[Differential study on the in vivo homing potential of human hematopoietic stem/progenitor cells from different sources in xenotransplanted NOD/SCID mouse model].
OBJECTIVE
To compare the in vivo homing potential of human hematopoietic stem/progenitor cells (HS/PCs) derived from fresh umbilical cord blood (UCB), cryopreserved UCB, mobilized peripheral blood (mPB) and bone marrow (BM) in xenotransplanted NOD/SCID mouse model, and to explore the relationship between the homing potential of HS/PCs and their expression levels of membrane receptor CXCR4.


METHODS
The expression levels of membrane CXCR4 on HS/PCs were assessed by flow cytometric analysis (FACS). CFSE-labeled human HS/PCs from different sources were transplanted into irradiated NOD/SCID mice. Human CD34 cells home in bone marrow and spleen of recipient mice were determined 20 hours after xenotransplantation by FACS and the homing efficiencies were calculated. Tissue sections of the recipient mice femurs were made and the distribution of CFSE-labeled human CD34 cells were observed under fluorescence microscope.


RESULTS
The expression levels of membrane CXCR4 on CD34+ cells from fresh UCB, cryopreserved UCB, mPB and BM were (49.52 +/- 1.12)%, (46.12 +/- 2.29)%, (48.50 +/- 2.48)% and (65.39 +/- 1.27)%, respectively. The homing efficiencies of CD34+ cells from fresh UCB, cryopreserved UCB, mPB and BM in recipient mice BM were (3.00 +/- 0.44)%, (2.84 +/- 0.46)%, (4.06 +/- 0.70)% and (5.76 +/- 0.52)% , respectively. Human CD34+ cells mainly located within endosteal region of recipient mice femurs.


CONCLUSIONS
CD34+ cells from UCB express lower levels of membrane CXCR4 than those from mPB and BM. The level of membrane CXCR4 on UCB CD34+ cells is down-regulated after freezing and thawing procedures. The homing efficiency of human CD34 cells from UCB in recipient mice is lower than that of mPB and BM.
Yang
Zhou
Z
State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, CAMS & PUMC, Tianjin 300020, China.
Lu
Shi-hong
SH
Li
Yan-han
YH
Liu
Bin
B
Wang
Hui-jun
HJ
Jia
Hai-rong
HR
Zheng
Yi-zhou
YZ
D000818:Animals; D018952:Antigens, CD34; D002465:Cell Movement; D002478:Cells, Cultured; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000276:immunology / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D019718:Receptors, CXCR4 / Q000378:metabolism*; D014183:Transplantation, Heterologous
D018952:Antigens, CD34; D019718:Receptors, CXCR4