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 / 中华血液学杂志

ABSTRACT

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>Female NOD/SCID mice were sublethally irradiated by (60)Co gamma-ray and transplanted with BMMSCs and different ratios of UCB CD34(+) cells. From day +3 till day +42 after transplantation, 20 microl peripheral blood (PB) was collected from the retro-orbital 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.</p><p><b>RESULTS</b>Compared with transplant of UCB CD34(+) cells alone, co-transplantation of BMMSCs and UCB CD34(+)cells at ratios of 1:1, 5:1 and 10:1, (1) significantly mitigated the decrease range (P < 0.01) and led to the recovery of WBC and platelet in PB one week earlier (P < 0.05), and the difference among the three groups was not statistically significant (P > 0.05); (2) significantly enhanced hematopoietic stem cells (PB, BM and spleen cells) engraftment in recipient mice, and the effect was most pronounced at the ratio of 10:1. huCD45(+) cells in PB, BM and spleen were increased by (2.75 +/- 0.63), (3.51 +/- 0.86) and (5.18 +/- 0.57) fold, respectively (P < 0.01).</p><p><b>CONCLUSION</b>The optimal hematopoiesis reconstruction is achieved by co-transplant of UCB CD34(+) cells and BMMSCs at a ratio of 1:10.</p>