title: Expression of integrin α2 receptor in human cord blood CD34+CD38-CD90+ stem cells engrafting long-term in NOD/SCID-IL2Rγ(c) null mice.
abstract: Human hematopoietic stem cells reside in the CD34+CD38-CD90+ population in cord blood and bone marrow. However, this cell fraction is heterogeneous, and the phenotype of the rare primitive stem cells remains poorly defined. We here report that primitive cord blood CD34+CD38-CD90+ stem cells, with the ability to reconstitute NOD/SCID-IL2Rγ(c) null (NSG) mice long-term, at 24 weeks after transplantation, can be prospectively isolated at an increased purity by using integrin α2 receptor as an additional stem cell marker. Using a limiting dilution transplantation assay, we found a highly significant enrichment of multilineage reconstituting stem cells in the CD34+CD38-CD90+ cell fraction expressing the integrin α2 receptor, with a frequency of 1/29 cells, as compared to a frequency of 1/157 in the corresponding integrin α2- cells. In line with this, long-term reconstituting stem cells within the cord blood CD34+CD38- cell population were significantly enriched in the integrin α2+ fraction, while stem cells and progenitors reconstituting short-term, at 8-12 weeks, were heterogeneous in integrin α2 expression. Global gene expression profiling revealed that the lineage-marker negative (Lin-) CD34+CD38-CD90+CD45RA- integrin α2+ cell population was molecularly distinct from the integrin α2- cell population and the more mature Lin-CD34+CD38-CD90-CD45RA- cell population. Our findings identify integrin α2 as a novel stem cell marker, which improves prospective isolation of the primitive human hematopoietic stem cells within the CD34+CD38-CD90+ cell population for experimental and therapeutic stem cell applications.
authors.affiliation: Hematopoietic Stem Cell Laboratory, Department of Laboratory Medicine, Lund University, Lund, Sweden.
authors.forename: Wan Man
authors.initials: WM
authors.lastname: Wong
authors.forename: Mikael
authors.initials: M
authors.lastname: Sigvardsson
authors.forename: Ingbritt
authors.initials: I
authors.lastname: Åstrand-Grundström
authors.forename: Donna
authors.initials: D
authors.lastname: Hogge
authors.forename: Jonas
authors.initials: J
authors.lastname: Larsson
authors.forename: Hong
authors.initials: H
authors.lastname: Qian
authors.forename: Marja
authors.initials: M
authors.lastname: Ekblom
mesh_terms: D051997:ADP-ribosyl Cyclase 1 / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D000818:Animals; D018952:Antigens, CD34 / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D036101:Cord Blood Stem Cell Transplantation; D005260:Female; D005312:Fetal Blood / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D015870:Gene Expression / Q000276:immunology*; D006085:Graft Survival; D006801:Humans; D016130:Immunophenotyping; D039421:Integrin alpha2 / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D053631:Interleukin Receptor Common gamma Subunit / Q000172:deficiency / Q000235:genetics* / Q000276:immunology; D017493:Leukocyte Common Antigens / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D008297:Male; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D018800:Thy-1 Antigens / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D014183:Transplantation, Heterologous
chemical_list: D018952:Antigens, CD34; D015415:Biomarkers; C507942:Il2rg protein, mouse; D039421:Integrin alpha2; D053631:Interleukin Receptor Common gamma Subunit; D018800:Thy-1 Antigens; D017493:Leukocyte Common Antigens; D051997:ADP-ribosyl Cyclase 1