Global gene expression profile of human cord blood-derived CD133+ cells

Human cord blood (CB)-derived CD133(+) cells carry characteristics of primitive hematopoietic cells and proffer an alternative for CD34(+) cells in hematopoietic stem cell (HSC) transplantation. To characterize the CD133(+) cell population on a genetic level, a global expression analysis of CD133(+) cells was performed using oligonucleotide microarrays. CD133(+) cells were purified from four fresh CB units by immunomagnetic selection. All four CD133(+) samples showed significant similarity in their gene expression pattern, whereas they differed clearly from the CD133(-) control samples. In all, 690 transcripts were differentially expressed between CD133(+) and CD133(-) cells. Of these, 393 were increased and 297 were decreased in CD133(+) cells. The highest overexpression was noted in genes associated with metabolism, cellular physiological processes, cell communication, and development. A set of 257 transcripts expressed solely in the CD133(+) cell population was identified. Colony-forming unit (CFU) assay was used to detect the clonal progeny of precursors present in the studied cell populations. The results demonstrate that CD133(+) cells express primitive markers and possess clonogenic progenitor capacity. This study provides a gene expression profile for human CD133(+) cells. It presents a set of genes that may be used to unravel the properties of the CD133(+) cell population, assumed to be highly enriched in HSCs.