Immune In Vitro Research Only

LL-37: The Human Cathelicidin — Antimicrobial Defense & Immune Research

37 Amino Acids — Sole Human Cathelicidin

LL-37 is the only known human cathelicidin — derived from the hCAP-18 precursor protein and produced by neutrophils, macrophages, NK cells, and epithelial cells as a critical front-line innate immune defense. In vitro research demonstrates direct antimicrobial activity against gram-positive and gram-negative bacteria, mycobacteria, fungi, and enveloped viruses including HIV, influenza A, and SARS-CoV-2. A Phase I/II clinical trial (Mangoni et al. 2016) confirmed reduction in bacterial load and improved healing in chronic venous leg ulcers.

For in vitro laboratory research use only. Not for human consumption. All findings described are from preclinical or in vitro models.

MECHANISMS OF ACTION

In vitro and preclinical mechanistic observations

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Direct Membrane Disruption

Disrupts bacterial, fungal, and viral membranes through electrostatic interactions — forming pores causing pathogen lysis against gram-positive, gram-negative bacteria, and enveloped viruses.

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LPS Endotoxin Neutralisation

Binds and neutralises lipopolysaccharide (LPS) — preventing endotoxin-mediated systemic inflammation and the sepsis cascade.

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TLR Signalling Modulation

Regulates Toll-Like Receptor signalling, modulating both pro- and anti-inflammatory responses contextually — essential for calibrated innate immune activation.

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Anti-Biofilm Activity

Disrupts established bacterial biofilms — critically relevant in chronic wound infections where biofilm formation prevents standard antimicrobial penetration.

KEY RESEARCH DATA

Quantitative findings from published preclinical research

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Only

Human Cathelicidin

Sole member of cathelicidin family

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Virus Types Inhibited

HIV, Influenza, RSV, HSV, SARS-CoV-2

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Ph I/II

Human Clinical Trial

Chronic venous leg ulcers

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3×

LL-37 Boost by Vit-D3

Gombart et al. (2005) FASEB J

LL-37 Antimicrobial Activity — Pathogen Susceptibility Spectrum

Gram-Positive

Gram-Negative

Mycobacteria

Fungi

Enveloped Viruses

Inhibition efficacy (%) in in vitro models. Source: compiled from Mookherjee et al. (2006) J Immunol; Hsieh & Hartshorn (2022) Biomolecules.

PRECLINICAL SAFETY PROFILE

Observed tolerability data from in vitro and animal model research

90%

Tolerability (Topical)

Low Severity

15%

Local Inflammation

Low Severity

Pro-inflammatory (High Dose)

Medium Severity

Safety data reflects preclinical observations only. Human clinical safety profiles may differ substantially. For in vitro laboratory research use only. Not for human consumption.