Serum and cell-mediated responses in tolerance and hyperacute rejection of transplanted mouse hearts

MHC-disparate recipients that have been sensitized intradermally or via a skin graft reject transplanted mouse hearts hyperacutely. However, transplant survival is prolonged after intraperitoneal or intravenous sensitization. These opposite in vivo events are not correlated with differences in serum antibody responses, but the correlation of hyperacute rejection with delayed-type hypersensitivity is fairly strong. Prolonged survival of heart transplants is probably related to suppressor cells, and adoptively transferable in MHC-compatible combinations. Intraperitoneal or intravenous sensitization, while prolonging survival of heart transplants, causes hyperacute rejection of skin grafts, indicating the importance of the target; it is probably related to differences in the establishment of a blood supply.