title: Stromal cell-derived factor-1/CXCL12 selectively counteracts inhibitory effects of myelosuppressive chemokines on hematopoietic progenitor cell proliferation in vitro.
abstract: A variety of cytokines and chemokines exert potent myelosuppressive effects that play a role in the maintenance of hematopoiesis, which, if unchecked, may result in pathological impairment of blood cell production. Processes that modulate these myelosuppressive effects are not well defined. Here we demonstrate that stromal cell-derived factor-1 (SDF-1/CXCL12), known for its ability to attract and to promote survival of hematopoietic progenitor cells (HPCs) and stem cells, blocks the effects of a broad range of myelosuppressive chemokines on proliferation of HPCs in vitro. The regulatory effects of SDF/CXCL12 on colony formation by mouse bone marrow granulocyte-macrophage (CFUGM), erythroid (BFU-E), and multipotential (CFU-GEMM) progenitor cells were assessed. These cells were stimulated to proliferate by combinations of growth factors, such that responses of immature HPCs could be assessed. SDF-1/CXCL12 potently blocked myelosuppressive responses induced by CCL2/MCP-1, CCL3/MIP-1alpha, CCL19/CKbeta-11, CCL25/TECK, CXCL4/PF4, CXCL8/IL-8, CXCL10/IP-10, and XCL1/Lymphotactin. However, SDF/CDL12 did not influence myelosuppression induced by tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, transforming growth factor (TGF)-beta or the iron-binding proteins H-ferritin or lactoferrin (LF). LF, previously shown to suppress release of growth factors, is shown here to also suppress proliferation of immature subsets of HPCs. HPCs from marrows of mice expressing an SDF-1/CXCL12 transgene were insensitive to inhibition by SDF/CXCL12-sensitive myelosuppressive chemokines, but not to SDF/CCL12-insensitive cytokines (TNF-alpha, IFN-gamma, TGF-beta, H-Ferritin, or LF). Thus, SDF-1/CXCL12 differentially and selectively regulates suppression of HPC proliferation by chemokines. These effects may counter myelosuppressive effects of certain chemokines in vivo, where proliferation of HPCs must be sustained.
authors.affiliation: Department of Microbiology and Immunology, Walther Oncology Center, Indiana University School of Medicine, Indianapolis, IN 46202, USA. hbroxmey@iupui.edu
authors.forename: Hal E
authors.initials: HE
authors.lastname: Broxmeyer
authors.forename: Scott
authors.initials: S
authors.lastname: Cooper
authors.forename: Giao
authors.initials: G
authors.lastname: Hangoc
authors.forename: Chang H
authors.initials: CH
authors.lastname: Kim
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D002460:Cell Line; D019070:Cell Lineage; D049109:Cell Proliferation; D002470:Cell Survival; D054377:Chemokine CXCL12; D018925:Chemokines / Q000378:metabolism*; D019743:Chemokines, CXC / Q000378:metabolism / Q000502:physiology*; D005293:Ferritins / Q000378:metabolism; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000378:metabolism; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000378:metabolism; D007501:Iron / Q000378:metabolism; D007781:Lactoferrin / Q000378:metabolism; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D013234:Stem Cells / Q000166:cytology; D016212:Transforming Growth Factor beta / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: C515255:CXCL12 protein, human; D054377:Chemokine CXCL12; D018925:Chemokines; D019743:Chemokines, CXC; C515256:Cxcl12 protein, mouse; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D005293:Ferritins; D007501:Iron; D007781:Lactoferrin