New strategies for BMT and organ transplantation.

Bone marrow transplantation (BMT) is now one of the most powerful strategies for the treatment of hematologic disorders (leukemia, aplastic anemia, etc), congenital immunodeficiencies, metabolic disorders, and also autoimmune diseases. Using various autoimmune-prone mice, we have previously shown that conventional allogeneic (allo) BMT can be used to treat a range of autoimmune diseases. We have very recently established new strategies for BMT and organ grafts. For BMT, to minimize the contamination of BMCs with T cells from the peripheral blood, we developed, using cynomolgus monkeys, a "Perfusion Method" to replace the conventional aspiration method for collecting bone marrow cells (BMCs). We injected the BMCs collected this way directly into the bone marrow cavity of recipients that had received fractionated irradiation (intra-bone marrow [IBM] injection). This "IBM-BMT" was found to be effective in treating autoimmune diseases in radiation-sensitive and chimeric-resistant MRL/lpr mice. in addition, this strategy was found to be applicable for the transplantation of organs, such as the skin and pancreas islets in mice and rats. We believe that these strategies for BMT and organ transplantation herald a new era in transplantation.