Fetal liver cell transplantation in various murine models.

Allogeneic fetal liver cell transplantation has been shown to be able to reconstitute lymphopoietic systems of mice when these systems are defective or destroyed. Lethally irradiated mice or mice with inherited severe combined immunodeficiency disease (SCID) were grafted with 14 days gestation allogeneic fetal liver cells, then subjected to a follow-up for the immune tolerance to the donor and the normal or subnormal immune reconstitution allowing prevention of diabetes in NOD mice or cure of leukemia in AKR mice and of immunodeficiency in SCID mice. Briefly, when normal CBA mice were lethally irradiated and then grafted with allogeneic fetal liver cells from Balb/c mice, a specific immune tolerance was induced to donor skin grafts. Unrelated skin grafts were rejected and a response to antigens was observed in these chimeras. However, despite the capacity to develop hyperacute rejection of skin allografts, following hyperimmunization, these chimeric mice did not produce anti-H2 cytotoxic antibodies. In SCID mice (CB17), the immune reconstitution occurred when mice were grafted with allogeneic (C57/B16) as well as with syngeneic fetal liver cells. Human cells were found in SCID mice following implantation of human fetal liver and thymus cells. When NOD mice were irradiated, then grafted with allogeneic fetal liver cells, a large part of donor cells were found in NOD recipients, correlating with a low incidence of diabetes. Leukemic AKR mice grafted with allogeneic fetal liver cells had virtually no leukemia relapse, suggesting a strong graft-versus-leukemia effect following such a transplant.