Pearce Daniel J, Bonnet Dominique
Hematopoietic Stem Cell Laboratory, Cancer Research UK, London Research Institute, London, UK.
Exp Hematol. 2007 Sep;35(9):1437-46. doi: 10.1016/j.exphem.2007.06.002. Epub 2007 Jul 25.
In murine hematopoietic tissue, direct repopulation experiments have demonstrated that the side population (SP) represents a remarkable enrichment of hematopoietic stem cells. Human SP has been phenotyped as negative for lineage antigens as well as CD34. However, in the 9 years since the original publication, no long-term hematopoietic reconstitution has been reported for the adult human SP/CD34(-) subset. Elevated levels of aldehyde dehydrogenase (ALDH) have been demonstrated in murine and human progenitor cells when compared to other hematopoietic cells.
Here, we report the phenotype of human cord blood SP cells. We established the technique of simultaneous phenotyping, Hoechst exclusion, and ALDH labeling on murine tissues. We then performed the simultaneous analysis of phenotype, SP, and ALDH activity on human cord blood and bone marrow cells. Finally, we analyzed the phenotype and functional potential of human cord blood ALDH(+) cells to determine whether Lin(-)/CD34(-) cells are identified via this technique.
We demonstrate that human Lin(-)/CD34(-)/ALDH(+) cells are capable of long-term repopulation. Although the SP technique identifies cells that overlap with the ALDH(+) cell population, this is restricted to the CD34(+) cell subset.
Hoechst exclusion ability does not seem to be the method of choice for the isolation of human hematopoietic stem cells.
在小鼠造血组织中，直接重建造血实验已证明侧群细胞（SP）显著富集了造血干细胞。人SP细胞已被鉴定为谱系抗原及CD34均呈阴性。然而，自最初发表以来的9年里，尚未有关于成人人类SP/CD34(-)亚群长期造血重建的报道。与其他造血细胞相比，已证实在小鼠和人类祖细胞中醛脱氢酶（ALDH）水平升高。
在此，我们报告人脐血SP细胞的表型。我们建立了在小鼠组织上同时进行表型分析、Hoechst拒染和ALDH标记的技术。然后我们对人脐血和骨髓细胞进行了表型、SP及ALDH活性的同步分析。最后，我们分析了人脐血ALDH(+)细胞的表型和功能潜能，以确定是否可通过该技术鉴定出Lin(-)/CD34(-)细胞。
我们证明人Lin(-)/CD34(-)/ALDH(+)细胞具有长期重建造血的能力。虽然SP技术鉴定出的细胞与ALDH(+)细胞群体有重叠，但这仅限于CD34(+)细胞亚群。
Hoechst拒染能力似乎并非分离人类造血干细胞的首选方法。
