Wang Jianfeng, Kimura Takafumi, Asada Rumiko, Harada Sachio, Yokota Shouhei, Kawamoto Yoshio, Fujimura Yoshihiro, Tsuji Takashi, Ikehara Susumu, Sonoda Yoshiaki
Department of Hygiene, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamigyoku, Kyoto, Japan.
Blood. 2003 Apr 15;101(8):2924-31. doi: 10.1182/blood-2002-09-2782. Epub 2002 Dec 12.
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.
由于缺乏针对这些稀有细胞的简单可靠检测系统，对人类CD34阴性（CD34(-)）造血干细胞（HSC）的精确分析受到了阻碍。在此，我们使用骨髓内注射（IBMI）技术成功鉴定出具有广泛淋巴系和髓系重建能力的人类脐带血来源的CD34(-)重症联合免疫缺陷（SCID）-重建细胞（SRC）。通过传统尾静脉注射，谱系阴性（Lin(-)）CD34(-)细胞未显示出SRC活性，这可能是由于它们的归巢受体表达水平低以及SDF-1/CXCR4介导的归巢能力差，而通过IBMI它们明显显示出高SRC活性。它们不仅在注射的左胫骨中产生CD34(+)子代，而且在迁移后在其他骨骼中也产生。此外，它们在体内显示出比CD34(+)细胞更慢的分化和重建动力学。这些体内产生的CD34(+)细胞在二次移植后显示出明显的SRC活性，清楚地表明了我们鉴定出的CD34(-)SRC在非肥胖糖尿病（NOD）/SCID小鼠中的长期人类细胞重建能力。通过IBMI揭示这类新型的原始人类CD34(-)SRC将为人类HSC区室的层级结构提供新的概念，并且对临床HSC移植以及HSC的基础研究具有重要意义。
