title: The expression profile of lipopolysaccharide-binding protein, membrane-bound CD14, and toll-like receptors 2 and 4 in chronic periodontitis.
abstract: BACKGROUND
  This study aimed to investigate the interrelationship of in vivo expression of lipopolysaccharide-binding protein (LBP) and membrane-bound CD14 (mCD14) in human gingival tissues as well as the coexpression of Toll-like receptors (TLR) 2 and 4 in association with periodontal conditions.
  
  
  METHODS
  Gingival biopsies were collected from 43 subjects with chronic periodontitis, including periodontal pocket tissues (PoTs) and clinically healthy gingival tissues (HT-Ps), and from 15 periodontally healthy subjects as controls (HT-Cs). The expression of LBP, CD14, TLR 2, and TLR 4 was detected by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR).
  
  
  RESULTS
  LBP and mCD14 peptides were simultaneously detected in 91% of PoTs, 85% of HT-Ps, and 100% of HT-Cs. LBP and mCD14 mRNAs were simultaneously detected in 55% of PoTs, 55% of HT-Ps, and 75% of HT-Cs. The expression of LBP was confined to the gingival epithelium, whereas mCD14 was observed around the epithelium-connective tissue interface. A positive correlation existed between LBP and mCD14 peptides in both detection expression (r(s) = 0.608; P <0.001) and expression levels (r = 0.304; P <0.05) of these two molecules. In PoTs, TLR 2 was detected in both pocket epithelia and macrophage-like cells in connective tissues, whereas TLR 4 was predominantly detected in connective tissues. In HT-Ps and HT-Cs, a weak expression of TLR 2 was found in gingival epithelia, and no TLR 4 expression was detected. In PoTs, mCD14 was codetected on CD68-labeled macrophages in the underlying connective tissues of pocket epithelium as well as on CD1a-labeled dendritic cells in the pocket epithelium and connective tissues interface. No similar expression profile was detected in HT-Ps and HT-Cs.
  
  
  CONCLUSIONS
  This study suggests that the in vivo expression of LBP and mCD14 may be interrelated. Altered cellular expression profiles of mCD14 and TLR 2 and 4 in periodontal pocket tissues imply that these pattern recognition receptors may play a role in periodontal pathogenesis.
authors.affiliation: Faculty of Dentistry, Periodontology, The University of Hong Kong, Hong Kong Special Administrative Region, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Ren
authors.forename: W Keung
authors.initials: WK
authors.lastname: Leung
authors.forename: Richard P
authors.initials: RP
authors.lastname: Darveau
authors.forename: Lijian
authors.initials: L
authors.lastname: Jin
mesh_terms: D000209:Acute-Phase Proteins / Q000032:analysis*; D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000473:pathology; D001706:Biopsy; D002352:Carrier Proteins / Q000032:analysis*; D002908:Chronic Disease; D003238:Connective Tissue / Q000473:pathology; D003713:Dendritic Cells / Q000473:pathology; D004848:Epithelium / Q000473:pathology; D005260:Female; D005881:Gingiva / Q000473:pathology; D006801:Humans; D018950:Lipopolysaccharide Receptors / Q000032:analysis*; D008070:Lipopolysaccharides / Q000032:analysis*; D008264:Macrophages / Q000473:pathology; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis*; D008875:Middle Aged; D017622:Periodontal Attachment Loss / Q000473:pathology; D010514:Periodontal Pocket / Q000473:pathology; D010518:Periodontitis / Q000473:pathology*; D051195:Toll-Like Receptor 2 / Q000032:analysis*; D051197:Toll-Like Receptor 4 / Q000032:analysis*; D000099231:Lipopolysaccharide-Binding Protein
chemical_list: D000209:Acute-Phase Proteins; D002352:Carrier Proteins; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D000099231:Lipopolysaccharide-Binding Protein