In human epidermis, beta-defensin 2 is packaged in lamellar bodies

The skin presents a mechanical, as well as an immunological barrier to infection, and displays considerable innate immune capacity. Recently, cultured human keratinocytes were described to produce and export a microbicidal peptide human beta-defensin 2 (HBD-2). Immunogold was used to label ultrathin cryosections of stimulated, cultured human epidermis. HBD-2 was found to be stored in the lamellar bodies (LBs) of the stimulated keratinocytes of the spinous layer of the epidermis. HBD-2 was also found in the intercellular space. These findings suggest that HBD-2 is released with the contents of the LBs. Along with other investigations, our findings indicate that the lipid "permeability" barrier of the skin contains antimicrobial substances.