Identifying who keeps watch in skin

As discussed in the accompanying commentary by Frank Nestle and Brian Nickoloff, these studies are crucial if we are to further our understanding of chronic inflammatory skin diseases, such as psoriasis, and to enhance the efficacy of vaccinations.

Detailed analysis of normal human skin enabled the authors to define two distinct populations of immune sentinel cells in the skin. The first, which was characterized by expression of CD11c, BDCA-1, HLA-DR, and CD45 was found mostly in the upper dermis and was able to stimulate T cell activation. The second, which was characterized by expression of FXIIIA and CD163 was found throughout the dermis and was unable to stimulate T cell activation. These populations correspond to immunostimulatory myeloid DCs and macrophages, respectively.-Journal of Clinical Investigation