Guardians of the Epidermis: Interplay Between Skin Microbiota and Antimicrobial Peptides

The skin employs various innate strategies within the epidermis and dermis to counteract microbial pathogens. Antimicrobial peptides (AMPs) play a pivotal role as a primary line of defense during the early stages of immune response. AMPs are attributed to distinctive structural features that allow them to disrupt microbial membranes and also trigger cytokine production in host cells, facilitating cell migration, promoting proliferation, fostering maturation, and enhancing extracellular matrix synthesis. The human skin consistently produces several AMPs, such as defensins, a cathelicidin-derived 37 amino acids long peptide (LL-37), and psoriasin, with a significant amount following infection, inflammation, or injury. The influence of AMPs on the skin microbiota is still largely unexplored. Here, we summarize the correlation between skin microbiota and host AMP along with their involvement in disease prevention.