title: Antimicrobial Peptide immunity protects human nasal and auricular cartilage against infection.
abstract: BACKGROUND
  Despite being impervious to surveillance by the adaptive immune system because of its lack of vascularity, infection of the nasal and auricular cartilage after surgery such as rhinoplasty or otoplasty is rare. Why is this so? Our goal was to determine whether the expression of antimicrobial peptides provides a previously unrecognized nonepithelial layer of innate immune defense within the nasal and auricular cartilage.
  
  
  METHODS
  Seven samples of nasal septum cartilage and 2 biopsies from auricular cartilage grafts were harvested during rhinoplasty and otoplasty procedures. Ten cadaveric samples of auricular and 9 samples of nasal cartilage were also obtained. Immunohistochemical staining was directed against the human beta-defensin antimicrobial peptides (hBD) 1, 2, and 3. A semiquantitative analysis was performed to measure immunoreactivity.
  
  
  RESULTS
  All 3 human beta-defensins were detected along the perichondral line and within the cartilage matrix in the nasal and auricular samples. Areas with positive immunohistochemical staining were also detected within chondrocyte cytoplasm.
  
  
  CONCLUSIONS
  We provide the first evidence of antimicrobial peptide expression (hBD-1, -2 and -3) within the perichondrium and cartilage matrix layers of the nasal and auricular cartilage. This previously unrecognized innate immune function of perichondrocytes and chondrocytes may explain the resistance of the nasal and auricular cartilage to infection after surgical procedures despite the absence of a vascular system.
authors.affiliation: Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Queensland, Australia. pwarnke@bond.edu.au
authors.forename: Patrick H
authors.initials: PH
authors.lastname: Warnke
authors.forename: Paul A J
authors.initials: PA
authors.lastname: Russo
authors.forename: Martin
authors.initials: M
authors.lastname: Hopfenziz
authors.forename: Bodo
authors.initials: B
authors.lastname: Kurz
authors.forename: Stephan T
authors.initials: ST
authors.lastname: Becker
authors.forename: Eugene
authors.initials: E
authors.lastname: Sherry
authors.forename: Ingo
authors.initials: I
authors.lastname: Springer
authors.forename: Sureshan
authors.initials: S
authors.lastname: Sivananthan
mesh_terms: D002102:Cadaver; D019902:Chondrocytes / Q000276:immunology; D004425:Ear Cartilage / Q000276:immunology* / Q000382:microbiology; D006801:Humans; D007124:Immunoenzyme Techniques; D009300:Nasal Septum / Q000276:immunology* / Q000382:microbiology; D013506:Otologic Surgical Procedures; D012225:Rhinoplasty; D013530:Surgical Wound Infection / Q000276:immunology* / Q000382:microbiology; D023083:beta-Defensins / Q000276:immunology*
chemical_list: D023083:beta-Defensins