Induction of H-2-restricted contact hypersensitivity by hapten-derivatized skin grafts. Evidence that the immunogenic signal includes H-2 determinants derived from the skin.

Contact hypersensitivity has been induced in mice grafted with skin derivatized with dinitrofluorobenzene. At optimal concentration of epicutaneously applied hapten (0.02%), it was found that syngeneic, but not allogeneic, skin grafts induced sensitivity. Genetic identity of graft donors and recipients at class I or class II loci of H-2 was essential and sufficient for induction of sensitization. The fact that Ia antigens on haptenated grafts restricted the response indicates that Langerhans cells, the only Ia-bearing cells of the normal murine epidermis, function as antigen presenting cells. Nonvital syngeneic, but not allogeneic, grafts were able to induce contact hypersensitivity, so it is proposed that the immunogenic signal derived from haptenated skin grafts consists of hapten and a class I or class II MHC gene product, but need not necessarily be delivered on a viable cell.