Successful acceptance of adult liver allografts by intra-bone marrow-bone marrow transplantation.

Previously, we have shown that liver allografts obtained from the fetus or young mice are accepted when bone marrow cells (BMCs) from adult mice of the same strain are co-grafted. However, for practical clinical use, it is more convenient to obtain both BMCs and liver from the same adult donors. C57BL/6 mice were irradiated with a single high-dose irradiation or two low-dose irradiations and injected with donor BALB/c (8 weeks old) BMCs intravenously (IV-BMT) or directly into the recipient BM cavity (IBM-BMT). Liver tissues taken from the same donor were, on the same day, engrafted under the kidney capsules. Higher survival rates and more complete reconstitution of donor cells were achieved in the IBM-BMT group than in the IV-BMT group, and this was the case in both irradiation protocols. The acceptance of donor liver tissue was seen in all mice in which hematolymphoid cells were replaced by donor-type cells. The liver grafts of the reconstituted mice showed normal morphology and stained positively with anti-albumin antibody and Periodic Acid Schiff (PAs) staining, indicating that the grafted livers were accepted, had grown, and were functioning. These results demonstrate that the acceptance of allogeneic liver can be achieved by cografting donor BMCs via the IBM route.