Endogenous Immune Defense
LL-37 (cathelicidin) is the only human cathelicidin antimicrobial peptide. It forms an amphipathic alpha-helical structure that physically disrupts bacterial cell membranes through two mechanisms: the toroidal pore model (inserting into and perforating the lipid bilayer) and the carpet model (coating and dissolving the membrane surface).
Beyond direct antimicrobial action, LL-37 serves as an immune modulator—recruiting neutrophils, enhancing macrophage phagocytosis, and promoting wound healing via angiogenesis.
Therapeutic Applications
Research interest in LL-37 centers on biofilm-resistant infections (where conventional antibiotics fail), chronic wound healing, and immune modulation in conditions like Crohn's disease where mucosal immunity is compromised.
LL-37 deficiency correlates with increased susceptibility to infections, poor wound healing, and chronic inflammatory conditions. Supplementation via SubQ injection or topical application is under investigation.