UV-induced immunosuppressive and anti-inflammatory actions: mechanisms and clinical applications

Immunotherapy. 2009 Mar;1(2):205-10. doi: 10.2217/1750743X.1.2.205.


The introduction in 1974 of psoralens UVA (PUVA) therapy followed in 1987 by extracorporeal photopheresis (ECP) has launched UV light in medicine field. A significant number of potential mechanisms could be linked to the basic cellular UV action (i.e., DNA damage and subsequent cells apoptosis). Phagocytosis by macrophages and dendritic cells (DCs) leads, through a receptor-mediated process, to their modulation. A state of antigen-specific tolerance is induced by induction of Treg cells, inhibition of DCs, which remain at a an immature state, inhibition of production of the proinflammatory cytokines IL-2, IFN-gamma, TNF-alpha and IL-12, and induction of production of cytokines IL-10, TGF-beta and IL-1Ra. Beside cutaneous T-cell lymphoma, use of ECP remains experimental except for graft-versus-host disease, especially the chronic-resistant form. The sparing action of corticosteroids as described in studies on transplantation deserves further attention.

Publication types

  • Review

MeSH terms

  • Animals
  • Anti-Inflammatory Agents
  • Apoptosis
  • DNA Damage
  • Graft Rejection
  • Humans
  • Immunosuppression Therapy
  • Macrophage Activation
  • Organ Transplantation
  • PUVA Therapy*
  • T-Lymphocytes, Regulatory / immunology
  • T-Lymphocytes, Regulatory / metabolism
  • T-Lymphocytes, Regulatory / pathology
  • Ultraviolet Rays


  • Anti-Inflammatory Agents