HUMAN BETA-DEFENSIN-2 IS A SALT-SENSITIVE PEPTIDE ANTIBIOTIC EXPRESSED IN HUMAN LUNG

Previous studies have implicated the novel peptide antibiotic human be ta-defensin 1 (hBD-1) in the pathogenesis of cystic fibrosis, We descr ibe in this report the isolation and characterization of the second me mber of this defensin family, human beta-defensin 2 (hBD-2). A cDNA fo r hBD-2 was identified by homology to hBD-1. hBD-2 is expressed diffus ely throughout epithelia of many organs, including the lung, where it is found in the surface epithelia and serous cells of the submucosal g lands. A specific antibody made of recombinant peptide detected hBD-2 in airway surface fluid of human lung. The fully processed peptide has broad antibacterial activity against many organisms, which is salt se nsitive and synergistic with lysozyme and lactoferrin, These data sugg est the existence of a family of beta-defensin molecules on mucosal su rfaces that in the aggregate contributes to normal host defense.