Bao Kai, Bostanci Nagihan, Selevsek Nathalie, Thurnheer Thomas, Belibasakis Georgios N
Oral Translational Research, Institute for Oral Biology, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.
Functional Genomics Center Zurich, University of Zurich, Zurich, Switzerland.
PLoS One. 2015 Mar 10;10(3):e0119222. doi: 10.1371/journal.pone.0119222. eCollection 2015.
Periodontitis is an infectious disease that causes the inflammatory destruction of the tooth-supporting (periodontal) tissues, caused by polymicrobial biofilm communities growing on the tooth surface. Aggressive periodontitis is strongly associated with the presence of Aggregatibacter actinomycetemcomitans in the subgingival biofilms. Nevertheless, whether and how A. actinomycetemcomitans orchestrates molecular changes within the biofilm is unclear. The aim of this work was to decipher the interactions between A. actinomycetemcomitans and other bacterial species in a multi-species biofilm using proteomic analysis. An in vitro 10-species "subgingival" biofilm model, or its derivative that included additionally A. actinomycetemcomitans, were anaerobically cultivated on hydroxyapatite discs for 64 h. When present, A. actinomycetemcomitans formed dense intra-species clumps within the biofilm mass, and did not affect the numbers of the other species in the biofilm. Liquid chromatography-tandem mass spectrometry was used to identify the proteomic content of the biofilm lysate. A total of 3225 and 3352 proteins were identified in the biofilm, in presence or absence of A. actinomycetemcomitans, respectively. Label-free quantitative proteomics revealed that 483 out of the 728 quantified bacterial proteins (excluding those of A. actinomycetemcomitans) were accordingly regulated. Interestingly, all quantified proteins from Prevotella intermedia were up-regulated, and most quantified proteins from Campylobacter rectus, Streptococcus anginosus, and Porphyromonas gingivalis were down-regulated in presence of A. actinomycetemcomitans. Enrichment of Gene Ontology pathway analysis showed that the regulated groups of proteins were responsible primarily for changes in the metabolic rate, the ferric iron-binding, and the 5S RNA binding capacities, on the universal biofilm level. While the presence of A. actinomycetemcomitans did not affect the numeric composition or absolute protein numbers of the other biofilm species, it caused qualitative changes in their overall protein expression profile. These molecular shifts within the biofilm warrant further investigation on their potential impact on its virulence properties, and association with periodontal pathogenesis.
牙周炎是一种由牙面生长的多种微生物生物膜群落引起的、导致牙齿支持（牙周）组织发生炎性破坏的感染性疾病。侵袭性牙周炎与龈下生物膜中伴放线聚集杆菌的存在密切相关。然而，伴放线聚集杆菌是否以及如何在生物膜内协调分子变化尚不清楚。这项工作的目的是使用蛋白质组学分析来解读伴放线聚集杆菌与多物种生物膜中其他细菌物种之间的相互作用。一种体外10物种“龈下”生物膜模型，或其另外包含伴放线聚集杆菌的衍生物，在羟基磷灰石圆盘上厌氧培养64小时。当存在时，伴放线聚集杆菌在生物膜团块内形成密集的种内团块，并且不影响生物膜中其他物种的数量。液相色谱 - 串联质谱用于鉴定生物膜裂解物的蛋白质组内容。在有或没有伴放线聚集杆菌的情况下，生物膜中分别鉴定出总共3225和3352种蛋白质。无标记定量蛋白质组学显示，728种定量细菌蛋白质（不包括伴放线聚集杆菌的蛋白质）中有483种受到相应调节。有趣的是，在伴放线聚集杆菌存在的情况下，中间普氏菌的所有定量蛋白质均上调，而直肠弯曲菌、咽峡炎链球菌和牙龈卟啉单胞菌的大多数定量蛋白质均下调。基因本体途径分析的富集表明，在通用生物膜水平上，受调节的蛋白质组主要负责代谢率、铁离子结合和5S RNA结合能力的变化。虽然伴放线聚集杆菌的存在不影响其他生物膜物种的数字组成或绝对蛋白质数量，但它导致了它们整体蛋白质表达谱的定性变化。生物膜内这些分子变化值得进一步研究它们对其毒力特性以及与牙周发病机制关联的潜在影响。
