[Adhesion and migration of epidermal dendritic cells].
Dendritic cells are characterized by their dendritic shape, by high level of class II MHC molecules expression, by their ability to induce primary antigen-specific T cell responses and by their motility. In the skin, the most well-characterized dendritic cells are Langerhans cells (LC). LC, which originate from bone marrow are mobile messenger cells which actually carry antigens from the skin to the lymph nodes. However, the driving and regulatory mechanisms for LC motility remain poorly understood. Studies in mice have revealed that epicutaneous hapten application induced a significant accumulation of antigen-bearing dendritic cells in draining lymph nodes. But signals in addition to simple antigen binding are probably necessary for the induction of migration. The production of specific cytokines by epidermal cells has to be considered. Indeed, TNF alpha has been shown to provide one signal for LC migration. In vitro studies showed that human epidermal LC interact with the surrounding extracellular matrix (ECM) through beta 1 integrin receptors and that interaction with the ECM environment may play a crucial role in the directed emigration of LC from the epidermis. In vitro hapten treatment resulted in a stimulation of LC migration through ECM, and fibronectin and type IV and type I collagen promoted the migration of hapten-modified LC. By contrast, contact of human LC with an irritant did not increase the number of migrating cells. ECM plays some important roles in LC migration from the epidermis to the dermis and this is regulated by some of the beta 1 integrins. These results demonstrate that the regulation of LC migration is a complex phenomenon, largely dependent on factors such as ECM proteins, cell adhesion molecules, cytokines.
Staquet
M J
MJ
Laboratoire de Recherche Dermatologique, Hôpital Edouard-Herriot, Lyon, France.
D002465:Cell Movement / Q000502:physiology*; D016326:Extracellular Matrix Proteins / Q000502:physiology*; D006241:Haptens / Q000276:immunology*; D006801:Humans; D066298:In Vitro Techniques; D016023:Integrins / Q000502:physiology*; D007801:Langerhans Cells / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D016326:Extracellular Matrix Proteins; D006241:Haptens; D016023:Integrins; D014409:Tumor Necrosis Factor-alpha
Adhérence et migration des cellules dendritiques épidermiques.