Abstract
Neutrophils, an abundant cell type at sites of inflammation, have the ability to produce a number of cytokines, including interleukin 1 (IL- 1), IL-8, granulocyte-macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor alpha (TNF-alpha). In this study, we have examined the ability of human neutrophils to produce the IL-1 receptor antagonist (IL-1Ra), a 17-23-kD protein recently isolated and cloned from macrophages. Since IL-1Ra has been shown to inhibit both the in vitro and in vivo effects of IL-1, its production by large numbers of tissue-invading neutrophils might provide a mechanism by which the effects of IL-1 are regulated in inflammation. Using antibodies that are specific for IL-1Ra and a cDNA probe encoding for this protein, we were able to show that neutrophils constitutively produce IL-1Ra. However, after activation by GM-CSF and TNF-alpha, IL-1Ra was secreted into the extracellular milieu where it constituted the major de novo synthesized product of activated neutrophils. None of a large array of other potent neutrophil agonists were found to affect the production of IL-1Ra by neutrophils. Quantitative measurements by enzyme-linked immunosorbent assay revealed that intracellular IL-1Ra is in eightfold excess of the amount secreted in supernatants when studying nonactivated neutrophils. However, in GM-CSF- and TNF-alpha-activated cells, this difference was reduced to values between four- and fivefold, as virtually all of the de novo synthesized IL-1Ra was secreted. In activated cells, the intracellular content of IL-1Ra was found to be in the 2-2.5-ng/ml range per 10(6) neutrophils, whereas levels reached the 0.5-ng/ml range in supernatants. This would imply that IL-1Ra is produced in excess of IL-1 by a factor of at least 100, an observation that is in agreement with the reported amounts of IL-1Ra needed to inhibit the proinflammatory effects of IL-1. Neutrophils isolated from an inflammatory milieu, the synovial fluid of patients with rheumatoid arthritis, were found to respond to GM-CSF and TNF- alpha in terms of IL-1Ra synthesis, indicating that the in vitro observations made in this study are likely to occur in an inflammatory setting in vivo.
Full Text
The Full Text of this article is available as a PDF (653.8 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Arend W. P., Joslin F. G., Thompson R. C., Hannum C. H. An IL-1 inhibitor from human monocytes. Production and characterization of biologic properties. J Immunol. 1989 Sep 15;143(6):1851–1858. [PubMed] [Google Scholar]
- Beaulieu A. D., Paquin R., Rathanaswami P., McColl S. R. Nuclear signaling in human neutrophils. Stimulation of RNA synthesis is a response to a limited number of proinflammatory agonists. J Biol Chem. 1992 Jan 5;267(1):426–432. [PubMed] [Google Scholar]
- Carter D. B., Deibel M. R., Jr, Dunn C. J., Tomich C. S., Laborde A. L., Slightom J. L., Berger A. E., Bienkowski M. J., Sun F. F., McEwan R. N. Purification, cloning, expression and biological characterization of an interleukin-1 receptor antagonist protein. Nature. 1990 Apr 12;344(6267):633–638. doi: 10.1038/344633a0. [DOI] [PubMed] [Google Scholar]
- Eisenberg S. P., Evans R. J., Arend W. P., Verderber E., Brewer M. T., Hannum C. H., Thompson R. C. Primary structure and functional expression from complementary DNA of a human interleukin-1 receptor antagonist. Nature. 1990 Jan 25;343(6256):341–346. doi: 10.1038/343341a0. [DOI] [PubMed] [Google Scholar]
- Georgilis K., Schaefer C., Dinarello C. A., Klempner M. S. Human recombinant interleukin 1 beta has no effect on intracellular calcium or on functional responses of human neutrophils. J Immunol. 1987 May 15;138(10):3403–3407. [PubMed] [Google Scholar]
- Jobin C., Kreis C., Gauthier J., Letarte J., Beaulieu A. D. Differential synthesis of 5-lipoxygenase in peripheral blood and synovial fluid neutrophils in rheumatoid arthritis. J Immunol. 1991 Apr 15;146(8):2701–2707. [PubMed] [Google Scholar]
- Klempner M. S., Dinarello C. A., Gallin J. I. Human leukocytic pyrogen induces release of specific granule contents from human neutrophils. J Clin Invest. 1978 May;61(5):1330–1336. doi: 10.1172/JCI109050. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Klempner M. S., Dinarello C. A., Henderson W. R., Gallin J. I. Stimulation of neutrophil oxygen-dependent metabolism by human leukocytic pyrogen. J Clin Invest. 1979 Oct;64(4):996–1002. doi: 10.1172/JCI109566. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kreis C., La Fleur M., Ménard C., Paquin R., Beaulieu A. D. Thrombospondin and fibronectin are synthesized by neutrophils in human inflammatory joint disease and in a rabbit model of in vivo neutrophil activation. J Immunol. 1989 Sep 15;143(6):1961–1968. [PubMed] [Google Scholar]
- La Fleur M., Beaulieu A. D., Kreis C., Poubelle P. Fibronectin gene expression in polymorphonuclear leukocytes. Accumulation of mRNA in inflammatory cells. J Biol Chem. 1987 Feb 15;262(5):2111–2115. [PubMed] [Google Scholar]
- Marucha P. T., Zeff R. A., Kreutzer D. L. Cytokine regulation of IL-1 beta gene expression in the human polymorphonuclear leukocyte. J Immunol. 1990 Nov 1;145(9):2932–2937. [PubMed] [Google Scholar]
- McColl S. R., Paquin R., Beaulieu A. D. Selective synthesis and secretion of a 23 kD protein by neutrophils following stimulation with granulocyte-macrophage colony-stimulating factor and tumor necrosis factor-alpha. Biochem Biophys Res Commun. 1990 Nov 15;172(3):1209–1216. doi: 10.1016/0006-291x(90)91577-f. [DOI] [PubMed] [Google Scholar]
- Seckinger P., Klein-Nulend J., Alander C., Thompson R. C., Dayer J. M., Raisz L. G. Natural and recombinant human IL-1 receptor antagonists block the effects of IL-1 on bone resorption and prostaglandin production. J Immunol. 1990 Dec 15;145(12):4181–4184. [PubMed] [Google Scholar]
- Tiku K., Tiku M. L., Liu S., Skosey J. L. Normal human neutrophils are a source of a specific interleukin 1 inhibitor. J Immunol. 1986 May 15;136(10):3686–3692. [PubMed] [Google Scholar]
- Wakabayashi G., Gelfand J. A., Burke J. F., Thompson R. C., Dinarello C. A. A specific receptor antagonist for interleukin 1 prevents Escherichia coli-induced shock in rabbits. FASEB J. 1991 Mar 1;5(3):338–343. doi: 10.1096/fasebj.5.3.1825816. [DOI] [PubMed] [Google Scholar]