We propose that the natural human host defense peptide LL-37 plays roles in the delicate balancing of inflammatory responses in homeostasis as well as in combating sepsis induced by certain TLR agonists.
SIC 1.84 bound both human and murine cathelicidins and was necessary and sufficient to promote covS mutant M1T1 GAS resistance to LL-37, growth in human whole blood and virulence in a murine model of systemic infection.
In fact, administration of citrullinated LL-37 plus endotoxin actually exacerbated sepsis due to the inability of LL-37 to neutralize LPS and the subsequent enhancement of systemic inflammation due to increased serum levels of IL-6.