Alterations in epidermal handling of HSV-1 antigens in vitro induced by in vivo exposure to UV-B light.

In order to investigate the cellular interactions involved in the immune response to herpes simplex virus type 1 (HSV-1) in a murine model, an in vitro antibody induction system was developed. This comprised HSV-1-primed T cells from infected mice, trinitrophenol (TNP)-primed B cells from mice primed with TNP-coupled calf erythrocytes, and TNP-HSV-1 as antigen. When antigen-presenting cells (APC) were removed from the assay system, the induced antibody response disappeared but could be reconstituted by the addition of APC derived from the peritoneal cavity or skin of normal mice. Since HSV-1 is an epidermal pathogen, it was decided to investigate the role of skin APC in HSV-1 immunity. Skin APC from mice irradiated 3 days previously with a suberythemal dose of ultraviolet (UV)-B were found to have a decreased capacity to present HSV-1 antigen in vitro. However, the APC capacity of their peritoneal cells was unaffected. The reduction in APC capacity is not only a local effect at the irradiated site, as APC from mice exposed to UV-B with one ear protected by black electrical tape were equally affected in both ears.