Effector mechanisms of interleukin-17 in collagen-induced arthritis in the absence of interferon-γ and counteraction by interferon-γ

Introduction  

Interleukin (IL)-17 is a pro-inflammatory cytokine in rheumatoid arthritis (RA) and collagen-induced arthritis (CIA). Since interferon (IFN)-γ inhibits Th17 cell development, IFN-γ receptor knockout (IFN-γR KO) mice develop CIA more readily. We took advantage of this model to analyse the mechanisms of action of IL-17 in arthritis. The role of IFN-γ on the effector mechanisms of IL-17 in an in vitro system was also investigated.     

The relationship between B-cell lymphoma 2, interleukin-1β, interleukin-17, and interleukin-33 and the development of diabetic nephropathy

Molecular Biology Reports - Diabetic nephropathy (DN) is among the main complications of diabetes mellitus and has been a major factor of renal failure. This study was designed to address the...     

Role of interleukin-1β, interleukin-6 and macrophage inflammatory protein-1β in prostaglandin-E2-induced hyperthermia in rats

The purpose of this study was to investigate the role of pyrogenic cytokines, such as IL-1β, IL-6 and MIP-1β, in the mechanisms underlying the hyperthermic response of rats to central injection of PGE₂. Thus, specific murine neutralizing antibodies against these cytokines were microinjected directly into the anterior hypothalamic, preoptic area (AH/POA) of unrestrained rats just before intracerebroventricular injection of PGE₂. The significant hyperthermia induced by PGE₂ was markedly suppressed by micro-injection of anti-IL-6 and partially attenuated by anti-IL-1β. However, the micro-injection of anti-MIP-1β failed to alter the hyperthermic response. The results indicate that PGE₂-induced hyperthermia is presumably mediated through actions of IL-6 on the thermosensitive cells of the AH/POA and confirm that distinct and alternate pathways exist in the rat brain for the induction of fever.     

Interleukin-10 attenuation of collagen-induced arthritis is associated with suppression of interleukin-17 and retinoid-related orphan receptor γt production in macrophages and repression of classically activated macrophages

Introduction

Our objective in the present study was to determine the signaling pathway of interleukin 10 (IL-10) for modulating IL-17 expression in macrophages and the importance of this mediation in collagen-induced arthritis (CIA).

Methods

IL-10-knockout (IL-10^−/−) mice and wild-type (WT) mice were immunized with chicken type II collagen (CII) to induce arthritis. The expression levels of IL-17 and retinoid-related orphan receptor γt (RORγt) in macrophages and joint tissues of IL-10^−/− and WT mice were analyzed by enzyme-linked immunosorbent assay, quantitative RT-PCR (qRT-PCR) and Western blotting. The F4/80 macrophages and positive IL-17-producing macrophages in synovial tissues of the mice were determined by immunohistochemistry. The populations of classically activated macrophage (M1) and alternatively activated macrophage (M2) phenotypes were analyzed by flow cytometry. The expression of genes associated with M1 and M2 markers was analyzed by qRT-PCR.

Results

Compared to WT mice, IL-10^−/− mice had exacerbated CIA development, which was associated with increased production of T helper 17 cell (Th17)/Th1 proinflammatory cytokines and CII-specific immunoglobulin G2a antibody after CII immunization. Macrophages in IL-10^−/− mice had increased amounts of IL-17 and RORγt compared with the amounts in WT mice with CIA. Immunofluorescence microscopy showed that the number of IL-17-producing macrophages in synovial tissues was significantly higher in IL-10^−/− mice than in WT mice. IL-10 deficiency might promote macrophage polarization toward the proinflammatory M1 phenotype, which contributes to the rheumatoid arthritis inflammation response.

Conclusion

IL-10 inhibits IL-17 and RORγt expression in macrophages and suppresses macrophages toward the proinflammatory M1 phenotype, which is important for the role of IL-10 in mediating the pathogenesis of CIA.     

Increasing levels of circulating Th17 cells and interleukin-17 in rheumatoid arthritis patients with an inadequate response to anti-TNF-α therapy

Introduction  

The objective of this study was to investigate the effects of tumor necrosis factor (TNF)-α inhibitors on circulating T helper-type 17 (Th17) cells and Th17-related cytokines in patients with rheumatoid arthritis (RA).     

Interleukin-23 is critical for full-blown expression of a non-autoimmune destructive arthritis and regulates interleukin-17A and RORγt in γδ T cells

Introduction  

Interleukin (IL)-23 is essential for the development of various experimental autoimmune models. However, the role of IL-23 in non-autoimmune experimental arthritis remains unclear. Here, we examined the role of IL-23 in the non-autoimmune antigen-induced arthritis (AIA) model. In addition, the regulatory potential of IL-23 in IL-17A and retinoic acid-related orphan receptor gamma t (RORγt) expression in CD4⁺ and TCRγδ⁺ T cells was evaluated systemically as well as at the site of inflammation.     

Synthesis and biological activities in vitro and in vivo of glycosylated human interleukin-1α, neoglyco IL-1α, coupled with N-acetylneuraminyl-galactose

In order to study the effect of glycosylation on its biological activities, and to develop IL-1α with less deleterious effects, recombinant human IL-1α was chemically coupled with N-acetylneuraminic acid (α1-6) galactose (Neu5Ac-Gal). Glycosylated IL-1α (Neu5Ac-Gal-IL-1α) was purified by anion-exchange chromatography and average number of carbohydrate molecules introduced per molecule of IL-1α was 2.5. Neu5Ac-Gal-IL-1α exhibited reduced activities about 1/15-fold compared to IL-1α in all the activities performed in vitro. Binding affinities of Neu5Ac-Gal-IL-1α to Type I and Type II IL-1 receptors were decreased to 1/15 and 1/10, respectively. Neu5Ac-Gal-IL-1α exhibited reduction in activities in vivo, including induction of serum amyloid A and NO$_x$, and down-regulation of serum glucose. However, Neu5Ac-Gal-IL-1α exhibited comparable activity to IL-1α in improvement of the recovery of peripheral white blood cells from myelosuppression in 5-fluorouracil-treated mice. In addition, tissue level of Neu5Ac-Gal-IL-1α was relatively high compared to IL-1α. These results indicate that coupling with Neu5Ac-Gal enabled us to develop neoIL-1α with selective activities in vivo. Published in 2004. This revised version was published online in July 2006 with corrections to the Cover Date.     

Interleukin-23 is critical for full-blown expression of a non-autoimmune destructive arthritis and regulates interleukin-17A and RORγt in γδ T cells

Introduction

A protein analysis using a mass spectrometry indicated that there are serum proteins showing significant quantitative changes after the administration of infliximab. Among them, connective tissue growth factor (CTGF) seems to be related to the pathogenesis of rheumatoid arthritis (RA). Therefore, this study was conducted to investigate how CTGF is associated with the disease progression of RA.

Methods

Serum samples were collected from RA patients in active or inactive disease stages, and before or after treatments with infliximab. CTGF production was evaluated by ELISA, RT-PCR, indirect immunofluorescence microscopy, and immunoblotting. Osteoclastogenesis was evaluated using tartrate-resistant acid phosphatase (TRAP) staining, a bone resorption assay and osteoclasts specific catalytic enzymes productions.

Results

The serum concentrations of CTGF in RA were greater than in normal healthy controls and disease controls. Interestingly, those were significantly higher in active RA patients compared to inactive RA patients. Furthermore, the CTGF levels significantly were decreased by infliximab concomitant with the disease amelioration. In addition, tumour necrosis factor (TNF)α can induce the CTGF production from synovial fibroblasts even though TNFα can oppositely inhibit the production of CTGF from chondrocytes. CTGF promoted the induction of the quantitative and qualitative activities of osteoclasts in combination with M-CSF and receptor activator of NF-κB ligand (RANKL). In addition, we newly found integrin αVβ3 on the osteoclasts as a CTGF receptor.

Conclusions

These results indicate that aberrant CTGF production induced by TNFα plays a central role for the abnormal osteoclastic activation in RA patients. Restoration of aberrant CTGF production may contribute to the inhibition of articular destruction in infliximab treatment.     

Therapeutic effects of antibodies to tumor necrosis factor-α, interleukin-6 and cytotoxic T-lymphocyte antigen 4 immunoglobulin in mice with glucose-6-phosphate isomerase induced arthritis

Introduction  

Immunization with glucose-6-phosphate isomerase (GPI) induces severe arthritis in DBA/1 mice. The present study was designed to identify the cytokines and co-stimulatory molecules involved in the development of GPI-induced arthritis.     

Changes of glycosylation of serum proteins in Sjögren's syndrome: correlation with interleukin-6 and soluble interleukin-2 receptor

A strong increase of the affinity for concanavalin A (Con A) of serum alpha 2-macroglobulin, a non-acute-phase protein, was observed by lectin blotting in patients with Sj?gren's syndrome (SS). On the contrary, the total Con A reactivity of serum proteins, measured by enzyme-linked lectin assay, was not augmented in SS, compared with normal donors, probably because positive changes of certain proteins were balanced by negative changes of others, as suggested by lectin blotting analysis. However, a significant increase of total Con A reactivity occurred in subjects with increased serum concentrations of soluble interleukin (IL)-2 receptor, compared with patients with normal concentrations of this marker of disease activity. On the other hand, the same parameter did not appear to be different in patients with normal or increased serum concentrations of IL-6, indicating that this cytokine was not probably responsible for the changes of glycosylation described here.     

Molecular characterization, tissue distribution and expression analysis of interleukin-12 receptor β2 chain in sheep

Agnathia-otocephaly is a rare, often lethal malformation characterized by absence or hypoplasia of the mandible, microstomia, hypoglossia/aglossia, and variable anterior midline fusion of the ears (melotia, synotia). Etiologies have been linked to both genetic and teratogenic factors and to date, a definitive, commonly identifiable cause has not been recognized. Mouse and human genetic studies have implicated OTX2 and PRRX1 as potential candidate genes for agnathia-otocephaly. In this study we report a sporadic case of agnathia-otocephaly complex with associated features of maldevelopment and examine the roles of OTX2 and PRRX1. The proband, a male born at 31 weeks, displayed severe micrognathia, microstomia, posteriorly-rotated and low set ears, and downward slanting palpebral fissures. Mutation analysis was performed after sequencing the entire coding regions of OTX2 and PRRX1 genes isolated from the proband and his parents. After thorough analysis, no DNA variations were detected. This suggests that mutations in different genes or environmental causes are responsible.     

Tumor necrosis factor α-induced adipose-related protein expression in experimental arthritis and in rheumatoid arthritis

Introduction  

Tumor necrosis factor-alpha (TNFα) plays a pivotal role in rheumatoid arthritis (RA); however, the mechanism of action of TNFα antagonists in RA is poorly defined. Immunization of DBA/1 mice with glucose-6-phosphate isomerase (GPI) induces severe acute arthritis. This arthritis can be controlled by TNFα antagonists, suggesting similar etiology to RA. In this study, we explored TNFα-related mechanisms of arthritis.     

Paget’s disease of bone is not associated with common polymorphisms in interleukin-6, interleukin-8 and tumor necrosis factor alpha genes

BackgroundCytokines, specially interleukin (IL)-6, play an important role in the differentiation and activation of osteoclasts and might be involved in osteoblast stimulation in Paget’s disease of bone (PDB).ObjectivesThe aim of this study was to investigate the association of polymorphisms in IL-6, IL-8 and tumor necrosis factors-alpha (TNFA) genes among Spanish patients with PDB.MethodsWe studied four single nucleotide polymorphisms (−174 G > C IL-6, −251 T > A IL-8, −238 G > A TNFA and −308 G > A TNFA) in 172 PDB patients and 150 healthy controls. Distribution of alleles and pro-inflammatory genotypes were studied for association with the presence of the disease and with clinical and laboratory data, as well as the response to bisphosphonate treatment in PDB patients.ResultsWe found no statistically significant association between genotype and allele distribution of any of the cytokines polymorphism studied and PDB. No association between the clinical and therapeutic characteristics of PDB and the investigated polymorphism were found.ConclusionsThis study does not support the hypothesis that the analyzed IL6, IL8 and TNFA polymorphism are associated with PDB.     

Tumor necrosis factor α-induced adipose-related protein expression in experimental arthritis and in rheumatoid arthritis

Introduction

Broad-range rDNA PCR provides an alternative, cultivation-independent approach for identifying bacterial DNA in reactive and other form of arthritis. The aim of this study was to use broad-range rDNA PCR targeting the 16S rRNA gene in patients with reactive and other forms of arthritis and to screen for the presence of DNA from any given bacterial species in synovial fluid (SF) samples.

Methods

We examined the SF samples from a total of 27 patients consisting of patients with reactive arthritis (ReA) (n = 5), undifferentiated arthritis (UA) (n = 9), rheumatoid arthritis (n = 7), and osteoarthritis (n = 6) of which the latter two were used as controls. Using broad-range bacterial PCR amplifying a 1400 bp fragment from the 16S rRNA gene, we identified and sequenced at least 24 clones from each SF sample. To identify the corresponding bacteria, DNA sequences were compared to the EMBL (European Molecular Biology Laboratory) database.

Results

Bacterial DNA was identified in 20 of the 27 SF samples (74, 10%). Analysis of a large number of sequences revealed the presence of DNA from more than one single bacterial species in the SF of all patients studied. The nearly complete sequences of the 1400 bp were obtained for most of the detected species. DNA of bacterial species including Shigella species, Escherichia species, and other coli-form bacteria as well as opportunistic pathogens such as Stenotrophomonas maltophilia and Achromobacter xylosoxidans were shared in all arthritis patients. Among pathogens described to trigger ReA, DNA from Shigella sonnei was found in ReA and UA patients. We also detected DNA from rarely occurring human pathogens such as Aranicola species and Pantoea ananatis. We also found DNA from bacteria so far not described in human infections such as Bacillus niacini, Paenibacillus humicus, Diaphorobacter species and uncultured bacterium genera incertae sedis OP10.

Conclusions

Broad-range PCR followed by cloning and sequencing the entire 16S rDNA, allowed the identification of the bacterial DNA environment in the SF samples of arthritic patients. We found a wide spectrum of bacteria including those known to be involved in ReA and others not previously associated with arthritis.     

Constitutive expression of TGF-bêta1, interleukin-6 and interleukin-8 by tumor cells as a major component of immune escape in human ovarian carcinoma

Tumors could use several mechanisms to coexist with the host's immune system or to protect themselves from an immune response. Thus, insufficient expression of cell surface molecules on tumor cells, which are important for T cell recognition or activation, could lead to induction of a state of tolerance. Tumor cells could also produce cytokines that would inhibit the immune response and allow tumor progression. Here, we studied, in vitro, the cell surface expression of immunologically important molecules in seven ovarian carcinoma (OVCA) cell lines and the constitutive expression of cytokines. All OVCA cell lines expressed MHC class I molecules, ICAM-1 and LFA-3 adhesion molecules, necessary to induce a specific cytotoxic T-cell response, as well as the CD40 costimulatory molecules. Conversely, the lack of the dominant costimulatory molecules, CD80 (B7.1) and CD86 (B7.2) could be a possible explanation of poor immunogenicity of OVCA tumors. Immunosuppressive TGF-beta1 was detected at the mRNA level in all cell lines but was weakly secreted in supernatants. By contrast, IL-10 was never found. Most of them constitutively produced IL-8 and IL-6, two cytokines known as tumor promoting factors whereas the proinflammatory cytokines TNF-alpha, IL-1beta and GM-CSF were rarely produced. Data from this study could be useful for designing new strategies of immunotherapy to improve immunogenicity and/or limit protumor cytokine production.     

Interferon-γ, tumor necrosis factor, and interleukin-18 cooperate to control growth of Mycobacterium tuberculosis in human macrophages

Mycobacterium tuberculosis (MTB) remains a leading infectious threat to human health. Macrophages are the cells targeted for infection by the bacterium as well as key effector cells for clearance of the pathogen. Interleukin (IL)-27 opposes macrophage-mediated control of MTB because supplying IL-12 and blocking the activity of IL-27 limits bacterial growth in primary human macrophages. The purpose of this study was to determine the immunological regulators of this macrophage mechanism to restrict MTB growth. Interferon (IFN)-γ, TNF-α, and IL-18 were all demonstrated to be important to the environment that limits bacterial growth when IL-12 is supplied and IL-27 is neutralized. We find IL-18 works in conjunction with IL-12 to achieve optimal IFN-γ production in this system. We also demonstrate novel interactions between these cytokines to influence the expression or responsiveness to one another. Quantitative assays show that IFN-γ enhances expression of the IL-18 receptor signaling chain, as well as TNF expression and secretion. In turn, TNF-α augments expression of the receptor for IFN-γ, the amount at the cell surface, and the extent of IFN-γ -induced signaling. We further define how the cytokine environment supports an enhanced state of classical macrophage activation. Collectively, these results describe novel immunological mechanisms that provide additional insights into the effects of IL-12 and IL-27 on macrophage regulation during MTB infection.