Intraosseus transplantation of donor-derived hematopoietic stem and progenitor cells induces donor-specific chimerism and extends composite tissue allograft survival.

We investigated the effect of the intraosseous allotransplantation of the donor-derived hematopoietic stem cells (HSC) CD90+ on chimerism induction and survival of rat hind limb transplants. Eighteen rat hind limb transplantations were performed between Lewis-Brown-Norway and Lewis rats in three groups. Isograft and allograft rejection controls received no treatment. In the experimental group, 0.8 to 1.2 x 10(6) of separated and purified CD90+ HSC cells were transplanted intramedullary into the bone marrow cavity of the recipient's tibia during opposite hind limb transplantation, without immunosuppressive therapy. Transplants from isograft group survived indefinitely. Allograft controls rejected transplants on day 7 posttransplant. The injection of separated and purified CD90+ cells of the donor origin extended survival of the transplanted limbs up to 15 days in group III. We introduced a novel method of transplantation of the CD90+ cells of the donor origin into the recipient's bone marrow cavity. This technique resulted in extended allograft survival, without immunosuppressive therapy.