Mouse beta-defensin 1 is a salt-sensitive antimicrobial peptide present in epithelia of the lung and urogenital tract.
One component of host defense at mucosal surfaces appears to be epithelium-derived peptides with antimicrobial activity called defensins. Human beta-defensin 1 (hBD-1) represents the first member of the beta-defensin family isolated from humans and has been implicated in the pathogenesis of cystic fibrosis. We describe in this report the isolation and characterization of a murine homolog of hBD-1 called mouse beta-defensin 1 (mBD-1). The predicted amino acid sequence shows the hallmark features of other known epithelial beta-defensins, including the ordered array of six cysteine residues. Analysis of a genomic clone of mBD-1 revealed two exons separated by a 15-kb intron. By use of fluorescence in situ hybridization, the mBD-1 gene was localized at the proximal portion of chromosome 8, the site where mouse alpha-defensins are found. Lysates from cells transfected with the mBD-1 cDNA showed antibacterial activity against gram-positive and gram-negative bacteria. mBD-1 transcripts were found in kidney, liver, and female reproductive organ tissues. In the airways, mBD-1 is expressed diffusely throughout the epithelial cells of the large proximal airways with less expression in the small distal airways and no expression in alveolar cells. The present study demonstrates that a beta-defensin potentially homologous to human beta-defensin 1 is present in the respiratory system and other mucosal surfaces in mice.
Bals
R
R
Department of Molecular and Cellular Engineering, The Institute for Human Gene Therapy, The University of Pennsylvania Medical Center, Philadelphia 19104-4268, USA.
Goldman
M J
MJ
Wilson
J M
JM
D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis*; D001483:Base Sequence; D001798:Blood Proteins / Q000032:analysis* / Q000235:genetics / Q000502:physiology; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D023082:Defensins; D005260:Female; D006801:Humans; D008168:Lung / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000032:analysis; D014566:Urogenital System / Q000276:immunology*; D023083:beta-Defensins
D000900:Anti-Bacterial Agents; D001798:Blood Proteins; C406407:DEFB1 protein, human; D023082:Defensins; D012333:RNA, Messenger; D023083:beta-Defensins