Mantri Chinmay K, Chen Chin-Ho, Dong Xinhong, Goodwin Jeffery Shawn, Pratap Siddharth, Paromov Victor, Xie Hua
School of Dentistry, Meharry Medical College, Nashville, Tennessee.
Microbiologyopen. 2015 Feb;4(1):53-65. doi: 10.1002/mbo3.221. Epub 2014 Dec 18.
Porphyromonas gingivalis is a keystone periopathogen that plays an essential role in the progress of periodontitis. Like other gram-negative bacteria, the ability of P. gingivalis to produce outer membrane vesicles is a strategy used to interact with, and survive within its biological niches. Here we compared the protein components associated with vesicles derived from a fimbriated strain (33277) and an afimbriated strain (W83) of P. gingivalis using proteomic analyses. Some well-known virulence factors were identified in vesicles from both strains, such as gingipains and hemagglutinin. In contrast, FimC, FimD, and FimE, minor components of long fimbriae were found exclusively in 33277 vesicles, while proteins with a tetratricopeptide repeat (TPR) domain were unique to W83 vesicles. We found that significantly more 33277 than W83 vesicles were internalized into human oral keratinocytes and gingival fibroblasts. Interestingly, FimA, a well-known adhesin responsible for the attachment and invasion of P. gingivalis into host cells, was not essential for the invasive capabilities of P. gingivalis vesicles. Rather minor components of long fimbriae were required for an efficient invasive activity of vesicles. The most striking finding was that P. gingivalis strains lacking or having a reduced FimA expression showed a significant reduction in vesiculation. These results suggest that production and pathogenicity of P. gingivalis vesicles may largely depend on expression of the fim locus, and that the integration of vesicle production and pathogenicity with fimbrial expression may allow P. gingivalis to confer upon itself certain functional advantages.
牙龈卟啉单胞菌是一种关键的牙周病原体，在牙周炎进展过程中起重要作用。与其他革兰氏阴性菌一样，牙龈卟啉单胞菌产生外膜囊泡的能力是其在生物微环境中相互作用并存活的一种策略。在此，我们使用蛋白质组学分析比较了来自牙龈卟啉单胞菌的有菌毛菌株（33277）和无菌毛菌株（W83）的囊泡相关蛋白质成分。在两种菌株的囊泡中都鉴定出了一些著名的毒力因子，如牙龈蛋白酶和血凝素。相比之下，长菌毛的次要成分FimC、FimD和FimE仅在33277囊泡中发现，而具有四肽重复（TPR）结构域的蛋白质是W83囊泡所特有的。我们发现，内化到人口腔角质形成细胞和牙龈成纤维细胞中的33277囊泡明显多于W83囊泡。有趣的是，FimA是一种负责牙龈卟啉单胞菌附着和侵入宿主细胞的著名黏附素，但它对牙龈卟啉单胞菌囊泡的侵入能力并非必不可少。相反，长菌毛的次要成分是囊泡有效侵入活性所必需的。最显著的发现是，缺乏FimA表达或FimA表达降低的牙龈卟啉单胞菌菌株的囊泡形成显著减少。这些结果表明，牙龈卟啉单胞菌囊泡的产生和致病性可能在很大程度上取决于菌毛基因座的表达，并且囊泡产生和致病性与菌毛表达的整合可能使牙龈卟啉单胞菌具有某些功能优势。
