LL-37

Cathelicidin Antimicrobial Peptide LL-37

Evidence & Status

  • Preliminary / Experimental
  • Preliminary

At a Glance

The only known human cathelicidin antimicrobial peptide, naturally produced by immune cells, skin, and mucosal surfaces as part of the innate immune defense. Studied for its broad-spectrum antimicrobial activity, wound healing support, and immunomodulatory role in host defense.

Plain English

Researchers study LL-37 because it is the body's own natural antibiotic peptide — part of the innate immune system's immediate defense against bacteria, fungi, and viruses. Scientists are interested in its ability to disrupt microbial membranes, prevent biofilm formation, recruit immune cells to sites of infection, and modulate the inflammatory response. With antibiotic resistance recognized as a growing global challenge, human antimicrobial peptides like LL-37 are of considerable research interest as potential templates for new anti-infective approaches.

Overview

The only known human cathelicidin antimicrobial peptide, generated by proteolytic cleavage of the precursor protein hCAP18. A key component of innate immunity, produced by neutrophils, epithelial cells, and macrophages. Disrupts bacterial cell membranes, neutralizes LPS, inhibits biofilm formation, and stimulates wound healing via keratinocyte migration. Also being investigated for anti-cancer properties.

Research Summary

LL-37 is the only known human cathelicidin antimicrobial peptide and is generated from hCAP18. Native LL-37 contributes to innate-immunity biology and has antimicrobial, endotoxin, biofilm, wound-related, and cancer-context research applications. The current evidence package is primarily mechanistic and preclinical; native LL-37, modified analogues, delivery systems, and the mouse homologue CRAMP are not interchangeable evidence entities. Human efficacy and a standardized clinical protocol are not established here.

Research Areas

  • Antimicrobial & anti-biofilm
  • Wound healing
  • Innate immune modulation
  • Anti-cancer
  • Endotoxin neutralization

Safety & Risks

Serious Risks

  • Pro-inflammatory at high concentrations; paradoxical immune activation; cancer studies show context-dependent pro/anti-tumor effects

Reported Side Effects

  • Topical: mild burning/stinging
  • Injectable: pain at injection site
  • Potential pro-inflammatory effects at high doses
United States
Research only
United Kingdom
Research only
Australia
Research only
Canada
Research only

Citations & Sources