Suppression of antibody responses to topically applied antigens by ultraviolet light irradiation. Induction of phototolerance.

C3Hf/HeN or BALB/c mice, exposed to acute ultraviolet (UV) irradiation and skin-sensitized through the irradiated skin site with soluble protein antigens, exhibit humoral tolerance to subsequent systemic challenge with antigen. We have termed this phenomenon "phototolerance" (PT). With the doses of UV radiation used, PT induction is restricted to the irradiated skin site and is observed only if sensitization is performed via the cutaneous route. PT is antigen specific and operates at the afferent level of the immune response. While single PT induction regimens result in transient humoral suppression, multiple inductions before each systemic challenge can maintain the response at low levels. The capacity to induce PT to a variety of soluble protein antigens may have potentially important clinical applications.