Cells In Donor Grafts Research Articles

Bone marrow transplantation across major histocompatibility barriers in mice: IV. Graft-versus-host disease in TLI-conditioned mice

We studied the effect of transplanting lymphohematopoietic grafts across major histocompatibility barriers into mice conditioned with either single dose 900 rad total body irradiation (TBI), fractionated 17 × 200 rad total lymphoid irradiation (TLI, or single dose 900 rad TLI plus cyclophosphamide (TLI + CY). In all three conditioning regimens, survival following BALB c → C57BL 6 grafting was inversely related to the number of immunocompetent T cells in the donor graft. These findings show that regardless of conditioning protocol (TBI or TLI), it was not possible to protect mice from lethal GvHD when the number of T cells in donor grafts approximated those found in patient bone marrow aspirates. When T cells were eliminated from the donor graft by pretreatment with monoclonal anti-Thy 1.2 plus complement prior to injection into TBI-conditioned recipients, long-term protection from lethal GvHD was indeed possible.