LL-37
LL-37 (Cathelicidin LL-37)
The only human cathelicidin antimicrobial peptide, LL-37 is a first-line innate immune defense molecule with broad-spectrum antimicrobial, antiviral, and immunomodulatory activity. Critical for mucosal immunity, wound healing, and defense against drug-resistant pathogens.
Mechanism of Action
LL-37 is derived from the C-terminus of the human cathelicidin protein hCAP18. It disrupts bacterial cell membranes via electrostatic interaction, neutralizes lipopolysaccharide (LPS) to prevent septic shock, and directly kills a broad spectrum of bacteria, fungi, and enveloped viruses. Beyond direct killing, it activates dendritic cells, promotes neutrophil recruitment, stimulates angiogenesis and keratinocyte migration for wound healing, and modulates TLR signaling to prevent excessive inflammation. It also has anti-biofilm activity against drug-resistant organisms including MRSA and Pseudomonas.
Health Claims & Evidence
Broad-spectrum antimicrobial activity including MRSA and drug-resistant pathogens
Antiviral activity against influenza, HIV, and respiratory viruses
Accelerates wound healing and skin repair
Prevents LPS-induced septic shock by neutralizing endotoxin
Anti-biofilm activity against chronic wound and implant infections
Immunomodulatory — reduces chronic inflammation while preserving acute response
Short-Term Effects
Reduced infection susceptibility, accelerated wound healing, improved mucosal immunity.
Long-Term Effects
Enhanced innate immune defense, reduced chronic infection burden, potential skin health benefits.
Side Effects
Injection site reactions common. High systemic doses may cause transient inflammation. Topical use generally well-tolerated.
Contraindications
Caution in autoimmune conditions — immunostimulatory effects may exacerbate. Avoid in known hypersensitivity to cathelicidin peptides.
This profile is provided for educational research only. It is not a treatment recommendation or dosing guide. Human evidence, safety information and regulatory status vary by substance. Verify primary sources and consult a qualified healthcare professional for medical decisions.
Research Papers
LL-37: the only human member of the cathelicidin family of antimicrobial peptides
Zanetti M · Biochimica et Biophysica Acta · 2004
Cathelicidin LL-37 promotes wound healing and angiogenesis
Koczulla R et al. · Journal of Clinical Investigation · 2003
Antiviral activity of cathelicidin peptides against respiratory viruses
Barlow PG et al. · PLOS ONE · 2011
Educational research only. This profile is not a treatment recommendation or dosing guide. Human evidence, safety information and regulatory status vary by substance. Consult a qualified healthcare professional for medical decisions.
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