title: CDCP1 is a novel marker for hematopoietic stem cells.
abstract: CDCP1 is a transmembrane protein that contains three CUB domains within the extracellular region and a hexalysine stretch within the cytoplasmic region. CDCP1 mRNA is highly expressed in lung and colon tumors and in the erythroleukemic cell line K562. To analyze CDCP1 protein expression, monoclonal antibodies against the extracellular domain of CDCP1 were raised. For this purpose, CDCP1 was overexpressed in NIH-3T3 cells. Balb/c mice were then immunized with the resultant cell line NIH-3T3/huCDCP1. After fusion of SP2/0 cells with immune spleen cells, hybridoma clones were selected that secreted antibodies reacting with NIH-3T3/huCDCP1 cells but not with parental cells. Four antibodies (CUB1-CUB4) were obtained that fulfilled these criteria. Screening of peripheral blood cells revealed that the antibodies did not recognize mature lymphocytes, monocytes, granulocytes, erythrocytes, or platelets. In contrast, multi-color analyses revealed that CDCP1 protein is almost exclusively expressed on a subset of CD34(+) stem/progenitor cells in bone marrow. Transplantation of purified CDCP1(+) cells into NOD/SCID mice resulted in engraftment of human cells with multi-lineage differentiation potential, suggesting that CDCP1 is a novel marker for hematopoietic stem cells.
authors.affiliation: Department of Internal Medicine II, Division of Hematology, Immunology, and Oncology, University of Tübingen, Tübingen, Germany.
authors.forename: Tim
authors.initials: T
authors.lastname: Conze
authors.forename: Reiner
authors.initials: R
authors.lastname: Lammers
authors.forename: Selim
authors.initials: S
authors.lastname: Kuci
authors.forename: Marwa
authors.initials: M
authors.lastname: Scherl-Mostageer
authors.forename: Norbert
authors.initials: N
authors.lastname: Schweifer
authors.forename: Lothar
authors.initials: L
authors.lastname: Kanz
authors.forename: Hans-Jorg
authors.initials: HJ
authors.lastname: Buhring
mesh_terms: D016475:3T3 Cells; D000818:Animals; D015703:Antigens, CD; D000951:Antigens, Neoplasm; D015415:Biomarkers; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D005434:Flow Cytometry; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D006801:Humans; D051379:Mice; D016513:Mice, SCID; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014162:Transfection
chemical_list: D015703:Antigens, CD; D000951:Antigens, Neoplasm; D015415:Biomarkers; C432044:CDCP1 protein, human; D015815:Cell Adhesion Molecules; D009363:Neoplasm Proteins; D012333:RNA, Messenger