LL-37
Immune Modulationaka Human cathelicidin · hCAP-18 C-terminal peptide · Cathelicidin antimicrobial peptide (CAMP)
Overview
LL-37 is the only human cathelicidin antimicrobial peptide — an endogenous host-defense molecule that sits at the intersection of innate immunity, biofilm control, inflammation, and tissue repair. It has both protective and potentially pro-inflammatory effects, so its literature is unusually dual-sided.
Mechanism
LL-37 kills or suppresses microbes, disrupts biofilms, and also acts as a host-signaling peptide. Mechanistically, published work links LL-37 to receptor systems including EGFR, FPR2, and P2X7, helping explain effects on epithelial migration, wound closure, immune-cell recruitment, autophagy, and mediator release. Excess or prolonged exposure has been implicated in rosacea-like inflammation, UVB-amplified inflammatory responses, mast-cell activation, and inflammasome signaling — so context, dose, tissue, and duration matter.