Expression of human alpha-defensin 5 (HD5) mRNA in nasal and bronchial epithelial cells

Background/Aims-Human defensins are antibiotic peptides expressed in myeloi d and epithelial cells. Human alpha-defensin 5 (HDS) has been detected in P aneth cell granules in the crypts of Lieberkuhn and has recently been ident ified in the female reproductive tract. The aim of this study was to invest igate the presence of HD5 mRNA in nasal and bronchial epithelial cells. Methods/Results-Semiquantitative reverse transcription polymerase chain rea ction (RT-PCR) analysis showed that HD5 mRNA was expressed infrequently and to varying degrees in bronchial and nasal epithelial cells. In situ hybrid isation resulted in a positive signal in the epithelial layer of nasal poly ps. HD5 mRNA was locally restricted to a specific area of epithelial cells and also occurred in submucosal glands. Conclusions-HDS mRNA expression in nasal and bronchial epithelial cells is rare and seemed to be locally induced. The results indicate that HD5 might play a role in innate defence in nasal and bronchial. epithelia.