title: Cytokine regulation of bone marrow natural suppressor cell activity in the suppression of lymphocyte function.
abstract: Natural suppressor (NS) cells, which nonspecifically suppress immune responses, are present in the spleen following exposure to radiation, chronic graft-versus-host disease, or cancer and in normal bone marrow. A model system is described which allows the study of cytokines activating and inhibiting NS cells, cytokines mediating NS activity, and NS effects on cytokine synthesis. Recombinant interleukin-3 (rIL-3) and granulocyte-macrophage colony-stimulating factor (rGM-CSF) efficiently activated NS cells present in normal bone marrow and were effective at concentrations as low as 5 U/ml. At high concentrations, GM-CSF, but not IL-3, did not activate NS cells. Recombinant interferon-gamma (rIFN-gamma) blocked the activation of bone marrow NS cells by rIL-3, but did not down-regulate NS cells once activated. The NS cells secreted one or more soluble suppressor factors, which blocked IL-2 synthesis and also inhibited IL-2-dependent T cell proliferation in the presence of excess IL-2.
authors.affiliation: Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock 72205.
authors.forename: S C
authors.initials: SC
authors.lastname: Moore
authors.forename: S A
authors.initials: SA
authors.lastname: Theus
authors.forename: J B
authors.initials: JB
authors.lastname: Barnett
authors.forename: L S
authors.initials: LS
authors.lastname: Soderberg
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000187:drug effects; D001854:Bone Marrow Cells; D002478:Cells, Cultured; D003470:Culture Media / Q000494:pharmacology; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D007371:Interferon-gamma / Q000494:pharmacology; D007376:Interleukin-2 / Q000494:pharmacology; D007377:Interleukin-3 / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D011994:Recombinant Proteins / Q000494:pharmacology; D013154:Spleen / Q000166:cytology / Q000187:drug effects; D013491:Suppressor Factors, Immunologic / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects* / Q000378:metabolism
chemical_list: D003470:Culture Media; D007376:Interleukin-2; D007377:Interleukin-3; D011994:Recombinant Proteins; D013491:Suppressor Factors, Immunologic; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor