间充质干细胞与人脐血CD34+细胞共移植对NOD/SCID小鼠造血重建的影响

目的 观察间充质干细胞(MSC)与不同比例脐血CD34+细胞共移植对NOD/SCID小鼠造血重建的影响,明确MSC与脐血CD34+细胞共移植的最适数量.方法 给60Coγ射线照射的雌性NOD/SCID小鼠共移植人MSC和不同比例的脐血CD34+细胞,观察共移植后42 d内小鼠外周血白细胞和血小板变化,并于移植后42 d处死小鼠,用流式细胞术检测外周血、骨髓和脾脏人源细胞含量.结果 与单纯脐血CD34+细胞移植相比较:①脐血CD34+细胞与1、5和10倍数量的MSC共移植时,可明显减轻外周血白细胞和皿小板的下降幅度(P<0.01),提前1周使白细胞和血小板恢复至正常水平(P<0.05),三组间差异无统计学意义(P>0.05);②MSC与不同比例的脐血CD34+细胞共移植均可明显提高外周血、骨髓和脾脏造血细胞植入率.比例为10:1时,外周血、骨髓和脾脏中的人源细胞(huCD45+细胞)含量分别增加了(2.8±0.6)倍、(3.5±0.9)倍和(5.2±0.6)倍,增加倍数差异均有统计学意义(P<0.01),达到了最佳的植入效果.结论 脐血CD34+细胞与10倍数量的MSC共移植可达到最佳的促进造血重建作用.

Study on hematopoiesis reconstitution by co-transplant of human bone marrow mesenchymal stem cells and umbilical cord blood CD34+ cells at different ratios in NOD/SCID mice

Objective To study the effect of co-transplant of human bone marrow mesenchymal stem cells (BMMSCs) and umbilical cord blood (UCB) CD34+ cells on hematopoiesis reconstruction in NOD/SCID mice and to investigate the optimal proportion between the two kind of cells. Methods Female NOD/SCID mice were sublethally irradiated by 60Co γ-ray and transplanted with BMMSCs and different ratios of UCB CD34+ cells. From day +3 till day +42 after transplantation, 20μl peripheral blood (PB) was collected from the retro-orhital plexus of mice weekly, and the variations of WBC and PLT were counted. Mice were sacrificed 42 days after transplantation, and human CD45 positive (huCD45+) cells in PB, BM, and spleen were detected by flow cytometry. Results Compared with transplant of UCB CD34+ cells alone, cothe decrease range (P< 0.01)and led to the recovery of WBC and platelet in PB one week earlier(P