The innate immune system utilizes many approaches for defense against invading microorganisms, including complement-mediated lysis, engulfment, formation of neutrophil extracellular traps (NETs) and release of antimicrobial peptides (AMPs). While classically thought to be driven by adaptive immunity, the development of autoimmune diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) is increasingly associated with dysregulated innate immune pathways. An emerging theme within this literature is the contribution of AMPs to the development of autoimmune disorders. This is best exemplified in atopic dermatitis and psoriasis where the defensins and the single human cathelicidin, LL-37, may contribute to disease. Further, in the past few years, a role for LL-37 has emerged in the pathogenesis of SLE, RA, atherosclerosis and possibly other diseases. This review discusses the role of LL-37 and its murine ortholog, mCRAMP, in the modulation of immune and inflammatory pathways and their effects on autoimmune and inflammatory diseases.
- Peptides