Love R M, McMillan M D, Park Y, Jenkinson H F
School of Dentistry, University of Otago, Dunedin, New Zealand.
Infect Immun. 2000 Mar;68(3):1359-65. doi: 10.1128/IAI.68.3.1359-1365.2000.
Cell wall-anchored polypeptides of the antigen I/II family are produced by many species of oral streptococci. These proteins mediate adhesion of streptococci to salivary glycoproteins and to other oral microorganisms and promote binding of cells to collagen type I and invasion of dentinal tubules. Since infections of the root canal system have a mixed anaerobic bacterial etiology, we investigated the hypothesis that coadhesion of anaerobic bacteria with streptococci may facilitate invasive endodontic disease. Porphyromonas gingivalis ATCC 33277 cells were able to invade dentinal tubules when cocultured with Streptococcus gordonii DL1 (Challis) but not when cocultured with Streptococcus mutans NG8. An isogenic noninvasive mutant of S. gordonii, with production of SspA and SspB (antigen I/II family) polypeptides abrogated, was deficient in binding to collagen and had a 40% reduced ability to support adhesion of P. gingivalis. Heterologous expression of the S. mutans SpaP (antigen I/II) protein in this mutant restored collagen binding and tubule invasion but not adhesion to P. gingivalis or the ability to promote P. gingivalis coinvasion of dentin. An isogenic afimbrial mutant of P. gingivalis had 50% reduced binding to S. gordonii cells but was unaffected in the ability to coinvade dentinal tubules with S. gordonii wild-type cells. Expression of the S. gordonii SspA or SspB polypeptide on the surface of Lactococcus lactis cells endowed these bacteria with the abilities to bind P. gingivalis, penetrate dentinal tubules, and promote P. gingivalis coinvasion of dentin. The results demonstrate that collagen-binding and P. gingivalis-binding properties of antigen I/II polypeptides are discrete functions. Specificity of antigen I/II polypeptide recognition accounts for the ability of P. gingivalis to coinvade dentinal tubules with S. gordonii but not with S. mutans. This provides evidence that the specificity of interbacterial coadhesion may influence directly the etiology of pulpal and periapical diseases.
抗原I/II家族的细胞壁锚定多肽由多种口腔链球菌产生。这些蛋白质介导链球菌与唾液糖蛋白以及其他口腔微生物的黏附，并促进细胞与I型胶原的结合以及牙本质小管的侵入。由于根管系统感染具有混合性厌氧菌病因，我们研究了以下假说：厌氧菌与链球菌的共黏附可能促进侵袭性牙髓病。牙龈卟啉单胞菌ATCC 33277细胞与戈登链球菌DL1（Challis）共培养时能够侵入牙本质小管，但与变形链球菌NG8共培养时则不能。戈登链球菌的一个同基因非侵袭性突变体，其SspA和SspB（抗原I/II家族）多肽的产生被消除，在与胶原结合方面存在缺陷，支持牙龈卟啉单胞菌黏附的能力降低了40%。变形链球菌SpaP（抗原I/II）蛋白在该突变体中的异源表达恢复了胶原结合和小管侵入能力，但未恢复与牙龈卟啉单胞菌的黏附能力或促进牙龈卟啉单胞菌共同侵入牙本质的能力。牙龈卟啉单胞菌的一个同基因无纤毛突变体与戈登链球菌细胞的结合能力降低了50%，但与戈登链球菌野生型细胞共同侵入牙本质小管的能力未受影响。戈登链球菌SspA或SspB多肽在乳酸乳球菌细胞表面的表达赋予了这些细菌结合牙龈卟啉单胞菌、穿透牙本质小管以及促进牙龈卟啉单胞菌共同侵入牙本质的能力。结果表明，抗原I/II多肽的胶原结合和牙龈卟啉单胞菌结合特性是不同的功能。抗原I/II多肽识别的特异性解释了牙龈卟啉单胞菌与戈登链球菌而非变形链球菌共同侵入牙本质小管的能力。这提供了证据表明细菌间共黏附的特异性可能直接影响牙髓和根尖周疾病的病因。
