Engraftment following T-cell-depleted marrow transplantation. I. The role of major and minor histocompatibility barriers.

These experiments describe a murine model for survival and engraftment of bone marrow transplantation across differing histocompatibility barriers. Anti-Thy-1.2 antibody and complement-treated C57BL/6 (B6) marrow was transplanted at varying cell dose levels into syngeneic (B6), major histocompatibility complex congenic (A.BY), semiallogeneic (B6AF1), and fully allogeneic (A/J) recipients. Survival was monitored and engraftment determined by hemoglobin and lymphocyte phenotype. Survival was cell-dose dependent and was equivalent in B6, A.BY, and B6AF1 recipients. Survival was poor in allogeneic A/J recipients due to bone marrow failure even at high marrow dose levels. Survival posttransplant did not always correlate with stable donor engraftment, and competitive host marrow repopulation was frequently seen in B6AF1 recipients but rarely in A.BY recipients. This repopulation could be prevented by transplanting a larger marrow dose.