title: All-trans retinoic acid induces functional maturation of epidermal Langerhans cells and protects their accessory function from ultraviolet radiation.
abstract: Retinoids provide some protection against ultraviolet radiation-induced skin damage. We have previously shown that topical all-trans retinoic acid prevents ultraviolet light from reducing the density of epidermal Langerhans cells in the epidermis but does not inhibit the development of immunosuppression to a locally applied contact sensitizer. We therefore investigated the ability of all-trans retinoic acid to modulate Langerhans cell induction of allogeneic T-cell proliferation in the mixed epidermal cell lymphocyte reaction. Langerhans cells isolated from all-trans retinoic acid-treated mice induced an enhanced mixed epidermal cell lymphocyte reaction. This is similar to Langerhans cells cultured with granulocyte-macrophage colony stimulating factor. Retinoic acid treatment also enhanced the allogeneic cell-stimulating capability of Langerhans cells isolated from ultraviolet-irradiated mice. Langerhans cells from all-trans retinoic acid-treated, ultraviolet-irradiated mice which were "matured" by 3 days in culture induced a larger mixed epidermal cell lymphocyte reaction than mice treated with solvent and ultraviolet irradiation. Thus all-trans retinoic acid treatment of mice causes Langerhans cell maturation and inhibits ultraviolet light from reducing their density or impairing their allogeneic cell-stimulating capacity. However, these mice remained immunosuppressed upon application of a contact sensitizer to irradiated or unirradiated skin. It is thus likely that, whereas all-trans retinoic acid protects local Langerhans cell numbers and function, it does not inhibit the production of an ultraviolet radiation-induced photoproduct which causes immunosuppression.
authors.affiliation: Department of Dermatology, University of Sydney, Royal Prince Alfred Hospital, New South Wales, Australia.
authors.forename: K J
authors.initials: KJ
authors.lastname: Dunlop
authors.forename: G M
authors.initials: GM
authors.lastname: Halliday
authors.forename: R S
authors.initials: RS
authors.lastname: Barnetson
mesh_terms: D000818:Animals; D015704:CD4 Antigens / Q000032:analysis; D002452:Cell Count / Q000187:drug effects / Q000528:radiation effects; D002478:Cells, Cultured; D016922:Cellular Senescence; D003877:Dermatitis, Contact / Q000517:prevention & control; D000078404:Epidermal Cells; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D007801:Langerhans Cells / Q000187:drug effects* / Q000502:physiology / Q000528:radiation effects*; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D008807:Mice, Inbred BALB C; D010853:Picryl Chloride; D014212:Tretinoin / Q000494:pharmacology*; D014466:Ultraviolet Rays
chemical_list: D015704:CD4 Antigens; D014212:Tretinoin; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D010853:Picryl Chloride