Antimicrobial Peptides – The Defence Never Rests

ABSTRACT The era of genomics has arrived bringing with it the promise of novel insights into the molecular basis of human health and disease. True to this promise, the field of innate immunity has seen extraordinary advances in the identification of key molecules for pathogen recognition, cellular signalling and microbicidal activity. Prominent among them in both epithelial tissues and granulocytes are the abundant and evolutionary-ancient defensins and cathelicidins. These molecules, recognized initially for their broad-spectrum antimicrobial properties, are now shown to occupy critical junctions in both the regulatory and effector arms of the innate immune system. This review will focus on these unique peptides, highlighting their structure, function and regulation in epithelial host defence, with an emphasis on clinical implications and a role as therapeutic targets.