Role of cytokines in epidermal Langerhans cell migration

In the epidermal compartment of skin, keratinocytes (KC), Langerhans cells (LC), and their soluble products, i.e. cytokines, constitute a unique immun ologic microenvironment. KC participate in cutaneous immune responses by pr oducing various cytokines, LC, a member of the dendritic cell(DC) family, r epresent the professional antigen-presenting cells in the epidermis. Althou gh it has been demonstrated that migration of LC from skin to lymph nodes i s a critical step for the antigen presentation, molecular mechanisms for su ch an event remain unclear. Recent studies suggest that cytokines are able to modulate LC/DC migration. There is accumulating evidence that proinflamm atory cytokines including interleukin (IL)-1 and tumor necrosis factor cu p romote LC emigration from the skin, whereas the anti-inflammatory cytokine IL-10 is a counter-regulator. LC/DC express chemokine receptors, Chemokines generated from lymphatic endothelial cells and lymph node cells play a rol e in the directional migration of LC/DC into lymph nodes, This article revi ews current studies on the role of cytokines in LC/DC migration.