title: Isolation and characterization of human beta -defensin-3, a novel human inducible peptide antibiotic.
abstract: The growing public health problem of infections caused by multiresistant Gram-positive bacteria, in particular Staphylococcus aureus, prompted us to screen human epithelia for endogenous S. aureus-killing factors. A novel 5-kDa, nonhemolytic antimicrobial peptide (human beta-defensin-3, hBD-3) was isolated from human lesional psoriatic scales and cloned from keratinocytes. hBD-3 demonstrated a salt-insensitive broad spectrum of potent antimicrobial activity against many potentially pathogenic microbes including multiresistant S. aureus and vancomycin-resistant Enterococcus faecium. Ultrastructural analyses of hBD-3-treated S. aureus revealed signs of cell wall perforation. Recombinant hBD-3 (expressed as a His-Tag-fusion protein in Escherichia coli) and chemically synthesized hBD-3 were indistinguishable from naturally occurring peptide with respect to their antimicrobial activity and biochemical properties. Investigation of different tissues revealed skin and tonsils to be major hBD-3 mRNA-expressing tissues. Molecular cloning and biochemical analyses of antimicrobial peptides in cell culture supernatants revealed keratinocytes and airway epithelial cells as cellular sources of hBD-3. Tumor necrosis factor alpha and contact with bacteria were found to induce hBD-3 mRNA expression. hBD-3 therefore might be important in the innate epithelial defense of infections by various microorganisms seen in skin and lung, such as cystic fibrosis.
authors.affiliation: Clinical Research Unit, Department of Dermatology, University Hospital Kiel, Schittenhelmstrasse 7, 24105 Kiel, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Harder
authors.forename: J
authors.initials: J
authors.lastname: Bartels
authors.forename: E
authors.initials: E
authors.lastname: Christophers
authors.forename: J M
authors.initials: JM
authors.lastname: Schroder
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents; D004847:Epithelial Cells / Q000502:physiology; D006801:Humans; D007113:Immunity, Innate; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D012879:Skin Physiological Phenomena; D013211:Staphylococcus aureus / Q000187:drug effects / Q000648:ultrastructure; D014018:Tissue Distribution; D023083:beta-Defensins / Q000302:isolation & purification* / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; C422950:DEFB103A protein, human; D023083:beta-Defensins