Dar Ayelet, Goichberg Polina, Shinder Vera, Kalinkovich Alexander, Kollet Orit, Netzer Neta, Margalit Raanan, Zsak Marion, Nagler Arnon, Hardan Izhar, Resnick Igor, Rot Antal, Lapidot Tsvee
Department of Immunology, Weizmann Institute of Science, Rehovot 76100, Israel.
Nat Immunol. 2005 Oct;6(10):1038-46. doi: 10.1038/ni1251. Epub 2005 Sep 18.
Regulation of the availability of chemokine SDF-1 (CXCL12) in bone marrow is still not fully understood. Here we describe a unique function for the chemokine receptor CXCR4 expressed on bone marrow endothelial cells, which efficiently internalize circulating SDF-1, resulting in its translocation into the bone marrow. Translocated SDF-1 increased the homing of transplanted human CD34(+) hematopoietic progenitors to the bone marrow. The chemokine transporter function of CXCR4 was a characteristic of endothelial and stromal cells but not of hematopoietic cells. Thus, chemokine translocation across the blood-bone marrow barrier allows effective transfer of functional SDF-1 from the periphery to the stem cell niche in the bone marrow during both homeostasis and 'alarm' situations.
骨髓中趋化因子SDF-1（CXCL12）可用性的调控仍未完全明确。在此，我们描述了骨髓内皮细胞上表达的趋化因子受体CXCR4的独特功能，该受体能有效内化循环中的SDF-1，使其转运至骨髓。转运至骨髓的SDF-1增强了移植的人CD34(+)造血祖细胞归巢至骨髓的能力。CXCR4的趋化因子转运功能是内皮细胞和基质细胞的特征，而非造血细胞的特征。因此，趋化因子跨血-骨髓屏障的转运使得功能性SDF-1在稳态和“应激”状态下均能从外周有效转移至骨髓中的干细胞龛。
