Effect of defensin peptides on eukaryotic cells: primary epithelial cells, fibroblasts and squamous cell carcinoma cell lines

Background: Although the usefulness of the antimicrobial peptides known as defensins has been suggested against oral and skin infections, possible adverse effects of the defensins on the host should be understood before clinical applications can be contemplated. Objective: In the present study, we investigated how alpha-defensin (HNP-1) and beta-defensins (hBD-1, -2, -3) affect cells including primary epithelial cells, fibroblasts and squamous cell carcinoma cell lines, SCC-9 and KB. Method: Cell proliferation was assessed by the direct cell counting and XTT assay. Results: We found that a-defensin promotes proliferation of the epithelial cells at low concentration but has a cytotoxic effect at high concentration. In contrast, beta-defensins have little effect on these cells at any concentration, suggesting that beta-defensins may have no adverse effects on the host. Conclusion: Therefore, in terms of host response beta-defensins may be more suitable antimicrobial agents for clinical applications than alpha-defensins. (C) 2004 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.