title: The monoclonal antibody W7C5 defines a novel surface antigen on hematopoietic stem cells.
abstract: We recently raised a monoclonal antibody, termed W7C5, against a surface antigen that is expressed at low levels on bone marrow and peripheral blood CD34+ stem/progenitor cells but at high levels on fetal liver CD34+ cells. A reasonable staining intensity was achieved using magnetofluorescent liposome conjugates to analyze expression of W7C5 antigen on CD34+CD38- bone marrow (BM) cells. Flow cytometric analyses revealed that W7C5 detects about 50% of immature CD34+CD38- BM cells that coexpressed the differentiation antigens CD164, CD133, and CD172a (SIRP alpha). In addition, W7C5 also recognized a CD34- BM fraction. These cells were negative for CD117 and CD133, but expressed CD45 and moderate levels of CD164. Injection of selected CD34+W7C5+ and CD34-W7C5+ cells into 55-60-day-old fetal sheep resulted in an engraftment of both fractions. Partial amino acid sequence analysis of affinity-purified lysates of KU-812 cells revealed that W7C5 detects a novel membrane protein. Together, W7C5 defines a novel molecule that is expressed on CD34+ as well as on CD34- stem cell subsets.
authors.affiliation: Department of Hematology and Oncology, University of Tübingen, 72076 Tübingen, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Giesert
authors.forename: G
authors.initials: G
authors.lastname: Almeida-Porada
authors.forename: A
authors.initials: A
authors.lastname: Scheffold
authors.forename: L
authors.initials: L
authors.lastname: Kanz
authors.forename: E D
authors.initials: ED
authors.lastname: Zanjani
authors.forename: H J
authors.initials: HJ
authors.lastname: Bühring
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D015703:Antigens, CD / Q000032:analysis; D000954:Antigens, Surface / Q000276:immunology*; D005326:Fetal Proteins / Q000276:immunology; D005434:Flow Cytometry; D006085:Graft Survival; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D006801:Humans; D016130:Immunophenotyping; D008099:Liver / Q000166:cytology / Q000196:embryology; D008565:Membrane Proteins / Q000276:immunology*; D051379:Mice; D008970:Molecular Weight; D009928:Organ Specificity; D017386:Sequence Homology, Amino Acid; D012756:Sheep; D014183:Transplantation, Heterologous
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000954:Antigens, Surface; D005326:Fetal Proteins; D008565:Membrane Proteins; C432084:W7C5 antigen, mouse