title: Induction of granulocyte and granulocyte-macrophage colony-stimulating factors from human monocytes stimulated by Fc fragments of human IgG.
abstract: The effect of human IgG on human haemopoiesis has been studied in vitro. Dialysed purified IgG stimulated haemopoietic colony growth by bone marrow mononuclear cells (MNC) but not by monocyte-depleted MNC. Culture media, conditioned by IgG-stimulated peripheral blood MNC, augmented formation of neutrophil-macrophage, eosinophil, and megakaryocyte colonies by monocyte-depleted marrow MNC. Serum-free IgG-conditioned media also contained colony-stimulating activity (CSA). IgG Fc fragments and heat-aggregated IgG promoted the secretion of CSA, but F(ab')2 fragments, Fab fragments or ultracentrifuged IgG did not. In the cell-selection studies, CSA was produced by highly enriched monocytes following stimulation with Fc fragments. The antiserum against human granulocyte colony-stimulating factor (G-CSF) and/or granulocyte-macrophage CSF (GM-CSF) neutralized the CSA produced by Fc fragment-activated monocytes. Enzyme immunoassays showed G-CSF and GM-CSF in media conditioned by monocytes stimulated with the Fc fragments, heat-aggregated IgG and anti-D-sensitized red blood cells (RBC). Northern hybridization analysis showed mRNA encoding G-CSF and GM-CSF in RNA extracted from MNC and monocytes cultured with the Fc fragments, but not in the RNA from unstimulated cells or monocyte-depleted MNC. These results indicate that IgG Fc fragments, aggregated IgG and antigen-antibody complexes induce monocytes to produce G-CSF and GM-CSF in vitro. The CSFs release induced by IgG may be involved in the in vivo regulatory network in haemopoiesis.
authors.affiliation: Department of Pediatrics, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Ishiguro
authors.forename: T
authors.initials: T
authors.lastname: Nakahata
authors.forename: K
authors.initials: K
authors.lastname: Koike
authors.forename: H
authors.initials: H
authors.lastname: Yoshida
authors.forename: T
authors.initials: T
authors.lastname: Shimbo
authors.forename: A
authors.initials: A
authors.lastname: Komiyama
mesh_terms: D002455:Cell Division / Q000276:immunology; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D016179:Granulocyte Colony-Stimulating Factor / Q000096:biosynthesis*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000096:biosynthesis*; D006412:Hematopoietic Stem Cells / Q000166:cytology; D006358:Hot Temperature; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology*; D009000:Monocytes / Q000276:immunology*; D011489:Protein Denaturation
chemical_list: D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D016179:Granulocyte Colony-Stimulating Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor