The effects of ultraviolet irradiation of the XXXX : alteration in immune function mediated by epidermal cells and in the course of @entity281 .

@entity778 @entity1910 @entity19 @entity2025 @entity281 @entity272
Previously, we demonstrated that Ia+ epidermal cells (EC) have @entity778 ( @entity778 ) antigen-presenting capacity in vitro and play an important role in resistance to @entity2025 in vivo. In the present study, we investigated the effects of in vivo ultraviolet (UV) irradiation of the skin on the @entity778 -immunity function of EC both in vitro and in vivo and on the pathogenesis of @entity2025 . Immune T cells cultured with EC and @entity778 antigen showed a proliferative response in vitro. Exposure of the skin to UV light 1 to 3 days before preparation of EC resulted in dose-dependent impairment of this proliferation. This UV-induced impairment of the accessory cell function of EC was accompanied by a parallel reduction of the number of Ia+ EC. We also transferred these EC-stimulated T cells to intracutaneously infected @entity19 . Immune T cells stimulated with EC obtained from irradiated @entity19 did not effectively clear @entity778 and allowed development of zosteriform @entity272 . In contrast normal-EC-stimulated immune T cells completely prevented the formation of a zosteriform @entity1910 . In addition, @entity19 irradiated with UV on shaved midflank skin 2 days before intracutaneous inoculation of @entity778 showed increased severity of @entity281 and a higher incidence of latency compared with control @entity19 . These studies indicate that in vivo UV irradiation of the skin abrogates the immune function of EC both in vitro and in vivo, and affects @entity778 pathogenesis. The implication of our results for the better understanding of the effect of UV on acute and recurrent @entity2025 is discussed.
