title: Expression of human beta-defensin-3 in gingival epithelia.
abstract: OBJECTIVE
  This study aimed to investigate the expression patterns of the newly discovered human beta-defensin-3 (hBD-3) in human gingiva.
  
  
  BACKGROUND
  Human beta-defensins (hBDs) are a group of small, broad-spectrum, cationic antimicrobial peptides. Our recent study showed that the expression levels of hBD-1 and 2 peptides were associated with periodontal conditions.
  
  
  METHODS
  A total of 49 gingival biopsies were collected, including 33 samples from 21 patients with chronic periodontitis and 16 samples from 16 periodontally healthy subjects. The expression of hBD-3 was detected by immunohistochemistry and in situ hybridization. Double staining was undertaken to identify hBD-3 peptide-positive cells, using CD-1a and cytokeratin 20 as markers for Langerhans cells and Merkel cells, respectively.
  
  
  RESULTS
  hBD-3 peptide was detected in 88% of the samples, which was confined to the gingival epithelia. In healthy control subjects, hBD-3 peptide was more frequently detected in the basal layer as compared to the patients (53% vs. 18%, p < 0.05). In patients, hBD-3 expression extended from the basal layer to the spinous layers (82%), in which hBD-3 was confined to the basal and deep spinous layers in clinically healthy tissues from patients, whereas it extended to the superficial spinous layers in pocket tissues from patients (0% vs. 50%, p < 0.05). In both groups, hBD-3 peptide was expressed not only in gingival keratinocytes, but also in Langerhans cells and Merkel cells. hBD-3 transcripts were detected in 90% of the samples and they were confined to the basal and/or suprabasal layers of gingival epithelia.
  
  
  CONCLUSIONS
  This study shows that hBD-3 is frequently expressed in gingival epithelia. The appropriate expression of hBD-3 peptide may contribute to the maintenance of periodontal homeostasis, possibly through its antimicrobial effect and promotion of adaptive immune responses.
authors.affiliation: Faculty of Dentistry, Periodontology, The University of Hong Kong, Hong Kong.
authors.forename: Qian
authors.initials: Q
authors.lastname: Lu
authors.forename: Lakshman P
authors.initials: LP
authors.lastname: Samaranayake
authors.forename: Richard P
authors.initials: RP
authors.lastname: Darveau
authors.forename: Lijian
authors.initials: L
authors.lastname: Jin
mesh_terms: D000293:Adolescent; D000328:Adult; D000890:Anti-Infective Agents / Q000032:analysis*; D018949:Antigens, CD1 / Q000032:analysis; D004848:Epithelium / Q000473:pathology; D005881:Gingiva / Q000473:pathology*; D006801:Humans; D007381:Intermediate Filament Proteins / Q000032:analysis; D053554:Keratin-20; D015603:Keratinocytes / Q000473:pathology; D007801:Langerhans Cells / Q000473:pathology; D018862:Merkel Cells / Q000473:pathology; D008875:Middle Aged; D010514:Periodontal Pocket / Q000473:pathology; D010518:Periodontitis / Q000473:pathology; D023083:beta-Defensins / Q000032:analysis*
chemical_list: D000890:Anti-Infective Agents; D018949:Antigens, CD1; C422950:DEFB103A protein, human; D007381:Intermediate Filament Proteins; C507499:KRT20 protein, human; D053554:Keratin-20; D023083:beta-Defensins