[UV-induced regulatory T cells]

Regulatory T cells belong to a subset of T lymphocytes which suppress immune reactions in an antigen-specific fashion. Regulatory T cells play an important role in the prevention of autoimmune diseases. Ultraviolet (UV) radiation suppresses the immune system in antigen-specific fashion. This effect is mediated by UV-induced regulatory T cells. UV-induced regulatory T cells express CD4 and CD25 and upon activation release the immunosuppressive cytokine interleukin-10. Upon intravenous injection UV-induced regulatory T cells primarily migrate into the lymph nodes, explaining why they preferentially suppress sensitization. Recently, the development of regulatory T cells was demonstrated in an experimental model of photopheresis. The further characterisation of these cells will determine whether they can be applied in the future therapeutically with the ultimate aim to induce specific immunosuppression.