Photoimmunology - illuminating the immune system through photobiology

We review the field of photoimmunology with emphasis on immunosuppression induced by ultraviolet B radiation. Recent studies have focused on UVB-induced alterations in epidermal Langerhans cell function, resulting in a shift from Th1 to Th2 phenotype and the activation of regulatory T cells as the source of IL-10 that is central to this form of immunosuppression.