Establishment of Haploidentical Bone Marrow Transplantation Model in Nonmyeloablative Conditioning

Objective To establish the haploidentical bone marrow transplantation mouse model in nonmyeloablative conditioning,which will provide a platform for studies on inducing immune tolerance and promoting engraftment after transplantation.Methods One day before transplantation,the receptions CB6F1female mice were exposed to a dose of 450cGy total body irradiation(TBI).Then they were divided into two groups randomly,and each mouse of the experiment group was transfused with 5×107 nucleated bone marrow cells from the donor C57BL/6 male mice.Recovery of receptions hemogarm,engraftment of the sex determining gene(SRY),chimerism of the donor cells,especially the CD3+ cells,and signs of aGVHD after transplantation,were examined.Results All control mice survived and the hemogram almost recovered to normal level within thirty days after transplantation.Most control mice shown slight graft-versus-host disease.For the experiment group,the sex determining gene SRY can be detected in the peripheral blood from receptions.Chimerism of the donor cells at day 14,30 and 60 after transplantation was 23.8%,49.9%,67.6% in lymphocytes,36.9%,53.2%,51.6% in monocytes,and 19.4%,54.4%,56.9% in granulocytes.In CD3+ cells,chimerism rates were 4.4%,21.2%,and 54.4%,respectively.No significant signs of graft-versus-host disease were observed.Conclusion In the nonmyeloablative conditioning,single dose 450 cGy TBI one day before transplantation can induce immune tolerance of receptions and enable donor bone marrow cells engraftment.The chimerism of donor cells was low until the end of observation.