Christ O, Günthert U, Haas R, Zöller M
Department of Tumor Progression and Immune Defense, German Cancer Research Center, Heidelberg.
J Leukoc Biol. 2001 Mar;69(3):343-52.
The adhesion molecule CD44 consists of many isoforms of which particularly CD44v7 is of major importance in hematopoietic progenitor cell homing. An increase of progenitor cells in the periphery was observed after treating mice with a CD44v7-specific antibody, concomitant with a substantially augmented marrow-repopulating ability (MRA). Because CD44v7 is expressed on a fraction of bone marrow cells (BMC) as well as on long-term bone marrow culture-derived stromal cells, we aimed to differentiate between the functional relevance of CD44v7 on either cell type by transferring CD44v7+/+ BMC into CD44v7-/- mice and vice versa. CD44v7+/+ BMC homed poorly in the bone marrow of CD44v7-/- mice and their MRA was severely impaired. CD44v7-/- BMC, instead, exhibited an improved MRA when transferred into the CD44v7+/+ host, although their MRA remained below that of CD44v7+/+ BMC. Thus, it is predominantly, but not exclusively, expression of CD44v7 on stromal cells which supports progenitor cell homing.
黏附分子CD44由多种异构体组成，其中特别是CD44v7在造血祖细胞归巢中起主要作用。在用CD44v7特异性抗体处理小鼠后，观察到外周血中祖细胞增加，同时骨髓重建能力（MRA）显著增强。由于CD44v7在一部分骨髓细胞（BMC）以及长期骨髓培养衍生的基质细胞上表达，我们旨在通过将CD44v7+/+ BMC移植到CD44v7-/-小鼠中，反之亦然，来区分CD44v7在这两种细胞类型上的功能相关性。CD44v7+/+ BMC在CD44v7-/-小鼠的骨髓中归巢能力差，其MRA严重受损。相反，当将CD44v7-/- BMC移植到CD44v7+/+宿主中时，其MRA有所改善，尽管其MRA仍低于CD44v7+/+ BMC。因此，主要但并非唯一地，是基质细胞上CD44v7的表达支持祖细胞归巢。
