Experimental Study Of NOD/SCID Mice With Human Cord Blood Hematopoietie Stem Cell Transplantation

ObjectiveTo explore the high level chimerism conditions of cord blood hematopoietic stem cells engrafed in NOD/SCID mice,NOD/SCID mice model chimera was established.The persistence of engrafed humanization gene were assessed in this model.The conditions of this xenograft model of human-mice will be helpful to created human genic heredity mice model.MethodsThe study consisted of two parts.In the first step,To estimating the irradiated effectiveness,recipient mice(8-to 12-week-old NOD/SCID mice)were irradiated respectively with 400cGy(split dose 2×200cGy)or 400cGy(single does).In the second step,Mononuclear cells(MNC)were isolated from cord blood.MNC and rHuSCF were then intravenously injected into each of the irradiated recipients to establish bone marrow chimeras,rhG-CSF were subcutaneouly injected into each of the mice after +7to+14 day transplantation.White cell counts were kinesis measured after transplantation. Human CD45~+ markers on cells from murine peripheral blood were detected by FCM from 4 to16 weeks after transplantation.After 10 week,DNA was obtained from murine peripheral blood of model and the human Cart-1 was detected by PCR.ResultThe survival rate showed a remarkable different after irradiated with 400cGy (split dose 2×200cGy)or 400cGy(single does).These mice have a gradual improvement of their white cell counts from 2 to 6 weeks.Human CD45~+ were detected by Flow cytometry in peripheral blood after 4 weeks and showed a high level expression with 66%-82%in murine peripheral blood total MNC levels, after 8 weeks transplantation.Undergoing 16 weeks,CD45~+ were still at a high level(23.1%-60.3%).The DNA of human Cart-1 were found in peripheral blood of all transplant mice.ConclusionFractional total body irradiation was helpful for engraftment,which can relieve the detrimental effect on the other tissue and accelerate the their repair.2×10~8MNC from cord blood can engraft NOD/SCID mice,repopulated their hematopoietic systems successfully and long-term chimerism express a high level humanization.