EPIDERMAL LANGERHANS-CELLS AND THEIR FUNCTION IN THE SKIN IMMUNE-SYSTEM

Objective: This article reviews the role of the epidermal Langerhans' cell in contact dermatitis and atopic dermatitis. Included in this rev iew are sections on the historical, morphologic, immunohistochemical, and electron microscopic aspects of the Langerhans' cell. Differences between freshly isolated and cultured Langerhans' cells are reviewed i n terms of cell surface markers and functional differences. The differ ent IgE binding structures on the surface of Langerhans' cells are rev iewed with discussion of their possible roles. The effects of differen t cytokines in the microenvironment are also commented upon. Other dis eases where the Langerhans' cell is important such as histiocytosis X, HIV-1 infection, and skin graft rejection are briefly reviewed. Data Sources: English literature search (1974-1994), indexing terms: Langer hans' cells, atopic dermatitis, IgE. Study Selection: The purpose of t his paper is to review the most recent knowledge of Langerhans' cell f unction and relate this to the allergist/immunologist. Results/Conclus ions: Epidermal Langerhans' cells play a central role in the immune re sponse in exhibiting multiple cell-surface receptors and secreting a v ariety of cytokines that are important in the pathogenesis of contact dermatitis, atopic dermatitis, histiocytosis X, HIV-1 infection, and s kin graft rejection.