LL-37
also known as hCAP-18, FALL-39, cathelicidin antimicrobial peptide, CAMP
Human cathelicidin-derived 37-amino-acid antimicrobial peptide, the sole cathelicidin in humans. Cleaved from hCAP-18 precursor at sites of inflammation. Exhibits broad-spectrum antimicrobial activity via membrane disruption and immunomodulatory functions including cytokine modulation, autophagy induction, and chemotaxis. Active against bacteria, fungi, parasites; implicated in wound healing, cancer, and systemic inflammation networks.
At a glance
Endogenous · Secreted at inflammation sites
Primary target — Bacterial membranes · Phosphatidylserine-exposed cells [he-2026][lu-2026].
Pathway — hCAP-18 precursor → Proteinase-3 cleavage → LL-37 release → Membrane insertion/disruption.
Downstream effect — Membrane permeabilization, cytokine induction, autophagy, phagosome-lysosome fusion, chemotaxis [ahmad-2026][zhang-2026].
Origin — Endogenous human cathelicidin (37-AA fragment, residues 134–170 of hCAP-18).
| Parameter | Value |
|---|---|
| Endogenous expression | Constitutive in neutrophils, epithelial tissuesUpregulated during infection and inflammation. [pinheiro-2026] |
| Exogenous (experimental) | Dose varies by study; antimalarial ~10–50 μM in vitroNo FDA-approved exogenous formulation. |
| Plasma levels (malaria) | Elevated in infected patients and mice [he-2026]Exogenous administration reduced parasitemia in murine models. [he-2026] |
| Evidence basis | In vitro, animal models, human observational |
Reconstitution
A pure mass-to-volume utility. Enter what you have in the vial; the atlas computes the volume per dose. No prescription information.
- — Active autoimmune disease (theoretical immune dysregulation)
- 01Natural secretion
LL-37 is constitutively expressed in neutrophils and epithelial cells, cleaved from hCAP-18 by proteinase-3 at sites of infection or inflammation.
- 02Experimental formulations
Synthetic LL-37 and derivatives (e.g., SAMP-12aa) tested in vitro and animal models. Administered via topical, intraperitoneal, or intravenous routes in research settings.
- 03Stability considerations
LL-37 is resistant to pepsin degradation at gastric pH. Synthetic short peptides designed to retain this stability while reducing toxicity. [lu-2026]
Sources
of 35 rendered claims carry a resolvable citation.
- [ahmad-2026]Ahmad 2026 — Targeting Drug-Resistant Tuberculosis with Antimicrobial Peptides: Opportunities and Challenges.
journal, 2026 - [he-2026]He 2026 — LL-37 selectively targets Plasmodium-infected erythrocytes and exhibits antimalarial activity.
journal, 2026 - [lu-2026]Lu 2026 — Design and Screening of the Peptide SAMP-12aa Derived from LL-37, Which Exhibits Anti-H. Pylori Activity and Immunomodulatory Effects.
journal, 2026 - [pinheiro-2026]Pinheiro 2026 — Antimicrobial Peptides and Systemic Inflammation: A Network Analysis.
journal, 2026 - [tanabe-2026]Tanabe 2026 — LL-37 and bacterial DNA complexes in dental plaque: Implications for biofilm structure, innate immunity, and periodontal pathogenesis.
journal, 2026 - [zhang-2026]Zhang 2026 — [Mechanisms underlying the antimicrobial and immunomodulatory activities of porcine antimicrobial peptides].
journal, 2026