Comparative gene expression in hematopoietic progenitor cells derived from embryonic stem cells

Objective The aim of this study was to characterize at the molecular level the hematopoietic progenitor cells derived from rhesus monkey embryonic stem (ES) cell differentiation. Materials and Methods We purified CD34+ and CD34+CD38− cells from rhesus monkey ES cell cultures and examined the expression of a variety of genes associated with hematopoietic development, by semiquantitative polymerase chain reaction analysis. For comparison, we examined cell preparations from fresh or cultured rhesus monkey bone marrow (BM) and from mouse ES cells and BM. Results We observed a high degree of similarity in the expression patterns of these genes, with only a few exceptions. Most notably, the message of the flt3 gene was undetectable in rhesus monkey ES cell-derived CD34+ and CD34+CD38− cells, whereas substantial flt3 expression was observed in the corresponding cells from fresh BM and in CD34+ cells from cultured BM. The integrin αL and interleukin-6 (IL-6) receptor genes also were expressed in CD34+CD38− cells from BM, but there was little or no expression of these genes in CD34+CD38− cells derived from ES cells. Parallel analyses, using CD34+Lin− cells derived from murine ES cell cultures, showed no apparent expression of flt3, integrin αL, or IL-6 receptor, whereas corresponding cell preparations isolated from mouse BM expressed high levels of all of these genes. Conclusions ES cell-derived hematopoietic progenitors, both from the rhesus monkey and from the mouse, exhibited the same alterations in gene expression compared with BM-derived cells from these animals. These observations could reflect the presence of different subpopulations in the cell fractions that were compared, or they may represent altered biologic properties of ES cell-derived hematopoietic stem cells.