title: Hematopoietic progenitors and synergism of interferon-gamma and stem cell factor.
abstract: Interferon-gamma (IFN-gamma), an immunoregulatory cytokine produced by activated T cells and natural killer cells in response to viral infection or other stimuli, is generally recognized as a suppressor of hematopoiesis. IFN-gamma inhibited in vitro colony formation by granulocyte-macrophage (GM), erythroid and multipotential progenitors. This cytokine exerted direct suppression on the proliferation process, but not on the commitment, of GM progenitors. The antiproliferative effects of IFN-gamma may, in part, result from the prolongation of the doubling time of GM progenitors. Clinically, IFN-gamma may play an important role in the pathogenesis of pancytopenia in aplastic anemia and in the hemophagocytic syndrome. However, as well as showing inhibitory effects, IFN-gamma increased the number of pure and mixed megakaryocyte colonies formed by post-5-fluorouracil treated bone marrow cells and, moreover, the addition of IFN-gamma to culture containing stem cell factor resulted in a synergistic effect on the development of both primitive hematopoietic progenitors and mature populations. These findings suggest that IFN-gamma has bifunctional activity in hematopoiesis.
authors.affiliation: Department of Pediatrics, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Shiohara
authors.forename: K
authors.initials: K
authors.lastname: Koike
authors.forename: T
authors.initials: T
authors.lastname: Nakahata
authors.forename: A
authors.initials: A
authors.lastname: Komiyama
mesh_terms: D000818:Animals; D004357:Drug Synergism; D016298:Hematopoietic Cell Growth Factors / Q000502:physiology*; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000502:physiology*; D006801:Humans; D007371:Interferon-gamma / Q000502:physiology*; D019089:Stem Cell Factor
chemical_list: D016298:Hematopoietic Cell Growth Factors; D019089:Stem Cell Factor; D007371:Interferon-gamma