title: Interleukin-4 regulation of human monocyte and macrophage interleukin-10 and interleukin-12 production. Role of a functional interleukin-2 receptor gamma-chain.
abstract: Interleukin-4 (IL-4) is the prototypic type 2 immunoregulatory cytokine that can suppress the production of many monocyte and macrophage pro-inflammatory mediators. In this study we investigated the regulation by IL-4 of IL-12 and IL-10 production. While IL-4 suppressed lipopolysaccharide (LPS)-induced IL-12 and IL-10 production by human peripheral blood monocytes, IL-4 suppressed LPS-induced IL-12, but not IL-10, production by synovial fluid mononuclear cells from patients with rheumatoid arthritis. IL-4 also suppressed IL-12, but not IL-10 production, by LPS-stimulated in vitro monocyte-derived macrophages. Similarly, IL-4 cannot suppress LPS-induced tumour necrosis factor-alpha (TNF-alpha) production by synovial fluid cells and monocyte-derived macrophages. The failure of IL-4 to regulate IL-10 production is not due to the failure of IL-4 to suppress TNF-alpha, and vice versa. The data suggest that the IL-4 receptor subunit, gammac, is essential for IL-4 regulation of LPS-induced IL-10 production and that a correlation exists between duration of monocyte culture, reduction in gammac mRNA in cultured cells and hyporesponsiveness of monocyte-derived macrophages to IL-4 for regulation of LPS-induced IL-10 production. This study highlights the importance of investigating responses to IL-4, as a potential therapeutic anti-inflammatory agent, by cells isolated from inflammatory sites and not by the more easily accessible blood monocytes. This study emphasizes the involvement of signalling from gammac in IL-4 regulation of LPS-induced IL-10 production by monocytes and macrophages.
authors.affiliation: Department of Microbiology and Infectious Diseases, School of Medicine, Flinders University of South Australia, GPO Box 2100, Adelaide, Australia 5001.
authors.forename: C S
authors.initials: CS
authors.lastname: Bonder
authors.forename: J J
authors.initials: JJ
authors.lastname: Finlay-Jones
authors.forename: P H
authors.initials: PH
authors.lastname: Hart
mesh_terms: D001172:Arthritis, Rheumatoid / Q000276:immunology*; D018929:Cell Culture Techniques; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D016753:Interleukin-10 / Q000096:biosynthesis / Q000235:genetics; D018664:Interleukin-12 / Q000096:biosynthesis; D015847:Interleukin-4 / Q000276:immunology*; D008264:Macrophages / Q000276:immunology*; D009000:Monocytes / Q000276:immunology*; D012333:RNA, Messenger / Q000235:genetics; D018123:Receptors, Interleukin / Q000235:genetics; D053701:Receptors, Interleukin-10; D015375:Receptors, Interleukin-2 / Q000276:immunology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013582:Synovial Fluid / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D012333:RNA, Messenger; D018123:Receptors, Interleukin; D053701:Receptors, Interleukin-10; D015375:Receptors, Interleukin-2; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D018664:Interleukin-12; D015847:Interleukin-4