Adoptive Tolerance Transferred by Bone Marrow, Spleen, Lymph Node or Thymus Cells

Abstract

The importance of cell dose and cell type for the transfer of adoptive tolerance has been determined. Ten million bone marrow cells, from C3H mice tolerant to CBA skin grafts, are capable of transferring adoptive tolerance to irradiated C3H mice. This adoptive tolerance is specific in that CBA and C3H skin grafts are accepted but C57BL/6 skin grafts are rejected. One million “CBA-tolerant” C3H bone marrow cells are capable of transferring adoptive tolerance in 40% of the cases only. Nine million spleen or lymph node cells, in the presence of one million bone marrow cells, are as effective in transferring adoptive tolerance as 10 million bone marrow cells alone. Nine million thymus cells, in the presence of 1 million bone marrow cells, are less effective in transferring adoptive tolerance to irradiated C3H mice. The successful transfer of adoptive tolerance appears to depend on the presence of both host (C3H) and donor (CBA) cells in the transfer inoculum. Adoptive tolerance can also be transferred to irradiated recipients of a third genotype (AKR). In this case, in addition to the graft-vs.-graft tolerance which exists among the two transplanted cell populations, a graft-vs.-host tolerance develops. When lymphoid tissues from the irradiated “tolerant” AKR mice are returned to irradiated C3H mice, tolerance to the AKR antigens can be retained. The irradiated C3H mice accept AKR, CBA and C3H skin grafts. The results are interpreted to suggest that the irradiated AKR mice recover from the X-ray damage and that during this recovery the AKR lymphoid tissues become tolerant to the antigens of both transplanted (CBA and C3H) cell populations (host-vs.-graft tolerance). This indicates the existence of three lymphoid cell populations of different genotype, each proliferating in a new environment, and maintaining a mutual tolerance.