Effect of human transferrin on the engraftment of allogeneic bone marrow in various strans of lethally irradiated mice.

The effect of human iron-saturated transferrin (siderophilin) on the engraftment of H-2-incompatible bone marrow and on the induction of durable allogeneic, hemopoietic chimerism was investigated in BALB/c mice grafted with bone marrow from C57BL/6 donors, and in C57BL/6 mice grafted with bone marrow from C3H/He donors. Administration of transferrin to mice after irradiation and marrow transplantation resulted in considerable protection, yielding permanent allogeneic chimerism in BALB/c mice. No effect was observed in the C57BL/6 mice in which transplantation of bone marrow from C3H/He donors provided a high survival rate even without any further treatment. Serum levels of transferrin were remarkably constant in these mice and no significant differences were seen in the circadian cycle, after lethal irradiation and at different times after marrow transfer. A modest rise of transferrin occurred only in the course of chronic graft-versus-host disease. It thus seems that the promoting effects of transferrin [Pierpaoli et al: Cell Immunol 1991; 134:225-234] depend on the murine, histoincompatible H-2 combination utilized and is not attributable to quantitative changes of transferrin levels after marrow transplantation. The utilization of more specific activity of the transferrin is thus feasible.