The Neuropeptide α‐MSH in Host Defense

: The presence of the ancient peptide a-melanocyte-stimulating hormone (α-MSH) in barrier organs such as gut and skin suggests that this potent anti-inflammatory molecule may be a component of the innate host defense. In tests of antimicrobial activities, α-MSH and its fragment KPV showed inhibitory influences against the gram-positive bacterium Staphylococcus aureus and the yeast Candida albicans. Anti-tumor necrosis factor and antimicrobial effects of a-MSH suggest that the peptide might likewise reduce replication of human immunodeficiency virus (HIV). Treatment with α-MSH reduced HIV replication in chronically and acutely infected human monocytes. At the molecular level, α-MSH inhibited activation of the transcription factor NF-κB known to enhance HIV expression. α-MSH that combines antipyretic, anti-inflammatory, and antimicrobial effects could be useful in the treatment of disorders in which infection and inflammation coexist.