Local recognition of histocompatibility differences in skin grafts

Studies in rabbits of skin grafts tagged with tritiated thymidine indicate a greater proliferation of endothelial cells and fibroblasts at the site of an allograft than at that of an autograft as early as the first day after grafting. It appears, therefore, that allogeneic differences can be recognized and responded to locally almost at once. Labeled nuclear material is found to be transferred from the epithelial cells of skin grafts to host cells of the adjacent tissues. A mechanism therefore exists which might effect a local transfer of information on histocompatibility differences.