Role of epidermal Langerhans cells in resistance to herpes simplex virus infection.

To investigate the role of epidermal Langerhans cells (LC) in resistance to herpes simplex virus (HSV) infection, nonadherent spleen cells taken from BALB/c mice immunized with HSV were cultured with syngeneic epidermal cells (EC) and ultraviolet light-inactivated HSV antigen. After five days of culture, T cell-dependent proliferative response was determined by 3H-thymidine incorporation. Treatment of EC with anti-Iad monoclonal antibody plus complement before cultivation prevented this proliferation, which suggested that LC induced stimulation of immune T cells. When these stimulated spleen cells were transferred to intracutaneously infected nude mice, the virus titer in the skin was reduced markedly and the formation of zosteriform skin lesions was completely inhibited. On the other hand, transfer of unstimulated cells, which were cultured with HSV antigen only or with HSV antigen and EC treated with anti-Iad monoclonal antibody plus complement, resulted in delayed viral clearance and development of the lesions. These results indicate that LC are of importance as accessory cells in the control of cutaneous HSV infection. Furthermore, Lyt 1+ T cells in the stimulated population were shown to have greater protective activity than Lyt 2+ T cells.