Functional Specializations of Human Epidermal Langerhans Cells and CD14+ Dermal Dendritic Cells

Summary Little is known about the functional differences between the human skin myeloid dendritic cell (DC) subsets, epidermal CD207 + Langerhans cells (LCs) and dermal CD14 + DCs. We showed that CD14 + DCs primed CD4 + T cells into cells that induce naive B cells to switch isotype and become plasma cells. In contrast, LCs preferentially induced the differentiation of CD4 + T cells secreting T helper 2 (Th2) cell cytokines and were efficient at priming and crosspriming naive CD8 + T cells. A third DC population, CD14 − CD207 − CD1a + DC, which resides in the dermis, could activate CD8 + T cells better than CD14 + DCs but less efficiently than LCs. Thus, the human skin displays three DC subsets, two of which, i.e., CD14 + DCs and LCs, display functional specializations, the preferential activation of humoral and cellular immunity, respectively.