Immunity to herpes simplex virus type 2: viral antigen-presenting capacity of epidermal cells and its impairment by ultraviolet irradiation.

Ia+ epidermal cells (EC) had accessory cell function for herpes simplex virus type 2 (HSV-2)-induced T cell proliferation of immune lymph node cells (LNC). The EC-mediated virus-induced proliferative response of immune LNC was inhibited by ultraviolet B (UVB) irradiation. When EC were pulsed with viral antigen before UVB irradiation, the response was partially restored by addition of epidermal cell-derived thymocyte-activating factor (ETAF). Although normal EC secreted prostaglandin E2, the levels secreted by UVB-irradiated EC were significantly reduced, and the UVB-induced suppression of the proliferative response of immune LNC was not corrected by indomethacin. Soluble factor(s) that suppresses proliferation was generated in supernatants from cultures containing UVB-irradiated but not nonirradiated EC. Sephadex chromatography revealed the presence of factors differentially modulating the proliferative response of HSV-stimulated immune LNC and concanavalin A-stimulated normal lymphoid cells.