Porcine antimicrobial peptides: New prospects for ancient molecules of host defense

Antimicrobial peptides (AMPs) are small, endogenous, polycationic molecules that constitute a ubiyuitous and significant component of innate immunity. These natural antibiotics have broad microbicidal activity against various bacteria, fungi, and enveloped viruses. Because most AMPs kill bacteria by physical disruption of cell membranes, which may prevent microorganisms fr om developing resistance against these agents, they are being explored as p ossible alternatives to conventional antibiotics. Pigs, like many other mam mals, produce an impressive array of AMPs, which are synthesized predominan tly by host leukocytic phagocytes or mucosal epithelial cells. Currently, m ore than a dozen distinct porcine AMPs have been identified and a majority belongs to the cathelicidin family. This review briefly summarizes recent a dvances in porcine AMP research with an emphasis on the diverse biological functions of each peptide. Mechanisms of action of these AMPs and their rol e in the resistance to infections are considered. Finally, the current stat us of pharmaceutical and agricultural uses of AMPs as well as future prospe cts for their application in the food animal industry is discussed.