Ultraviolet radiation, resistance to XXXX , and vaccination responses.

@entity1 @entity630 @entity1956 @entity19 @entity566 @entity281 @entity166 @entity272 @entity792
Exposure to ultraviolet (UV) radiation, as in sunlight, can modulate immune responses in animals and @entity1 . This immunomodulation can lead to positive health effects especially with respect to certain @entity792 and @entity566 . However, UV-induced immunomodulation has also been shown to be deleterious. Experimental animal studies have revealed that UV exposure can impair resistance to many infectious agents, such as bacteria, parasites, viruses, and fungi. Importantly, these effects are not restricted to @entity272 , but also concern @entity281 . The real consequences of UV-induced immunomodulation on resistance to @entity166 are not known for @entity1 . Risk estimations have been performed through extrapolation of animal data, obtained from infection models, to the @entity1 situation. This estimation indicated that UV doses relevant to outdoor exposure can impair the @entity1 immune system sufficiently to have effects on resistance to infections. To further quantify and validate this risk estimation, data, e.g., from @entity1 volunteer studies, are necessary. Infection models in @entity1 are not allowed for ethical reasons. However, vaccination against an @entity166 evokes a similar immune response as the pathogen and thereby provides an opportunity to measure the effect of UV radiation on the immune system and an estimate of the possible consequences of altered resistance to infectious agents. Effects of controlled UVB exposure on immune responses after @entity1956 vaccination have been established in @entity19 and @entity1 volunteers. In @entity19 , cellular and @entity630 -associated humoral immune responses to @entity1956 were significantly impaired, whereas in @entity1 volunteers no significant effect of UVB on these responses could be found. Preliminary data indicate that cytokine polymorphisms might be, at least in part, responsible for interindividual differences in immune responses and in susceptibility to UVB-induced immunomodulation. In addition, adaptation to UV exposure needs to be considered as a possible explanation for the difference between @entity19 and @entity1 that was observed in the @entity1956 vaccination model.
