【摘要】 目的　探讨脐血造血干 /祖细胞在不同细胞因子支持的体外扩增过程中端粒酶活性的表达及意义。方法　应用PCR ELISA方法检测脐血造血干 /祖胞体外扩增前后的端粒酶活性、细胞扩增倍数及免疫表型的变化。结果　新分离的脐血CD34+细胞表达弱的端粒酶活性 ,体外培养 7d ,细胞端粒酶活性达最高 ,干 /祖细胞扩增倍数也明显增高 ,随着培养时间的延长 ,细胞分化成熟 ,端粒酶活性减低。结论　端粒酶的活性的升高与造血干 /祖细胞的扩增相一致 ;从临床应用价值来看 ,脐血CD 34+细胞体外扩增时间应以 7d内为宜 ;IL 3促分化能力大于G CSF。更多还原

【Abstract】 Objective To explore expression and significance of telomerase activity in umbilical cord blood(UCB) stem/progenitor cells during expansion in vitro with hematopoietic growth factors(HGFs). Methods The number of total nucleated cells(TNC) was counted;cellular phenotypes were analyzed with flow cytometric; telomerase activity was detected by PCR ELISA during ex vivo expansion. Results CD34 + enriched fresh UCB cells expressed a low level telomerase activity; The CD34 + cells were cultured in vitro with different HGFs combined for 7 d and the telomerase activity was upregulated to the highest point companyed with extensive stem/progenitor cells expansion but was downregulated as culture time extended. Conclusion Upregulation of telomerase activity accords with hematopoietic stem/progenitor cells amplication. The optimal expansion time in vitro is 7 d or so, and the ability of IL 3 to facilitate differentiation is higher than that of G CSF.更多还原