title: Enrichment and characterization of murine hematopoietic stem cells that express c-kit molecule.
abstract: The proto-oncogene c-kit encodes a transmembrane tyrosine kinase receptor for stem cell factor (SCF). The c-kit/SCF signal is expected to have an important role in hematopoiesis. A monoclonal antibody (ACK-2) against the murine c-kit molecule was prepared. Flow cytometric analysis showed that the bone marrow cells that expressed the c-kit molecule (approximately 5%) were B220(B)-, TER119(erythroid)-, Thy1negative-low, and WGA+. A small number of Mac-1(macrophage)+ or Gr-1(granulocyte)+ cells were c-kit-low positive. Colony-forming unit in culture (CFU-C) and day-8 and day-12 CFU-spleen (CFU-S) existed exclusively in the c-kit-positive fraction. About 20% of the Lin(lineage)-c-kit+ cells were rhodamine-123low and this fraction contained more day-12 CFU-S than day-8 CFU-S. On the basis of these findings, murine hematopoietic stem cells were enriched with normal bone marrow cells. One of two and one of four Thy-1lowLin-WGA+c-kit+ cells were CFU-C and CFU-S, respectively. Long-term repopulating ability was investigated using B6/Ly5 congenic mice. Eight and 25 weeks after transplantation of Lin-c-kit+ cells, donor-derived cells were found in the bone marrow, spleen, thymus, and peripheral blood. In peripheral blood, T cells, B cells, and granulocyte-macrophages were derived from donor cells. Injection of ACK-2 into the irradiated mice after bone marrow transplantation decreased the numbers of day-8 and day-12 CFU-S in a dose-dependent manner. Day-8 spleen colony formation was completely suppressed by the injection of 100 micrograms ACK-2, but a small number of day-12 colonies were spared. Our data show that the c-kit molecule is expressed in primitive stem cells and plays an essential role in the early stages of hematopoiesis.
authors.affiliation: Department of Medicine, Jichi Medical School, Tochigi-ken, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Okada
authors.forename: H
authors.initials: H
authors.lastname: Nakauchi
authors.forename: K
authors.initials: K
authors.lastname: Nagayoshi
authors.forename: S
authors.initials: S
authors.lastname: Nishikawa
authors.forename: S
authors.initials: S
authors.lastname: Nishikawa
authors.forename: Y
authors.initials: Y
authors.lastname: Miura
authors.forename: T
authors.initials: T
authors.lastname: Suda
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D001853:Bone Marrow / Q000528:radiation effects; D001854:Bone Marrow Cells; D016026:Bone Marrow Transplantation; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D006410:Hematopoiesis; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D011518:Proto-Oncogene Proteins / Q000032:analysis / Q000276:immunology / Q000502:physiology*; D019009:Proto-Oncogene Proteins c-kit; D013154:Spleen / Q000166:cytology
chemical_list: D000911:Antibodies, Monoclonal; D011518:Proto-Oncogene Proteins; D019009:Proto-Oncogene Proteins c-kit