LL-37
preclinicalAlso known as: Cathelicidin, hCAP-18
**Mechanism of Action** LL-37, the C-terminal active fragment of the human cathelicidin hCAP-18, exerts broad-spectrum antimicrobial activity primarily through membrane disruption via electrostatic interactions with negatively charged bacterial lipid bilayers, leading to pore formation and cell lysis. Beyond direct killing, LL-37 modulates innate immunity by chemoattracting immune cells (e.g., neutrophils, monocytes, T cells) via formyl peptide receptor-like 1 (FPRL1) and promoting cytokine release (e.g., IL-8, IL-6). It also enhances wound healing by stimulating keratinocyte migration, angiogenesis, and re-epithelialization through transactivation of epidermal growth factor receptor (EGFR) pathways. **Key Research Findings** Preclinical studies demonstrate LL-37’s efficacy against Gram-positive and Gram-negative bacteria, including multidrug-resistant strains (e.g., MRSA, *P. aeruginosa*), as well as biofilm disruption. In murine wound models, topical LL-37 accelerates closure and reduces bacterial burden. However, its therapeutic potential is limited by susceptibility to proteolytic degradation and salt sensitivity in physiological conditions. Elevated LL-37 levels are linked to autoimmune conditions (e.g., psoriasis, rosacea), suggesting context-dependent dual roles in host defense and inflammation. **Clinical Relevance** Despite over 2,400 PubMed references, LL-37 remains in preclinical development. Challenges include optimizing stability (e.g., via peptide analogs or delivery systems) and mitigating pro-inflammatory effects in chronic inflammatory diseases. Its pleiotropic actions position it as a candidate for infected wounds, cystic fibrosis, and immunocompromised states, but no clinical trials have advanced to human efficacy studies. For research purposes only — not medical advice.
Key data
C205H340N60O53Research & studies
LL-37 bound multiple domains of the SARS-CoV-2 Spike protein and inhibited its interaction with the hACE2 receptor in vitro; Up to seven LL-37 molecules were observed surrounding Spike, forming a halo-like structure that may block receptor engagement; LL-37 bound accessory proteins ORF7a and ORF8, potentially impairing their disruption of host cell processes; LL-37's interaction with ORF7a may prevent SNAP29 degradation, restoring autophagy and promoting viral clearance
LL-37 decreased endothelial cell markers and increased mesenchymal cell markers.; LL-37 reduced vascular network formation and increased cell migration.; LL-37-induced EndMT was inhibited by Akt and NF-κB inhibitors.; LL-37 may act as an EndMT inducer in atherosclerosis pathogenesis.
LL-37 acts as an immunomodulator in sepsis, influencing inflammation and vascular permeability.; Blood concentrations of LL-37 change dynamically during sepsis.; Exogenous LL-37 increases survival in mice with experimentally induced sepsis.; Stable analogs of LL-37 may advance sepsis diagnosis and therapy.
LL-37 is an endogenous peptide with antimicrobial properties and multiple biological functions in heart disease.; LL-37 regulates atherosclerosis, thrombosis, inflammatory responses, and cardiac hypertrophy.; Engineered LL-37-related peptides have been developed and shown to regulate disease development.; The review clarifies LL-37's role in heart disease and provides direction for future research.
Abstract text is unavailable; only a figure placeholder is present.; Methodology cannot be summarized.; Main result cannot be summarized.
Vitamin D (50 nM) enhances CAMP mRNA levels ~170-fold in THP-1 cells.; hCAP18/LL-37 protein increases 3-4 times in cell lysates after vitamin D stimulation.; Proteasome inhibitor MG132 further elevates hCAP18/LL-37, indicating proteasomal degradation.; Synthetic LL-37 at 1.04 μM reduces MG63 osteoblast viability but less so for THP-1 cells.
LL-37 inhibits growth of fungi such as Aspergillus, Candida, Colletotrichum, Fusarium, Malassezia, Pythium, and Trichophyton.; Key antifungal mechanisms include destruction of cell wall integrity, membrane permeabilization, induction of oxidative stress, disruption of ER homeostasis, autophagy-like structure formation, gene expression alterations, and cell cycle inhibition.; LL-37 may also function as an anti-virulence peptide, suggesting potential for drug development.
Frequently asked questions
What is LL-37?
**Mechanism of Action** LL-37, the C-terminal active fragment of the human cathelicidin hCAP-18, exerts broad-spectrum antimicrobial activity primarily through membrane disruption via electrostatic interactions with negatively charged bacterial lipid bilayers, leading to pore formation and cell lysis. Beyond direct kil
How does LL-37 work?
Human cathelicidin antimicrobial peptide with broad-spectrum antibacterial, immunomodulatory, and wound-healing activity.
What is the research status of LL-37?
LL-37 is currently classified as preclinical, with 2,546 research references on record. This is for research purposes only and is not medical advice.
What is the molecular weight of LL-37?
LL-37 has a molecular weight of approximately 4493 g/mol (formula C205H340N60O53).
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