Molecular mechanisms involved in the migration of epidermal dendritic cells in the skin

The murine epidermis contains two types of dendritic cells (DC), Thy-1(+) d endritic epidermal T cells (DETC) and Langerhans cells. In this review, we introduce our data obtained using a skin organ culture system to examine th e migratory capacity of DETC and Langerhans cells into the epidermis, DETC or Langerhans cells were depleted by topical application of clobetazole pro pionate (CP) solution onto the murine ears. CP-treated or untreated ear ski n was co-cultured with syngeneic (semi-syngeneic, or allogenic, in experime nts with Langerhans cells) epidermal cell suspension. We found (i) that don or DETC or Langerhans cells migrated into the CP-treated epidermis as well as into untreated epidermis, (ii) that leukosialin Ly48 recognized by monoc lonal antibody S11. and TNF-alpha strongly inhibited donor Langerhans cell migration into the epidermis. We mention other molecules that may participa te in the migration of Langerhans cells such as chemotactic cytokines, mono cyte chemoattractant protein (MCP)-1, TGF-beta and skin-homing molecule, cu taneous lymphocyte-associated antigen (CLA) on Langerhans cells.