Abiko Yuki, Nagano Keiji, Yoshida Yasuo, Yoshimura Fuminobu
Department of Microbiology, School of Dentistry, Aichi Gakuin University Nagoya, Aichi, Japan.
PLoS One. 2014 Nov 17;9(11):e113565. doi: 10.1371/journal.pone.0113565. eCollection 2014.
Treponema denticola, a gram-negative and anaerobic spirochete, is associated with advancing severity of chronic periodontitis. In this study, we confirmed that two major antigenic proteins were Msp and TmpC, and examined their physiological and pathological roles using gene-deletion mutants. Msp formed a large complex that localized to the outer membrane, while TmpC existed as a monomer and largely localized to the inner membrane. However, TmpC was also detected in the outer membrane fraction, but its cell-surface exposure was not detected. Msp defects increased cell-surface hydrophobicity and secretion of TNF-α from macrophage-like cells, whereas TmpC defects decreased autoagglutination and chymotrypsin-like protease activities. Both mutants adhered to gingival epithelial cells similarly to the wild-type and showed slightly decreased motility. In addition, in Msp-defective mutants, the TDE1072 protein, which is a major membrane protein, was abolished; therefore, phenotypic changes in the mutant can be, at least in part, attributed to the loss of the TDE1072 protein. Thus, the major antigenic proteins, Msp and TmpC, have significant and diverse impacts on the characteristics of T. denticola, especially cell surface properties.
齿垢密螺旋体是一种革兰氏阴性厌氧螺旋体，与慢性牙周炎病情的进展相关。在本研究中，我们证实了两种主要抗原蛋白为Msp和TmpC，并使用基因缺失突变体研究了它们的生理和病理作用。Msp形成一个定位于外膜的大型复合物，而TmpC以单体形式存在，主要定位于内膜。然而，在外膜组分中也检测到了TmpC，但未检测到其细胞表面暴露。Msp缺陷增加了细胞表面疏水性以及巨噬细胞样细胞中TNF-α的分泌，而TmpC缺陷降低了自凝作用和类胰凝乳蛋白酶活性。两种突变体与野生型一样能类似地黏附于牙龈上皮细胞，且运动性略有降低。此外，在Msp缺陷突变体中，主要膜蛋白TDE1072蛋白缺失；因此，突变体中的表型变化至少部分可归因于TDE1072蛋白的缺失。因此，主要抗原蛋白Msp和TmpC对齿垢密螺旋体的特性，尤其是细胞表面特性，具有显著且多样的影响。
