Origin and migratory properties of dendritic cells in the skin

The professional antigen presenting cells of the skin, namely Langerhans cells and dermal dendritic cells, are continuously exposed to environmental stimuli. The population of antigen-carrying dendritic cells that migrates from this site to the draining lymph nodes is highly dynamic, and its density, composition and function changes as a consequence of dendritic cell recruitment and activation in tissues, as well as interactions with T lymphocytes in the specialized lymph node microenvironments. Therefore dendritic cells within the skin are the key regulators of both quantitative and qualitative aspects of immune responses to local antigenic challenge.