Successful bone marrow transplantation by bone grafts in chimeric-resistant combination

It has been shown that the bone marrow cells (BMCs) of DBA/2 mice do not readily take in bone marrow from C57BL/6 mice, even if more than 5 x 10(6) cells are injected. In this paper, we show that such chimerism resistance can be overcome by cografting DBA/2 bones from which the hematopoietic cells have been removed but in which the stromal cells remain. C57BL/6 mice reconstituted with BMCs plus bones of DBA/2 mice survive significantly longer than C57BL/6 mice reconstituted with DBA/2 BMC alone. In the former, not only the hematolymphoid cells but also the stromal cells are replaced by donor-type cells, whereas in the latter, the donor hematolymphoid cells are rejected. These findings indicate that the stromal cells in the engrafted bones play a crucial role in the prevention of graft rejection in bone marrow transplantation.