The Chemokine SDF-1 Is a Chemoattractant for Human CD34+ Hematopoietic Progenitor Cells and Provides a New Mechanism to Explain the Mobilization of CD34+ Progenitors to Peripheral Blood |
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| Authors: | A. Aiuti I.J. Webb C. Bleul T. Springer J.C. Gutierrez-Ramos |
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| Affiliation: | From the *Center for Blood Research, Inc., and the ‡Department of Genetics, §Department of Pathology, and ‖Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115; ¶Blood Component Laboratory, Dana-Farber Cancer Institute, Boston, Massachusetts 02115; and **Millennium Pharmaceuticals, Inc., Cambridge, Massachusetts 02139 |
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| Abstract: | Hematopoietic progenitor cells migrate in vitro and in vivo towards a gradient of the chemotactic factor stromal cell-derived factor-1 (SDF-1) produced by stromal cells. This is the first chemoattractant reported for human CD34+ progenitor cells. Concentrations of SDF-1 that elicit chemotaxis also induce a transient elevation of cytoplasmic calcium in CD34+ cells. SDF-1-induced chemotaxis is inhibited by pertussis toxin, suggesting that its signaling in CD34+ cells is mediated by seven transmembrane receptors coupled to Gi proteins. CD34+ cells migrating to SDF-1 include cells with a more primitive (CD34+/CD38− or CD34+/DR−) phenotype as well as CD34+ cells phenotypically committed to the erythroid, lymphoid and myeloid lineages, including functional BFU-E, CFU-GM, and CFU-MIX progenitors. Chemotaxis of CD34+ cells in response to SDF-1 is increased by IL-3 in vitro and is lower in CD34+ progenitors from peripheral blood than in CD34+ progenitors from bone marrow, suggesting that an altered response to SDF-1 may be associated with CD34 progenitor mobilization. |
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