Mechanisms of Complement Evasion by Treponema denticola

齿垢密螺旋体逃避补体的机制

• 批准号: 8397780
• 负责人: Daniel Patrick Miller
• 金额: $ 3.42万
• 依托单位: VIRGINIA COMMONWEALTH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-10 至 2015-07-09
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8397780
• 关键词: Adult; Affect; Amino Acid Sequence; Bacteria; Bathing; Binding; Binding Proteins; Biochemical; C-reactive protein; Cell Culture Techniques; Cell surface; Cells; Cleaved cell; Clinical; Communicable Diseases; Complement; Complement 3b; Complement Activation; Complement Factor H; Development; Disease Progression; Fibrinogen; Future; Gingival Crevicular Fluid; Gram-Negative Bacteria; Human; Immune; Immune response; Immune system; Immunoblotting; Immunoglobulins; Infection; Inflammation; Kinetics; Length; Liquid substance; Mass Spectrum Analysis; Mediating; Molecular; Oral; Pathogenesis; Peptide Hydrolases; Peptide Sequence Determination; Periodontal Diseases; Periodontal Infection; Periodontal Pocket; Periodontitis; Periodontium; Phase; Prevention strategy; Production; Property; Recombinant Proteins; Recombinants; Regulation; Serum; Serum Proteins; Site; Surface; Surface Plasmon Resonance; Therapeutic; Tissues; Tooth structure; Treponema denticola; Vaccine Design; Variant; Work; antimicrobial peptide; base; cofactor; complement C3 precursor; dentilisin; design; genetic regulatory protein; killings; middle age; novel therapeutics; pathogen; periopathogen; protein expression; protein purification; therapeutic vaccine

DESCRIPTION (provided by applicant): Periodontal disease is the most common infectious disease of middle-aged adults. Treponema denticola is an oral, bacterial species that is strongly associated with the development of periodontitis. The periodontal pocket, the site of infection between the tooth and the gums, is bathed in crevicular fluid containing antimicrobial peptides, immunoglobulin and highly abundant complement proteins. Complement is an innate immune system that can kill Gram-negative bacteria, mark pathogens for destruction, and modulate local inflammation. T. denticola can evade complement- mediated destruction by production of FhbB and dentilisin. FhbB binds the host negative complement regulator factor H and is critical to the survival of the bacterium in human serum. Dentilisin is capable of cleaving the central complement components C3 and C3b as well as factor H. T. denticola may cause a dysregulation of the local immune response leading to inflammation-associated tissue damage that is a hallmark of periodontitis. This project aims to sequence fhbB from a variety of clinical isolates of T. denticola then apply biochemical approaches such as recombinant protein expression and purification, surface plasmon resonance, immunoblotting and allelic exchange to determine if protein sequence variation affects the FhbB:FH interaction and protective function. Additionally, this study aims to identify a dentilisin generated factor H fragment, which remains bound to the cell, by purification and mass spectrometry. Several biochemical and cell culture techniques will be applied to determine if the factor H fragment retains regulatory activity, can protect T. denticola from complement destruction, and alter host cell binding of full length FH. A more complete picture of immune dysregulation caused by T. denticola during periodontal infection will aid in potential future therapeutic and vaccine design. PUBLIC HEALTH RELEVANCE: An understanding of the interaction between bacteria associated with severe periodontal diseases and the immune system is critical. Inflammation caused by these pathogens results in the tissue damage associated with severe periodontal diseases. This project aims to characterize the interactions between Treponema denticola and the immune system leading to future therapeutic design.

描述（申请人提供）：牙周病是中年人最常见的传染病。齿垢密螺旋体是一种口腔细菌，与牙周炎的发生密切相关。牙周袋是牙齿和牙龈之间的感染部位，沐浴在含有抗菌肽、免疫球蛋白和高丰富补体蛋白的沟液中。补体是一种先天免疫系统，可以杀死革兰氏阴性细菌，标记病原体以进行破坏，并调节局部炎症。 T. denticola 可以通过产生 FhbB 和 dentilisin 来逃避补体介导的破坏。 FhbB 与宿主负补体调节因子 H 结合，对于细菌在人血清中的存活至关重要。 Dentilisin 能够裂解中央补体成分 C3 和 C3b 以及因子 H。T. denticola 可能会导致局部免疫反应失调，从而导致炎症相关的组织损伤，这是牙周炎的标志。该项目旨在对来自各种 T. denticola 临床分离株的 fhbB 进行测序，然后应用重组蛋白表达和纯化、表面等离子共振、免疫印迹和等位基因交换等生化方法来确定蛋白质序列变异是否影响 FhbB:FH 相互作用和保护性。功能。此外，本研究旨在通过纯化和质谱法鉴定牙菌素生成的 H 因子片段，该片段仍与细胞结合。将应用多种生化和细胞培养技术来确定 H 因子片段是否保留调节活性，是否可以保护 T. denticola 免受补体破坏，并改变全长 FH 的宿主细胞结合。更全面地了解牙周感染期间由牙菌引起的免疫失调将有助于未来潜在的治疗和疫苗设计。 公共卫生相关性：了解与严重牙周病相关的细菌与免疫系统之间的相互作用至关重要。这些病原体引起的炎症会导致与严重牙周病相关的组织损伤。该项目旨在表征齿垢密螺旋体与免疫系统之间的相互作用，从而引导未来的治疗设计。