Technical Details:
The human CD34+/CD38-/Lin- cell subset comprises ~1-10% of the CD34+ cell population and includes few of the less primitive hematopoietic (lineage-committed) progenitor cells (HPCs), yet contains most of the primitive in vivo engrafting (lympho-) hematopoietic stem cells (HSCs). We analyzed gene expression in CD34+/CD38-/Lin- cell populations isolated from bone marrow (BM), placental/umbilical cord blood (CB), and mobilized peripheral blood stem-progenitor cell (PBSC) preparations from normal human donors. 4746 genes were expressed in CD34+/CD38-/Lin- cells from all three tissues. We also isolated and determined the genes expressed in the stem cell-depleted, progenitor cell-enriched CD34+/[CD38/Lin]++ cell population from each tissue. Comparison of the transcripts expressed in CD34+/CD38-/Lin- (HSC-enriched) versus CD34+/[CD38/Lin]++ (HSC-depleted) cells from each tissue yielded 81 genes that were over-represented and 90 genes under-represented in the transcriptome (i.e., global gene expression profile) of all three of the CD34+/CD38-/Lin- cell populations. These transcripts include a number of known genes (e.g., transcription factors, receptors, and signaling molecules) and unknown genes that may play roles in survival, self-renewal, differentiation and/or migration/adhesion of human HSCs. Notably, CD52 was highly over-represented in the CD34+/CD38-/Lin- population. Preliminary immunostaining and flow cytometry experiments revealed CD52++ and CD52- subpopulations within the CD34+/CD38-/Lin- population, suggesting that CD52 may be a marker for further purification of hematopoietic stem-progenitor (HSPC) subpopulations.
Looking for Partners:
Identification of genes that are functionally important in stem or progenitor cells. Identification of gene encoding proteins that may be markers for stem or progenitor cells. Identification of the near-full transcriptomic signature of stem and progenitor cells.
