Antimicrobial peptides are ancient weapons of the innate immunity. Cathelicidin antimicrobial peptides (AMPs) support the epithelial barrier against infection and are constitutively secreted in the bloodstream by immune cells. Current knowledge claims that cathelicidins are up regulated upon infection. Directly bactericidal, cathelicidins possess many additional immunomodulatory properties. Here, we show that LL-37, the human cathelicidin, is down regulated during septic shock. Furthermore, we show that these effects are not related to vitamin D serum levels, a potent inducer of LL-37 gene expression, pointing out that the mechanisms that control antimicrobial peptides activity involve multiple pathways.
- Copyright © 2013 by The American Association of Immunologists, Inc.