The low-dose model of UVB-induced immunosuppression.

Recent interest in photoimmunology has led to the development of the low-dose model of UVB-induced immunosuppression, an experimental framework in which inhibition of contact hypersensitivity is associated with alterations in the morphology and the antigen-presenting function of Langerhans cells in locally irradiated skin, and with the appearance of hapten-specific T-suppressor cells in systemic circulation. This article reviews the scientific data that has been generated from the utilization of this model. It focuses particular attention on current evidence that identifies distinct epidermal cell populations as key sources of the immunosuppression evoked by low-dose UVB.