Plasmacytoid Dendritic Cells in Cutaneous Disorders

Skin immune surveillance is granted by a complex contingent of sentinel innate immune cells with antigen-presenting function. The latter include Langerhans cells (LCs), multiple subsets of dermal dendritic cells (DDCs), and dermal macrophages (DMs). As for other peripheral nonlymphoid tissues, the microenvironment of the normal skin is lacking plasmacytoid dendritic cells (PDCs), a circulating DCs subset that mainly populates primary and secondary lymphoid organs. PDCs accumulation in the skin is observed in different cutaneous inflammatory disorders, including autoimmunity and viral infection. This review will summarize current knowledge on the biology of skin DCs and will highlight the functional role of PDCs in the complex microenvironment of well-characterized cutaneous disease models. © 2012 Springer Science+Business Media New York.