Cathelicidin antimicrobial peptide (CAMP) (CAMP)

Human cathelicidin antimicrobial peptide (CAMP), also known as hCAP-18, is the only member of the cathelicidin family found in humans. It is synthesized as a propeptide and cleaved by proteases like proteinase 3 or kallikreins to release the active 37-amino acid peptide, LL-37 (UniProt P49913). LL-37 exhibits broad-spectrum antimicrobial activity by disrupting microbial membranes and also functions as a signaling molecule in the innate immune system (NCBI Gene 820). It promotes chemotaxis of neutrophils, monocytes, and T cells, and stimulates angiogenesis and wound healing (PMID: 30101319). Dysregulation of LL-37 is implicated in various diseases; for instance, its overexpression is a hallmark of rosacea and psoriasis, while its deficiency is linked to increased infection risk in conditions like Morbus Kostmann (PMID: 29055231). Pharmacological modulation includes the use of Vitamin D to induce its expression or the development of synthetic analogs for antimicrobial and wound-healing applications. LL-37 can also bind to self-nucleic acids, triggering toll-like receptors and contributing to autoimmune responses. In oncology, its role is complex, as it can either inhibit or promote tumor growth depending on the cancer type and microenvironment.

Other names

LL-37hCAP-18Human cationic antimicrobial protein 18FALL-39CAP-18

LL-37 acts through direct antimicrobial activity by disrupting microbial cell membranes via pore formation and through immunomodulatory pathways by binding to host receptors such as FPR2 and P2X7, which recruits immune cells and regulates cytokine production (PMID: 30101319). It also neutralizes lipopolysaccharides (LPS) and can modulate Toll-like receptor (TLR) signaling by forming complexes with nucleic acids (PMID: 29055231).