Soluble Receptor Isoform of IFN-Beta (sIFNAR2) in Multiple Sclerosis Patients and Their Association With the Clinical Response to IFN-Beta Treatment.

Purpose: Interferon beta receptor 2 subunit (IFNAR2) can be produced as a transmembrane protein, but also as a soluble form (sIFNAR2) generated by alternative splicing or proteolytic cleavage, which has both agonist and antagonist activities for IFN-ß. However, its role regarding the clinical response to IFN-ß for relapsing-remitting multiple sclerosis (RRMS) is unknown. We aim to evaluate the in vitro short-term effects and after 6 and 12 months of IFN-ß therapy on sIFNAR2 production and their association with the clinical response in MS patients. Methods: Ninety-four RRMS patients were included and evaluated at baseline, 6 and 12 months from treatment onset. A subset of 41 patients were classified as responders and non-responders to IFN-ß therapy. sIFNAR2 serum levels were measured by ELISA. mRNA expression for IFNAR1, IFNAR2 splice variants, MxA and proteases were assessed by RT-PCR. The short-term effect was evaluated in PBMC from RRMS patients after IFN-ß stimulation in vitro. Results: Protein and mRNA levels of sIFNAR2 increased after IFN-ß treatment. According to the clinical response, only non-responders increased sIFNAR2 significantly at both protein and mRNA levels. sIFNAR2 gene expression correlated with the transmembrane isoform expression and was 2.3-fold higher. While MxA gene expression increased significantly after treatment, IFNAR1 and IFNAR2 only slightly increased. After short-term IFN-ß in vitro induction of PBMC, 6/7 patients increased the sIFNAR2 expression. Conclusions: IFN-ß administration induces the production of sIFNAR2 in RRMS and higher levels might be associated to the reduction of therapeutic response. Thus, levels of sIFNAR2 could be monitored to optimize an effective response to IFN-ß therapy.

Integrative analysis highlighted susceptibility genes for rheumatoid arthritis.

Genetic factors underlying susceptibility to rheumatoid arthritis (RA) are largely unknown. The aim of this study was to identify potential genes for RA. We conducted summary statistic data-based Mendelian randomization (SMR) analysis to detect potential causal genes for RA. Further, we performed additional bioinformatics analysis to show the potential relevance of the identified genes to RA. We identified 140 genes that showed causal association with RA. Among these genes, 24 have not been reported to be associated with RA (e.g., IFNAR2, FLOT1, ITPR3, PPP2R3C and SLC35B2). The unreported genes were highly connected with some well-known RA-related genes (e.g., HLA-DQB1, CD226, PTPN22, CD40, IFNGR2, BLK, TRAF1, SYNGR1 and CCR6) that were also found to be causally associated with RA. The identified genes were involved in the significant enriched RA-related biological pathways. We found integrative evidence in support of IFNAR2 as a potential causal gene of RA in SMR, differential expression, weighted gene co-expression network, protein-protein interaction and functional enrichment analyses. The present study highlights a list of potential causal genes for RA. The findings provide new insights into the mechanism underlying known genome-wide associated RA susceptibility loci.

Decreased Methylation of IFNAR Gene Promoter from Peripheral Blood Mononuclear Cells Is Associated with Oxidative Stress in Chronic Hepatitis B.

Type I interferons (IFNs) play an antiviral effect by binding to type I interferon receptor (IFNAR). Oxidative stress might induce the gene promoter methylation. The purpose of our study was to evaluate the potential relationship between the methylation of IFNAR promoter and the status of oxidative stress in chronic hepatitis B (CHB). The methylation level of the IFNAR promoter in patients with CHB and healthy controls (HCs) was determined by methylation-specific polymerase chain reaction (MS-PCR). The quantitative real-time PCR (RT-qPCR) was used to evaluate the IFNAR mRNA status in peripheral blood mononuclear cells from CHB and HCs. Level of plasma-soluble IFNAR and oxidative stress parameters, including malondialdehyde (MDA) and glutathione (GSH) were determined by enzyme-linked immunosorbent assay (ELISA). The frequency of IFNAR promoter methylation in CHB patients was significantly lower than that of HCs. The IFNAR mRNA level of patients with CHB was higher than HCs. MDA level was higher in CHB patients, whereas GSH level was lower in CHB patients than that of HCs. In CHB patients, plasma MDA level was significantly higher with IFNAR promoter methylation than unmethylation, and soluble IFNAR in the circulation of methylated patients with CHB was decreased than unmethylated patients with CHB. Our results indicated that the IFNAR promoter methylation might have a potential relationship with the status of oxidative stress.

Brief Report: Increased Expression of the Type I Interferon Receptor on CD4+ T Lymphocytes in HIV-1-Infected Individuals.

BACKGROUND: Type I interferons (IFN1s; eg, interferon-alpha and interferon-beta) are potent cytokines that inhibit the replication of human immunodeficiency virus-1 (HIV-1) and other viruses. The antiviral and immunoregulatory activities of IFN1 are mediated through ligand-receptor interactions with the IFN1 receptor complex (IFNAR). Variation in the cell-surface density of IFNAR could play a role in HIV-1 pathogenesis. METHODS: In this cross-sectional study of fresh whole blood, we used flow cytometry to evaluate the expression of IFNAR2 on lymphocyte subsets from HIV-1-infected (n = 33) and HIV-1-uninfected (n = 22) individuals. RESULTS: In comparison with healthy blood bank donors, we observed that the HIV-1-infected individuals, particularly those having advanced to disease, exhibited the increased expression of IFNAR2 on CD4 T cells (relative fluorescence intensity 6.9 vs. 9.0; P = 0.027). The CD4:CD4 T-cell IFNAR2 expression-level ratio provides an internally standardized measure of this alteration. The observed increased expression of IFNAR2 was largely restricted to CD4 T cells that expressed the chemokine receptor CXCR4 and lacked the expression of CCR5. CONCLUSIONS: HIV-1-infected individuals exhibit an increased expression of the IFN1 receptor on CD4 T cells. The level of IFNAR2 expression seems to increase with disease progression. These findings provide insight for the immunologic alterations associated with HIV-1 infection and possibly new therapeutic approaches.

Decreased soluble IFN-ß receptor (sIFNAR2) in multiple sclerosis patients: A potential serum diagnostic biomarker.

BACKGROUND: The soluble isoform of the interferon-ß (IFN-ß) receptor (sIFNAR2) could modulate the activity of both endogenous and systemically administered IFN-ß. Previously, we described lower serum sIFNAR2 levels in untreated multiple sclerosis (MS) than in healthy controls (HCs). OBJECTIVE: To assess sIFNAR2 levels in a new cohort of MS patients and HCs, as well as in patients with clinically isolated syndrome (CIS) and with other inflammatory neurological disorders (OIND) and to assess its ability as a diagnostic biomarker. METHODS: The cross-sectional study included 148 MS (84 treatment naive and 64 treated), 87 CIS, 42 OIND, and 96 HCs. Longitudinal study included 94 MS pretreatment and after 1 year of therapy with IFN-ß, glatiramer acetate (GA), or natalizumab. sIFNAR2 serum levels were measured by a quantitative ELISA developed and validated in our laboratory. RESULTS: Naive MS and CIS patients showed significantly lower sIFNAR2 levels than HCs and OIND patients. The sensitivity and specificity to discriminate between MS and OIND, for a sIFNAR2 cutoff value of 122.02 ng/mL, were 70.1%, and 79.4%, respectively. sIFNAR2 increased significantly in IFN-ß-treated patients during the first year of therapy in contrast to GA- and natalizumab-treated patients who showed non-significant changes. CONCLUSION: The results suggest that sIFNAR2 could be a potential diagnostic biomarker for MS.

Development and validation of an ELISA for quantification of soluble IFN-ß receptor: assessment in multiple sclerosis.

AIM: The soluble isoform of the IFN-ß receptor (sIFNAR2) can bind IFN-ß and modulate its activity, although its role in autoimmune diseases remains unknown. METHODS: A recombinant human sIFNAR2 protein was cloned, expressed and purified after which we developed and validated an ELISA for its quantification in human serum. Serum sIFNAR2 were assessed in multiple sclerosis (MS) patients and healthy controls. RESULTS: The ELISA has a dynamic range of 3.9-250 ng/ml and a detection limit of 2.44 ng/ml. Serum sIFNAR2 were significantly lower in untreated-MS patients than in healthy controls. CONCLUSION: The ELISA is suitable for quantification of sIFNAR2 in serum and should facilitate the study of sIFNAR2 in neuroimmunological diseases such as MS.

Impaired HCV clearance in HIV/HCV coinfected subjects treated with PegIFN and RBV due to interference of IFN signaling by IFNαR2a.

Enhanced endogenous interferon (IFN) stimulated gene (ISG) signature has been associated with nonresponsiveness to hepatitis C treatment using pegylated-IFNα (pegIFNα) and ribavirin (RBV) in human immunodeficiency virus/hepatitis C virus (HIV/HCV) coinfected patients. Using a proteomic approach, we identified high levels of IFNα receptor 2a (IFNαR2a) in the serum of null responders to pegIFNα/RBV. IFNαR2a inhibited antiviral activity of all formulations of IFNα in JFH/Huh7.5 cells. Furthermore, serum from null responders, but not from those who achieved sustained virologic response, suppressed IFN-signaling and ISG expression in IFNα-stimulated PBMCs of healthy donors in an IFNαR2a specific fashion. An IFNαR2a transgenic mice model (C57BL/6) was generated that had significantly higher levels of IFNαR2a in the serum than the controls (P=0.001). Total ISG expression in the lymph nodes was significantly higher compared to wild-type mice (P value=0.0016). In addition, IFITM1 and SP110 had significantly increased expression in the liver, IFITM1 and ISG15 in the lymph node, and ISG15 and PLSCR1 in the spleen (P value<0.05). The underlying mechanism of resistance to hepatitis C treatment may involve transsignaling of the JAK/STAT pathway by the sIFNαR2a-IFNα/ß complex and result in the enhanced ISG signature observed in null responders. In this regard, the transgenic mice model simulated nonresponders to IFNα therapy and provides valuable insights into the role of sIFNαR2a-IFNα interactions in vivo.

Peripheral type I interferon receptor correlated with oxidative stress in chronic hepatitis B virus infection.

Type I interferon receptor (IFNAR) has been involved in the progression of chronic hepatitis B (CHB). Oxidative stress is also associated with hepatitis B virus (HBV) infection and might contribute to the structure and function of protein synthesis including the IFNAR family. This study was aimed to determine the possible associations between oxidative stress and peripheral IFNAR expression in chronic HBV infection. Fifty-four CHB patients and 31 liver cirrhosis (LC) patients were consecutively collected, as well as 11 healthy subjects as controls. Expression levels of IFNAR1 and IFNAR2 in peripheral blood lymphocytes and monocytes were measured by flow cytometry. IFNAR1 and IFNAR2c mRNA were detected by real-time reverse transcription-polymerase chain reaction. Levels of plasma-soluble IFNAR and oxidative stress parameters, including xanthine oxidase (XOD), malondialdehyde (MDA), glutathione (GSH), glutathione S-transferase (GST), and glutathione peroxidase (GSH-Px) were detected by enzyme linked immunosorbent assay (ELISA). The frequencies of IFNAR1 and IFNAR2 in lymphocytes and monocytes were significantly increased in CHB and LC patients than in healthy controls. Expression levels of IFNAR1 and IFNAR2c mRNA and plasma-soluble IFNAR level in CHB and LC patients were upregulated compared with healthy controls. Mean fluorescence intensity (MFI) of IFNAR2 in monocytes of CHB patients was higher than that in LC patients. Levels of plasma XOD, MDA, and GST were significantly increased in CHB and LC patients compared with healthy controls. Meanwhile, GSH and GSH-Px in CHB and LC patients were decreased than that in healthy controls. Furthermore, plasma MDA, GSH, and GST levels in CHB patients were higher than that in LC patients. In CHB patients, plasma GST level was negatively correlated with MFI of IFNAR2 in lymphocytes. Our results suggested that oxidative stress play an important role in the regulation of IFNAR in chronic HBV infection.

Expression of IFNAR2 mRNA in peripheral blood mononuclear cells of patients with HCV infection.

BACKGROUND: To investigate the differences of interferon-alpha/beta receptor 2 (IFNAR2) mRNA expression level in peripheral blood mononuclear cells (PBMCs) between different stages of hepatitis C virus (HCV) infection and to determine the correlation with the effectiveness of interferon therapy. METHODOLOGY: 58 patients, positive for anti-HCV antibodies, were divided into three groups depending on their clinical symptoms: acute hepatitis (4 cases), chronic hepatitis (46 cases) and liver cirrhosis (8 cases). 15 volunteers served as healthy controls. PBMCs were purified by density gradient centrifugation and IFNAR2 mRNA was amplified from these cells by a reverse transcription-polymerase chain reaction (RT-PCR) assay. RESULTS: The detection rate of IFNAR2 mRNA was 87.9% (51/58 cases) in the PBMCs of patients with HCV infection, significantly higher than that in the control group (333%, 5/15 cases; P < 0.05). While the positive rate was 93.5% (43/46 cases) in the chronic hepatitis group, which was significantly higher than that in the liver cirrhosis group (50%, 4/8 cases; P < 0.05). Furthermore, there is no significant difference in the positive rates for HCV-RNA of PBMCs among groups (P > 0.05). The positive rate of IFNAR2 mRNA in PBMCs was not correlated with the viral load of HCV-RNA in serum (P > 0.05). However, higher expression of IFNAR2 mRNA in the PBMCs did correlate with the effectiveness of interferon therapy (P < 0.05). CONCLUSIONS: HCV infection up-regulates the expression of IFNAR2 mRNA in PBMCs. IFNAR2 mRNA expression in the chronic hepatitis group was higher than that in the liver cirrhosis group, and significantly correlated with the effectiveness of interferon therapy, which was independent of the viral load.

Interferon (alpha, beta and omega) receptor 2 is a prognostic biomarker for lung cancer.

OBJECTIVES: It has been reported that the type I interferon receptor subunit, interferon (alpha, beta and omega) receptor 2 (IFNAR2), is overexpressed in several malignancies, primarily adenocarcinomas (ADCs); however, the biological significance of IFNAR2 in human lung cancer has not yet been studied. METHODS: Immunohistochemical analysis of 113 surgically resected lung specimens was performed, and the results were evaluated in association with clinical variables, including survival. Serum concentrations of IFNAR2 were also determined by an enzyme-linked immunosorbent assay in 157 lung cancer patients and 164 healthy volunteers. RESULTS: IFNAR2 overexpression was observed in all histological types of lung cancer examined. Furthermore, strong IFNAR2 expression was associated with shorter progression-free survival (PFS) and overall survival (OS) (p < 0.0001 and p = 0.0110, respectively) in non-small cell lung cancer patients. Multivariate analyses confirmed its independent prognostic value for PFS and OS (p < 0.0001 and p = 0.0222, respectively). IFNAR2 serum levels were also significantly higher in lung cancer patients than in healthy volunteers (p < 0.0001). CONCLUSIONS: IFNAR2 overexpression was observed in various histological types of lung cancer, and appears to be associated with lung cancers that behave aggressively. The results of this study strongly support the potential of IFNAR2 to be a prognostic biomarker for lung cancer.

Alteration of interferon-α/ß receptors in chronic hepatitis B patients.

BACKGROUND: The present study determined type I interferon (IFN) receptor (interferon-α/ß receptor (IFNAR)) and its predicable role in interferon-α2b treatment in chronic hepatitis B (CHB) patients. METHODS: Expression of IFN-α/ßR-1 and IFN-α/ßR-2 in peripheral blood mononuclear cells and in liver tissue was measured by flow cytometry, immunofluorescence, immunohistochemistry and RT-PCR. RESULTS: IFN-α/ßR-1 and IFN-α/ßR-2 in monocytes and lymphocytes increased in CHB patients. Expression of IFNAR-1 and IFNAR-2 in liver had positive correlation with HBV-DNA in liver tissue. Expression of IFN-α/ßR in lymphocytes and monocytes increased in the first month, but then decreased during the subsequent interferon-α2b treatment, patients who had higher levels of IFN-α/ßR-2 in monocytes prior to therapy showed better viral response than those with lower levels. CONCLUSIONS: Expression of IFN-α/ßR-2 in monocytes can be used as a predictable parameter to evaluate the effect of IFN-α treatment in CHB patients.

Serum evaluation of soluble interferon-alpha/beta receptor and high-sensitivity C-reactive protein for diagnosis of the patients with gastrointestinal and hepatobiliary-pancreatic cancer.

Serum soluble interferon-alpha/beta receptor (sIFN-alpha/betaR) and high-sensitivity C-reactive protein (hs-CRP) levels were evaluated in the patients with gastrointestinal and hepatobiliary-pancreatic cancer. We compared the sensitivity and specificity of serum sIFN-alpha/betaR with that of serum hs-CRP and evaluated the two diagnostic parameters in combination. Serum sIFN-alpha/betaR levels were measured in 92 patients and 25 healthy individuals by enzyme-linked immunosorbent assay. The diagnoses were 37 cases of hepatocellular carcinoma, 17 cases of pancreatic cancer, 15 cases of colon cancer, 13 cases of biliary tract cancer, and 10 cases of gastric cancer. Serum levels of sIFN-alpha/betaR and hs-CRP were significantly higher in the patients than in healthy individuals (p<0.05). The optimal cut-off values of sIFN-alpha/betaR and hs-CRP were 3600pg/ml and 0.5microg/ml, respectively. The sensitivity and specificity for these thresholds were 94.6% and 88.0%, whereas positive predictive and negative predictive values were 96.7% and 81.5%. These results suggest that a combination of serum sIFN-alpha/betaR and hs-CRP thresholds may be more reliable diagnostic parameter for gastrointestinal and hepatobiliary-pancreatic cancer.

[Expression of IFN-alpha/beta receptor in the PBMCs and liver of patients with hepatitis B and its clinical significance].

OBJECTIVE: To explore the role of interferon (IFN)-alpha/beta receptor beta subunit (IFNAR2) in the patients' response to IFN-alpha therapy as influenced by the grade of chronic hepatic inflammation, and understand the relation of IFNAR2 expression in the peripheral blood mononuclear cells (PBMCs) with HBV infection. METHODS: Liver tissue specimens were obtained from 21 patients with chronic hepatitis B for examination of the hepatic inflammation, and PBMCs were isolated from another 16 patients with chronic hepatitis B and 15 health control subjects. Both the hepatic tissues and PBMCs were examined for IFNAR2 expression using immunohistochemistry. RESULTS: The 21 patients with chronic hepatitis B were divided into 3 groups according to the severity of hepatic inflammation, namely G(1) (n=3), G(2) (n=7) and G(3) (n=11) groups. The patients in G(3) group showed had significantly higher IFNAR2 expressions in liver (25.1307-/+7.0700) than those of the G(1) (5.6913-/+1.8422) and G(2) (7.4706-/+5.3572) groups (P=0.000). The IFNAR2 levels in the PBMCs, however, did not show significant difference between patients with chronic hepatitis B and the healthy control subjects. CONCLUSION: In patients with chronic hepatitis B, IFNAR2 expression level is positively correlated to the severity of hepatic inflammation, and increased IFNAR2 expression in severe hepatic inflammation is therefore likely to result in increased response rate to INF-alpha therapy. The expression of IFNAR2 in the PBMCs is not associated with HBV infection.

Decreased type I interferon receptor-soluble isoform in antiretroviral-treated HIV-positive children.

We developed a real-time PCR assay to simultaneously measure the mRNA level of type I interferon (IFN) receptor (IFNAR) components in peripheral blood cells of children with chronic immune stimulation due to HIV infection. All patients were undergoing antiretroviral therapy and were divided into two groups on the basis of the induction of MxA mRNA, a marker of type I IFN bioactivity. We found that IFNAR-2 subunit mRNA was higher than that of the IFNAR-1 subunit, that the mRNA for the IFNAR-2.2 functional isoform was more expressed than that for the truncated IFNAR-2.1 isoform, and both were much more represented than that of the IFNAR-2.3 soluble isoform. We also demonstrated that soluble isoform mRNA was significantly diminished in the subgroup of patients with MxA mRNA below the cutoff value (determined as the 99th percentile of MxA measured in healthy controls). These results suggest that downregulation of the soluble receptor isoform, which would not compete with the functional isoform for binding to the target cytokine, would give type I IFN, eventually induced in these patients in the case of viral reactivation, the opportunity to promptly exert its antiviral activity.