Search

BackgroundSchnitzler syndrome (SchS) is a rare autoinflammatory disease characterized by urticarial exanthema, bone and joint alterations, fever and monoclonal IgM gammopathy. Overactivation of the interleukin(IL)-1 system is reported, even though the exact pathophysiological pathways remain unknown.ObjectiveTo determine ex vivo cytokine profiles of Peripheral Blood Mononuclear Cells (PBMCs) from SchS patients prior to treatment and after initiation of anti-IL-1 therapy (anakinra). The sera cytokine profile was studied in parallel.MethodsWe collected blood samples from thirty-six untreated or treated SchS. PBMCs were cultured with and without LPS or anti-CD3/CD28. Cytokine levels were evaluated in serum and cell culture supernatants using Luminex technology.ResultsSpontaneous TNFα, IL-6, IL-1β, IL-1α, and IL-1RA release by PBMCs of SchS patients were higher than in controls. LPS-stimulation further induced the secretion of these cytokines. In contrast, after T-cell stimulation, TNFα, IL-10, IFNγ, IL-17A, and IL-4 production decreased in SchS patients compared to healthy controls, but less in treated patients. Whereas IL-1β serum level was not detected in most sera, IL-6, IL-10, and TNFα serum levels were higher in patients with SchS and IFNγ and IL-4 levels were lower. Of note, IL-6 decreased after treatment in SchS (p = 0.04).ConclusionOur data strengthen the hypothesis of myeloid inflammation in SchS, mediated in particular by IL-1β, TNFα, and IL-6, associated with overproduction of the inhibitors IL-1RA and IL-10. In contrast, we observed a loss of Th1, Th2, and Th17 cell functionalities that tends to be reversed by anakinra.

In psoriasis, a specific cytokine network has been described to play a central role in the pathophysiology of the disease. Anti-cytokine therapeutic approaches have been largely developed and TNFα constitutes the main target. Adalimumab is a human anti-TNFα monoclonal antibody that has been reported to demonstrate clinical efficacy and safety, resulting in reversal of epidermal hyperplasia and cutaneous inflammation. We aimed to analyse changes in the skin inflammatory transcriptomic profile in psoriatic patients during adalimumab therapy. In addition, the circulating cytokine profile was analysed to define systemic inflammation. Eighteen patients with chronic plaque psoriasis were treated with adalimumab. After four and 16 weeks, clinical efficacy was assessed using PASI and DLQI, and skin mRNA profiles were determined and circulating cytokines quantified. We identified a rapid effect of adalimumab therapy on a large array of Th17 cytokines of the skin, which may account for the modification of keratinocyte expression profile and clinical response. In contrast, analysis of serum cytokine concentrations was uninformative, confirming the need for characterization of local cytokines in skin lesions. Finally, in non-responders, local cytokine expression was shown to be unchanged. We show that TNFα inhibition in psoriasis patients treated with adalimumab has a broad effect on the expression profile of cytokines and keratinocyte markers of skin inflammation, which may account for its clinical efficacy.

Pancreatic acinar cells are major targets of IL-22. Our aim is to study early plasma levels of IL-22, of pro- and anti-inflammatory cytokines in acute pancreatitis, and their association with severity or necrosis infection.Consecutive patients admitted to the Department of Hepato-Gastroenterology at Poitiers University of Medicine Hospital (France) with a diagnosis of AP were prospectively enrolled. Plasma concentrations of IL-22, IL-6, IL-8, IL-1 α, IL-1β, TNF- α, IFN-γ, IL-17A, IL-10, IL-1ra and IL-4 were assessed by multiple immunoassay at the admission time. A thoracoabdominal contrast-enhanced CT scan was performed at day 2.Sixty-two patients were included; 13 patients (21%) had a severe acute pancreatitis, 5 patients (8%) developed necrosis infection and 29 patients (47%) had pleural effusion. Plasma levels of IL-22 were high in AP (135 ± 31 vs 4.2 ± 1.8 pg/ml for controls, p0.05), but did not correlate with the severity of the disease, whereas IL-6, IL-10 and IL-1ra where enhanced in patients with severe acute pancreatitis and with pleural effusion. Patients who further developed necrosis infection had higher levels of IL-1ra at admission (p = 0.0004).In acute pancreatitis, high plasma levels of IL-22 are observed, regardless the severity of the disease. In contrast, severe forms were associated with increased levels of IL-6, IL-10 and IL-1ra. The beneficial or deleterious role of IL-22 in AP remains to be further studied.

The mevalonate kinase deficiency (MKD), including hyperimmunoglobulinemia D periodic fever syndrome (HIDS) and the more severe mevalonic aciduria are rare, autosomal recessive, autoinflammatory diseases belonging to the hereditary periodic fever (HPF) family. Other members include: familial mediterranean fever (FMF), the cryopyrin-associated periodic syndromes (CAPS) and TNFR-associated periodic syndromes (TRAPS). MKD is caused by mutations in the gene encoding mevalonate kinase (MK), an enzyme of the cholesterol pathway, leading to its inactivation. The molecular mechanisms linking MKD and abnormalities of isoprenoid biosynthesis to cytokine production and inflammation have yet to be fully elucidated. Statins, which are extensively prescribed for lowering cholesterol, are potent inhibitors of 3-hydroxy-3-methylglutaryl-CoA reductase, the enzyme directly upstream of MK. In this review, we discuss recent reports demonstrating that in vitro inhibition of the mevalonate pathway by statins specifically increases the production, by activated monocytes, of cytokines of the IL-1 family, by enhancing caspase-1 activity, the enzyme responsible for IL-1beta and IL-18 maturation. The molecular mechanisms involve geranylgeranylation and the enhancement of the activity of G proteins such as Rac-1. Interestingly, activated fibroblasts from MKD patients secrete more IL-1beta than fibroblasts from healthy donors. Taken together, these data highlight the specific enhancement of the IL-1 family of cytokines, the maturation of which is caspase-1-dependent in MKD. Finally, the spectacular decrease in febrile attacks in patients with severe HIDS under IL-1 receptor antagonist (anakinra) treatment, reinforces this hypothesis. Deregulated caspase-1 activation could be responsible for the inflammatory component of MKD, thereby mechanistically linking MKD to FMF and CAPS through cytokines of the IL-1 family.

International audience; To determine whether glutamine (Gln) reduces the ratio of oxidized to total glutathione (GSSG/GSH) and extracellular signal-regulated kinase (ERK1/2) activation in dystrophic muscle. Four-week old mdx mice, an animal model for Duchenne muscular dystrophy and control (C57BL/10) received daily intraperitoneal injections of l-Gln (500 mg/kg/d) or 0.9% NaCl for 3 d. GSH and GSSG concentrations in gastrocnemius were measured using a standard enzymatic recycling procedure. Free amino acid concentrations in gastrocnemius were determined by ion exchange chromatography. Phosphorylated protein levels of ERK1/2 in quadriceps were examined using Western Blot. l-Gln decreased GSSG and GSSG/GSH (an indicator of oxidative stress). This was associated with decreased ERK1/2 phosphorylation. Muscle free Gln, glutamate (Glu), and the sum (Gln + Glu) were higher in mdx versus C57BL/10, at the basal level. Exogenous Gln decreased muscle free Glu and Gln + Glu in mdx only, whereas Gln was not affected. In conclusion, exogenous Gln reduces GSSG/GSH and ERK1/2 activation in dystrophic skeletal muscle of young mdx mice, which is associated with decreased muscle free Glu and Gln + Glu. This antioxidant protective mechanism provides a molecular basis for Gln's antiproteolytic effect in Duchenne muscular dystrophy children.

IL-21 is a cytokine that regulates the activation of T and NK cells and promotes the proliferation of B cells activated via CD40. In this study, we show that rIL-21 strongly induces the production of all IgG isotypes by purified CD19+ human spleen or peripheral blood B cells stimulated with anti-CD40 mAb. Moreover, it was found to specifically induce the production of IgG1 and IgG3 by CD40-activated CD19+CD27− naive human B cells. Although stimulation of CD19+ B cells via CD40 alone induced γ1 and γ3 germline transcripts, as well as the expression of activation-induced cytidine deaminase, only stimulation with both anti-CD40 mAb and rIL-21 resulted in the production of Sγ/Sμ switch circular DNA. These results show that IL-21, in addition to promoting growth and differentiation of committed B cells, is a specific switch factor for the production of IgG1 and IgG3.

M-CSF is a pleiotropic cytokine involved in the survival, proliferation, and differentiation of cells of the monocyte/macrophagelineage. M-CSF is produced by numerous cells including CD3-activated Tcells. M-CSF serum levels are increased during acute graft rejection. We tested the in vitro production of M-CSF, GM-CSF, IL-2, and IL-4 byT-cell clones costimulated by CD3 and accessory activation pathways and the effects of cyclosporin A and methylprednisolone. The nine clonesstudied and CD4+ cells purified from peripheral bloodmononuclear cells (PBMC) spontaneously produced low levels of M-CSF, which PMA and CD3 mAb strongly enhanced. In contrast to IL-2, CD28 mAbdid not further enhance this production. CsA inhibited M-CSF productionby clones and purified CD4 T cells. Addition of IL-2, anti IL-2, oranti CD25 mAb to the cultures demonstrated that CsA down-regulatedM-CSF synthesis by activated T cells through its inhibition of IL-2synthesis. These results could help to better understand the complexmechanisms of acute graft rejection and immunosuppression.

In order to clarify the inflammatory mechanism underlying familial Mediterranean fever (FMF), we aimed to evaluate the ex vivo cytokine profile of FMF patients during acute attacks and attack-free periods, and compare it with that of healthy controls. The study included 34 FMF patients, of whom 9 were studied during attack and remission and 24 healthy controls. Cytokine levels were evaluated by Luminex technology in serum and supernatants of PBMC (Peripheral Blood Mononuclear Cells) cultures with and without 24h stimulation of monocytes by LPS and T lymphocytes by anti-CD3/CD28 beads. Levels of IL-6 and TNF-α were higher in unstimulated and LPS-stimulated PBMC supernatants of FMF patients in crises compared to controls. In response to LPS stimulation, higher levels of IL-1β and IL-1α were found in PBMC supernatants of patients during crises compared to those in remission and to controls. IFN-γ and IL-4 levels were the lowest in unstimulated and anti-CD3/CD28 stimulated PBMCs supernatants of patients during crises compared to remission and controls. The Th17 cytokines IL-17 and IL-22 were respectively higher in anti-CD3/CD28 stimulated PBMC supernatants of FMF patients during and between crises compared to controls. Amongst cytokines tested in serum, only IL-6 and TNFα were enhanced in FMF patients. The ex vivo study represents an interesting approach to evaluate cytokines' involvement in FMF. Our results suggest an ongoing subclinical inflammation and define an elevated inflammatory cytokine signature, distinctly for M694V homozygous patients. The absence of spontaneous IL-1β release by PBMCs reflects no constitutive activation of the inflammasome in FMF physiopathology.

Objective A new class of autoinflammatory syndromes called NLRP12-associated disorders (NLRP12AD) has been associated with mutations in NLRP12. Conflicting data on the putative role of NLRP12 in interleukin-1β (IL-1β) signaling have been found in in vitro analyses. This prospective study was undertaken to assess the secretion of IL-1β and 3 IL-1β–induced cytokines (IL-1 receptor antagonist [IL-1Ra], IL-6, and tumor necrosis factor α [TNFα]) in patients' peripheral blood mononuclear cells (PBMCs) cultured ex vivo and to evaluate the patients' response to IL-1Ra (anakinra), a major drug used in the treatment of autoinflammatory disorders. Methods Patients' disease manifestations and cytokine measurements were recorded before anakinra treatment was started, during 14 months of therapy, and after discontinuation of anakinra treatment. Results Spontaneous secretion of IL-1β by patients' PBMCs was found to be dramatically increased (80–175 fold) compared to healthy controls. Consistent with these findings, anakinra initially led to a marked clinical improvement and to a rapid near-normalization of IL-1β secretion. However, a progressive clinical relapse occurred secondarily, associated with an increase in TNFα secretion, persistent elevated levels of IL-1Ra and IL-6, and a reactivation of IL-1β secretion. Anakinra was discontinued after 14 months of therapy. Conclusion Our findings provide in vivo evidence of the crucial role of IL-1β in the pathophysiology of NLRP12AD. This is the first time anakinra has been used to treat this disorder. This study provides new insights into the mechanisms underlying resistance to anti–IL-1 therapy observed in a few patients with autoinflammatory syndromes. Our data also point to the potential of ex vivo cytokine measurements as predictors of response to treatment.

International audience; Several thalidomide analogues were synthesized and compared to thalidomide and its more active analogue, lenalidomide, for their ability to inhibit the production of the pro-inflammatory cytokine tumour necrosis factor (TNF)-alpha and interleukin (IL)-6 by LPS-activated peripheral blood mononuclear cells (PBMCs). Among these compounds, two analogues containing sulfonyl group displayed interesting downregulation of TNF-alpha and IL-6 production. (C) 2010 Elsevier Ltd. All rights reserved.

(IF : 2,984); International audience; Objective. The effects of statins (3-hydroxy-3-methylglutaryl coenzyme A reductase-HMGR-inhibitors) on the inflammatory response remain unclear. HMGR is implicated in the mevalonate pathway, directly upstream of cholesterol biosynthesis. We studied the impairment by this pathway of cytokine production by peripheral blood mononuclear cells (PBMCs) and THP-1 cells. The aim was to identify a specific cytokine "signature" of cells under simvastatin treatment in order to link pharmacological inhibition of the mevalonate pathway and inflammation. Methods. Normal human PBMCs and THP-1 cells were cultured with inhibitors of HMGR (simvastatin), geranylgeranyltransferase (GGTI-298), farnesyltransferase (FTI-277), and/or caspase-1 (Z-VAD(Ome)-FMK). Following culture, cytokine production, caspase-1 activity, IL-1beta mRNA and Rac-1 activity were determined. Results. Pharmacological inhibition of the mevalonate pathway specifically enhanced the release of IL-1alpha, IL-1beta and IL-18 and inhibited IL-1ra production by LPS-activated PBMCs and THP-1 cells. Simvastatin did not modify pro-IL-1beta expression, but enhanced caspase-1 activity, the enzyme responsible for IL-1beta and IL-18 maturation. GGTI-298 also enhanced IL-1-family cytokine production, showing that geranylgeranylation is involved in caspase-1 activation. Additionally, simvastatin enhanced Rac-1 activity. Conclusion. Pharmacological inhibition of the mevalonate pathway by statins highlighted the specific induction of the proinflammatory cytokines of the IL-1 family whose maturation is either directly (i.e. IL-1beta and IL-18), or indirectly (i.e. IL-1alpha) dependant on caspase-1.

Summary Interleukin (IL)-22 is a T cell-derived cytokine that has been reported recently to induce cutaneous inflammation in an experimental murine model of psoriasis, and to induce in vitro an inflammatory-like phenotype. In the present study, we assessed the presence of IL-22 and the IL-22 receptor 1 (IL-22R1) in skin lesions, skin-derived T cells, as well as IL-22 levels in sera from patients with psoriasis. IL-22R1 and IL-10R2 transcripts are expressed at a similar level in psoriatic and healthy skin. In contrast, IL-22 mRNA expression was up-regulated in psoriatic skin lesions compared to normal skin, whereas IL-22 mRNA levels in peripheral blood mononuclear cells from psoriatic patients and normal subjects were similar. Circulating IL-22 levels were significantly higher in psoriatic patients than in normal subjects. T cells isolated from psoriatic skin produced higher levels of IL-22 in comparison to peripheral T cells isolated from the same patients. IL-10 was expressed at similar levels in skin biopsies and peripheral blood mononuclear cells of psoriatic patients and normal subjects. Finally, we show here that supernatants of lesional psoriatic skin-infiltrating T cells induce an inflammatory response by normal human epidermal keratinocytes, resembling that observed in psoriatic lesions. Taken together, the results reported in this study indicate that IL-22 is a cytokine produced by skin-infiltrating lymphocytes that is potentially involved in initiation and/or maintenance of the pathogenesis of psoriasis.