[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 (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.


RESULTS
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).


CONCLUSIONS
The optimal hematopoiesis reconstruction is achieved by co-transplant of UCB CD34(+) cells and BMMSCs at a ratio of 1:10.
Ma
Li-Jun
LJ
Department of Hematology, Changhai Hospital, The Second Military Medical University, Shanghai 200433, China.
Hu
Xiao-Xia
XX
Zhou
Hong
H
Gao
Lei
L
Xie
Lin-Na
LN
Qiu
Hui-Ying
HY
Wang
Jian-Min
JM
D000818:Animals; D018952:Antigens, CD34; D016026:Bone Marrow Transplantation; D002478:Cells, Cultured; D036101:Cord Blood Stem Cell Transplantation; D005260:Female; D005312:Fetal Blood / Q000166:cytology; D006410:Hematopoiesis; D006801:Humans; D045164:Mesenchymal Stem Cell Transplantation; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID
D018952:Antigens, CD34