Effect of Pre-irradiation of Transplanted Bone Marrow Cells on the Survival of Lethally Irradiated Recipient Mice

Summary

Mice of two different strains, SAS/4 (non-inbred) and CBA (inbred), were irradiated with potentially lethal doses and then transplanted with bone marrow cells, from donors of the same strain, which had been pre-irradiated with different doses. The total number of viable stem cells (colony forming units, CFU) injected into the mice of each strain was kept constant. When unirradiated donors were used, 10⁷ bone marrow cells were injected into the SAS/4 mice and 5 × 10⁵ bone marrow cells into the CBA mice, within each strain. The 30 day survival was the same irrespective of the radiation dose given to the donors. However, it was higher in the CBA than in the SAS/4 mice. The pre-irradiation of the donor bone marrow did not modify the graft versus host (gvh) reaction in the SAS/4 mice as expressed by mortality, 31–90 days after transplantation. The mortality of the CBA mice, during this time period, was minimal, confirming its criticality as a criterion of gvh reaction.