脐血CD34+细胞与单个核细胞的体外扩增特性研究

目的　探讨CD34+ 富集细胞和单个核细胞 (MNC)的体外扩增特性。方法　利用Min iMACS系统富集CD34+ 细胞 ,在相同条件下与同批MNC进行对照培养 ;观察了再次富选和MNC培养上清 (MNC SN)对CD34+ 富集细胞扩增的影响 ;并尝试了MNCCD34- 细胞的培养。结果　虽然CD34+ 富集细胞具有很高的扩增潜力 ,但在培养过程中 ,其集落密度和CD34 + 细胞含量却始终呈下降趋势 ,而MNC在培养中却出现了一个上升的趋势 ,集落密度和CD34+ 细胞含量分别由第 0天的 (4 12± 16 7) 10 5细胞和 (1.12± 0 .4 2 ) %增至第 7天的 (116 2± 5 6 6 ) 10 5细胞和 (4 .17± 1.4 4 ) % ;再次富选可以使培养过的CD34+ 富集细胞的总细胞和CD34+ 细胞扩增能力大大提高 ;MNCCD34- 细胞具有集落形成和转化为CD34+ 细胞的能力 ;MNC SN对CD34+ 富集细胞的集落形成有促进作用 ,而同时又对CD34+ 细胞有促分化作用。结论　CD34+ 富集细胞在体外大量扩增的同时存在大量分化 ,其在培养过程中产生的CD34-细胞对CD34+ 细胞的扩增有抑制作用 ;脐血MNC中大量的CD34- 细胞含有造血干 祖细胞 ,其分泌的细胞因子有促进CD34+ 细胞向较为成熟的集落形成祖细胞分化的作用。

Study on the ex vivo expansion characteristics of umbilical cord blood CD34+ cells and mononuclear cells

OBJECTIVE: To explore the ex vivo expansion characteristics of selected CD(34)(+) cells and mononuclear cells (MNC). METHODS: CD(34)(+) cells were isolated from umbilical cord blood MNC by MiniMACS system, expanded under the same conditions as that for MNC. The effects of re-isolation and the MNC supernatant (MNC-SN) on the selected CD(34)(+) cells were investigated. And the CD(34)(-) cells of MNC were cultured ex vivo. RESULTS: In the culture of selected CD(34)(+) cells, both the colony density and the proportion of the CD(34)(+) cells declined continuously with the culturing, although they presented a high proliferation potential. However, in the culture of the MNC, from day 0 to day 7, the colony density and the proportion of CD(34)(+) cells were increased from 412 +/- 167/10(5) cells and (1.12 +/- 0.42)% to 1 162 +/- 566/10(5) cells and (4.17 +/- 1.44)%, respectively. It was found that both the total cells and the CD(34)(+) cells restored expansion potential by re-isolating. CD(34)(-) cells of MNC had the ability to form colony and could transform to CD(34)(+) cells. MNC-SN can promote colony forming ability and lead to CD(34)(+) cells differentiation at the same time. CONCLUSIONS: In ex vivo culture, selected CD(34)(+) cells presented a high proliferation and differentiation potentials, and the CD(34)(-) cells produced during the cultivation had inhibition effect on CD(34)(+) cells expansion. CD(34)(-) cell population from cord blood MNC contained hematopoietic stem/progenitor cells and the cytokines secreted by CD(34)(-) cells could induce CD(34)(+) cells to more mature colony-forming cells.