EFFECT OF GLUCOCORTICOIDS ON THE SYNTHESIS OF ANTIMICROBIAL PEPTIDES IN AMPHIBIAN SKIN

Gene-encoded peptide antibiotics are widespread in insects, plants and vertebrates and confer protection against bacterial and fungal infect ions, NF-kappa B is an important transcription factor for many immunit y-related mammalian proteins and also for insect immune genes, The act ivity of NF-kappa B is regulated by the interaction,vith an inhibitor, I kappa B, It was recently demonstrated that glucocorticoids induce t he synthesis of I kappa B in human cell lines, So far, all genes for p eptide antibiotics have promoter motifs with NF-kappa B binding sites, but its actual function in peptide regulation has been studied only i n insects, Here me show that glucocorticoid treatment of the frog Rana esculenta inhibits the transcription of all genes encoding antibacter ial peptides by inducing the synthesis of I kappa B alpha. These resul ts suggest that also in vertebrates peptide-mediated innate immunity i s controlled by NF-kappa B-regulated transcription. (C) 1997 Federatio n of European Biochemical Societies.