Cytokine-mediated regulation of antimicrobial proteins

Abstract

Antimicrobial proteins are an ancient mechanism of defence against pathogens at skin and mucosal surfaces. As discussed in this Progress article, new studies identify dynamic cross-regulation between cytokines and antimicrobial peptides, which contributes to immunity and homeostasis at these sites. Antimicrobial proteins constitute a phylogenetically ancient form of innate immunity that provides host defence at skin and mucosal surfaces. Although some components of this system are constitutively expressed, new evidence reviewed in this Progress article shows that the production of certain antimicrobial proteins by epithelial cells can also be regulated by cytokines of the innate and adaptive immune systems. In particular, the effector cytokines interleukin-17 and interleukin-22, which are produced by the T-helper-17-cell subset, are emerging as crucial regulators of antimicrobial-peptide production in the gut and the lungs. This suggests that this T-cell lineage and its cytokines have important roles in skin and mucosal immunity.