Onai N, Zhang Y y, Yoneyama H, Kitamura T, Ishikawa S, Matsushima K
Department of Molecular Preventive Medicine and CREST, School of Medicine, University of Tokyo, Tokyo, Japan.
Blood. 2000 Sep 15;96(6):2074-80.
Both SDF-1 and CXCR4 disruption are lethal to mice at the embryonic stage and cause abnormalities in B lymphopoiesis, myelopoiesis, cardiogenesis, vasculogenesis, and cerebellar development. To investigate the role of SDF-1 and CXCR4 in hematopoiesis during the adult stage, mice reconstituted with bone marrow-derived hematopoietic progenitor cells transduced with either the SDF-1 or a genetically modified SDF-1-intrakine gene using a retroviral expression vector were analyzed. Flow cytometric (FCM) analysis showed a dramatic reduction of CXCR4 expression on the cells of intrakine-transduced mice, whereas CCR7 and CCR1 expression was unchanged or marginally decreased on splenocytes. Migration of splenocytes and bone marrow cells to SDF-1 was markedly suppressed in intrakine-transduced mice. FCM analysis of bone marrow cells of intrakine-transduced mice exhibited decreased numbers of pro-B (B220(+) CD43(+)), pre-B (B220(+) CD43(-)), and immature B (B220(+) IgM(+)) cells and a decreased number of granulocytes/myeloid (Gr1(+) CD11b(+)) cells. Impaired B lymphopoiesis and myelopoiesis in intrakine-transduced mice were confirmed by an in vitro colony-forming assay of bone marrow cells. In contrast, B lymphopoiesis and myelopoiesis were enhanced in SDF-1-transduced mice. Interestingly, T-cell maturation in the thymus was impaired both in intrakine- and SDF-1-transduced mice, suggesting that SDF-1 and CXCR4 play an important role in T lymphopoiesis as well as in B lymphopoiesis and myelopoiesis in adults. These results demonstrate an essential role of CXCR4 and its ligand SDF-1 in adult hematopoiesis, and they indicate the intrakine method as a powerful tool for functional analysis of chemokines/chemokine receptors in vivo and as a potential therapeutic approach for acquired immunodeficiency syndrome.
基质细胞衍生因子-1（SDF-1）和CXC趋化因子受体4（CXCR4）的缺失在胚胎期对小鼠都是致命的，并会导致B淋巴细胞生成、骨髓生成、心脏发生、血管生成及小脑发育异常。为研究SDF-1和CXCR4在成年期造血过程中的作用，对用逆转录病毒表达载体转导了SDF-1或基因改造的SDF-1细胞内趋化因子基因的骨髓源性造血祖细胞重建的小鼠进行了分析。流式细胞术（FCM）分析显示，转导细胞内趋化因子基因的小鼠细胞上CXCR4表达显著降低，而脾细胞上CCR7和CCR1表达未变或略有降低。在转导细胞内趋化因子基因的小鼠中，脾细胞和骨髓细胞向SDF-1的迁移明显受到抑制。对转导细胞内趋化因子基因的小鼠骨髓细胞进行FCM分析，显示前B细胞（B220(+) CD43(+)）、前B细胞（B220(+) CD43(-)）和未成熟B细胞（B220(+) IgM(+)）数量减少，粒细胞/髓细胞（Gr1(+) CD11b(+)）数量也减少。通过骨髓细胞的体外集落形成试验证实了转导细胞内趋化因子基因的小鼠B淋巴细胞生成和骨髓生成受损。相反，在转导SDF-1基因的小鼠中，B淋巴细胞生成和骨髓生成增强。有趣的是，在转导细胞内趋化因子基因和SDF-1基因的小鼠中，胸腺中的T细胞成熟均受损，这表明SDF-1和CXCR4在成年期T淋巴细胞生成以及B淋巴细胞生成和骨髓生成中均起重要作用。这些结果证明了CXCR4及其配体SDF-1在成年期造血中的重要作用，并表明细胞内趋化因子方法是体内趋化因子/趋化因子受体功能分析的有力工具，也是获得性免疫缺陷综合征的一种潜在治疗方法。
