LL-37
LL-37 (human cathelicidin antimicrobial peptide)
Also known as: Cathelicidin
The main human cathelicidin antimicrobial peptide, central to innate immunity and wound healing, with a complex double-edged role in disease.
Overview
LL-37 is the active form of the only human cathelicidin, a key part of innate immune defense. It kills microbes directly, supports wound healing, and shapes immune responses. Its biology is genuinely double-edged: it protects against infection but is also implicated in some inflammatory and autoimmune conditions. It is a research peptide, not an approved therapy.
Mechanism of action
Disrupts microbial membranes and modulates immune cell activity, wound repair, and inflammation.
Key studies & citations
- Review2006
LL-37, the only human member of the cathelicidin family of antimicrobial peptides
Reviews the 37-residue amphipathic helix, its broad-spectrum antimicrobial activity, LPS neutralization, chemoattraction and wound re-epithelialization roles.
Biochimica et Biophysica Acta - In vitro2007
Plasmacytoid dendritic cells sense self-DNA coupled with antimicrobial peptide
LL-37 converts inert self-DNA into a trigger of interferon production in psoriasis, the basis for its double-edged role in autoimmunity.
Nature - Human2014
Treatment with LL-37 is safe and effective in enhancing healing of hard-to-heal venous leg ulcers: a randomized, placebo-controlled clinical trial
First-in-man trial in 34 patients: 0.5 mg/mL topical LL-37 raised the healing rate about sixfold versus placebo, with no safety concerns.
Wound Repair and Regeneration - Human2021
Evaluation of LL-37 in healing of hard-to-heal venous leg ulcers: a multicentric prospective randomized placebo-controlled clinical trial
Phase 2b in 148 patients: no significant improvement in healing versus placebo in the full population; a benefit appeared only in a post hoc subgroup with large wounds.
Wound Repair and Regeneration
Frequently asked questions
Is LL-37 safe to use?
It is a research peptide with a complex, double-edged biology, being both protective and, in some conditions, harmful. It is not an approved therapy.