IN HUMAN EPIDERMIS, BETA-DEFENSIN 2 IS PACKAGED IN LAMELLAR BODIES.

• TR Number: 301
• Authors: Oren1,2, A., Ganz1, T., Liu1, L., Meerloo3, T. 1Geffen School of Medicine at University of California, Los Angeles, CA, 2Veterans Administration Medical Center West Los Angeles, Los Angeles, CA, 3University of California at San Diego School of Medicine, San Diego, CA.
• Materials Tested: EPI-200-3S, Electron microscopy (EM)-grade paraformaldehyde, Interleukin (IL-1a)

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-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.