Host anti-microbial response to Helicobacter pylori infection.

beta-Defensin peptides are known to be potent anti-bacterials with a wide spectrum of activity. They, therefore, represent an important aspect of innate immunity. In the present study, we have extended our understanding of the regulation of the beta-defensins in response to Helicobacter pylori (H. pylori) infection. We found elevated levels of hBD2 and hBD3 transcripts within gastric cells following infection. This was reflected by increased secretion of the corresponding peptide. The relative bactericidal potency of the beta-defensins was also assessed. Our findings show that hBD3 was the most potent peptide tested followed by hBD2 and hBD1. Relatively modest synergy between hBD1 and hBD2 was also noted. More importantly, we observed endogenous production of putative anti-microbial factors by infected gastric epithelial cells. Our study highlights the active participation of the epithelium in protection against potential pathogens.