Reduced antimicrobial peptide expression in human burn wounds.

Severely burned skin ceases to perform its natural protective role and surrenders itself as a nidus and portal for bacterial invasion. Antimicrobial peptides are part of a non-specific chemical defence system, separate from cellular and humoral immunity. Two of these peptides, human beta-defensins 1 and 2 have been recently found in skin and are produced by keratinocytes. Beta defensins have potent bactericidal activity against a wide spectrum of bacterial and fungal organisms commonly responsible for burn wound infections. To date, expression of beta defensins has not been examined in the human burn wound. Our findings demonstrate that expression of hBD-2 is greatly decreased in the burn wound whereas hBD-1 appears to be preserved. These results may have important implications in the pathogenesis and treatment of invasive burn sepsis.