Molecular mechanisms of ultraviolet radiation-induced immunosuppression

Eur J Cell Biol. 2011 Jun-Jul;90(6-7):560-4. doi: 10.1016/j.ejcb.2010.09.011. Epub 2010 Oct 29.


Solar ultraviolet radiation (UVR) is well known for its immunosuppressive properties. UVR can suppress immune reactions both in a local and a systemic fashion. One of the major molecular mediators of photoimmunosuppression is UVR-induced DNA damage. In contrast to immunosuppressive drugs, UVR does not act in a general but antigen-specific fashion. This is due to the induction of regulatory T cells. Epidermal Langerhans cells harboring UVR-induced DNA damage appear to be essentially involved in the induction of these cells. Cytokines including interleukin (IL)-12, -18 and -23 exert the capacity to reduce UVR-induced DNA damage via induction of DNA repair. Accordingly, these cytokines prevent UVR-mediated immunosuppression. In contrast to IL-18, IL-12 and IL-23 can also inhibit the suppressive activity of regulatory T cells by a mechanism which still needs to be determined. Clarification of the molecular mechanisms underlying UVR-induced immunosuppression will help to develop new immunosuppressive therapeutic strategies by utilizing UVR-induced regulatory T cells for the treatment of immune-mediated diseases. In addition, these insights will contribute to a better understanding of photocarcinogenesis since suppression of the immune system by UVR essentially contributes to the induction of skin cancer.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Humans
  • Immune System / immunology
  • Immune System / radiation effects*
  • Mice
  • Ultraviolet Rays*