Primitive Human Hematopoietic Progenitors Adhere to P-Selectin (CD62P)

• Published in: Blood Vol. 85; no. 12; pp. 3466 - 3477
• Main Authors: Zannettino, A.C.W., Berndt, M.C., Butcher, C., Butcher, E.C., Vadas, M.A., Simmons, P.J.
• Format: Journal Article
• Language: English
• Published: Washington, DC Elsevier Inc 15.06.1995; The Americain Society of Hematology
• Subjects: Antigens, CD - biosynthesis; Antigens, CD - immunology; Antigens, CD34; Base Sequence; Biological and medical sciences; Bone Marrow - immunology; Bone Marrow Cells; Cell Adhesion; Cell differentiation, maturation, development, hematopoiesis; Cell physiology; Fundamental and applied biological sciences. Psychology; Hematopoietic Stem Cells - cytology; Hematopoietic Stem Cells - immunology; Humans; Molecular and cellular biology; Molecular Sequence Data; P-Selectin; Platelet Membrane Glycoproteins - immunology; Polymerase Chain Reaction; RNA - analysis; Antigen; Human; Hematopoiesis; Stem cell; P selectin; Cell adhesion molecule; Hematopoietic cell; Adhesion; Cell surface
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V85.12.3466.bloodjournal85123466

P-selectin was shown to bind committed human hematopoietic progenitors (colony-forming unit-granulocyte-macro-phage [CFU-GM] and burst-forming unit-erythroid [BFU-E]) as identified by their expression of the CD34 antigen and by in vitro clonogenic assays. In addition, P-selectin bound all precursors (pre-CFU) of committed myeloid progenitors assayed by their ability to sustain hematopoiesis in both conventional stroma-containing and stroma-free, cytokine-de-pendent systems. Binding of CD34+ cells to P-selectin was temperature-independent and shear-resistant, occurred only in the presence of divalent cations, was protease sensitive, and was completely blocked by anti-P-selectin antibody. Neuraminidase treatment of CD34+ cells completely abrogated their binding to P-selectin, implying a prominent role for sialic acid in the structure and function of the P-selectin ligand on hematopoietic progenitors. Monoclonal antibodies (MoAbs) CSLEX-1 and HECA-452, which identify carbohydrate epitopes involving sialic acid, bound to 33% and 35% of CD34+ cells, respectively, and included the majority of CFU-GM and pre-CFU. Three-color flow cytometric analysis showed a precise codistribution of CSLEX-1 and HECA-452 antigens on CD34+ cells, implying recognition of the same glycoprotein antigen by the two MoAbs. Treatment of CD34+ cells with neuraminidase completely abolished binding of both MoAbs. In addition, HECA-452 partially blocked the adhesion of CD34+ cells to P-selectin. P-selectin glycoprotein ligand (PSGL-1), recently molecularly cloned from the pro-myelocytic leukemia cell line HL60, was expressed by CD34+ cells as determined by reverse transcription polymerase chain reaction. Combined with the functional and biochemical characteristics, these data suggest that PSGL-1 may comprise an important P-selectin ligand expressed by primitive hematopoietic cells, but do not preclude the existence of additional P-selectin ligands on these cells.