title: Monoclonal antibodies that bind to hemopoietic stem cells: characterization and immunohistochemical localization of cells expressing gp50-65.
abstract: The cell surface of hemopoietic stem cells has been shown to express several antigens in common with more mature hemopoietic cells. One set of stem cell antigens is defined by a group of three monoclonal antibodies (13C6, 1C10, and 1A9), selected on the basis of binding to subpopulations of spleen colony-forming stem cells (CFU-S). These antibodies are shown to recognize cell surface glycoproteins of 50-65 kd (gp50-65) that occur widely on hemopoietic cells. Each cell type investigated shows a distinctive pattern of expression of these glycoproteins. To further investigate the presence of gp50-65 on stem cells, low-density bone marrow cells were labeled with 1C10 and sorted according to fluorescence intensity. Most (73%) of the stem cells (CFU-S10) were recovered in the two most highly fluorescent fractions containing 2.6% of starting marrow cells. Immunohistochemistry of frozen sections of normal spleen and spleens during repopulation after lethal irradiation and bone marrow transplantation showed that the most strongly 1C10-labeled cells occurred under the splenic capsule and along trabeculae. Although many of these cells were also alpha-naphthylacetate esterase positive and Mac-1 positive, indicating cells of the monocyte-macrophage lineage, a distinctive population of singular cells were stained with 1C10 alone. These cells were negative for surface Ig and closely corresponded with a small population of cells in a similar location that were doubly labeled with 1C10 and anti-Thy-1. These results show that stem cells express high levels of gp50-65 and suggest that stem cells can be identified by immunohistochemical methods using dual labeling procedures.
authors.affiliation: Malaghan Institute of Medical Research, Wellington School of Medicine, New Zealand.
authors.forename: M V
authors.initials: MV
authors.lastname: Berridge
authors.forename: G
authors.initials: G
authors.lastname: Hoffmann-Fezer
authors.forename: A S
authors.initials: AS
authors.lastname: Tan
authors.forename: P J
authors.initials: PJ
authors.lastname: McCaffery
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000954:Antigens, Surface / Q000276:immunology; D015153:Blotting, Western; D016026:Bone Marrow Transplantation / Q000276:immunology; D002469:Cell Separation; D005434:Flow Cytometry; D006023:Glycoproteins / Q000276:immunology; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D007124:Immunoenzyme Techniques; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology; D051379:Mice; D008815:Mice, Inbred Strains; D008970:Molecular Weight; D013154:Spleen / Q000166:cytology / Q000276:immunology; D018800:Thy-1 Antigens; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D006023:Glycoproteins; D018800:Thy-1 Antigens