title: The expression of cytokine receptors by purified hemopoietic stem cells.
abstract: Sorted fractions from mouse bone marrow containing highly purified hemopoietic stem and progenitor cells were studied for the expression of growth factor receptors. With the use of rhodamine 123 WGA+, 15-1.1-, low density cells were separated into quiescent pluripotent stem cells and committed progenitor cells. RNA was extracted and cDNA was prepared by reverse transcription. Using primers specific for growth factor receptors, the cDNA of each sorted fraction was amplified by polymerase chain reaction (PCR). The quiescent rhodamine 123 dull stem cell fraction was found to express the interleukin 3 (IL-3) receptor beta unit and c-kit, but not the granulocyte-macrophage colony stimulating factor (GM-CSF) receptor beta unit nor flk-2. The rhodamine 123 bright fraction with activated stem cells and mostly committed progenitor cells similarly expressed the IL-3-R beta, and c-kit. However, this fraction also expressed flk-2 and GM-CSF-R beta. Since the expression of c-kit in the stem cell fraction does not correspond with the poor response to the kit-ligand stem cell factor (SCF) by these cells, we further analyzed the fractions with respect to their binding of biotinylated SCF. The SCF-binding cells were found to be all rhodamine 123 bright. This indicates that the expression of c-kit is not sufficient to yield a functional receptor for SCF; c-kit probably needs a partner molecule to form a functional high-affinity binding site for SCF. Similar to the beta unit of the GM-CSF receptor, this partner is then not expressed in the stem cell fraction.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Institute of Applied Radiobiology and Immunology TNO, Rijswijk, The Netherlands.
authors.forename: J W
authors.initials: JW
authors.lastname: Visser
authors.forename: H
authors.initials: H
authors.lastname: Rozemuller
authors.forename: M O
authors.initials: MO
authors.lastname: de Jong
authors.forename: A
authors.initials: A
authors.lastname: Belyavsky
mesh_terms: D000818:Animals; D001483:Base Sequence; D001854:Bone Marrow Cells; D002469:Cell Separation; D018076:DNA, Complementary / Q000235:genetics; D005456:Fluorescent Dyes; D016298:Hematopoietic Cell Growth Factors / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011505:Protein-Tyrosine Kinases / Q000096:biosynthesis / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics; D019009:Proto-Oncogene Proteins c-kit; D012194:RNA-Directed DNA Polymerase; D020794:Receptor Protein-Tyrosine Kinases / Q000096:biosynthesis / Q000235:genetics; D011956:Receptors, Cell Surface / Q000096:biosynthesis*; D016184:Receptors, Colony-Stimulating Factor / Q000096:biosynthesis / Q000235:genetics; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor / Q000096:biosynthesis / Q000235:genetics; D016185:Receptors, Interleukin-3 / Q000096:biosynthesis / Q000235:genetics; D020112:Rhodamine 123; D012235:Rhodamines; D019089:Stem Cell Factor; D051941:fms-Like Tyrosine Kinase 3
chemical_list: D018076:DNA, Complementary; D005456:Fluorescent Dyes; D016298:Hematopoietic Cell Growth Factors; D011518:Proto-Oncogene Proteins; D011956:Receptors, Cell Surface; D016184:Receptors, Colony-Stimulating Factor; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor; D016185:Receptors, Interleukin-3; D012235:Rhodamines; D019089:Stem Cell Factor; D020112:Rhodamine 123; C497971:Flt3 protein, mouse; D011505:Protein-Tyrosine Kinases; D019009:Proto-Oncogene Proteins c-kit; D020794:Receptor Protein-Tyrosine Kinases; D051941:fms-Like Tyrosine Kinase 3; D012194:RNA-Directed DNA Polymerase