In vivo function of Langerhans cells and dermal dendritic cells.

In the past few years there has been an explosion in the characterization of skin-resident dendritic cells (DCs). This is largely because of the development of several lines of mice with genetic alterations that allow for selective targeting of many of these subsets. There are now considerable data derived from in vivo experiments using these mice. This review focuses on the relative contribution of murine skin-resident DCs in the generation of immune responses to epicutaneous application of ovalbumin and during contact hypersensitivity. We describe a model in which the two best-characterized skin-resident DCs, langerhans cells (LCs) and Langerin(+) dermal DCs (dDCs) have distinct functions: Langerin(+) dDCs initiate and LCs suppress T cell responses.