title: SCID-repopulating cell activity of human cord blood-derived CD34- cells assured by intra-bone marrow injection.
abstract: Precise analysis of human CD34-negative (CD34(-)) hematopoietic stem cells (HSCs) has been hindered by the lack of a simple and reliable assay system of these rare cells. Here, we successfully identify human cord blood-derived CD34(-) severe combined immunodeficiency (SCID)- repopulating cells (SRCs) with extensive lymphoid and myeloid repopulating ability using the intra-bone marrow injection (IBMI) technique. Lineage-negative (Lin(-)) CD34(-) cells did not show SRC activity by conventional tail-vein injection, possibly due to their low levels of homing receptor expression and poor SDF-1/CXCR4- mediated homing abilities, while they clearly showed a high SRC activity by IBMI. They generated CD34(+) progenies not only in the injected left tibia but also in other bones following migration. Moreover, they showed slower differentiating and reconstituting kinetics than CD34(+) cells in vivo. These in vivo-generated CD34(+) cells showed a distinct SRC activity after secondary transplantation, clearly indicating the long-term human cell repopulating capacity of our identified CD34(-) SRCs in nonobese diabetic (NOD)/SCID mice. The unveiling of this novel class of primitive human CD34(-) SRCs by IBMI will provide a new concept of the hierarchy in the human HSC compartment and has important implications for clinical HSC transplantation as well as for basic research of HSC.
authors.affiliation: Department of Hygiene, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamigyoku, Kyoto, Japan.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Wang
authors.forename: Takafumi
authors.initials: T
authors.lastname: Kimura
authors.forename: Rumiko
authors.initials: R
authors.lastname: Asada
authors.forename: Sachio
authors.initials: S
authors.lastname: Harada
authors.forename: Shouhei
authors.initials: S
authors.lastname: Yokota
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kawamoto
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Fujimura
authors.forename: Takashi
authors.initials: T
authors.lastname: Tsuji
authors.forename: Susumu
authors.initials: S
authors.lastname: Ikehara
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Sonoda
mesh_terms: D000818:Animals; D018952:Antigens, CD34 / Q000032:analysis; D001853:Bone Marrow; D016026:Bone Marrow Transplantation; D019070:Cell Lineage; D002465:Cell Movement; D002469:Cell Separation; D002999:Clone Cells / Q000637:transplantation; D003114:Colony-Forming Units Assay; D036101:Cord Blood Stem Cell Transplantation; D006085:Graft Survival; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D007231:Infant, Newborn; D007267:Injections; D008214:Lymphocytes / Q000166:cytology; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D022423:Myeloid Cells / Q000166:cytology; D019718:Receptors, CXCR4 / Q000032:analysis; D016511:Severe Combined Immunodeficiency / Q000473:pathology; D018183:Transplantation Chimera; D014183:Transplantation, Heterologous
chemical_list: D018952:Antigens, CD34; D019718:Receptors, CXCR4