Histocompatibility linked immune responsiveness and restrictions imposed on sensitized lymphocytes

Delayed-type hypersensitivity (DTH) transfer to GAT was restricted by the I-A region of the major histocompatibility complex (MHC). Sensitized cells from F1 hybrid mice between responder and nonresponder strains transferred DTH to syngeneic F1 mice and to naive parental strain recipients of the responder but not of the nonresponder haplotypes. These results are interpreted to favor the postulate that the MHC-linked Ir genes exert their effects by coding for components which allow interactions between particular I region gene products and the region to form stable structures immunogenic for DTH T cells.