ABSTRACT
The skin is an important target tissue for toxicity induced by chemicals, drugs, and ultraviolet irradiation. The integrated skin immune system comprises epidermal Langerhans cells, dermal dendritic cells, mast cells, tissue macrophages, and also T-lymphocytes that pass through the skin. Key players in the induction and regulation of skin-immune responses are epidermal Langerhans cells that also represent an important source of cytokines. Epidermal Langerhans cells (LC) derive from the bone marrow. An important function of LC is transport of antigen from the skin to draining lymph nodes. The chapter considers two aspects of LC characterization: evaluation of LC migration and induced alterations in phenotype. The migration of LC from the skin is necessary for skin sensitization, or at least for optimal sensitization. The migration of LC from the skin, or culture of LC with appropriate cytokines, results in a number of phenotypic modifications associated with changes in location and/or function.
