UV-B and the immune system. A review with special emphasis on T cell-mediated immunity.
The immunosuppressive activity of ultraviolet light-B (UV-B) has become a major topic of interest, especially now that there are indications of an increased exposure to UV-B on the earth's surface, caused by a decreased thickness of the ozone layer. This review indicates that the thymus-dependent immune system is a prime target for damage by UV-B. Especially the systemic effects of UV-B on T cell mediated immunity are described and analyzed with respect to the mode of action. In summary, this review demonstrated that UV-B can alter T cell mediated immune responses by different pathways in which cytokines (e.g. TNF-alpha) and other soluble mediators (e.g. cis-urocanic acid) may play a role. Effects of UV-B on the location and morphology of different cells in the skin affect functionality of the immune system. Thus, UV-B may suppress local immunity against skin tumours and skin-associated infections as well as systemic immunity against non skin-associated infectious diseases and tumours.
Goettsch
W
W
National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands.
Garssen
J
J
de Gruijl
F R
FR
van Loveren
H
H
D000818:Animals; D006801:Humans; D007108:Immune Tolerance / Q000528:radiation effects; D007109:Immunity / Q000528:radiation effects*; D015603:Keratinocytes / Q000528:radiation effects; D007801:Langerhans Cells / Q000528:radiation effects; D008407:Mast Cells / Q000528:radiation effects; D010786:Photoreceptor Cells / Q000502:physiology; D013601:T-Lymphocytes / Q000276:immunology / Q000528:radiation effects*; D014466:Ultraviolet Rays