LL-37
Also: Human cathelicidin (hCAP-18), hCAP-18/LL-37, CAP-18, CAMP gene product, FALL-39
This profile summarizes research context only. It is not medical advice and does not describe how to use this compound in humans or animals — no dosing, administration, or protocols. Learn more
LL-37 is the principal peptide derived from the human cathelicidin precursor protein hCAP-18, named for its two N-terminal leucine residues and length of 37 amino acids. In the research literature it is discussed mainly as a cationic host-defense and immunomodulatory peptide, with the large majority of published work conducted in vitro and in animal models. Activities described in that literature include interactions with microbial membranes and modulation of innate-immune signaling, but the evidence is largely preclinical and requires careful interpretation due to study-design and translation limitations. RUO Report covers LL-37 for documentation and research-context purposes only, and makes no claims regarding safety, efficacy, or use.
Mechanism as described in the literature
LL-37 is described as a cationic, amphipathic peptide released by proteolytic cleavage from the C-terminal portion of the hCAP-18 precursor (encoded by the human cathelicidin gene, CAMP). In vitro studies report an alpha-helical conformation that can associate with and destabilize negatively charged microbial membranes, a mechanism commonly attributed to many cationic host-defense peptides. These observations are drawn largely from cell-free and cell-based systems.
Beyond membrane interactions, the research literature also discusses immunomodulatory roles reported in preclinical systems, including binding of bacterial lipopolysaccharide, effects on immune-cell chemotaxis, and modulation of cytokine signaling. These mechanisms are characterized mainly in isolated cell and animal models, are frequently described as concentration- and context-dependent, and how they translate to other settings remains uncertain. The descriptions here are mechanistic observations reported in the literature, not statements of effect or outcome.
Research areas
- Innate immunity and host-defense peptide biology
- Microbial membrane interactions described in vitro
- Immunomodulation and cytokine signaling reported in preclinical models
- Wound- and tissue-repair biology as studied in animal and cell systems
- Associations with inflammatory and autoimmune conditions (observational and mechanistic literature)
Documentation notes
References
Frequently asked questions
What is LL-37?+
LL-37 is the mature peptide derived from the human cathelicidin precursor hCAP-18. It is named for its two N-terminal leucine residues and its length of 37 amino acids, and it is discussed in the research literature as a host-defense and immunomodulatory peptide. RUO Report describes it for documentation and research-context purposes only.
Is LL-37 the same thing as cathelicidin?+
LL-37 is the principal peptide product of the single human cathelicidin gene (CAMP). 'Cathelicidin' generally refers to the broader precursor and peptide family, while LL-37 is the specific cleaved peptide. Naming conventions vary between sources and benefit from editorial verification against primary literature.
What is the state of the evidence for LL-37?+
Most published LL-37 research is preclinical, conducted in vitro or in animal models, and describes mechanisms rather than outcomes. Human clinical evidence is comparatively limited, and findings should be interpreted cautiously given study-design and translation limitations. No safety or efficacy conclusions can be drawn from this literature.