Abstract:

Abstract:Objective
 To establish rat model of immune tolerance induced in embryonic stage and to explore the possibility of replacing for human leukocyte antigen （HLA ）matching in hematopoietic stem cell transplantation.Methods The rats were randomly divided into four groups：induced tolerance group,control group,irradiation-transplantation group and irradiation group.Each group had 20 Wistar rats and 20 SD rats.Host female Wistar rats’ peripheral blood mononuclear cells were injected in yolk sac of SD rats during pregnancy to induce immune tolerance.The host female Wister rats were irradiated with lethal dose and accepted bone marrow transplantation from the induced mature male offspring.The survival and the graft- versus- host disease（GVHD） were observed after transplantation.Meanwhile the skin was used to observe the engraftment of solid organ.Results The 30 d　survival rate of the rats accepted the bone marrow of the immune tolerant donor(86.7%)  was significantly longer  than that in control group (0%)(P<0.01),and there was no pathological GVHD occurred. While in control group,the incidence of GVHD was clearly visible.The skin engraftment rate between the host and the immune tolerant donor in induced tolerance group was significantly higher than that of non-related rats (84.6% vs 0%).Conclusion The induction of immune tolerance in embryo can cross the HLA barrier and offer a good donor for hematopoietic stem cell transplantation and solid organ transplantation

Key words:  embryo;immune tolerance;transplantation