Authors:
Norval M, Hart PH
Authors notes:
Handbook of Photomedicine: Taylor & Francis; 2013. p. 111-122.
Keywords:
Ultraviolet radiation, immune response, chromophores, antigen
Abstract:
Despite considerable advances, the exact mechanism whereby UVR can lead to changes in immune responses is not entirely clear at present, and no unifying scenario has been proposed.
Several chromophores located at or near the skin surface are involved as initiators of the process following their absorption of UV photons, and then several pathways are possible, ending with the generation of a variety of antigen-specific immune regulatory cells and mediators that suppress immunity.
In this chapter, the chromophores and the production of immune mediators will be described first, followed by sections on the mechanisms involved when the antigen is applied directly to the irradiated site (termed local UV-induced immunosuppression) and when the antigen is applied to a site distant from the site of UVR (termed systemic UV-induced immunosuppression) exposure.
The beneficial and harmful consequences of the downregulation in immunity for human health are then considered before various conclusions are reached.