title: In vitro induction of inhibitory macrophage differentiation by granulocyte-macrophage colony-stimulating factor, stem cell factor and interferon-gamma from lineage phenotypes-negative c-kit-positive murine hematopoietic progenitor cells.
abstract: CD11b+Gr-1+ inhibitory macrophages (iMacs) were implicated in profound depression of T cell functions sometimes observed during cyclophosphamide treatments and overwhelming infections, through a secretion of nitric oxide (NO). Myeloid origin and maturation stages of iMacs are still unknown. As tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) contributed crucially to the activation of inducible NO synthase (iNOS) gene transcription and to the differentiation of macrophages, we tested their roles in the induction of iMacs differentiation from bone marrow hematopoietic progenitor cells (HPC) of uncompromised mice. Lineage phenotypes-negative (lin)) c-kit+ cells of Balb/c mice were cultured 6 days with granulocyte-macrophage colony-stimulating factor (GM-CSF), stem cell factor (SCF, c-kit ligand) in presence or not of TNF-alpha or IFN-gamma. CD11b+Gr-1+ cells only derived in presence of [GM-CSF + SCF + TNF-alpha] or [GM-CSF + SCF + IFN-gamma] could express iNOS upon in vitro stimulation with [IFN-gamma + TNF-alpha] or [IFN-gamma + LPS] known to boost iNOS expression in murine macrophages. However, whereas [GM-CSF + SCF + TNF-alpha] induced only weakly iMacs generation and contributed also to the differentiation of CD11b+Gr-1-CD11c+ myeloid dendritic cells, [GM-CSF + SCF + IFN-gamma] induced exclusively and importantly iMacs differentiation. Moreover [GM-CSF + SCF + IFN-gamma]-generated iMacs were more mature than [GM-CSF + SCF + TNF-alpha]-derived iMacs since IFN-gamma increased more strongly CD11b+Gr-1+ cells expressing Ly-6C and generated lesser cells expressing MHC class II and CD86 molecules. Finally [GM-CSF + SCF + IFN-gamma]-generated CD11b+ cells showing a powerful suppressive activity on T cell proliferations, correlated with NO secretion. In conclusion, our study showed, for the first time, that IFN-gamma induced very efficiently the differentiation of functional iMacs from lin- c-kit+ murine HPC in vitro, and indicated clearly that iMacs progenitors may be present in bone marrow of naïve mice.
authors.affiliation: Immuno-endocrinology Unit, ENVN/INRA/University, ENVN, Atlanpole-La Chantrerie, BP 40706, 44307 Nantes Cedex 03, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Ferret-Bernard
authors.forename: Pierre
authors.initials: P
authors.lastname: Saï
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Bach
mesh_terms: D000818:Animals; D039481:CD11b Antigen / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects*; D019070:Cell Lineage; D002478:Cells, Cultured; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D007371:Interferon-gamma / Q000494:pharmacology*; D008264:Macrophages / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D019001:Nitric Oxide Synthase / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism*; D019089:Stem Cell Factor / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D039481:CD11b Antigen; D019089:Stem Cell Factor; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D019009:Proto-Oncogene Proteins c-kit