title: Analysis of myeloid-associated genes in human hematopoietic progenitor cells.
abstract: The distribution of myeloid lineage-associated cytokine receptors and lysosomal proteins was analyzed in human CD34+ cord blood cell (CB) subsets at different stages of myeloid commitment by reverse-transcriptase polymerase chain reaction (RT-PCR). The highly specific granulomonocyte-associated lysosomal proteins myeloperoxidase (MPO) and lysozyme (LZ), as well as the transcription factor PU.1, were already detectable in the most immature CD34+Thy-1+ subset. Messenger RNA (mRNA) levels for the granulocyte-colony stimulating factor (G-CSF) receptor, granulocyte-macrophage (GM)-CSF receptor alpha subunit and tumor necrosis factor (TNF) receptors I (p55) and II (p75) were also detected in this subset in addition to c-kit and flt-3, receptors known to be expressed on progenitor cells. By contrast, the monocyte-macrophage colony stimulating factor (M-CSF) receptor was largely absent at this stage and in the CD34+Thy-1-CD45RA- subsets. The M-CSF receptor was first detectable in the myeloid-committed CD34+Thy-l-CD45RA+ subset. All other molecules studied were found to be expressed at this stage of differentiation. Different cocktails of the identified ligands were added to sorted CD34+Thy-1+ single cells. Low proliferative capacity was observed after 1 week in culture in the presence of stem cell factor (SCF) + Flt-3 ligand (FL) + G-CSF. Addition of GM-CSF to this basic cocktail consistently increased the clonogenic capacity of single CD34+Thy-1+ cells, and this effect was further enhanced (up to 72.3 +/- 4.3% on day 7) by the inclusion of TNF-alpha. In conclusion, the presence of myeloid-associated growth factor receptor transcripts in CD34+ CB subsets does not discriminate the various stages of differentiation, with the exception of the M-CSF receptor. In addition, we show that TNF-alpha is a potent costimulatory factor of the very immature CD34+Thy-1+ CB subset.
authors.affiliation: Institute of Immunology-Vienna International Research Cooperation Center at SFI, University of Vienna, Austria.
authors.forename: C
authors.initials: C
authors.lastname: Bello-Fernández
authors.forename: M
authors.initials: M
authors.lastname: Matyash
authors.forename: H
authors.initials: H
authors.lastname: Strobl
authors.forename: C
authors.initials: C
authors.lastname: Scheinecker
authors.forename: W
authors.initials: W
authors.lastname: Knapp
mesh_terms: D015703:Antigens, CD / Q000032:analysis; D018952:Antigens, CD34 / Q000032:analysis; D005312:Fetal Blood / Q000166:cytology; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D008247:Lysosomes / Q000378:metabolism; D009113:Muramidase / Q000096:biosynthesis*; D009195:Peroxidase / Q000096:biosynthesis*; D016133:Polymerase Chain Reaction; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis; D018121:Receptors, Cytokine / Q000096:biosynthesis*; D018417:Th1 Cells / Q000166:cytology / Q000276:immunology / Q000502:physiology; D015534:Trans-Activators / Q000096:biosynthesis; D014158:Transcription, Genetic; D000099232:Proto-Oncogene Protein Spi-1
chemical_list: D015703:Antigens, CD; D018952:Antigens, CD34; D009113:Muramidase; D009195:Peroxidase; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D018121:Receptors, Cytokine; D015534:Trans-Activators; D000099232:Proto-Oncogene Protein Spi-1