OBJECTIVE

The peroxisome proliferator-activated receptor gamma (PPARgamma) is a member of the nuclear receptor superfamily of ligand-dependent transcription factors related to retinoid, steroid, and thyroid hormone receptors. The thiazolidinedione rosiglitazone is a PPARgamma ligand that modulates the transcription of target genes. The aim of this study was to investigate the effects of rosiglitazone on the inflammatory response in mice with collagen-induced arthritis (CIA).

METHODS

CIA was induced in DBA/1J mice by an intradermal injection of 100 microl of an emulsion of bovine type II collagen (CII; 100 microg) in Freund's complete adjuvant (CFA) at the base of the tail. On day 21, a second injection of CII in CFA was administered. Rosiglitazone (10 mg/kg/day) or vehicle (10% DMSO) was administered beginning on day 25 (arthritis onset) until day 35. Clinical, radiographic, histopathologic, and laboratory assessments were performed.

RESULTS

Mice immunized with CII in CFA developed erosive arthritis of the hind paws. Macroscopic evidence of CIA first appeared as periarticular erythema and edema of the hind paws. The incidence of CIA was 100% by day <em>27</em> in the CII-challenged mice, and the severity progressed over the 35-day study period. Radiographic evaluation revealed focal resorption of bone. Histopathologic features of CIA included erosion of cartilage at the joint margins. Rosiglitazone treatment ameliorated the clinical signs on days 26-35 and improved the histologic findings in the joint and paw. The degree of oxidative and nitrosative damage was significantly reduced in rosiglitazone-treated mice, as indicated by elevation of malondialdehyde levels, formation of nitrotyrosine, and activation of poly(ADP-ribose) polymerase. Plasma levels of the proinflammatory cytokines tumor necrosis factor, <em>interleukin</em>-1beta, and <em>interleukin</em>-6 were also significantly reduced by rosiglitazone treatment.

CONCLUSIONS

These data demonstrate that rosiglitazone exerts an antiinflammatory effect on chronic inflammation and is able to ameliorate the tissue damage associated with CIA.

Glioblastoma multiforme (GBM) is one of the most lethal forms of cancer, with a survival rate of only 13% to <em>27</em>% within 2 years of diagnosis despite optimal medical treatment. We hypothesize that the presence of a unique IL-13Rα2 decoy receptor prevents GBM apoptosis. This receptor has a high affinity for <em>interleukin</em>-13 (IL-13), binds the cytokine, and competitively inhibits the intracellular signaling cascade initiated by IL-13. In cells lacking the IL-13Rα2 decoy receptor, IL-13 initiates the production of 15-lipoxygenase-1 (15-LOX-1), which has been implicated in cellular apoptosis. Our group and others have shown that induction of 15-LOX-1 correlates with tumor cell death in colorectal, pancreatic, and prostate cancer. How 15-LOX-1 induces apoptosis remains unclear. Preliminary evidence in GBM cells implicates an apoptotic process mediated by PPARγ. 15-LOX-1 metabolites can modulate PPARγ and activation of PPARγ can suppress tumor growth. We hypothesize that in GBM, IL-13 can induce 15-LOX-1, which regulates cell apoptosis via signaling through PPARγ and that expression of IL-13Rα2 prevents apoptosis and contributes to tumor growth. Our in vitro and in vivo data support this. Knocking down IL-13Rα2 with short interfering RNA dramatically induces 15-LOX-1 expression, promotes apoptosis, and reduces GBM tumor growth in vivo. These findings identify a mechanism for eliminating the blockade of endogenous IL-13 signaling and for promotion of apoptosis, and characterize a role for 15-LOX-1 in GBM apoptosis. Identifying a mechanistic pathway that can be targeted for pharmacologic intervention will have applied implications to developing novel and effective treatments of GBM.

Calcium stone formers (CaSF) with idiopathic hypercalciuria (IH) have been shown to have decreased bone mineral density (BMD). The mechanism of their bone loss remains obscure. Monokines like <em>interleukin</em>-1 beta (IL-1 beta), IL-6, tumor necrosis factor-alpha (TNF-alpha), and granulocyte macrophage stimulating factor (GM-CSF) are involved in bone remodeling, but only IL-1 excess has been incriminated in the bone loss of CaSF with IH. Therefore, to more precisely delineate the role of monocyte activation in the pathogenesis of bone loss in these patients, we studied the production of IL-1 beta, IL-6, TNF-alpha, and GM-CSF by unstimulated or lipopolysaccharide (LPS)-stimulated cultured peripheral blood monocytes in 15 CaSF with IH, in 10 CaSF with dietary calcium-dependent hypercalciuria (DH), and in 10 healthy controls (C). Cytokines were measured in the culture medium by sensitive enzyme-linked immunosorbent assay and vertebral BMD by single energy computed tomography. The decrease of vertebral BMD in IH compared with DH, was confirmed (Z score: -1.2 +/- 0.2 vs. -0.5 +/- 0.2; P = 0.04; Mann-Whitney). In the supernatant of unstimulated peripheral blood monocytes, IL-1 beta and TNF-alpha levels were higher in IH than in C (respectively, 40 +/- 21 vs. 7 +/- 1 pg/mL, P = 0.008 and 236 +/- 136 vs. 39 +/- 23 pg/mL, P = 0.03); those of GM-CSF were greater in IH than in DH and C (respectively, 52 +/- <em>27</em> vs. 6 +/- 2, P = 0.04 and 6 +/- 2 pg/mL, P = 0.01) and those of IL-6 were not significantly different among the groups. After in vitro stimulation by LPS (10 micrograms/mL), the levels of the various monokines were not significantly different. In IH patients, the post-LPS levels of IL-6 were negatively correlated to vertebral BMD (n = 15, Z = -1.97, P = 0.04; Spearman), whereas those of GM-CSF were positively related to vertebral BMD (n = 15, Z = 2.01, P = 0.04). In this study, calcium stone formers with IH have bone mineral decrease and a particular profile of peripheral blood monocytes activation. This latter is characterized by a spontaneously increased synthesis of IL-1 beta, TNF-alpha, and GM-CSF. Furthermore, post-LPS levels of IL-6 and GM-CSF are correlated with vertebral BMD. These results suggest that monocyte activation may be involved in the bone loss of calcium stone formers with IH.

OBJECTIVE

To evaluate markers of infection in critically ill neonates and children, comparing lipopolysaccharide-binding protein (LBP) with procalcitonin (PCT), interleukin-6 (IL-6), and C-reactive protein (CRP).

METHODS

Prospective, observational study in the level III multidisciplinary neonatal and pediatric intensive care unit.

METHODS

Sixty patients with systemic inflammatory response syndrome (SIRS) and suspected infection classified into two groups: SIRS/sepsis ( n=33) and SIRS/no sepsis ( n=27). We included 29 neonates aged less than 48 h (neonates <48 h), 12 neonates older than 48 h (neonates >48 h), and 19 children. Median disease severity was high in neonates aged under 48 h and moderate in neonates aged over 48 h and children.

METHODS

Serum LBP, PCT, IL-6, and CRP were measured on two consecutive days. Area under the receiver operating characteristic (ROC) curve (AUC), sensitivity, specificity, and predictive values were evaluated.

RESULTS

Serum LBP was higher in patients with SIRS/sepsis than in patients with SIRS/no sepsis. AUC for LBP on the first day of suspected infection was 0.89 in the younger neonates, 0.93 in the older neonates, and 0.91 in children.

CONCLUSIONS

In critically ill neonates aged under 48 h LBP on the first day of suspected infection is a better marker of sepsis than IL-6 and PCT, and is similar to CRP. In critically ill neonates aged over 48 h and children LBP is a better marker than IL-6 and CRP, and is similar to PCT.

To elucidate the local tissue cytokine response of dogs infected with Leishmania chagasi, cytokine mRNA levels were measured in bone marrow aspirates from <em>27</em> naturally infected dogs from Brazil and were compared with those from 5 uninfected control animals. Interferon-gamma mRNA accumulation was enhanced in infected dogs and was positively correlated with humoral (IgG1) but not with lymphoproliferative responses to Leishmania antigen in infected dogs. Increased accumulation of mRNA for <em>interleukin</em> (IL)-4, IL-10, and IL-18 was not observed in infected dogs, and mRNA for these cytokines did not correlate with antibody or proliferative responses. However, infected dogs with detectable IL-4 mRNA had significantly more severe symptoms. IL-13 mRNA was not detectable in either control or infected dogs. These data suggest that clinical symptoms are not due to a deficiency in interferon-gamma production. However, in contrast to its role in human visceral leishmaniasis, IL-10 may not play a key immunosuppressive role in dogs.

OBJECTIVE

Although underlying mechanisms of coronary artery ectasia (CAE) are clearly unknown, destruction of extracellular matrix may be responsible for the ectasia formation. Thus, we investigated the role of matrix metalloproteinases (MMP), tissue inhibitor of matrix metalloproteinases (TIMP-1), and inflammatory markers [high-sensitive C-reactive protein, interleukins (ILs)] in CAE patients.

METHODS

This study consisted of 28 consecutive CAE patients, 27 obstructive coronary artery disease (CAD) patients, and 22 controls with normal coronary arteries undergoing cardiac catheterization. Plasma levels of MMP-3, MMP-9, TIMP-1, and inflammatory markers were measured.

RESULTS

Plasma level of MMP-3 was significantly higher in CAE patients compared with both CAD patients and controls (17.2+/-6.1, 11.2+/-3.2, and 9.2+/-3.4 ng/ml, respectively, both P=0.001) and so did MMP-9 level (27.4+/-5.9, 24.8+/-4.4, and 20.6+/-4.6 ng/ml, respectively, both P<0.05). IL-6 level was also higher in CAE patients than in controls (60.9+/-22.1 vs. 36.1+/-21.5 pg/ml, P=0.001) but were comparable in CAE and CAD patients. Plasma high-sensitive C-reactive protein, IL-1, and TIMP-1 levels were similar in three groups. MMP-3 levels correlated with diffuse (r=0.46, P=0.01) and multivessel ectasia (r=0.45, P=0.02).

CONCLUSIONS

Our results suggest that the increased level of MMP-3, MMP-9, and IL-6 may be responsible for ectasia formation in patients with CAE.

OBJECTIVE

Treatment of inflammatory bowel disease would benefit from specific targeting of therapeutics to the intestine. We developed a strategy for localized delivery of the immunosuppressive cytokine <em>interleukin</em> (IL)-<em>27</em>, which is synthesized actively in situ by the food-grade bacterium Lactococcus lactis (LL-IL-<em>27</em>), and tested its ability to reduce colitis in mice.

METHODS

The 2 genes encoding mouse IL-<em>27</em> were synthesized with optimal codon use for L lactis and joined with a linker; a signal sequence was added to allow for product secretion. The construct was introduced into L lactis. Colitis was induced via transfer of CD4(+)CD45RB(hi) T cells into Rag(-/-) mice to induce colitis; 7.5 weeks later, LL-IL-<em>27</em> was administered to mice via gavage. Intestinal tissues were collected and analyzed.

RESULTS

LL-IL-<em>27</em> administration protected mice from T-cell transfer-induced enterocolitis and death. LL-IL-<em>27</em> reduced disease activity scores, pathology features of large and small bowel, and levels of inflammatory cytokines in colonic tissue. LL-IL-<em>27</em> also reduced the numbers of CD4(+) and IL-17(+) T cells in gut-associated lymphoid tissue. The effects of LL-IL-<em>27</em> required production of IL-10 by the transferred T cells. LL-IL-<em>27</em> was more effective than either LL-IL-10 or systemic administration of recombinant IL-<em>27</em> in reducing colitis in mice. LL-IL-<em>27</em> also reduced colitis in mice after administration of dextran sodium sulfate.

CONCLUSIONS

LL-IL-<em>27</em> reduces colitis in mice by increasing the production of IL-10. Mucosal delivery of LL-IL-<em>27</em> could be a more effective and safer therapy for inflammatory bowel disease.

<em>Interleukin</em>-2 (IL-2) is one of the most studied cytokines driving T-cell proliferation, activation and survival. It binds to the IL-2 receptor consisting of three chains, the α (CD25), β and common γ (γc). The binding of the CD25 chain to IL-2 is necessary to expose high-affinity binding sites for the β and γc chains, which, in turn, are responsible for downstream signalling. A high level of soluble CD25 (sCD25) has been associated with a poor prognosis in patients with non-Hodgkin's lymphoma. The function and source of origin of this soluble receptor is not well investigated. In the present study we hypothesized that T regulatory (Treg) cells may release CD25 to act as a decoy receptor for IL-2, thereby depriving T-effector cells of IL-2. Peripheral blood from patients with B-cell malignancies (n = 26) and healthy controls (n = <em>27</em>) was investigated for the presence and function of FoxP3(+) Treg cells and sCD25 by multi-colour flow cytometry and enzyme-linked immunosorbent assay. Further, the proliferative capacity of T cells was evaluated with or without the presence of recombinant sCD25. The results demonstrate that Treg cells from patients had lower CD25 expression intensity and that they released CD25 in vitro. Further, high levels of Treg cells correlated with sCD25 plasma concentration. Recombinant sCD25 could suppress T-cell proliferation in vitro. In conclusion, the release of sCD25 by Treg cells may be a mechanism to deprive IL-2 and thereby inhibit anti-tumour T-cell responses.

OBJECTIVE

Circulating plasma interleukin-6 (IL-6) concentrations are elevated in patients with abdominal aortic aneurysms (AAAs) compared with controls. In vitro studies suggest that the aneurysm is the source of the IL-6. Because IL-6 is an independent risk factor for cardiovascular mortality, elevation of this cytokine may be significant in these patients, who represent a group at increased risk from cardiovascular death. The aim of this study was to directly measure in vivo aortic IL-6 concentrations, testing the hypothesis that aneurysms secrete IL-6 into the circulation.

METHODS

Before endovascular aneurysm repair took place, blood was sampled from the entire length of the aorta in 27 patients with AAA and nine with thoracic aneurysms (TAs). A control group consisted of 15 patients without aneurysms undergoing angiography. Plasma IL-6 was determined using enzyme-linked immunosorbent assay, and high-sensitivity C-reactive protein (hs-CRP) was measured turbidimetrically. Aneurysm surface area was calculated from axial computed tomography scans.

RESULTS

Mean IL-6 concentrations (pg/mL) were higher in the TA and AAA groups compared with controls (10.4 +/- 3.7 and 4.9 +/- 0.5 vs 2.7 +/- 0.5, P = .002). There was a significant difference in plasma IL-6 concentration corresponding to aneurysm position in the AAA (P = .002) and TA (P = .008) groups, with both patterns conforming to a linear trend. This pattern was not observed in the control group, in which no significant difference in IL-6 concentrations was found throughout the aorta. Peak IL-6 occurred earlier in TAs compared with AAAs (descending aorta vs iliac artery) corresponding to aneurysm position (P = .0007). Linear regression revealed a positive correlation between aneurysm surface area and mean plasma IL-6 (Spearman's correlation, P = .003). The mean surface areas of the TAs, at 0.07 m2 (interquartile range [IQR], 0.06 to 0.09), were higher than those of the AAAs at 0.03 m2 (IQR, 0.02 to 0.04; P = .002). High-sensitivity CRP was within normal limits, and no significant differences were found between the AAA group and the controls.

CONCLUSIONS

Circulating IL-6 is elevated within the aorta in patients with aneurysms and corresponds to aneurysm position. Furthermore, aneurysm surface area and mean plasma IL-6 are correlated. In the absence of any evidence of systemic inflammation in the form of elevated hs-CRP, these data support the hypothesis that aneurysms secrete IL-6 into the circulation. This may contribute to the high cardiovascular mortality observed in patients with aneurysms.

<em>Interleukin</em>-6 is a pleiotropic, pro-inflammatory cytokine that can promote both innate and adaptive immune responses. In humans with respiratory virus infections, such as Respiratory Syncytial Virus (RSV), elevated concentrations of IL-6 are associated with more severe disease. In contrast the polymorphisms in the Il6 promoter which favour lower IL-6 production are associated with increased risk of both RSV and Rhinovirus infections. To determine the precise contribution of IL-6 to protection and pathology we used murine models of respiratory virus infection. RSV infection resulted in increased IL-6 production both in the airways and systemically which remained heightened for at least 2 weeks. IL-6 depletion early, but not late, during RSV or Influenza A virus infection resulted in significantly increased disease associated with an influx of virus specific TH1 and cytotoxic CD8+ T cells, whilst not affecting viral clearance. IL-6 acted by driving production of the immunoregulatory cytokine IL-<em>27</em> by macrophages and monocytes, which in turn promoted the local maturation of regulatory T cells. Concordantly IL-<em>27</em> was necessary to regulate TH1 responses in the lungs, and sufficient to limit RSV induced disease. Overall we found that during respiratory virus infection the prototypic inflammatory cytokine IL-6 is a critical anti-inflammatory regulator of viral induced immunopathology in the respiratory tract through its induction of IL-<em>27</em>.

BACKGROUND

In men, obesity and the metabolic syndrome are accompanied by decreased testosterone levels, but little is known about the associations between visceral adipose tissue (VAT), VAT-related inflammation and sex steroids.

OBJECTIVE

To examine the relative impact of VAT, abdominal subcutaneous adipose tissue (SAT) and interleukin 6 (IL-6), a marker of VAT-induced inflammation, on testosterone (T) and 17β-oestradiol (E2) levels in dysmetabolic men.

METHODS

We study the NUMEVOX cohort of 229 men, aged 27-77 years, who all had at least one metabolic syndrome criterion (on average three). IL-6, C-reactive protein, Homeostasis Model Assessment of (HOMA) insulin resistance index (HOMA-IR), liver enzymes, E2, LH, sex hormone-binding globulin (SHBG), T, waist circumference and body mass index (BMI) were measured; bioavailable testosterone (BT) was calculated from T and SHBG; MRI-assessed VAT and SAT were analysed in 109 of these men.

RESULTS

Visceral adipose tissue was strongly correlated with E2 (Spearman r = 0.38, P < 0.001) and with BT/E2 ratio (r = -0.42, P < 0.001), while SAT was not correlated with either. IL-6 was correlated with E2 (r = 0.19, P = 0.007), BT (r = -0.19, P = 0.006) and BT/E2 ratio (r = -0.30 P < 0.001). In multivariate linear analysis, the relation between VAT and E2 was independent of age, BMI (P = 0.008), leptin (P < 0.001), T and SHBG. Log(IL-6) was significantly inversely related with log(BT) (P = 0.032) independently of age, VAT, leptin and HOMA-IR.

CONCLUSIONS

17β-oestradiol levels were positively associated with VAT, but not with SAT, while T and BT were negatively and independently associated with IL-6. The significant inverse association between IL-6 and T suggests an important role of low-grade visceral fat inflammation in the central hypogonadism associated with the metabolic syndrome.

BACKGROUND

Ustekinumab is a fully human IgG1κ monoclonal antibody that blocks the biologic activity of interleukin-12/23. Ustekinumab is approved for treatment of plaque psoriasis and has been shown to be effective for induction and maintenance of clinical response in anti-TNF resistant Crohn's disease (CD). The aim of the study was to describe the real-life experience with open-label use of ustekinumab in anti-TNF resistant CD patients.

METHODS

A retrospective observational open-label study. Clinical response was defined by physician's global assessment combined with decision to continue therapy. The clinical response was evaluated at 3, 6, 12months and last follow-up.

RESULTS

Thirty-eight patients were included in the study. Initial clinical response was achieved in 28/38 (73.7%) of the patients. Among the initial responders, 80% with follow-up data maintained their response for 6months. At 12months of follow-up, 88.9% of patients responding at 6months maintained their response. At the last follow-up (7.9±5.2 mo) 27/38 (71%) of the patients were responding, and 73.3% were able to discontinue corticosteroids. Dose escalation was required in 47.7% of the patients and was successful in 61.1% of them.

CONCLUSIONS

In this real-life cohort of severe anti-TNF resistant CD, an initial clinical response to subcutaneous ustekinumab was observed in 73.7% of the patients. The initial response was successfully maintained in the majority of patients for up to 12months. Subcutaneous ustekinumab is an effective therapeutic option in this challenging patient cohort. The optimal dosing and injection schedule remain to be established in future studies.

<em>Interleukin</em>-<em>27</em> (IL-<em>27</em>) is a cytokine belonging to the IL-6/IL-12 cytokine family. It is secreted by antigen-presenting cells, strongly acts on T cells, and also stimulates innate immune cells. In most studies, the effects of IL-<em>27</em> on T cells were investigated; however, not much is known about possible effects of IL-<em>27</em> on other cell types. IL-<em>27</em> signals via the common IL-6-type cytokine receptor chain gp130 and the IL-<em>27</em>-specific chain WSX-1. Given the importance of gp130 in regulating liver responses such as the acute phase response or liver regeneration, we investigated whether IL-<em>27</em> could also have a function in liver cells. We find that IL-<em>27</em> stimulates hepatoma cells and hepatocytes by inducing a sustained signal transducer and activator of transcription (STAT)1 and STAT3 activation. Whereas the STAT3 mediated responses to IL-<em>27</em> (gamma-fibrinogen and hepcidin induction) are not detectable, we observe an interferon-gamma (IFN-gamma)-like STAT1 response leading to the induction of interferon-regulated proteins such as STAT1, STAT2, interferon response factor (IRF)-1, IRF-9, myxovirus resistance A and guanylate binding protein 2.

CONCLUSIONS

Our study provides evidence for a function of IL-<em>27</em> in hepatoma cells and hepatocytes and shows that IL-<em>27</em> responses are not restricted to the classical immune cells. Our results suggest that IL-<em>27</em> exerts IFN-like functions in liver cells and that it can contribute to the antiviral response in these cells.

OBJECTIVE

In patients with type 2 diabetes mellitus (T2DM), biomarkers reflecting inflammation and endothelial dysfunction have been linked to cardiovascular disease (CVD biomarkers) and metabolic regulation. In T2DM patients, metformin and insulin secretagogues have demonstrated equal anti-hyperglycaemic potency. Here, we report the effect of metformin versus an insulin secretagogue, repaglinide, on CVD biomarkers in non-obese T2DM patients.

METHODS

Single-centre, double-masked, double-dummy, crossover study during 2x4 months involving 96 non-obese (body mass index< or =<em>27</em> kg/m(2)) insulin-naïve T2DM patients. At enrolment, previous oral hypoglycaemic agents were stopped and the patients entered a 1-month run-in on diet-only treatment. Hereafter, patients were randomized to either 2 mg repaglinide thrice daily followed by 1 g metformin twice daily or vice versa each during 4 months with a 1-month washout between interventions.

RESULTS

Levels of tumour necrosis factor-alpha, plasminogen activator inhibitor-1 antigen, tissue-type plasminogen activator antigen, von Willebrand factor, soluble intercellular adhesion molecule-1 and soluble E-selectin were significantly lower during metformin versus repaglinide treatments. In contrast, Amadori albumin and heart rate were higher during metformin versus repaglinide. Levels of interleukin-6, fibrinogen, soluble vascular cell adhesion molecule-1, asymmetric dimethylarginine and advanced glycation end products as well as glycaemic levels (previously reported) and 24-h blood pressure were similar between treatments. Adjustment for known macrovascular disease did not affect the between-treatment effects.

CONCLUSIONS

In non-obese T2DM patients, metformin was more effective in reducing selected biomarkers reflecting inflammation and endothelial dysfunction compared with repaglinide despite similar glycaemic levels between treatments.

OBJECTIVE

Anti-inflammatory therapeutic approaches are considered for the management of type 2 diabetes and for the prevention of its complications. There is limited evidence regarding the effects of prebiotics on inflammation, especially in patients with type 2 diabetes. This trial aims to examine the effects of oligofructose-enriched inulin on glycemic status, inflammation markers, and metabolic endotoxemia in female patients.

METHODS

Over a period of 8 wk, 52 women with body mass indices of >25 kg/m(2) but <35 kg/m(2) with type 2 diabetes were randomly assigned to either an intervention group, in which participants were given oligofructose-enriched inulin (n = <em>27</em>, consuming 10 g/d of oligofructose-enriched inulin), or to a control group, in which participants were given maltodextrin (n = 25, consuming 10 g/d of maltodextrin). Fasting plasma glucose, glycosylated hemoglobin, high-sensitivity C-reactive protein, <em>interleukin</em>-6, tumor necrosis factor-α, interferon-γ, <em>interleukin</em>-10, and plasma lipopolysaccharide were measured before and after the intervention. Data were analyzed with the use of SPSS software version 13. Paired and unpaired Student t tests and analysis of covariance were used to compare quantitative variables.

RESULTS

Oligofructose-enriched inulin caused a significant decrease in the levels of fasting plasma glucose (19.2 mg/dL; 9.50%), glycosylated hemoglobin (1.0%; 8.40%), interleukin-6 (1.3 pg/mL; 8.15%), tumor necrosis factor-α (3.0 pg/mL; 19.80%) and plasma lipopolysaccharide (6.0 EU/mL; 21.95%) as compared with maltodextrin (P < 0.05). Decreases in levels of interferon-γ (0.3 pg/mL; 16.50%) and high-sensitivity C-reactive protein (3.9 ng/mL; 31.70%) and an increase in the level of interleukin-10 (0.4 pg/mL, 11.50%) were not significant in the oligofructose-enriched inulin group as compared with the maltodextrin group.

CONCLUSIONS

In women with type 2 diabetes and suboptimal daily dietary fiber intake, oligofructose-enriched inulin may help to modulate some inflammatory markers.

Interface hepatitis, the histological lesion typical of autoimmune hepatitis (AIH), is composed of CD4 and CD8 T lymphocytes and of innate immunity cells, particularly monocytes. Studies in AIH have focused on autoreactive CD4 and CD8 T cells and impairment of CD4+CD25+ regulatory T cells (T-regs), whereas little is known about the role of monocytes and their relationship with T-regs. We have investigated 51 patients with autoimmune liver disease (AILD) and <em>27</em> healthy subjects, finding that monocytes were higher in number (P = 0.044), had a more vigorous spontaneous migration (P < 0.0005 in patients with inactive disease [ID], and P < 0.001 in those with active disease [AD]), displayed a higher tumor necrosis factor alpha (TNF-alpha) over <em>interleukin</em> (IL)-10 production (P = 0.07 in ID and P = 0.0005 in AD), and expressed higher levels of Toll-like receptor (TLR) 4 (P = 0.048 in ID and P = 0.03 in AD). Addition of conventional T-regs (cT-regs) in AILD enhanced monocyte migration (P = 0.05 in ID and P = 0.08 in AD), magnified TNF-alpha over IL-10 production (P = 0.0005 in ID and P = 0.006 in AD), and markedly increased TLR4 expression levels (P = 0.01 in ID and P = 0.004 in AD), whereas in normal subjects it either restrained or left unchanged monocyte function. Because a CD1<em>27</em>-negative subpopulation within CD4+CD25+ T cells exerts the strongest regulatory activity, we performed additional experiments using purified CD4+CD25+CD1<em>27</em>- T cells (true T-regs [tT-regs]). Addition of tT-regs to monocytes decreased monocyte migration (P = 0.03) and promoted IL-10 production (P = 0.009), leaving unchanged TLR4 expression in healthy subjects, whereas in patients with AILD it induced only a marginal increase in IL-10 production (P = 0.045 in ID and P = 0.13 in AD).

CONCLUSIONS

Monocyte overactivation and inability of cT-regs and tT-regs to restrain it may contribute to the loss of immune tolerance and perpetuation of the autoimmune attack in AILD.

OBJECTIVE

The aim of this study was to compare the effects of interleukin (IL)-17A and IL-17F on gene expression and signalling in human rheumatoid arthritis (RA) synoviocytes.

METHODS

IL-17A- and IL-17F-induced mRNA expression was analysed using Affymetrix microarrays. IL-6 and IL-8 secretion was evaluated by ELISA. Inhibition of two receptors (IL-17RA and IL-17RC) was achieved by small interfering RNA (saran). The effects on mitogen-activated protein kinase (MAPK), activator protein 1 (AP-1) and nuclear factor κB (NF-κB) expression and activation were evaluated by western blotting, qRT-PCR and DNA binding assay.

RESULTS

IL-17A and IL-17F induced a molecular pattern characterised by 27 inflammation-related genes for IL-17F and 165 for IL-17A. Virtually all IL-17A and IL-17F inducible genes were dependent on NF-κB activation, whereas a small number were modulated by p38. IL-17A induced activation of all three MAPKs (ERK, p38 and JNK) and downstream transcription factors AP-1 and p65 NF-κB. IL-17F was less potent but induced activation of p50 NF-κB. IL-17A was more potent at inducing IL-6 secretion than IL-17F, which was inactive alone. IL-17A and, to a lesser extent, IL-17F induced TRAF6 but not MyD88. Inhibition of either IL-17RA or IL-17RC expression via siRNA led to near complete abrogation of IL-6 expression mediated by IL-17A and the combination of IL-17F and tumour necrosis factor α.

CONCLUSIONS

Like IL-17A, IL-17F regulates proinflammatory gene expression by a very similar but not identical signalling pathway involving IL-17RA and IL-17RC.

BACKGROUND

<em>Interleukin</em> (IL)-<em>27</em> is a novel member of the IL-6/IL-12 family cytokines that are produced early by antigen-presenting cells in T helper (Th)1-mediated inflammation. Elevated expression of IL-<em>27</em> has been detected in the synovial membranes and fluid of rheumatoid arthritis (RA).

METHODS

We investigated the in vitro effects of IL-<em>27</em>, alone or in combination with inflammatory cytokine tumor necrosis factor (TNF)-α or IL-1 β on the pro-inflammatory activation of human primary fibroblast-like synoviocytes (FLS) from RA patients and normal control subjects, and the underlying intracellular signaling molecules were determined by intracellular staining using flow cytometry.

RESULTS

Significantly higher plasma concentration of IL-<em>27</em> was found in RA patients (n = 112) than control subjects (n = 46). Both control and RA-FLS constitutively express functional IL-<em>27</em> receptor heterodimer, gp130 and WSX-1, with more potent IL-<em>27</em>-mediated activation of signal transducers and activators of transcription (STAT)1 in RA-FLS. IL-<em>27</em> was found to induce significantly higher cell surface expression of intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 and release of inflammatory chemokine IL-6, CCL2, CXCL9, CXCL10 and matrix metalloproteinase-1 of RA-FLS than that of control FLS (all P < 0.05). Moreover, an additive or synergistic effect was observed in the combined treatment of IL-<em>27</em> and TNF-α or IL-1 β on the surface expression of ICAM-1 and VCAM-1 and the release of CXCL9 and CXCL10 of RA-FLS. Further investigations showed that the expression of ICAM-1, VCAM-1 and chemokines stimulated by IL-<em>27</em> was differentially regulated by intracellular activation of phosphatidylinositol 3-OH kinase-AKT, c-Jun amino-terminal kinase and Janus kinase pathways.

CONCLUSIONS

Our results therefore provide a new insight into the IL-<em>27</em>-activated immunopathological mechanisms mediated by distinct intracellular signal transductions in joint inflammation of RA.

Epidermal cells (EC) are well known as a source of cytokines, including <em>interleukin</em> (IL)-6. In the present study, we investigated whether ultraviolet (UV) light and corticosteroids (CS) affect IL-6 production by normal (HNK) or malignant (KB) human keratinocytes. Supernatants derived from UVB (100 J/m2)- but not from UVA (100-1500 kJ/m2)-exposed EC (HNK and KB) contained significantly increased levels of IL-6 activity. This was also confirmed by Western blot analysis, resulting in specific bands at 23 kD and <em>27</em> kD. Northern blot analysis revealed an enhanced IL-6 mRNA expression after UVB exposure. Addition of hydrocortisone, prednisolone, or dexamethasone immediately after UVB irradiation significantly blocked UVB or IL-1-induced IL-6 mRNA expression and production by EC. The suppressive effect was observed at doses in the physiologic (10(-7)-10(-9) M) as well as pharmacologic (10(-5)-10(-7) M) range. In contrast, the nonactive steroid prednisone did not affect EC IL-6 mRNA expression. These findings indicate that increased IL-6 production by EC after UVB irradiation may mediate local and systemic inflammatory reactions following extensive sun exposure. Thus, the therapeutic effect of corticosteroids observed in various inflammatory diseases may be partly due to their downregulating capacity of IL-6 production.

T cells take part in the chronic inflammatory reaction in atherosclerotic plaques, but their specific role in atherosclerosis has not yet been fully elucidated. Nevertheless, one may anticipate that activated T cells may secrete cytokines capable of modulating the morphology and hence the stability of plaques by regulating cell proliferation, lipid metabolism, and extracellular matrix (ECM) synthesis and/or degradation. This study has been designed to investigate the functional properties of T cells in atherosclerotic lesions. For this purpose, T-cell clones were generated from atherosclerotic plaques isolated from human aortas obtained at autopsy from six subjects. Cloned cells were activated with PMA and OKT-3 to initiate cytokine production and cytokine profiles of CD4-positive clones were measured by ELISA. The majority of the T-cell clones (125/155, 81 per cent) produced both interferon (IFN)-gamma and <em>interleukin</em> (IL)-4 (type 0 cytokine profile). Moreover, the production of IFN-gamma was dominant in the majority of these clones. A type 1 cytokine profile (high levels of IFN-gamma and low levels of IL-4) was found in 17 per cent of the clones (<em>27</em>/155). Only three clones (2 per cent) showed a type 2 cytokine secretion pattern (high levels of IL-4 and low levels of IFN-gamma). No cytolytic activity could be established in plaque-derived T cells. Our results show that the T-cell population in atherosclerotic lesions is heterogeneous, but the most dominant T cell by far is the one with a type 0 cytokine profile. The dominant secretion of IFN-gamma by T-cell clones suggest an important role for plaque T cells in modulating the growth and differentiation of other cells, such as macrophages and smooth muscle cells in atherosclerotic plaques.

Cytokines are involved early in the pathogenesis of HIV infection and disease progression as a component of immunologic dysregulation and immunodeficiency and as determinants controlling virus replication. Several steps, before and after retroviral integration into host DNA in T cells and macrophages, are affected by cytokines whereas CCR5 and CXCR4 binding chemokines can interfere with viral entry. A growing number of potential players--including the gamma-common <em>interleukin</em> (IL)-7, IL-15, and IL-21 together with IL-17, IL-18, IL-19, IL-20, IL-23, and IL-<em>27</em>--are discussed in terms of their perturbation in HIV infection and of their effects on virus replication. Thus, an increasing intersection of HIV infection and the cytokine network represents a crucial determinant of virus replication and immunologic dysregulation and will likely play a key role in the development of effective strategies of HIV prevention and immunologic reconstitution.

<em>Interleukin</em>-6 (IL-6) is a cytokine which is not only produced by a wide variety of different cells but one which also affects the function of diverse tissues. We have studied the expression of the IL-6 gene in freshly explanted human umbilical vein endothelial cells (HUVEC) and have also evaluated the effect of IL-6 on HUVEC proliferation. Cytokines like <em>interleukin</em>-1 alpha (IL-1 alpha) and tumor necrosis factor (TNF) as well as bacterial products such as the lipopolysaccharide (LPS) rapidly enhance production of biologically active IL-6 by HUVEC (IL-6 bioassay: increase in alpha 1-antichymotrypsin secretion by Hep3B2 cells and its neutralization by antiserum to E. coli-derived human IL-6). The two inducible RNA start sites in the IL-6 gene that are used in cytokine-induced fibroblasts (at +1 and -21) are also used in the same relative proportion (+1 greater than -21) in cytokine or LPS-induced HUVEC as determined by S1-nuclease protection assays for IL-6 transcripts. Immunoaffinity chromatography followed by Western blotting shows that IL-6 species secreted by IL-1 alpha-induced HUVEC are of molecular mass 23-25, <em>27</em>-30 and 45 kDa as judged by SDS-PAGE under reducing conditions. Finally, rIL-6 inhibits [3H]-thymidine incorporation by HUVEC in a dose-dependent manner. Thus IL-6 is not only produced by HUVEC but may also affect its proliferation. The ability of the vascular endothelium to rapidly secrete IL-6 in response to inflammation-associated cytokines is of strategic value since it generates a circulatory signal which helps mobilize the acute phase plasma protein response and enlists the immune system in host defence.

The host response to infection is associated with several alterations in lipid metabolism that promote lipoprotein production. These changes can be reproduced by lipopolysaccharide (LPS) administration. LPS stimulates hepatic cholesterol synthesis and suppresses the conversion of cholesterol to bile acids. LPS down-regulates hepatic cholesterol 7alpha-hydroxylase, the rate-limiting enzyme in the classic pathway of bile acid synthesis. We now demonstrate that LPS markedly decreases the activity of sterol <em>27</em>-hydroxylase, the rate-limiting enzyme in the alternate pathway of bile acid synthesis, in the liver of Syrian hamsters. Moreover, LPS progressively decreases hepatic sterol <em>27</em>-hydroxylase mRNA levels by 75% compared with controls over a 24-h treatment period. LPS also decreases oxysterol 7alpha-hydroxylase mRNA levels in mouse liver. In vitro studies in HepG2 cells demonstrate that tumor necrosis factor and <em>interleukin</em> (IL)-1 decrease sterol <em>27</em>-hydroxylase mRNA levels by 48 and 80%, respectively, whereas IL-6 has no such effect. The IL-1-induced decrease in sterol <em>27</em>-hydroxylase mRNA expression occurs early, is sustained for 48 h, and requires very low doses. In vivo IL-1 treatment also lowers hepatic sterol <em>27</em>-hydroxylase mRNA levels in Syrian hamsters. Studies investigating the molecular mechanisms of LPS-induced decrease in sterol <em>27</em>-hydroxylase show that LPS markedly decreases mRNA and protein levels of hepatocyte nuclear factor-1 (HNF-1), a transcription factor that regulates sterol <em>27</em>-hydroxylase, in the liver. Moreover, LPS decreases the binding activity of HNF-1 by 70% in nuclear extracts in hamster liver, suggesting that LPS may down-regulate sterol <em>27</em>-hydroxylase by decreasing the binding of HNF-1 to its promoter. Coupled with our earlier studies on cholesterol 7alpha-hydroxylase, these data indicate that LPS suppresses both the classic and alternate pathways of bile acid synthesis. A decrease in bile acid synthesis in liver would reduce cholesterol catabolism and thereby contribute to the increase in hepatic lipoprotein production that is induced by LPS and cytokines.

OBJECTIVE

In the present work, we investigate the role of <em>interleukin</em> (IL)<em>27</em>/IL<em>27</em> receptor alpha (Ralpha) (WSX-1) in the development of autoimmune disorders in the MRL/lpr mouse, which is considered as an experimental model of systemic lupus erythaematosus (SLE) in humans.

METHODS

We generated two strains of WSX-1 transgenic mice in the MRL/lpr background with different expression levels of WSX-1, and investigated the effect of WSX-1 overexpression on survival, glomerulonephritis and immunological properties.

RESULTS

In comparison with wild type (WT) MRL/lpr and transgenic (Tg) low (TgL) mice, Tg high (TgH) mice exhibited a prolonged lifespan and no apparent development of autoimmune nephritis. Production of anti-dsDNA antibody and total IgG and IgG2a were significantly lower in TgH mice than those of TgL and WT mice. The expressed amounts of interferon (IFN)gamma and IL4 mRNA by CD4+ T cells from Tg mice decreased in a dose-dependent fashion. CD4+ splenic lymphocytes in TgH mice were more subject to the IL<em>27</em>-mediated suppression of cytokine production. In vitro stimulation of CD4+ T cells by IL<em>27</em> resulted in over phosphorylation of STAT3 in TgH cells than in WT cells.

CONCLUSIONS

WSX-1 overexpression in the MRL/lpr background rendered the autoimmune prone mice protected from the development of autoimmune diseases. Our results suggest that IL<em>27</em> signalling may be a therapeutic target against autoimmune diseases, including human SLE.