title: Contrasting effects of interferon-gamma and interleukin-4 on the interleukin-6 activity of stimulated human monocytes.
abstract: Stimulated human monocytes/macrophages are a source of interleukin-6 (IL-6), which is a likely mediator involved in immune and inflammatory reactions. The means to control production of IL-6 by these cells could therefore have therapeutic applications. We report here, for lipopolysaccharide (LPS)-stimulated human monocytes in vitro, that the lymphokine, interferon-gamma (IFN-gamma) (100 U/ml), enhanced the level of IL-6 activity, whereas another lymphokine, interleukin-4 (IL-4) (greater than or equal to 0.1 U/ml; greater than or equal to 1.2 x 10(-11) M), suppressed it. The effects of the two lymphokines were manifested at the level of mRNA. The action of the IL-4 was similar to that of the glucocorticoid, dexamethasone, but observed at a lower molar concentration. Such regulation of monocyte IL-6 activity is similar to that found previously for interleukin-1 (IL-1) and tumour necrosis factor-alpha (TNF-alpha) synthesis.
authors.affiliation: University of Melbourne, Department of Medicine, Royal Melbourne Hospital, Parkville, Australia.
authors.forename: D L
authors.initials: DL
authors.lastname: Cheung
authors.forename: P H
authors.initials: PH
authors.lastname: Hart
authors.forename: G F
authors.initials: GF
authors.lastname: Vitti
authors.forename: G A
authors.initials: GA
authors.lastname: Whitty
authors.forename: J A
authors.initials: JA
authors.lastname: Hamilton
mesh_terms: D003907:Dexamethasone / Q000276:immunology; D004334:Drug Administration Schedule; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology*; D015847:Interleukin-4 / Q000008:administration & dosage / Q000276:immunology*; D015850:Interleukin-6 / Q000235:genetics / Q000276:immunology*; D008070:Lipopolysaccharides / Q000276:immunology; D009000:Monocytes / Q000276:immunology*; D012333:RNA, Messenger / Q000032:analysis; D011994:Recombinant Proteins / Q000276:immunology
chemical_list: D015850:Interleukin-6; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D011994:Recombinant Proteins; D015847:Interleukin-4; D003907:Dexamethasone; D007371:Interferon-gamma