The role of epidermal cells in the induction of delayed-type hypersensitivity to alloantigens.

Recent studies suggest that skin graft rejection and delayed-type hypersensitivity (DTH) are different manifestations of the same mechanism. In order to investigate the alloantigenicity of epidermal cells and epidermal Langerhans cells (LC), we used epidermal cell suspensions; experiments were performed to try to induce DTH to alloantigens by the subcutaneous administration of epidermal cells. Our study establishes the precise conditions for the induction of DTH response to alloantigens using epidermal cells. Transfer experiments have shown that effector cells were Thy-1+, Lyt-1+, and Lyt-2-cells. Furthermore, the experiments using congenic strains of mice and grafted skin revealed the contribution of gene products coded by MHC and non-MHC, and also the epidermal LC in the induction of DTH response.