scholarly journals Interleukin 6 Is Required for the Development of Collagen-induced Arthritis

1998 ◽  
Vol 187 (4) ◽  
pp. 461-468 ◽  
Author(s):  
Tonino Alonzi ◽  
Elena Fattori ◽  
Domenico Lazzaro ◽  
Patrizia Costa ◽  
Lesley Probert ◽  
...  

Interleukin-6 (IL-6) is overproduced in the joints of patients with rheumatoid arthritis (RA) and, based on its multiple stimulatory effects on cells of the immune system and on vascular endothelia, osteoclasts, and synovial fibroblasts, is believed to participate in the development and clinical manifestations of this disease. In this study we have analysed the effect of ablating cytokine production in two mouse models of arthritis: collagen-induced arthritis (CIA) in DBA/1J mice and the inflammatory polyarthritis of tumor necrosis factor α (TNF-α) transgenic mice. IL-6 was ablated by intercrossing an IL-6 null mutation into both arthritis-susceptible genetic backgrounds and disease development was monitored by measuring clinical, histological, and biochemical parameters. Two opposite responses were observed; while arthritis in TNF-α transgenic mice was not affected by inactivation of the IL-6 gene, DBA/1J, IL-6−/− mice were completely protected from CIA, accompanied by a reduced antibody response to type II collagen and the absence of inflammatory cells and tissue damage in knee joints. These results are discussed in the light of the present knowledge of cytokine networks in chronic inflammatory disorders and suggest that IL-6 receptor antagonists might be beneficial for the treatment of RA.

2002 ◽  
Vol 282 (4) ◽  
pp. L735-L742 ◽  
Author(s):  
James L. Carroll ◽  
Diann M. McCoy ◽  
Stephen E. McGowan ◽  
Ronald G. Salome ◽  
Alan J. Ryan ◽  
...  

Tumor necrosis factor (TNF)-α is a major cytokine implicated in inducing acute and chronic lung injury, conditions associated with surfactant phosphatidylcholine (PtdCho) deficiency. Acutely, TNF-α decreases PtdCho synthesis but stimulates surfactant secretion. To investigate chronic effects of TNF-α, we investigated PtdCho metabolism in a murine transgenic model exhibiting lung-specific TNF-α overexpression. Compared with controls, TNF-α transgenic mice exhibited a discordant pattern of PtdCho metabolism, with a decrease in PtdCho and disaturated PtdCho (DSPtdCho) content in the lung, but increased levels in alveolar lavage. Transgenics had lower activities and increased immunoreactive levels of cytidylyltransferase (CCT), a key PtdCho biosynthetic enzyme. Ceramide, a CCT inhibitor, was elevated, and linoleic acid, a CCT activator, was decreased in transgenics. Radiolabeling studies revealed that alveolar reuptake of DSPtdCho was significantly decreased in transgenic mice. These observations suggest that chronic expression of TNF-α results in a complex pattern of PtdCho metabolism where elevated lavage PtdCho may originate from alveolar inflammatory cells, decreased surfactant reuptake, or altered surfactant secretion. Reduced parenchymal PtdCho synthesis appears to be attributed to CCT enzyme that is physiologically inactivated by ceramide or by diminished availability of activating lipids.


2002 ◽  
Vol 11 (5) ◽  
pp. 325-328 ◽  
Author(s):  
E. Jablonska

Background: It has recently been shown that soluble interleukin-6 receptor (sIL-6R) alone or complexed with interleukin (IL)-6, besides their regulatory role in a wide variety of both normal and abnormal biologic reactions mediated by IL-6, could be an effective stimulator of the cell function.Aims: The key question of the present study is whether the sIL-6Rα or sIL-6R with IL-6 released by polymorphonuclear leukocytes (PMN) can influence cytokine secretion such as tumor necrosis factor-α (TNF-α) by peripheral blood mononuclear cells (PBMC), which together with PMN develop the inflammatory and immune response of a host.Methods: Cells were isolated from heparinized whole blood of healthy persons. The PMN were cultured for 1 h at 37°C in 5% CO2. After incubation, the culture supernatant of PMN was removed and was added to PBMC. The PBMC were cultured for 1 h at 37°C in the same conditions. In the culture supernatants and lysates of PMN, we examined the concentrations of sIL-6R by enzyme-linked immunosorbent assay (ELISA). TNF-α was measured at both protein and mRNA levels. Protein levels were determined by ELISA. To examine TNF-α mRNA expression, we isolated mRNA from PBMC after culture, using TRIZOL Reagent. The quantity of mRNA TNF-α was determined by the Quantikine mRNA assay.Results and conclusion: The results obtained revealed that sIL-6R with IL-6 secreted by PMN may play a regulatory role in the immune response by modulating the TNF-α expression and its production by PBMC. This may have a significant influence on an early phase of the inflammation and other reactions mediated by TNF-α.


1995 ◽  
Vol 144 (3) ◽  
pp. 457-462 ◽  
Author(s):  
G Haskó ◽  
I J Elenkov ◽  
V Kvetan ◽  
E S Vizi

Abstract The effect of selective block of α2-adrenoreceptors on plasma levels of tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6) and corticosterone induced by bacterial lipopolysaccharide (LPS) was investigated in mice using ELISA and RIA. It was found that the LPS-induced TNF-α response was significantly blunted in mice pretreated with CH-38083, a novel and highly selective α2-adrenoreceptor antagonist (the α2/α1 ratio is >2000). In contrast, LPS-induced increases in both corticosterone and IL-6 plasma levels were further increased by CH-38083. Since it has recently been shown that the selective block of α2-adrenoreceptors located on noradrenergic axon terminals resulted in an increase in the release of noradrenaline (NA), both in the central and peripheral nervous systems, and, in our experiments, that propranolol prevented the effect of α2-adrenoreceptor blockade on TNF-α plasma levels induced by LPS, it seems likely that the excessive stimulation by NA of β-adrenoreceptors located on cytokine-secreting immune cells is responsible for this action. Since it is generally accepted that increased production of TNF-α is involved in the pathogenesis of inflammation and endotoxin shock on the one hand, and corticosterone and even IL-6 are known to possess anti-inflammatory properties on the other hand, it is suggested that the selective block of α2-adrenoreceptors might be beneficial in the treatment of inflammation and/or endotoxin shock. Journal of Endocrinology (1995) 144, 457–462


1989 ◽  
Vol 32 (5) ◽  
pp. 594-600 ◽  
Author(s):  
Yasuyuki Takai ◽  
Nobuo Seki ◽  
Hachiro Senoh ◽  
Takashi Yokota ◽  
Frank Lee ◽  
...  

1999 ◽  
Vol 277 (3) ◽  
pp. G702-G708 ◽  
Author(s):  
Alix de la Coste ◽  
Monique Fabre ◽  
Nathalie McDonell ◽  
Arlette Porteu ◽  
Helène Gilgenkrantz ◽  
...  

Fas ligand (CD95L) and tumor necrosis factor-α (TNF-α) are pivotal inducers of hepatocyte apoptosis. Uncontrolled activation of these two systems is involved in several forms of liver injury. Although the broad antiapoptotic action of Bcl-2 and Bcl-xL has been clearly established in various apoptotic pathways, their ability to inhibit the Fas/CD95- and TNF-α-mediated apoptotic signal has remained controversial. We have demonstrated that the expression of BCL-2 in hepatocytes protects them against Fas-induced fulminant hepatitis in transgenic mice. The present study shows that transgenic mice overexpressing[Formula: see text]in hepatocytes are also protected from Fas-induced apoptosis in a dose-dependent manner. Bcl-xL and Bcl-2 were protective without any change in the level of endogenous[Formula: see text]or Bax and inhibited hepatic caspase-3-like activity. In vivo injection of TNF-α caused massive apoptosis and death only when transcription was inhibited. Under these conditions,[Formula: see text]mice were partially protected from liver injury and death but PK-BCL-2 mice were not. A similar differential protective effect of Bcl-xL and Bcl-2 transgenes was observed when Fas/CD95 was activated and transcription blocked. These results suggest that apoptosis triggered by activation of both Fas/CD95 and TNF-α receptors is to some extent counteracted by the transcription-dependent protective effects, which are essential for the antiapoptotic activity of Bcl-2 but not of Bcl-xL. Therefore, Bcl-xL and Bcl-2 appear to have different antiapoptotic effects in the liver whose characterization could facilitate their use to prevent the uncontrolled apoptosis of hepatocytes.


1995 ◽  
Vol 132 (6) ◽  
pp. 668-672 ◽  
Author(s):  
Ismail Çelik ◽  
Sema Akalin ◽  
Tomris Erbaş

Çelik I, Akalin S, Erbaş T. Serum levels of interleukin 6 and tumor necrosis factor-α in hyperthyroid patients before and after propylthiouracil treatment. Eur J Endocrinol 1995;132:668–72. ISSN 0804–4643 Contrary to the usual inhibitory role of tumor necrosis factor-α (TNF-α) thyroid metabolism, it also has specific stimulatory effects in autoimmune thyroid disorders, including induction of HLA class II antigen-presenting cell—T cell interaction. Despite high intrathyroidal concentrations, various studies were not able to demonstrate high serum levels of TNF-α in patients with Graves' disease. To investigate this discrepancy we determined TNF-α and interleukin 6 (IL-6) levels in 25 hyperthyroid patients who responded to propylthiouracil treatment (16 with Graves' disease and nine with toxic multinodular goiter) and compared them with the levels found in euthyroid patients with simple diffuse goiter (n = 15) and normal healthy controls (n = 15). Median IL-6 levels were high in both Graves' disease and toxic multinodular goiter patients before propylthiouracil treatment (23 and 26.5 pg/ml, respectively). After restoring euthyroidism there was a statistically significant decline to near-normal levels (3 and 10 pg/ml, respectively). On the other hand, median serum TNF-α levels were high only in Graves' disease patients (20 pg/ml) and could not be normalized with antithyroid medication (20 pg/ml) compared to that of controls (5 pg/ml). Tumor necrosis factor-α, but not IL-6, was found to be high in the sera of Graves' disease patients when euthyroid, which may be due to an ongoing antigen–antibody interaction, a feature of autoimmune attack. It remains to be determined whether the degree of TNF-α and/or IL-6 elevation will be a predictor of disease recurrence. Ismail Çelik, Section of Oncology, Dept. of Medicine, Hacettepe University Institute of Oncology, Ankara 06100, Turkey


2012 ◽  
Vol 39 (5) ◽  
pp. 979-985 ◽  
Author(s):  
ALESSANDRO ANTONELLI ◽  
POUPAK FALLAHI ◽  
SILVIA MARTINA FERRARI ◽  
DILIA GIUGGIOLI ◽  
MICHELE COLACI ◽  
...  

Objective.We evaluated the effect of interferon-γ (IFN-γ) and/or tumor necrosis factor-α (TNF-α) on the secretion of prototype proinflammatory cytokine interleukin 6 (IL-6), compared to T-helper 1 [Th1; chemokine (C-X-C motif) ligand 10 (CXCL10)] or Th2 [chemokine (C-C motif) ligand 2 (CCL2)] chemokines, in primary cultured fibroblasts from patients with systemic sclerosis (SSc) at an early stage of the disease.Methods.Fibroblast cultures from 5 SSc patients (disease duration < 2 yrs) and 5 healthy controls were evaluated for the production of IL-6, CXCL10, and CCL2 at the basal level and after stimulation with IFN-γ and/or TNF-α.Results.SSc fibroblasts basally produced higher levels of IL-6 than controls, while no difference was observed about CCL2 and CXCL10. TNF-α was able to dose-dependently induce IL-6 and CCL2 secretion in SSc, but not in control fibroblasts. By stimulation with increasing doses of IFN-γ, SSc fibroblasts were induced to secrete CCL2 and CXCL10, while no effect was observed on IL-6. The combination of IFN-γ and TNF-α induced a strong secretion of IL-6 and CCL2 in SSc fibroblasts but not in controls. In contrast, the synergistic effect of IFN-γ and TNF-α on CXCL10 secretion was similar in SSc fibroblasts and in controls.Conclusion.SSc fibroblasts participate in the self-perpetuation of inflammation by releasing IL-6, CXCL10, and CCL2 under the influence of IFN-γ and/or TNF-α. SSc fibroblasts are more active than controls in the secretion of IL-6 at baseline, and in the production of IL-6 and CCL2 under the combined IFN-γ/TNF-α stimulation.


Gut ◽  
1998 ◽  
Vol 42 (2) ◽  
pp. 208-213 ◽  
Author(s):  
A C Warhurst ◽  
S J Hopkins ◽  
G Warhurst

Background—Production of chemoattractant factors by the intestinal epithelium may contribute to mucosal infiltration by inflammatory cells in inflammatory bowel disease. Secretion of the α chemokine interleukin 8 (IL-8), a neutrophil chemoattractant, has been widely studied, but little is known about epithelial secretion of β chemokines, which are preferentially involved in recruiting monocytes.Aims—To investigate the profiles of α and β chemokine secretion in colonic cell lines and their differential modulation by interferon γ (IFN-γ), a product of activated T lymphocytes and natural killer cells.Methods and results—HT29-19A, a model of the Cl− secretory crypt cell, exhibited a parallel secretion of the α chemokines IL-8 and GROα, which could be markedly upregulated by tumour necrosis factor α (TNF-α) and IL-1β. These cells showed no significant expression of the β chemokines RANTES (regulated upon activation T cell expressed and secreted), MIP-1α (macrophage inflammatory protein 1α), and MCP-1 (monocyte chemotactic protein 1) under these conditions, but IFN-γ in combination with TNF-α caused a dose dependent induction of RANTES and MCP-1 secretion. This was accompanied by a marked increase of RANTES mRNA. In contrast, IFN-γ had no significant effect on TNF-α stimulated IL-8 secretion. Caco-2 cells, with features more typical of villus absorptive cells, were relatively poor secretors of α chemokines but secreted high levels of MCP-1 in response to IL-1β. IFN-γ did not influence α or β chemokine secretion in these cells.Conclusions—These studies suggest that intestinal epithelial cells may produce chemokines capable of attracting both neutrophils and monocytes. The ability of IFN-γ to activate the expression of β chemokines preferentially could facilitate the development of chronic inflammatory infiltrates.


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