UVA-induced immune suppression in human skin: protective effect of vitamin E in human epidermal cells in vitro

• Published in: British journal of dermatology (1951) Vol. 134; no. 1; pp. 77 - 84
• Main Authors: CLEMENT-LACROIX, P., MICHEL, L., MOYSAN, A., MORLIERE, P., DUBERTRET, L.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-01-1996; Blackwell
• Subjects: Adolescent; Adult; Antigen Presentation - radiation effects; Biological and medical sciences; Cell Culture Techniques; Cell Division - immunology; Epidermis - drug effects; Epidermis - immunology; Epidermis - radiation effects; Female; General and cellular metabolism. Vitamins; Humans; Immune Tolerance - drug effects; Immune Tolerance - radiation effects; Langerhans Cells - immunology; Lipid Metabolism; Lymphocyte Activation - drug effects; Lymphocyte Activation - radiation effects; Lymphocytes - immunology; Medical sciences; Middle Aged; Oxidation-Reduction; Pharmacology. Drug treatments; Thiobarbiturates - metabolism; Ultraviolet Rays; Vitamin E - pharmacology; Human; Immunoprotection; Cell culture; Oxidative stress; Immunosuppression; UVA radiation; Medium effect; Vitamin; Phototoxicity; Epidermis; α-Tocopherol; In vitro
• ISSN: 0007-0963; 1365-2133
• DOI: 10.1046/j.1365-2133.1996.d01-732.x

Summary
UVA (320–400nm) radiation damage to membranes, proteins, DNA and other cellular targets is predominantly related to oxidative processes. In the present study, we demonstrated that cutaneous UVA‐induced immunosuppression can be related, at least in part, to the appearance of these oxidative processes. The UVA‐induced oxidative processes in freshly isolated epidermal cells were monitored by measuring the thiobarbituric acid reactive substances (TBARS) as an index of peroxidation. The in vitro immunosuppressive effects of UVA were demonstrated by measuring the allogeneic lymphocyte proliferation induced by epidermal cells or purified Langerhans cells in the mixed epidermal cell–lymphocyte reaction (MECLR). In addition, the effects of a potent antioxidant (vitamin E) on these two UVA‐induced processes were analysed. Our results showed that the antigen‐presenting function of Langerhans cells measured in the MECLR is dose‐dependently decreased by UVA radiation (up to 20 J/cm2). Overnight incubation of epidermal cells with vitamin E (400 μmol/1) before irradiation partially protected epidermal cells from the immunosuppressive effects of UVA radiation, and decreased TBARS release into the supernatant (a decrease of 35% compared with a control without vitamin E). Our results suggest that UVA radiation may alter cellpresenting antigen function partly via the generation of reactive oxygen species which trigger peroxidative processes, and these data contribute to the understanding of the role of oxidative mechanisms in immune suppression induced by UVA radiation. Our in vitro model can be used to quantify UV‐mediated epidermal cell damage and the degree of immune photoprotection provided by various agents.