Department of Microbiology and Immunology, Medical College of Virginia at Virginia Commonwealth University, Richmond, VA 23298, USA.
Mol Oral Microbiol. 2013 Aug;28(4):316-30. doi: 10.1111/omi.12027. Epub 2013 Apr 22.
Treponema denticola is an anaerobic spirochete whose abundance in the subgingival crevice correlates with the development and severity of periodontal disease. The ability of T. denticola to survive and thrive in the hostile environment of the periodontal pocket is due, at least in part, to its ability to bind factor H (FH), a negative regulator of the alternative complement pathway. The FH binding protein of T. denticola has been identified as FhbB and its atomic structure has been determined. The interaction of FH with T. denticola is unique in that FH bound to the cell surface is cleaved by the T. denticola protease, dentilisin. It has been postulated that FH cleavage by T. denticola leads to immune dysregulation in periodontal pockets. In this study, we conduct a comparative assessment of the sequence, properties, structure and ligand binding kinetics of the FhbB proteins of strains 33521 and 35405. The biological outcome of the interaction of these strains with FH could differ significantly as 33521 lacks dentilisin activity. The data presented here offer insight into our understanding of the interactions of T. denticola with the host and its potential to influence disease progression.
齿密螺旋体是一种厌氧螺旋体，其在龈下沟中的丰度与牙周病的发展和严重程度相关。齿密螺旋体能够在牙周袋这种恶劣环境中生存和繁殖，这至少部分归因于其能够结合补体途径的负调控因子 FH。齿密螺旋体的 FH 结合蛋白已被鉴定为 FhbB，其原子结构也已被确定。FH 与齿密螺旋体的相互作用是独特的，因为结合到细胞表面的 FH 会被齿密螺旋体蛋白酶 dentilisin 切割。据推测，齿密螺旋体对 FH 的切割会导致牙周袋中的免疫失调。在这项研究中，我们对菌株 33521 和 35405 的 FhbB 蛋白的序列、特性、结构和配体结合动力学进行了比较评估。由于 33521 缺乏 dentilisin 活性，这些菌株与 FH 的相互作用的生物学后果可能会有很大差异。这里呈现的数据为我们理解齿密螺旋体与宿主的相互作用及其影响疾病进展的潜力提供了深入的认识。
