Drug-induced tolerance to allografts in mice. IX. Establishment of complete chimerism by allogeneic spleen cell transplantation from donors made tolerant to H-2-identical recipients.

Graft-versus-host reaction (GVH) after allogeneic spleen cell transplantation was completely suppressed in an H-2-matched murine combination (AKR/J Sea [H-2k]----lethally irradiated C3H/He Slc [H-2k]) by pretreatment of the donors with recipient spleen cell antigen plus cyclophosphamide (CP). Irradiated recipients receiving cells became chimeric. In contrast to the H-2 matched combination, lethal GVH reaction could not be prevented in an H-2-mismatched fully allogeneic combination (C57BL/6 Cr Slc [H-2b]----lethally irradiated C3H/He Slc [H-2k]) by pretreatment of the donors. The results suggest that the effectors responsible for the GVH reaction were abrogated by pretreatment of the donors with allogeneic recipient spleen cells plus CP in the H-2-matched combination, but donor pretreatment failed to abrogate GVH reaction in the H-2-mismatched combination.