Differential expression of human beta-defensin 2 in keratinized and non-keratinized oral epithelial lesions; immunohistochemistry and in situ hybridization

Human beta -defensin(hBD)-2, an antimicrobial peptide, is produced by vario us epithelial cells. Because hBD-2 expression in the oral epithelium has no t been assessed, we investigated its localization in normal oral epithelium and epithelial lesions. hBD-2 expression was studied using immunohistochem istry and in situ hybridization on formalin-fixed, paraffin-embedded tissue sections from 30 cases of squamous cell carcinoma and 6 cases of leukoplak ia. Immunostaining for hBD-2 was more intense in hyperkeratinized than in o rtho- or nonkeratinized epithelium. In contrast, signals for hBD-2 mRNA wer e frequently stronger in non-keratinized epithelium than in hyper- or ortho -keratinized epithelium. The results suggest that keratinization in oral ep ithelium plays an important role in the biological function of hBD-2 both a t the mRNA level and in the retention of the peptide in the epithelium.