphate; Immunofluorescence Microscopy; Infection; Inflammatory; Integrins; Isomerase; Lead; Life; Link; Measures; Mediating; Microbial Biofilms; Modeling; Monitor; N-terminal; Oral; Oral cavity; Organism; Pathology; Peptides; Periodontal Diseases; Periodontitis; Play; Population; Porphyromonas gingivalis; Proteins; Reaction; Role; Safety; Signal Transduction; Staging; Staining method; Stains; Structure of gingival sulcus; Surface; Testing; Therapeutic; Tissues; Transglutaminases; Water; base; covalent bond; crosslink; electric impedance; in vivo; inhibitor/antagonist; microorganism; mutant; novel; oral anaerobes; oral bacteria; pathogen; peptide P3; prevent; protein crosslink; public health relevance; receptor; stable cell line; synthetic peptide; uptake

DESCRIPTION (provided by applicant): Porphyromonas gingivalis (Pg), a Gram negative anaerobe is part of a destructive biofilm found in the oral cavity. There Pg interacts with other bacteria and host cells lining the gingival sulcus. Additionally, the bacteria can be found inside oral epithelial and gingival cells in vivo. We showed previously that Pg hijacks the hosts' clathrin-mediated endocytosis pathway to promote its own uptake. Many microorganisms bind to specific cell surface receptors and are internalized by the same mechanism. Pg is able to bind to several host proteins and many potential receptors have been proposed for Pg. In this application we hypothesize that tissue transglutaminase (TG2) plays a major role in Pg attachment and subsequent internalization. TG2 can be found on the surface of host cells where it forms covalent bonds between free amine and protein- or peptide-bound glutamine residues. TG2 crosslinking activity is Ca2+-dependent and in our preliminary studies we found that Pg association with host cells is much higher in the presence of Ca2+. In addition, TG2-inhibitors block binding of Pg to epithelial cells and there is not interaction of Pg with host cells detectabe in the absence of TG2. Also, TG2 is part of the integrin-network by binding to fibronectin on cell surfaces. In our hypothesized model we propose that TG2 plays a major role in the initial stages of Pg binding to epithelial cells. In Specific Aim 1 we will identify TG2 domains and therefore TG2 activities that are involved in Pg-host associations. In Specific Aim 2 we will analyze the effect of selected TG2 inhibitors on Pg binding to host cells and the effect of inhibitors on host cell viability. TG2 is a major component in several host pathologies and the search for TG2 inhibitors is a very active field. With this application we want to identify safe and stable TG2 inhibitors that might be useful in future animal studies to treat periodontitis.

描述（由申请人提供）：牙龈卟啉单胞菌（Pg）是一种革兰氏阴性厌氧菌，是口腔中发现的破坏性生物膜的一部分。 Pg 与龈沟内的其他细菌和宿主细胞相互作用。此外，这种细菌还存在于体内口腔上皮和牙龈细胞内。我们之前表明，Pg 劫持宿主的网格蛋白介导的内吞途径以促进其自身的摄取。许多微生物与特定的细胞表面受体结合并通过相同的机制内化。 Pg 能够与多种宿主蛋白​​结合，并且已为 Pg 提出了许多潜在的受体。在此应用中，我们假设组织转谷氨酰胺酶 (TG2) 在 Pg 附着和随后的内化中起主要作用。 TG2 存在于宿主细胞表面，在游离胺和蛋白质或肽结合的谷氨酰胺残基之间形成共价键。 TG2 交联活性是 Ca2+ 依赖性的，在我们的初步研究中，我们发现在 Ca2+ 存在的情况下，Pg 与宿主细胞的关联要高得多。此外，TG2抑制剂阻断Pg与上皮细胞的结合，并且在没有TG2的情况下不存在可检测到的Pg与宿主细胞的相互作用。此外，TG2 通过与细胞表面的纤连蛋白结合而成为整合素网络的一部分。在我们的假设模型中，我们提出 TG2 在 Pg 与上皮细胞结合的初始阶段发挥主要作用。在具体目标 1 中，我们将识别 TG2 域，从而识别参与 Pg-宿主关联的 TG2 活动。在具体目标 2 中，我们将分析所选 TG2 抑制剂对 Pg 与宿主细胞结合的影响以及抑制剂对宿主细胞活力的影响。 TG2 是多种宿主病理学的主要组成部分，并且寻找 TG2 抑制剂是一个非常活跃的领域。通过这一应用，我们希望找到安全稳定的 TG2 抑制剂，这些抑制剂可能在未来治疗牙周炎的动物研究中有用。