人脐血CD34+细胞在NOD/SCID小鼠免疫重建及其抗HBV作用的初步探讨

Objective: To study the multilineage differentiation ability of human umbilical cord blood (HUCB) CD34+ cells in NOD/SCID mice and its response to H.BV. Methods: HUCB CD34+ cells were transplanted into NOD/SOD mice post-irradiated by Co60 3.5 Gy via tail vein 6×10^4 per mouse. Human cells in mice peripheral blood (PB)were detected by flow cytometry at determined time points (2, 4, 6, and 9 weeks). 4 weeks after transplanted, mice were infected HBV by human serum (contain RB V-DNA 6.8×107 copy/mL, 0.5 mL per mouse) and detected HBV-DNA level at 1, 7, 10, and 15 days. Results: Two weeks after transplanted, human cells differentiated from UCB CD34+ could be observed in NOD/SCID mice, CD3+CD8+T cells. CD3+CD4+T cells, CD19+B cells and CD56+NK cells were 18.6%. 16.1%, 13.1% and 27.8% respectively in NOD/SOD mice, the proportion of cells changed with the age of mice. All mice survive to nine weeks. After infected by HBV-DNA positive human serum, the HBV-DNA maintain 103 level till 15 days in the mice without transplanted, contrarily, HBV-DNA could only be detected at first day in mice which transplanted FIUCB CD34+ cells. Conclusion: CD34+ cells derived from HUCB cells could rebuild human immune system in NOD/SCID mouse without any stimulator; it could survive for long time and had ability to clear HBV.