Spangrude G J, Muller-Sieburg C E, Heimfeld S, Weissman I L
Department of Pathology, Stanford University School of Medicine, California 94305.
J Exp Med. 1988 May 1;167(5):1671-83. doi: 10.1084/jem.167.5.1671.
Two-color FACS analysis of mouse bone marrow reveals a rare population, comprising 0.1-0.3% of the total, that expresses low levels of the Thy-1 antigen but does not express any of five surface markers that characterize differentiated hematolymphoid cells. We demonstrate here that this fraction of mouse bone marrow is enormously enriched in cells that can home to the thymus and differentiate into mature T lymphocytes, subsequently migrating to peripheral lymphoid organs. Only a subset of the FACS-isolated fraction (1/90 after intrathymic injection) is capable of responding to the thymic microenvironment with a productive commitment to the T cell lineage. A second fraction of mouse bone marrow, which expresses how levels of Thy-1 but is also positive for at least one of five hematolymphoid lineage-specific markers, also contains cells that home to the thymus and establish colonies of thymocytes. The two fractions each contribute approximately equal amounts of thymic colony-forming units (CFUt) to the bone marrow, and together can account for at least half of the CFUt in whole bone marrow.
对小鼠骨髓进行的双色荧光激活细胞分选（FACS）分析显示，存在一个罕见的细胞群体，占总数的0.1 - 0.3%，该群体表达低水平的Thy-1抗原，但不表达表征分化的血液淋巴细胞的五个表面标志物中的任何一个。我们在此证明，小鼠骨髓的这一部分富含能够归巢至胸腺并分化为成熟T淋巴细胞、随后迁移至外周淋巴器官的细胞。FACS分离的细胞群体中只有一个亚群（胸腺内注射后为1/90）能够对胸腺微环境作出反应，并有效地定向分化为T细胞谱系。小鼠骨髓的另一部分细胞表达低水平的Thy-1，但对五个血液淋巴细胞谱系特异性标志物中的至少一个呈阳性，这部分细胞也包含归巢至胸腺并形成胸腺细胞集落的细胞。这两个部分对骨髓中的胸腺集落形成单位（CFUt）的贡献大致相等，并且一起至少可占全骨髓CFUt的一半。
