Enhancement of allogeneic hematopoietic stem cell engraftment and prevention of GVHD by intra-bone marrow bone marrow transplantation plus donor lymphocyte infusion.

We examined the effect of intra-bone marrow (IBM)-bone marrow transplantation (BMT) in conjunction with donor lymphocyte infusion (DLI) on the engraftment of allogeneic bone marrow cells (BMCs) in mice. Recipients that had received 6 Gy of radiation completely rejected donor BMCs, even when IBM-BMT was carried out. However, when BMCs were IBM injected and donor peripheral blood mononuclear cells (PBMNCs) were simultaneously injected intravenously (DLI), donor cell engraftment was observed 7 days after BMT and complete donor chimerism continued thereafter. It is of interest that the cells of recipient origin did not recover, and that the hematolymphoid cells, including progenitor cells (Lin-/c-kit+ cells) in the recipients, were fully reconstituted with cells of donor origin. The cells in the PBMNCs responsible for the donor BMC engraftment were CD8+. Recipients that had received 6 Gy of radiation, IBM-BMT, and DLI showed only a slight loss of body weight, due to radiation side effects, and had no macroscopic or microscopic symptoms of graft-versus-host disease. These findings suggest that IBM-BMT in conjunction with DLI will be a valuable strategy for allogeneic BMT in humans.