非清髓同种异基因小鼠外周血造血干细胞移植模型的建立及其相关研究

目的探讨不同方式异基因外周造血干细胞移植(allo-PBHSCT)后联合供者淋巴细胞输注(DLI)对嵌合率及移植物抗宿主病(GVHD)发病率的影响。方法 C57BL/6受鼠(H-2b)接受全身照射(TBI)预处理后,4 h内分别经尾静脉(IV)或髓腔内(IBM)输注BALB/c小鼠(H-2d)经rhG-CSF动员后的外周造血干细胞3×107个,并予5×106个供鼠DLI,第2天腹腔注射200 mg/kg环磷酰胺。结果移植后第7天各组均为混合嵌合状态,IBM-PBCST-DLI组嵌合率明显高于其他各组;尾静脉移植组均出现不同程度GVHD症状,以IV-PBSCT-DLI组较为显著,而髓腔内移植组均无明显GVHD症状;IV-PBSCT-DLI组CD4+CD25+调节性T细胞(Treg)比例明显下降,髓腔内移植组则显著升高。结论经rhG-CSF动员后髓腔内注射可以成功建立非清髓性allo-PBHSCT小鼠移植模型,DLI进一步促进了供者嵌合;IBM明显降低了GVHD的发病率,其机制可能与T细胞亚群的改变有关。

Establishment of a nonmyeloablative allogeneic peripheral blood stem cell transplantation model in mice and its related study

Objective To explore the effect of different types of infusion of allogeneic hematopoietic stem cells transplantation(HSCT) combined with donor lymphocytes infusion(DLI) on chimerism rate and incidence of graft-versushost disease(GVHD).Methods Female C57BL/6 mice(H-2b,B6) as recipients received total body irradiation(TBI),followed by the tail vein infusion(VI) or intra-bone marrow infusion(IBM) of allogeneic hematopoietic stem cells(3×107) transplantation(allo-HSCT) from mobilized male BALB/c with granulocyte-colony stimulating factor(rhG-CSF) and DLI(5×106),cyclophosphamide(200 mg/kg) was injected intraperitoneally two days later.Results Mixed chimeras was detected in all groups on day 7.The rate of mixed chimeras of IV-PBSCT-DLI group was much higher than the others.The GVHD was presented in the group of transplantation by VI,in which the IV-PBSCT-DLI group was more significant.However,there was no GVHD in the group which was transplanted by IBM.CD4+CD25+ obviously declined in IV-PBSCT-DLI group while rose in the IBM-PBSCT or IBM-PBSCT-DLI group.Conclusion Mixed-chimerism can be achieved by using a nonmyeloablative TBI and CTX-based conditioning regimen in combination with infusion of peripheral blood stem cells mobilized by rhG-CSF in fully H-2-mismatched recipient mice.DLI evidently promotes the donor chimers and the incidence of GVHD is reduced remarkably.Additionally,the mechanism involved in this process is probably associated with the changes of T-cell sub-group.