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Many patients with multiple myeloma (MM) have comorbidities and are treated with PPAR agonists. Immunomodulatory agents (IMiDs) are the cornerstones for MM therapy. Currently, little is known about how co-administration of PPAR agonists impacts lenalidomide treatment in patients with MM. Here, we determined the effects of PPAR agonists on anti-myeloma activities of lenalidomide in vitro and in a myeloma xenograft mouse model. Genetic overexpression and CRISPR/cas9 knockout experiments were performed to determine the role of CRBN in the PPAR-mediated pathway. A retrospective cohort study was performed to determine the correlation of PPAR expression with the outcomes of patients with MM. PPAR agonists down-regulated CRBN expression and reduced the anti-myeloma efficacy of lenalidomide in vitro and in vivo. Co-treatment with PPAR antagonists increased CRBN expression and improved sensitivity to lenalidomide. PPAR expression was higher in bone marrow cells of patients with newly diagnosed MM than in normal control bone marrow samples. High PPAR expression was correlated with poor clinical outcomes. Our study provides the first evidence that PPARs transcriptionally regulate CRBN and that drug-drug interactions between PPAR agonists and IMiDs may impact myeloma treatment outcomes.

Enhanced expression of cyclooxygenase 2 (COX2) in podocytes contributes to glomerular injury in diabetic kidney disease, but some basal level of podocyte COX2 expression might be required to promote podocyte attachment and/or survival. To investigate the role of podocyte COX2 expression in diabetic kidney disease, we deleted COX2 specifically in podocytes in a mouse model of Type 1 diabetes mellitus (Akita mice). Podocyte-specific knockout (KO) of COX2 did not affect renal morphology or albuminuria in nondiabetic mice. Albuminuria was significantly increased in wild-type (WT) and KO Akita mice compared with nondiabetic controls, and the increase in albuminuria was significantly greater in KO Akita mice compared with WT Akita mice at both 16 and 20 wk of age. At the 20-wk time point, mesangial expansion was also increased in WT and KO Akita mice compared with nondiabetic animals, and these histologic abnormalities were not improved by KO of COX2. Tubular injury was seen only in diabetic mice, but there were no significant differences between groups. Thus, KO of COX2 enhanced albuminuria and did not improve the histopathologic features of diabetic kidney disease. These data suggest that 1) KO of COX2 in podocytes does not ameliorate diabetic kidney disease in Akita mice, and 2) some basal level of podocyte COX2 expression in podocytes is necessary to attenuate the adverse effects of diabetes on glomerular filtration barrier function.

The cytokine-inducible isoform of nitric oxide synthase (NOS2) is constitutively expressed in human respiratory epithelia and is upregulated in inflammatory lung disease. Here, we sought to better define the protein interactions that may be important for NOS2 activity and stability, as well as to identify potential targets of NOS2-derived NO, in the respiratory epithelium. We overexpressed Flag-tagged, catalytically-inactive NOS2 in A549 cells and used mass spectrometry to qualitatively identify NOS2 co-immunoprecipitating proteins. Stable isotope labeling of amino acids in cell culture (SILAC) was used to quantify the coordinate effects of cytokine stimulation on NOS2-protein interactions. Multi-protein networks dominated the NOS2 interactome, and cytokine-inducible interactions with allosteric activators and with the ubiquitin-proteasome system were correlated with cytokine-dependent increases in NO metabolites and in NOS2 ubiquitination. The ubiquitin ligase scaffolding protein, FBXO45, was identified as a novel, direct NOS2 interactor. Similar to the SPRY domain-containing SOCS box (SPSB) proteins, FBXO45 requires Asn27 in the (23)DINNN(27) motif of NOS2 for its interaction. However, FBXO45 is unique from the SPSBs in that it recruits a distinct E3 ligase complex containing MYCBP2 and SKP1. Collectively, these findings demonstrate the general utility of interaction proteomics for defining new aspects of NOS2 physiology.

IL-1β plays a crucial role in the differentiation of human Th17 cells. We report here that IL-1RI expression is significantly increased in both naive and memory CD4+ T cells derived from relapsing-remitting multiple sclerosis (RR MS) patients in comparison to healthy controls. Interleukin 1 receptor (IL-1R)I expression is upregulated in the in vitro-differentiated Th17 cells from RR MS patients in comparison to the Th1 and Th2 cell subsets, indicating the role of IL-1R signaling in the Th17 cell differentiation in RR MS. When IL-1RI gene expression was silenced using siRNA, human naive CD4+ T cells cultured in the presence of Th17-polarizing cytokines had a significantly decreased expression of interleukin regulatory factor 4 (IRF4), RORc, IL-17A, IL-17F, IL-21, IL-22, and IL-23R genes, confirming that IL-1RI signaling induces Th17 cell differentiation. Since IL-1R gene expression silencing inhibited IRF4 expression and Th17 differentiation, and IRF4 gene expression silencing inhibited Th17 cell differentiation, our results indicate that IL-1RI induces human Th17 cell differentiation in an IRF4-dependant manner. Our study has identified that IL-1RI-mediated signaling pathway is constitutively activated, leading to an increased Th17 cell differentiation in IRF4-dependent manner in patients with RR MS.

To improve the classical lossless compression of low efficiency, a method of image lossless compression with high efficiency is presented. Its theory and the algorithm implementation are introduced. The basic approach of medical image lossless compression is then briefly described. After analyzing and implementing differential plus code modulation (DPCM) in lossless compression, a new method of combining an integer wavelet transform with DPCM to compress medical images is discussed. The analysis and simulation results show that this new method is simpler and useful. Moreover, it has high compression ratio in medical image lossless compression.

Mitochondria have important roles in intracellular energy generation, modulation of apoptosis, and redox-dependent intracellular signaling. Although reactive oxygen species (ROS) participate in the regulation of intracellular signaling pathways, including activation of nuclear factor (NF)-kappaB, there is only limited information concerning the role of mitochondrially derived ROS in modulating cellular activation and tissue injury associated with acute inflammatory processes.To examine involvement of the mitochondrial electron transport chain complex I on LPS-mediated NF-kappaB activation in neutrophils and neutrophil-dependent acute lung injury.Neutrophils incubated with rotenone or metformin were treated with bacterial lipopolysaccharide (LPS) to determine the effects of mitochondrial complex I inhibition on intracellular concentrations of reactive oxygen species, NF-kappaB activation, and proinflammatory cytokine expression. Acute lung injury was produced by intratracheal injection of LPS into control, metformin, or rotenone-treated mice.Inhibition of complex I with either rotenone or the antihyperglycemic agent metformin was associated with increased intracellular levels of both superoxide and hydrogen peroxide, as well as inhibition of LPS-induced I kappaB-alpha degradation, NF-kappaB nuclear accumulation, and proinflammatory cytokine production. Treatment of LPS-exposed mice with rotenone or metformin resulted in inhibition of complex I in the lungs, as well as diminished severity of lung injury.These results demonstrate that mitochondrial complex I plays an important role in modulating Toll-like receptor 4-mediated neutrophil activation and suggest that metformin, as well as other agents that inhibit mitochondrial complex I, may be useful in the prevention or treatment of acute inflammatory processes in which activated neutrophils play a major role, such as acute lung injury.

The apxIC and apxIIC genes of the Actinobacillus pleuropneumoniae serovar 1 strain SLW01, encoding the ApxI- and ApxII-activating proteins, respectively, were deleted successively by a method involving sucrose counterselection. The resulting strain, SLW03, contained no foreign DNA and could secrete unactivated ApxIA and ApxIIA RTX toxins with complete antigenicity. Strain SLW03 was attenuated at least 1000-fold in Balb/C mice and caused no adverse effects in pigs at doses of up to 1 × 109 CFU mL−1. SLW03 was able to induce a significant immune response and provide complete protection from clinical signs upon homologous (serovar 1) and heterologous (serovar 9) challenge of A. pleuropneumoniae. Pigs vaccinated via the intranasal (i.n.) route had significantly higher serum titers and fewer pulmonary lesions than pigs vaccinated via the intramuscular route postchallenge. These results suggest that the mutant strain SLW03 could be used as a candidate live vaccine that can induce reliable cross-serovar protection following i.n. immunization.

A series of isoforms of α-KT × 14 (short chain potassium channel scorpion toxins) were isolated from the venom of Buthus martensii Karsch by RACE and screening cDNA library methods. These isoforms adding BmKK1 - 3 and BmSKTx1 - 2 together shared high homology (more than 97%) with each other. The result of genomic sequence analysis showed that a length 79bp intron is inserted Ala codes between the first and the second base at the 17th amino acid of signal peptide. The introns of these isoforms also share high homology with those of BmKK2 and BmSKT × 1 reported previously. Sequence analysis of many clones of cDNA and genomic DNA showed that a species population or individual polymorphism of α-KT × 14 genes took place in scorpion Buthus martensii Karsch and accelerated evolution played an important role in the forming process of α-KT × 14 scorpion toxins subfamily. The result of southern hybridization indicated that α-KT × 14 toxin genes existed in scorpion chromosome with multicopies. All findings maybe provided an important evidence for an extensive evolutionary process of the scorpion “pharmacological factory”: at the early course of evolution, the ancestor toxic gene duplicated into a series of multicopy genes integrated at the different chromosome; at the late course of evolution, subsequent functional divergence of duplicate genes was generated by mutations, deletions and insertion. IUBMB Life, 57: 513-521, 2005

S-nitrosylation of nuclear factor κB (NF-κB) on the p65 subunit of the p50/p65 heterodimer inhibits NF-κB DNA binding activity. We have recently shown that p65 is constitutively S-nitrosylated in the lung and that LPS-induced injury elicits a decrease in SNO-p65 levels concomitant with NF-κB activation in the respiratory epithelium and initiation of the inflammatory response. Here, we demonstrate that TNFα-mediated activation of NF-κB in the respiratory epithelium similarly induces p65 denitrosylation. This process is mediated by the denitrosylase thioredoxin (Trx), which becomes activated upon cytokine-induced degradation of thioredoxin-interacting protein (Txnip). Similarly, inhibition of Trx activity in the lung attenuates LPS-induced SNO-p65 denitrosylation, NF-κB activation, and airway inflammation, supporting a pathophysiological role for this mechanism in lung injury. These data thus link stimulus-coupled activation of NF-κB to a specific, protein-targeted denitrosylation mechanism and further highlight the importance of S-nitrosylation in the regulation of the immune response.

IFN-β-1b is a first-line immunomodulatory therapy for relapsing–remitting multiple sclerosis (RR MS). However, its effects on B cells have not been characterized. In vitro studies of B cells derived from RR MS patients revealed that IFN-β-1b decreases B cells’ stimulatory capacity, as detected by inhibition of the Ag-specific T cell proliferative response upon Ag presentation by IFN-β-1b–treated B cells. Our study has identified that IFN-β-1b inhibited B cells’ stimulatory capacity in RR MS patients and healthy controls through the suppression of CD40 and CD80 expression, whereas the MHC class I and II expression was not changed. IFN-β-1b in vitro treatment inhibited B cell secretion of IL-1β and IL-23 and induced IL-12 and IL-27. Supernatants transferred from IFN-β-1b–treated B cells inhibited Th17 cell differentiation, as they suppressed gene expression of the retinoic acid-related orphan nuclear hormone receptor C and IL-17A and secretion of IL-17A. In addition, IFN-β-1b induced B cells’ IL-10 secretion, which may mediate their regulatory effect. Studies of B cells derived from RR MS patients treated with recombinant s.c. injected IFN-β-1b revealed that they induced a significantly lower proliferative response in allogenic MLR than the B cells from untreated patients. Further confirming the IFN-β-1b in vitro-induced changes in B cell cytokine secretion, B cells derived from the IFN-β-1b–treated patients secreted significantly lower levels of IL-1β and IL-23 and higher levels of IL-12 and IL-27 in comparison with the B cells derived from untreated patients. We conclude that IFN-β-1b exerts its therapeutic effects in part by targeting B cells’ functions that contribute to the autoimmune pathogenesis of RR MS.

IL-1 cytokine family plays a key role in the innate immune response against pathogen- and danger-associated molecular patterns. More recently, IL-1 receptor type 1 (IL-R1) signaling has been identified as a critical step in the differentiation and commitment of Th17 cells, which mediate the development of autoimmune diseases. Given its significance in the induction of the adoptive immune response, this complex signaling pathway is tightly regulated. Upon binding of IL-1 to IL-1R1, IL-1R accessory protein (AcP) is recruited to form a high affinity IL-1R1-IL-1RAcP heterodimeric receptor, which initiates the downstream signaling cascade. Multiple negative regulators of this pathway, including inhibitory membrane-bound IL-RII, secreted soluble (s)IL-1RI, sIL-RII and sIL-1RAcP, the regulatory IL-1R1 antagonist (IL-1R1a) and the IL-1R1-signlaing-induced single Ig-IL-1R-related (SIGIRR), provide a negative feedback control of this pathway, and suppress excessive IL-1 signaling and Th17 cell differentiation. IL-1R1 signaling induces human Th17 cell differentiation, leading to the expression of IL-1R-associated protein kinase (IRAK)4 and retinoic acid-related orphan nuclear hormone receptor (ROR), Th17 cell lineage transcription factors, which together with signal transducer and activator of the transcription (STAT)3, activate this cell lineage's specific cytokine expression profile, including IL-17A, IL-17F, IL-21 and IL-22. Given the role of IL-1 signaling and Th17 cells in the development of the autoinflammatory and autoimmune diseases, therapeutic strategies inhibiting IL-1R1 signaling are discussed as a novel approach for the treatment of autoimmune diseases and particularly multiple sclerosis (MS).

Reactive oxygen species are known to participate in the regulation of intracellular signaling pathways, including activation of NF-kappaB. Recent studies have indicated that increases in intracellular concentrations of hydrogen peroxide (H(2)O(2)) have anti-inflammatory effects in neutrophils, including inhibition of the degradation of I kappaB alpha after TLR4 engagement. In the present experiments, we found that culture of lipopolysaccharide-stimulated neutrophils and HEK 293 cells with H(2)O(2) resulted in diminished ubiquitination of I kappaB alpha and decreased SCF(beta-TrCP) ubiquitin ligase activity. Exposure of neutrophils or HEK 293 cells to H(2)O(2) was associated with reduced binding between phosphorylated I kappaB alpha and SCF(beta-TrCP) but no change in the composition of the SCF(beta-TrCP) complex. Lipopolysaccharide-induced SCF(beta-TrCP) ubiquitin ligase activity as well as binding of beta-TrCP to phosphorylated I kappaB alpha was decreased in the lungs of acatalasemic mice and mice treated with the catalase inhibitor aminotriazole, situations in which intracellular concentrations of H(2)O(2) are increased. Exposure to H(2)O(2) resulted in oxidative modification of cysteine residues in beta-TrCP. Cysteine 308 in Blade 1 of the beta-TrCP beta-propeller region was found to be required for maximal binding between beta-TrCP and phosphorylated I kappaB alpha. These findings suggest that the anti-inflammatory effects of H(2)O(2) may result from its ability to decrease ubiquitination as well as subsequent degradation of I kappaB alpha through inhibiting the association between I kappaB alpha and SCF(beta-TrCP).

IFN-β-1a has been used over the past 15 years as a primary therapy for relapsing-remitting multiple sclerosis (MS). However, the immunomodulatory mechanisms that provide a therapeutic effect against this CNS inflammatory disease are not yet completely elucidated. The effect of IFN-β-1a on Th17 cells, which play a critical role in the development of the autoimmune response, has not been extensively studied in humans. We have investigated the effect of IFN-β-1a on dendritic cells (DCs) and naive CD4+CD45RA+ T cells derived from untreated MS patients and healthy controls in the context of Th17 cell differentiation. We report that IFN-β-1a treatment down-regulated the expression of IL-1β and IL-23p19 in DCs, whereas it induced the gene expression of IL-12p35 and IL-27p28. We propose that IFN-β-1a-mediated up-regulation of the suppressor of cytokine signaling 3 expression, induced via STAT3 phosphorylation, mediates IL-1β and IL-23 down-regulation, while IFN-β-1a-induced STAT1 phosphorylation induces IL-27p28 expression. CD4+CD45RA+ naive T cells cocultured with supernatants from IFN-β-1a-treated DCs exhibited decreased gene expression of the Th17 cell markers retinoic acid-related orphan nuclear hormone receptor c (RORc), IL-17A, and IL-23R. A direct IFN-β-1a treatment of CD45RA+ T cells cultured in Th17-polarizing conditions also down-regulated RORc, IL-17A, and IL-23R, but up-regulated IL-10 gene expression. Studies of the mechanisms involved in the Th17 cell differentiation suggest that IFN-β-1a inhibits IL-17 and induces IL-10 secretion via activated STAT1 and STAT3, respectively. IFN-β’s suppression of Th17 cell differentiation may represent its most relevant mechanism of selective suppression of the autoimmune response in MS.

Rationale: Although reactive oxygen species (ROS) are generally considered to be proinflammatory and to contribute to cellular and organ dysfunction when present in excessive amounts, there is evidence that specific ROS, particularly hydrogen peroxide (H2O2), may have antiinflammatory properties. Objectives: To address the role that increases in intracellular H2O2 may play in acute inflammatory processes, we examined the effects of catalase inhibition or the absence of catalase on LPS-induced inflammatory responses. Methods: Neutrophils from control or acatalasemic mice, or control neutrophils incubated with the catalase inhibitor aminotriazole, were treated with LPS, and levels of reactive oxygen species, proteasomal activity, NF-κB activation, and proinflammatory cytokine expression were measured. Acute lung injury (ALI) was produced by intratracheal injection of LPS into control, acatalasemic-, or aminotriazole-treated mice. Measurements and Main Results: Intracellular levels of H2O2 were increased in acatalasemic neutrophils and in neutrophils exposed to aminotriazole. Compared with LPS-stimulated neutrophils from control mice, neutrophils from acatalasemic mice or neutrophils treated with aminotriazole demonstrated reduced 20S and 26S proteasomal activity, IκB-α degradation, NF-κB nuclear accumulation, and production of the proinflammatory cytokines TNF-α and macrophage inhibitory protein (MIP)-2. The severity of LPS-induced ALI was less in acatalasemic mice and in mice treated with aminotriazole as compared with that found in control mice. Conclusions: These results indicate that H2O2 has antiinflammatory effects on neutrophil activation and inflammatory processes, such as ALI, in which activated neutrophils play a major role.

High mobility group box 1 protein (HMGB1), originally characterized as a nuclear DNA-binding protein, has also been described to have an extracellular role when it is involved in cellular activation and proinflammatory responses. In this study, FLAG-tagged HMGB1 was inducibly expressed in the presence of culture media with or without added IL-1β, IFN-γ, or TNF-α. HMGB1 purified from cells grown in culture media alone only minimally increased cytokine production by MH-S macrophages and had no effect on murine neutrophils. In contrast, HMGB1 isolated from cells cultured in the presence of IL-1β, IFN-γ, and TNF-α had enhanced proinflammatory activity, resulting in increased production of MIP-2 and TNF-α by exposed cells. IL-1β was bound to HMGB1 isolated from cells cultured with this cytokine, and purified HMGB1 incubated with recombinant IL-1β acquired proinflammatory activity. Addition of anti-IL-1β Abs or the IL-1 receptor antagonist to cell cultures blocked the proinflammatory activity of HMGB1 purified from IL-1β-exposed cells, indicating that such activity was dependent on interaction with the IL-1 receptor. These results demonstrate that HMGB1 acquires proinflammatory activity through binding to proinflammatory mediators, such as IL-1β.

The apxIC and apxIIC genes of the Actinobacillus pleuropneumoniae serovar 1 strain SLW01, encoding the ApxI- and ApxII-activating proteins, respectively, were deleted successively by a method involving sucrose counterselection. The resulting strain, SLW03, contained no foreign DNA and could secrete unactivated ApxIA and ApxIIA RTX toxins with complete antigenicity. Strain SLW03 was attenuated at least 1000-fold in Balb/C mice and caused no adverse effects in pigs at doses of up to 1 x 10(9) CFU mL(-1). SLW03 was able to induce a significant immune response and provide complete protection from clinical signs upon homologous (serovar 1) and heterologous (serovar 9) challenge of A. pleuropneumoniae. Pigs vaccinated via the intranasal (i.n.) route had significantly higher serum titers and fewer pulmonary lesions than pigs vaccinated via the intramuscular route postchallenge. These results suggest that the mutant strain SLW03 could be used as a candidate live vaccine that can induce reliable cross-serovar protection following i.n. immunization.

Nitric oxide synthase 2 (NOS2) is expressed in human respiratory epithelium and is induced in inflammatory airway diseases. However, relatively little is known about the mechanisms underlying the regulation of NOS2 activity or the targets of NOS2-derived NO in this cell-type. We hypothesized that the large-scale identification of NOS2-protein interactions, and quantification of changes to the NOS2 “interactome” in response to inflammatory stimuli, would provide new insights into the function and regulation of NOS2. We overexpressed Flag-tagged NOS2 in airway epithelial (A549) cells and used mass spectrometry to identify NOS2 co-immunoprecipitating proteins. We further utilized stable isotope labeling of amino acids in cell culture (SILAC) to quantify the coordinate effects of cytokine stimulation on these interactions. Multi-protein networks dominated the NOS2 interactome, and inducible interactions with allosteric activators and with the ubiquitin–proteasome system were correlated with cytokine-dependent increases in NO metabolites and in NOS2 ubiquitination, respectively. We also identified a novel NOS2-interacting protein and associated ubiquitin ligase complex that may be one of several regulators of NOS2 stability in the A549 cell. We will discuss the significance of these findings and the applicability of these proteomic techniques for studying NOS2 in other cellular systems.

Activation of the pro-inflammatory transcription factor NF-Kappa B (p50–p65) is inhibited via S-nitrosylation of the p65 subunit (SNO-p65). In the respiratory epithelium, cytokine stimulation induces rapid denitrosylation of p65 concomitant with NF-Kappa B activation and initiation of the pulmonary immune response. However, the mechanism for NF-Kappa B denitrosylation has remained unclear. We hypothesize that thioredoxin (Trx), an oxidoreductase with denitrosylating activity, mediates this response. We utilized cytokine-stimulated respiratory epithelial cells (A549) and C57BL6 mice exposed to aerosolized LPS (5 mg/m 3 ) to test this hypothesis. Trx reductase (TrxR) activity was inhibited in mice and in cells by pretreatment with the organic gold compounds auranofin and aurothioglucose, respectively. Trx protein expression, SNO-p65 formation and NF-Kappa B activity were quantified in cell lysates and in lung homogenates. Bronchoalveolar lavage fluid was analyzed for markers of airway inflammation (WBC count and cytokines). We found that TrxR inhibition prevented cytokine-mediated denitrosylation of p65, NF-Kappa B activation, and LPS-induced airway inflammation. Trx1 co-immunoprecipitated with p65 at baseline, but this interaction was not increased with cytokine stimulation nor did cytokines alter TrxR activity. Cytokine-induced and Trx-dependent denitrosylation of p65 was, however, dependent upon the ERK MAP kinase pathway, and the regulatory mechanisms for ERK-dependent denitrosylation will be discussed.

Background: IFNβ-1b is a first-line immunomodulatory therapy for relapsing remitting multiple sclerosis (RRMS), however its effects on B-cells have not been characterized. Methods: We have characterized the effect of the IFNβ-1b administered to RRMS patients on the B-cells’ antigen presenting capacity using allogenic MLR and cytokine secretion using ELISA. B-cells were derived from 7 treated and 7 untreated RRMS patients Results: B-cells derived from RRMS patients treated with recombinant subcutaneously injected IFNβ-1b revealed that they induced a significantly lower proliferative response in allogenic mixed lymphocyte reaction (MLR) than the B-cells from untreated patients (p=0.018). Further confirming the IFNβ-1b in-vitro induced changes in B-cell cytokine secretion that collectively inhibit Th17 cell differentiation, B-cells derived from the IFNβ-1b-treated patients secreted significantly lower levels of IL-1β(p=0.046) and IL-23(p=0.028), and higher levels of IL-12(p=0.046) and IL-27(p=0.028) in comparison to the B-cells derived from untreated RRMS patients.Conclusion: IFNβ-1b exerts its therapeutic effects in part by inhibiting B-cells’ antigen presenting capacity and by modifying their secretion of Th17-regulatory cytokines, which contribute to the autoimmune pathogenesis of RRMS.

BACKGROUND: IL-1β plays a crucial role in the development of human Th17 cells. However, its mechanisms of action are still not completely elucidated. Recent has study discovered that Th17 cells are characterized by IL-1R1 expression. RESULTS: Our study has revealed that IL-1R1 and IL-1R2 gene expression is significantly increased in both naïve and memory CD4+ T-cells derived from patients with relapsing-remitting multiple sclerosis (RRMS) in comparison to matched healthy controls. IL-1R1 expression is up-regulated in the in vitro differentiated Th17 cells in comparison to the Th1 and Th2 cell subsets. IL-17A production was induced by IL-1β. This induction was blocked by IL-1R antagonist in the naïve CD4+cells cultured in the presence of Th17 polarizing cytokines. When IL-1R1 gene expression was silenced using siRNA, human naïve CD4+ T-cells cultured in the presence of Th17 polarizing cytokines had a significantly decreased expression of IL-21, IL-22, IL-23R, IRF4, RORC, IL-17A and IL-17F genes, confirming that IL-1R1 signaling induces Th17 cell differentiation. IRF4 gene expression silencing, similarly inhibited Th17 cell differentiation in the presence of IL-1b, indicating that IL-1R1 signals upstream of IRF4. CONCLUSION: Our study has identified that IL-1R1-mediated signaling pathway may be constitutively activated, leading to an increased Th17 cell expansion and autoimmune response in patients with RR MS.