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ObjectiveIt remains unclear whether viral infections interfere with multiple sclerosis (MS) disease progression. We evaluated the prognostic role of antibody responses toward viruses determined at disease onset on long-term disease outcomes.MethodsHumoral immune responses against Epstein-Barr virus (EBV)-encoded nuclear antigen EBNA1, viral capsid antigen (VCA) and early antigen, and toward cytomegalovirus (HCMV), human herpesvirus 6 and measles were investigated in a cohort of 143 patients with MS for their association with long-term disability and inflammation disease outcomes.ResultsMedian (IQR) follow-up was 20 (17.2–22.8) years. In univariable analysis, increased HCMV levels were associated with a lower risk to Expanded Disability Status Scale 4.0 (HR 0.95; 95% CI 0.91 to 0.99; p=0.03), to develop a secondary progressive MS (HR 0.94; 95% CI 0.90 to 0.99; p=0.02) and to first-line treatment (HR 0.98; 95% CI 0.96 to 0.99; p=0.04). High HCMV IgG levels were associated with a longer time to first-line treatment (p=0.01). Increased immune responses against EBV-VCA were associated with higher risk for first-line (HR 1.45; 95% CI 1.12 to 1.88; p=0.005) and second-line treatments (HR 2.03; 95% CI 1.18 to 3.49; p=0.01), and high VCA IgG levels were associated with shorter time to first-line (p=0.004) and second-line (p=0.02) therapies. EBNA1-specific IgG levels correlated with disease severity (0.17; p=0.04) and with an increased relapse rate during follow-up (relapse rate 1.26; 95% CI 1.03 to 1.56; p=0.02) that remained stable in multivariable analysis.ConclusionsThese results indicate that elevated immune responses against HCMV at disease onset have protective effects on long-term disability and inflammation disease outcomes. Our data also indicate that increased immune responses against EBV in early phases may influence long-term disease prognosis.

Background: Inflammasomes are involved in the pathogenesis of different neuroimmune and neurodegenerative diseases, including multiple sclerosis (MS). In a previous study by our group, the nucleotide-binding oligomerization domain, leucine-rich repeat receptor and pyrin-domain containing 3 (NLRP3) inflammasome was reported to be associated with the response to interferon-beta in MS. Based on recent data showing the potential for the oral therapy fingolimod to inhibit NLRP3 inflammasome activation, here we investigated whether fingolimod could also be implicated in the response to this therapy in MS patients. Methods: NLRP3 gene expression levels were measured by real-time PCR in peripheral blood mononuclear cells at baseline and after 3, 6, and 12 months in a cohort of MS patients treated with fingolimod (N=23), dimethyl fumarate (N=21), and teriflunomide (N=21), and classified into responders and non-responders to the treatment according to clinical and radiological criteria. In a subgroup of fingolimod responders and non-responders, the percentage of ASC specks in monocytes was determined by flow cytometry, and the levels of IL-1β, IL-18, IL-6, TNFα, and galectin-3 were quantified by ELISA.Results: NLPR3 expression levels were significantly increased in fingolimod non-responders after 3 and 6 months of treatment but remained comparable in responders at all time points. These changes were not observed in non-responders to the other oral therapies tested. ASC speck formation in monocytes following LPS and ATP stimulation was significantly decreased in responders, but increased in non-responders after 6 months of fingolimod treatment. Pro-inflammatory cytokine release from stimulated PBMC was comparable between responders and non-responders, but galectin-3 levels on cell supernatants, as a marker of cell damage, were significantly increased in fingolimod non-responders. Conclusions: The differential effect of fingolimod on ASC speck formation in monocytes between responders and non-responders could be used as response biomarker after 6 months of fingolimod treatment, and suggests that fingolimod may exert their beneficial effects by reducing inflammasome signaling in a subset of MS patients.

Autoimmune; Multiple sclerosis Autoinmune; Esclerosis múltiple Autoimmune; Esclerosi múltiple Intronic single-nucleotide polymorphisms (SNPs) in the ANKRD55 gene are associated with the risk for multiple sclerosis (MS) and rheumatoid arthritis by genome-wide association studies (GWAS). The risk alleles have been linked to higher expression levels of ANKRD55 and the neighboring IL6ST (gp130) gene in CD4+ T lymphocytes of healthy controls. The biological function of ANKRD55, its role in the immune system, and cellular sources of expression other than lymphocytes remain uncharacterized. Here, we show that monocytes gain capacity to express ANKRD55 during differentiation in immature monocyte-derived dendritic cells (moDCs) in the presence of interleukin (IL)-4/granulocyte-macrophage colony-stimulating factor (GM-CSF). ANKRD55 expression levels are further enhanced by retinoic acid agonist AM580 but downregulated following maturation with interferon (IFN)-γ and lipopolysaccharide (LPS). ANKRD55 was detected in the nucleus of moDC in nuclear speckles. We also analyzed the adjacent IL6ST, IL31RA, and SLC38A9 genes. Of note, in healthy controls, MS risk SNP genotype influenced ANKRD55 and IL6ST expression in immature moDC in opposite directions to that in CD4+ T cells. This effect was stronger for a partially correlated SNP, rs13186299, that is located, similar to the main MS risk SNPs, in an ANKRD55 intron. Upon analysis in MS patients, the main GWAS MS risk SNP rs7731626 was associated with ANKRD55 expression levels in CD4+ T cells. MoDC-specific ANKRD55 and IL6ST mRNA levels showed significant differences according to the clinical form of the disease, but, in contrast to healthy controls, were not influenced by genotype. We also measured serum sgp130 levels, which were found to be higher in homozygotes of the protective allele of rs7731626. Our study characterizes ANKRD55 expression in moDC and indicates monocyte-to-dendritic cell (Mo–DC) differentiation as a process potentially influenced by MS risk SNPs. This research was supported by grants to KV from MINECO (SAF2016-74891-R), Instituto de Salud Carlos III (FIS-PI20/00123), Gobierno Vasco RIS3 (Ref. 2019222043), and Red Española de Esclerosis Múltiple (REEM; RD16/0015/0005). NV and LMV were supported by ISCIII (FIS-PI18/00572) and REEM (RD16/0015/0001). RTN is a recipient of a fellowship from the Secretaría Nacional de Ciencia y Tecnología e Innovación (SENACYT; Convocatoria Doctorado de Investigación Ronda III, 2018; Ref. BIDP-III-2018-12) of the Gobierno Nacional, República de Panamá.

ObjectiveThere is a lack of sensitive and specific biomarkers for use in progressive multiple sclerosis (MS). The study aimed to assess the potential of serum neurofilament light chain (sNfL) levels as biomarker of disability progression in patients with progressive MS.MethodsWe performed a prospective observational cohort study in 51 patients with progressive MS who participated in a 2-year phase II single-centre, randomised, double-blind, placebo-controlled trial of interferon-beta. Mean (SD) follow-up duration was 13.9 (6.2) years. Levels of sNfL were measured using a single molecule array immunoassay at baseline, 1, 2 and 6 years. Univariable and multivariable analyses were carried out to evaluate associations between sNfL levels and disability progression at short term (2 years), medium term (6 years) and long term (at the time of the last follow-up).ResultsA sNfL cut-off value of 10.2 pg/mL at baseline discriminated between long-term progressors and non-progressors with a 75% sensitivity and 67% specificity (adjusted OR 7.8; 95% CI 1.8 to 46.4; p=0.01). Similar performance to discriminate between long-term progressors and non-progressors was observed using age/body mass index-adjusted sNfL Z-scores derived from a normative database of healthy controls. A cut-off increase of 5.1 pg/mL in sNfL levels between baseline and 6 years also discriminated between long-term progressors and non-progressors with a 71% sensitivity and 86% specificity (adjusted OR 49.4; 95% CI 4.4 to 2×103; p=0.008).ConclusionssNfL can be considered a prognostic biomarker of future long-term disability progression in patients with progressive MS. These data expand the little knowledge existing on the role of sNfL as long-term prognostic biomarker in patients with progressive MS.

Background: Vitamin D is considered to play a role in multiple sclerosis (MS) etiopathogenesis. We recently identified a polymorphism located in the cytochrome P450 family 24 subfamily A member 1 (CYP24A1) gene, rs2762943, that was found to be associated with an increased risk for MS. CYP24A1 codes for a protein that is involved in the catabolism of the active form of vitamin D. Here, we investigated the immunological effects of carrying the risk allele for the rs2762943 polymorphism, as well as its role as genetic modifier in MS patients. Methods: Serum levels of 25‐hydroxyvitamin D (25OHD) and 1,25-dihydroxyvitamin D (1,25(OH)2D) were measured in a cohort of 167 MS patients. In a subgroup of these patients, expression levels of MHC class II and co-stimulatory molecules were determined by flow cytometry in blood cell populations, and the levels of proinflammatory (IFNG, GM-CSF, CXCL13) and anti-inflammatory (IL-10) cytokines and neurofilament light chain were measured by single-molecule array assays in serum samples. The effect of the rs2762943 polymorphism on disease activity and disability progression measures was evaluated in a cohort of 340 MS patients. Results: Compared to non-carriers, MS patients carrying the risk allele for rs2762943 were characterized by reduced levels of 1,25(OH)2D (p=0.0001), and elevated levels of IFNG (p=0.03) and GM-CSF (p=0.008), whereas no significant differences were observed between risk allele carriers and non-carriers groups for the other evaluated markers. The presence of the risk allele for rs2762943 had no significant impact on the annualized relapse rate, EDSS and MSSS measures during follow-up. However, risk allele carriers were younger at disease onset (p=0.04). Discussion: These findings suggest that the CYP24A1 rs2762943 gene variant plays a more important role on MS susceptibility than on disease prognosis, and is associated with lower 1,25(OH)2D levels and heightened pro-inflammatory environment in MS patients.

Inflammasomes are multimeric protein complexes that can sense a plethora of microbe- and damage-associated molecular signals. They play important roles in innate immunity and are key regulators of inflammation in health and disease. Inflammasome-mediated processing and secretion of pro-inflammatory cytokines such as interleukin 1β (IL-1β) and IL-18 and induction of pyroptosis, a pro-inflammatory form of cell death, has been associated with the development and progression of common immune-mediated and degenerative central nervous system (CNS) diseases such as Alzheimer's disease, multiple sclerosis, brain injury, stroke, epilepsy, Parkinson's disease, and amyotrophic lateral sclerosis. A growing number of pharmacological compounds inhibiting inflammasome activation and signalling shows therapeutic efficacy in preclinical models of the aforementioned disease conditions. Here, we illustrate regulatory mechanisms of inflammasome activation during CNS homeostasis and tissue injury. We highlight the evidence for inflammasome activation as a mechanistic underpinning in a wide range of CNS diseases and critically discuss the promise and potential limitations therapeutic strategies that aim to inhibit the inflammasome components in neurological disorders. This article is protected by copyright. All rights reserved.

[Background] Multiple sclerosis (MS) is a disease in which biomarker identification is fundamental to predict response to treatments and to deliver the optimal drug to patients. We previously found an association between rs7298096, a polymorphism upstream to the NINJ2 gene, and the 4-year response to interferon-β (IFNβ) treatment in MS patients., [Objectives] To analyse the association between rs7298096 and time to first relapse (TTFR) during IFNβ therapy in MS patients and to better investigate its functional role. [Methods] Survival analysis was applied in three MS cohorts from different countries (n = 1004). We also studied the role of the polymorphism on gene expression using GTEx portal and a luciferase assay. We interrogated GEO datasets to explore the relationship between NINJ2 expression, IFNβ and TTFR. [Results] Rs7298096AA patients show a shorter TTFR than rs7298096G-carriers (Pmeta-analysis = 3 × 10−4, hazard ratio = 1.41). Moreover, rs7298096AA is associated with a higher NINJ2 expression in blood (p = 7.0 × 10−6), which was confirmed in vitro (p = 0.009). Finally, NINJ2 expression is downregulated by IFNβ treatment and related to TTFR. [Conclusions] Rs7298096 could influence MS disease activity during IFNβ treatment by modulating NINJ2 expression in blood. The gene encodes for an adhesion molecule involved in inflammation and endothelial cells activation, supporting its role in MS.

Genome-wide association studies and meta-analysis have contributed to the identification of more than 200 loci associated with multiple sclerosis (MS). However, a proportion of MS heritability remains unknown. We aimed to uncover new genetic variants associated with MS and determine their functional effects. For this, we resequenced the exons and regulatory sequences of 14 MS risk genes in a cohort of MS patients and healthy individuals (n = 1070) and attempted to validate a selection of signals through genotyping in an independent cohort (n = 5138). We identified three new MS-associated variants at C-X-C motif chemokine receptor 5 (CXCR5), Ts translation elongation factor, mitochondrial (TSFM) and cytochrome P450 family 24 subfamily A member 1 (CYP24A1). Rs10892307 resulted in a new signal at the CXCR5 region that explains one of the associations with MS within the locus. This polymorphism and three others in high linkage disequilibrium mapped within regulatory regions. Of them, rs11602393 showed allele-dependent enhancer activity in the forward orientation as determined by luciferase reporter assays. Immunophenotyping using peripheral blood mononuclear cells from MS patients associated the minor allele of rs10892307 with increased percentage of regulatory T cells expressing CXCR5. This work reports a new signal for the CXCR5 MS risk locus and points to rs11602393 as the causal variant. The expansion of CXCR5+ circulating regulatory T cells induced by this variant could cause its MS association., The genotyping service was carried out at CEGEN-PRB2-ISCIII and was supported by grant PT13/0001, ISCIII-SGEFI/FEDER. This work was also supported by the following grants: BFU2016-77961-P (AEI/FEDER); 2017-SGR-00702 (Direcció General de Recerca, Generalitat de Catalunya); Unidad de Excelencia María de Maeztu funded by the MINECO (MDM-2014-0370); Proyectos de Investigación en Salud (FIS PI12/02229, PI15/00587, PI16/01259); Red Española de Esclerosis Múltiple (RD16/0015/0004 to M.C., RD16/0015/0002; RD16/0015/0005 to K.V.; RD16/0015/0016) integrated in the Plan Estatal I+D+I and cofunded by Instituto de Salud Carlos III and the Fondo Europeo de Desarrollo Regional (FEDER; “Otra forma de hacer Europa”); SAF2016-80595-C2-1-P (Ministerio de Economía, Industria y Competitividad).

Genome-wide association studies and meta-analysis have contributed to the identification of more than 200 loci associated with multiple sclerosis (MS). However, a proportion of MS heritability remains unknown. We aimed to uncover new genetic variants associated with MS and determine their functional effects. For this, we resequenced the exons and regulatory sequences of 14 MS risk genes in a cohort of MS patients and healthy individuals (n = 1070) and attempted to validate a selection of signals through genotyping in an independent cohort (n = 5138). We identified three new MS-associated variants at C-X-C motif chemokine receptor 5 (CXCR5), Ts translation elongation factor, mitochondrial (TSFM) and cytochrome P450 family 24 subfamily A member 1 (CYP24A1). Rs10892307 resulted in a new signal at the CXCR5 region that explains one of the associations with MS within the locus. This polymorphism and three others in high linkage disequilibrium mapped within regulatory regions. Of them, rs11602393 showed allele-dependent enhancer activity in the forward orientation as determined by luciferase reporter assays. Immunophenotyping using peripheral blood mononuclear cells from MS patients associated the minor allele of rs10892307 with increased percentage of regulatory T cells expressing CXCR5. This work reports a new signal for the CXCR5 MS risk locus and points to rs11602393 as the causal variant. The expansion of CXCR5+ circulating regulatory T cells induced by this variant could cause its MS association.

Although genome-wide association studies have identified a number of common variants associated with multiple sclerosis (MS) susceptibility, little is known about the relevance of rare variants. Here, we aimed to explore the role of rare variants in 14 MS risk genes (FCRL1, RGS1, TIMMDC1, HHEX, CXCR5, LTBR, TSFM, GALC, TRAF3, STAT3, TNFSF14, IFI30, CD40, and CYP24A1) by targeted resequencing in an Iberian population of 524 MS cases and 546 healthy controls. Four rare variants-enriched regions within CYP24A1, FCRL1, RGS1, and TRAF3 were identified as significantly associated with MS. Functional studies revealed significantly decreased regulator of G protein signaling 1 (RGS1) gene expression levels in peripheral blood mononuclear cells from MS patients with RGS1 rare variants compared to noncarriers, whereas no significant differences in gene expression were observed for CYP24A1, FCRL1, and TRAF3 between rare variants carriers and noncarriers. Immunophenotyping showed significant decrease in RGS1 expression in peripheral blood B lymphocytes from MS patients with RGS1 rare variants relative to noncarriers. Lastly, peripheral blood mononuclear cell from MS patients carrying RGS1 rare variants showed significantly lower induction of RGS1 gene expression by interferon-β compared to MS patients lacking RGS1 variants. The presence of rare variants in RGS1 reinforce the ideas of high genetic heterogeneity and a role of rare variants in MS pathogenesis., This work was supported by grants from the Fondo de Investigación Sanitaria (FIS; grant number PI12/02229; Ministry of Science and Innovation, Spain), Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarollo Regional (FEDER; grant number BFU2016‐77961‐P), Direcció General de Recerca ‐ Generalitat de Catalunya (2017‐SGR‐00702), Unidad de Excelencia María de Maeztu (MINECO; MDM‐2014‐0370), and Vall d'Hebrón Institut de Recerca (predoctoral grants program 2014).

Primary progressive multiple sclerosis is a poorly understood disease entity with no specific prognostic biomarkers and scarce therapeutic options. We aimed to identify disease activity biomarkers in multiple sclerosis by performing an RNA sequencing approach in peripheral blood mononuclear cells from a discovery cohort of 44 untreated patients with multiple sclerosis belonging to different clinical forms and activity phases of the disease, and 12 healthy control subjects. A validation cohort of 58 patients with multiple sclerosis and 26 healthy control subjects was included in the study to replicate the RNA sequencing findings. The RNA sequencing revealed an interleukin 1 beta (IL1B) signature in patients with primary progressive multiple sclerosis. Subsequent immunophenotyping pointed to blood monocytes as responsible for the IL1B signature observed in this group of patients. Functional experiments at baseline measuring apoptosis-associated speck-like protein containing a CARD (ASC) speck formation showed that the NOD-leucine rich repeat and pyrin containing protein 3 (NLRP3) inflammasome was overactive in monocytes from patients with primary progressive multiple sclerosis, and canonical NLRP3 inflammasome activation with a combination of ATP plus lipopolysaccharide was associated with increased IL1B production in this group of patients. Primary progressive multiple sclerosis patients with high IL1B gene expression levels in peripheral blood mononuclear cells progressed significantly faster compared to patients with low IL1B levels based on the time to reach an EDSS of 6.0 and the Multiple Sclerosis Severity Score. In agreement with peripheral blood findings, both NLRP3 and IL1B expression in brain tissue from patients with primary progressive multiple sclerosis was mainly restricted to cells of myeloid lineage. Treatment of mice with a specific NLRP3 inflammasome inhibitor attenuated established experimental autoimmune encephalomyelitis disease severity and improved CNS histopathology. NLRP3 inflammasome-specific inhibition was also effective in reducing axonal damage in a model of lipopolysaccharide-neuroinflammation using organotypic cerebellar cultures. Altogether, these results point to a role of IL1B and the NLRP3 inflammasome as prognostic biomarker and potential therapeutic target, respectively, in patients with primary progressive multiple sclerosis.

We aimed to investigate whether NLR family, pyrin domain containing 3 (NLRP3) polymorphisms are associated with the response to interferon-beta (IFNβ) in multiple sclerosis (MS) patients. A total of 14 NLRP3 polymorphisms were genotyped in a cohort of 665 relapsing-remitting MS patients recruited across 5 centers and classified into responders and non-responders according to clinical-radiological criteria after 1 year of IFNβ treatment. A meta-analysis failed to demonstrate significant associations between the response to IFNβ and NLRP3 polymorphisms. These findings do not support a role of polymorphisms located in the NLRP3 gene and the response to IFNβ in MS patients.

Multiple sclerosis (MS) is considered a chronic autoimmune disease of the central nervous system that leads to gliosis, demyelination, axonal damage and neuronal death. The MS disease aetiology is unknown, though a polymorphism of the TNFRSF1A gene, rs1800693, is known to confer an increased risk for MS. Using retroviral delivery of reprogramming transgenes, we generated six MS patient-specific iPSC lines with two distinct genotypes, CC or TT, of the polymorphism rs1800693. iPSC lines had normal karyotype, expressed pluripotency genes and differentiated into the three germ layers. These lines offer a good tool to study MS pathomechanisms and for drug testing.

The IL22RA2 locus is associated with risk for multiple sclerosis (MS) but causative variants are yet to be determined. In a single nucleotide polymorphism (SNP) screen of this locus in a Basque population, rs28385692, a rare coding variant substituting Leu for Pro at position 16 emerged significantly (p = 0.02). This variant is located in the signal peptide (SP) shared by the three secreted protein isoforms produced by IL22RA2 (IL-22 binding protein-1(IL-22BPi1), IL-22BPi2 and IL-22BPi3). Genotyping was extended to a Europe-wide case-control dataset and yielded high significance in the full dataset (p = 3.17 × 10−4). Importantly, logistic regression analyses conditioning on the main known MS-associated SNP at this locus, rs17066096, revealed that this association was independent from the primary association signal in the full case-control dataset. In silico analysis predicted both disruption of the alpha helix of the H-region of the SP and decreased hydrophobicity of this region, ultimately affecting the SP cleavage site. We tested the effect of the p.Leu16Pro variant on the secretion of IL-22BPi1, IL-22BPi2 and IL-22BPi3 and observed that the Pro16 risk allele significantly lowers secretion levels of each of the isoforms to around 50%–60% in comparison to the Leu16 reference allele. Thus, our study suggests that genetically coded decreased levels of IL-22BP isoforms are associated with augmented risk for MS.

Multiple sclerosis (MS) is a disease in which biomarker identification is fundamental to predict response to treatments and to deliver the optimal drug to patients. We previously found an association between rs7298096, a polymorphism upstream to theTo analyse the association between rs7298096 and time to first relapse (TTFR) during IFNβ therapy in MS patients and to better investigate its functional role.Survival analysis was applied in three MS cohorts from different countries (Rs7298096Rs7298096 could influence MS disease activity during IFNβ treatment by modulating

Up to 50% of multiple sclerosis (MS) patients do not respond to interferon-beta (IFN-β) treatment and determination of response requires lengthy clinical follow-up of up to 2 years. Response predictive genetic markers would significantly improve disease management. We aimed to identify IFN-β treatment response genetic marker(s) by performing a two-stage genome-wide association study (GWAS). The GWAS was carried out using data from 151 Australian MS patients from the ANZgene/WTCCC2 MS susceptibility GWAS (responder (R)=51, intermediate responders=24 and non-responders (NR)=76). Of the single-nucleotide polymorphisms (SNP) that were validated in an independent group of 479 IFN-β-treated MS patients from Australia, Spain and Italy (R=273 and NR=206), eight showed evidence of association with treatment response. Among the replicated associations, the strongest was observed for FHIT (Fragile Histidine Triad; combined P-value 6.74 × 10-6) and followed by variants in GAPVD1 (GTPase activating protein and VPS9 domains 1; combined P-value 5.83 × 10-5) and near ZNF697 (combined P-value 8.15 × 10-5). Refereed/Peer-reviewed

Immunological hallmarks of multiple sclerosis include the production of antibodies in the central nervous system, expressed as presence of oligoclonal bands and/or an increased immunoglobulin G index-the level of immunoglobulin G in the cerebrospinal fluid compared to serum. However, the underlying differences between oligoclonal band-positive and -negative patients with multiple sclerosis and reasons for variability in immunoglobulin G index are not known. To identify genetic factors influencing the variation in the antibody levels in the cerebrospinal fluid in multiple sclerosis, we have performed a genome-wide association screen in patients collected from nine countries for two traits, presence or absence of oligoclonal bands (n = 3026) and immunoglobulin G index levels (n = 938), followed by a replication in 3891 additional patients. We replicate previously suggested association signals for oligoclonal band status in the major histocompatibility complex region for the rs9271640*A-rs6457617*G haplotype, correlated with HLA-DRB1*1501, and rs34083746*G, correlated with HLA-DQA1*0301 (P comparing two haplotypes = 8.88 × 10(-16)). Furthermore, we identify a novel association signal of rs9807334, near the ELAC1/SMAD4 genes, for oligoclonal band status (P = 8.45 × 10(-7)). The previously reported association of the immunoglobulin heavy chain locus with immunoglobulin G index reaches strong evidence for association in this data set (P = 3.79 × 10(-37)). We identify two novel associations in the major histocompatibility complex region with immunoglobulin G index: the rs9271640*A-rs6457617*G haplotype (P = 1.59 × 10(-22)), shared with oligoclonal band status, and an additional independent effect of rs6457617*G (P = 3.68 × 10(-6)). Variants identified in this study account for up to 2-fold differences in the odds of being oligoclonal band positive and 7.75% of the variation in immunoglobulin G index. Both traits are associated with clinical features of disease such as female gender, age at onset and severity. This is the largest study population so far investigated for the genetic influence on antibody levels in the cerebrospinal fluid in multiple sclerosis, including 6950 patients. We confirm that genetic factors underlie these antibody levels and identify both the major histocompatibility complex and immunoglobulin heavy chain region as major determinants. ispartof: Brain vol:138 issue:Pt 3 pages:632-643 ispartof: location:England status: published

Herein, we have used bioinformatics tools to predict five clusters defining ligand-binding sites on the extracellular domain of human CD300b receptor, presumably involved in the formation of both homodimers and heterodimers with other CD300 family members. Site-directed mutagenesis revealed residues glutamic acid 28 and glutamine 29 in cluster 5 to be necessary for the formation of CD300b complexes. Surprisingly, the disruption of cluster 2 and 4 reconstituted the binding capability lost by the mutation of residues glutamic acid 28 to alanine, glutamine 29 to alanine (E28A-Q29G). We identified a missense mutation arginine 33 to glutamine (R33Q) in CD300f by direct sequencing of exon 2 in peripheral blood samples from 50 patients with multiple sclerosis (MS). Levels of expression of CD300f were almost undetectable on monocytes from the patient bearing the R33Q mutation compared with healthy individuals. Whereas R33Q mutation had no effect in the formation of CD300f complexes, the inhibition of protein synthesis with cycloheximide indicated that CD300f R33Q is less stable than native CD300f. Finally, we report that the levels of expression of CD300f on the surface of classical and intermediate monocytes from MS patients are significantly lower when compared to the same cell populations in healthy individuals.

Background: Whereas cellular immune function depends on energy supply and mitochondrial function, little is known on the impact of immunotherapies on cellular energy metabolism. Objective: The objective of this paper is to assess the effects of interferon-beta (IFN-β) on mitochondrial function of CD4+ T cells. Methods: Intracellular adenosine triphosphate (iATP) in phytohemagglutinin (PHA)-stimulated CD4+ cells of multiple sclerosis (MS) patients treated with IFN-β and controls were analyzed in a luciferase-based assay. Mitochondrial-transmembrane potential (ΔΨm) in IFN-β-treated peripheral blood mononuclear cells (PBMCs) was investigated by flow cytometry. Expression of genes involved in mitochondrial oxidative phosphorylation (OXPHOS) in CD4+ cells of IFN-β-treated individuals and correlations between genetic variants in the key metabolism regulator PGC-1α and IFN-β response in MS were analyzed. Results: IFN-β-treated MS patients exhibited a dose-dependent reduction of iATP levels in CD4+ T cells compared to controls ( p < 0.001). Mitochondrial effects were reflected by depolarization of ΔΨm. Expression data revealed changes in the transcription of OXPHOS-genes. iATP levels in IFN-β-responders were reduced compared to non-responders ( p < 0.05), and the major T allele of the SNP rs7665116 of PGC-1α correlated with iATP-levels. Conclusion: Reduced iATP-synthesis ex vivo and differential expression of OXPHOS-genes in CD4+ T cells point to unknown IFN-β effects on mitochondrial energy metabolism, adding to potential pleiotropic mechanisms of action.

Chitinase 3-like 1 (CHI3L1) plays a prognostic role in patients with multiple sclerosis (MS). Here, we investigated a potential association between CHI3L1 and the response to interferon-beta (IFNβ) and glatiramer acetate (GA). Serum CHI3L1 levels were measured by ELISA in 117 relapsing-remitting MS (RRMS) patients, 76 IFNβ-treated and 41 GA-treated patients. CHI3L1 levels were increased by GA (p = 0.014) but unchanged by IFNβ (p = 0.830). CHI3L1 was associated with IFNβ response and levels were higher in non-responder group (p = 0.020), while GA showed no responder effect (p = 0.943). These results suggest a role for CHI3L1 as response biomarker to IFNβ in RRMS patients., The authors thank the “Red Española de Esclerosis Múltiple (REEM)” sponsored by the “Fondo de Investigación Sanitaria” (FIS), Ministry of Science and Innovation, Spain, and the “Ajuts per donar Suport als Grups de Recerca de Catalunya”, sponsored by the “Agència de Gestió d'Ajuts Universitaris i de Recerca” (AGAUR), Generalitat de Catalunya, Spain.

Multiple sclerosis (MS) is a prevalent neurological disease of complex etiology. Here, we describe the characterization of a multi-incident MS family that nominated a rare missense variant (p.G420D) in plasminogen (PLG) as a putative genetic risk factor for MS. Genotyping of PLG p.G420D (rs139071351) in 2160 MS patients, and 886 controls from Canada, identified 10 additional probands, two sporadic patients and one control with the variant. Segregation in families harboring the rs139071351 variant, identified p.G420D in 26 out of 30 family members diagnosed with MS, 14 unaffected parents, and 12 out of 30 family members not diagnosed with disease. Despite considerably reduced penetrance, linkage analysis supports cosegregation of PLG p.G420D and disease. Genotyping of PLG p. G420D in 14446 patients, and 8797 controls from Canada, France, Spain, Germany, Belgium, and Austria failed to identify significant association with disease (P = 0.117), despite an overall higher prevalence in patients (OR = 1.32; 95% CI = 0.931.87). To assess whether additional rare variants have an effect on MS risk, we sequenced PLG in 293 probands, and genotyped all rare variants in cases and controls. This analysis identified nine rare missense variants, and although three of them were exclusively observed in MS patients, segregation does not support pathogenicity. PLG is a plausible biological candidate for MS owing to its involvement in immune system response, blood-brain barrier permeability, and myelin degradation. Moreover, components of its activation cascade have been shown to present increased activity or expression in MS patients compared to controls; further studies are needed to clarify whether PLG is involved in MS susceptibility. We are grateful to all individuals who generously participated in this study. We thank Kevin Atkins for data collection and extraction. We also thank Genethon, L'Association Francaise contre les Myopathies (AFM), la Fondation pour l'Aide a la Recherche sur la Sclerose en Plaques (ARSEP), and the Biological Resources Centre (BRC) of The French Multiple Sclerosis Genetics Group (CRB-REFGENSEP). This research was undertaken thanks to funding from the Canada Research Chair [950-228408] and Canada Excellence Research Chair programs [214444], Canadian Institutes of Health Research [MOP-137051], Vancouver Coastal Health Research Institute, the Milan & Maureen Ilich Foundation [11-32095000], and the Vancouver Foundation [ADV14-1597]. Replication studies received funding from the program "Investissements d'avenir" ANR-10-IAIHU-06. Fondo de Investigacion Sanitaria (FIS)-Instituto de Salud Carlos III (ISCIII)-Fondos Europeos de Desarrollo Regional (FEDER), Union Europea [grant numbers P12/00555, PI13/01527, PI13/01466 and PI13/0879 to F.M., A.A. and G.I.] and Junta de Andalucia - FEDER [grant number CTS2704 to F.M.]. B.D. is a Clinical Investigator of the Research Foundation Flanders (FWO-Vlaanderen). A.G. and B.D. are supported by the Research Fund KU Leuven (OT/11/087 and CREA/14/023) and the Research Foundation Flanders (G073415N). A.L.T. reports personal fees from Biogen Idec, Chugai, Medimmune, Teva Innovation, and EMD Serono, and grants and personal fees from Genzyme Sanofi and Roche. All other authors report no disclosures.

The tumor necrosis factor receptor superfamily, member 1A (TNFRSF1A) gene encodes the TNF-R1, one of the main TNF receptors that mediates its inflammatory actions. In a recent study, serum levels of the soluble TNF-R1 and mRNA levels of the full-length receptor were found to be significantly increased in multiple sclerosis (MS) patients carrying the R92Q mutation. Interestingly, R92Q-mutated patients were younger at disease onset and progressed slower as compared to non-carriers. Building on these previous findings, here we aimed to investigate by means of both in silico and in vitro approaches the mechanisms relating the R92Q substitution with functional changes of the receptor and their potential effects modulating MS disease course. Models of the extracellular domains of the human TNF-R1 and human TNF-R1 carrying the R92Q mutation, alone or bound to TNF, were constructed and submitted to molecular dynamics. TRAF2 and CASP3 mRNA expression levels were determined by real-time PCR in peripheral blood mononuclear cells (PBMC) from 61 MS patients, 9 R92Q carriers and 52 non-carriers (CT and CC genotypes for SNP rs4149584, respectively). Molecular dynamic studies revealed that the R92Q mutation increased the contact area between receptor and TNF (1070 and 1388A(2) for native and mutated receptor) and decreased the distance between them (28.7 to 27.9A), while Van der Waals and electrostatic interaction energies were increased. In PBMC from MS patients carrying the R92Q mutation, CASP3 mRNA expression levels were significantly increased compared to non-carriers, whereas a trend was observed for TRAF2. These data suggest that the R92Q mutation gives rise to a stronger interaction between the receptor and its ligand, which results in the potentiation of TNF-mediated pathways. Although further studies are needed, these functional changes may be related with the modulation in disease course reported in MS patients carrying the R92Q mutation.

Several variants in strong linkage disequilibrium (LD) at the SP140 locus have been associated with multiple sclerosis (MS), Crohn's disease (CD) and chronic lymphocytic leukemia (CLL). To determine the causal polymorphism, we have integrated high-density data sets of expression quantitative trait loci (eQTL), using GEUVADIS RNA sequences and 1000 Genomes genotypes, with MS-risk variants of the high-density Immunochip array performed by the International Multiple Sclerosis Genetic Consortium (IMSGC). The variants most associated with MS were also correlated with a decreased expression of the full-length RNA isoform of SP140 and an increase of an isoform lacking exon 7. By exon splicing assay, we have demonstrated that the rs28445040 variant was the causal factor for skipping of exon 7. Western blots of peripheral blood mononuclear cells from MS patients showed a significant allele-dependent reduction of the SP140 protein expression. To confirm the association of this functional variant with MS and to compare it with the best-associated variant previously reported by GWAS (rs10201872), a case-control study including 4384 MS patients and 3197 controls was performed. Both variants, in strong LD (r(2) = 0.93), were found similarly associated with MS [P-values, odds ratios: 1.9E-9, OR = 1.35 (1.22-1.49) and 4.9E-10, OR = 1.37 (1.24-1.51), respectively]. In conclusion, our data uncover the causal variant for the SP140 locus and the molecular mechanism associated with MS risk. In addition, this study and others previously reported strongly suggest that this functional variant may be shared with other immune-mediated diseases as CD and CLL.

Objective A recent large-scale study in multiple sclerosis (MS) using the ImmunoChip platform reported on 11 loci that showed suggestive genetic association with MS. Additional data in sufficiently sized and independent data sets are needed to assess whether these loci represent genuine MS risk factors. Methods The lead SNPs of all 11 loci were genotyped in 10 796 MS cases and 10 793 controls from Germany, Spain, France, the Netherlands, Austria and Russia, that were independent from the previously reported cohorts. Association analyses were performed using logistic regression based on an additive model. Summary effect size estimates were calculated using fixed-effect meta-analysis. Results Seven of the 11 tested SNPs showed significant association with MS susceptibility in the 21 589 individuals analysed here. Meta-analysis across our and previously published MS case-control data (total sample size n=101 683) revealed novel genome-wide significant association with MS susceptibility (p −8 ) for all seven variants. This included SNPs in or near LOC100506457 (rs1534422, p=4.03×10 −12 ), CD28 (rs6435203, p=1.35×10 −9 ), LPP (rs4686953, p=3.35×10 −8 ), ETS1 (rs3809006, p=7.74×10 −9 ), DLEU1 (rs806349, p=8.14×10 −12 ), LPIN3 (rs6072343, p=7.16×10 −12 ) and IFNGR2 (rs9808753, p=4.40×10 −10 ). Cis expression quantitative locus effects were observed in silico for rs6435203 on CD28 and for rs9808753 on several immunologically relevant genes in the IFNGR2 locus. Conclusions This study adds seven loci to the list of genuine MS genetic risk factors and further extends the list of established loci shared across autoimmune diseases.

Evidence exists for a potential modulation of inflammasome activity by interferon beta. Here, we investigated the roles of inflammasomes [absent in melanoma 2 (AIM2); NLR family, CARD domain containing 4 (NLRC4); NLR family, pyrin domain containing 1 and 3 (NLRP1 and NLRP3)] and related cytokines (IL1B, IL10, IL18) in the response to interferon beta in patients with relapsing-remitting multiple sclerosis. Ninety-seven patients treated with interferon beta were classified into responders and non-responders according to clinical criteria after 24 months and clinical-radiological criteria after 12 months of treatment. Messenger RNA expression levels of inflammasomes and cytokines were determined by real-time polymerase chain reaction in peripheral blood mononuclear cells collected before treatment with interferon beta. In a subgroup of patients, NLRP3 and IL1B expression was also determined after 3 months (n = 32) and 12 months (n = 20) of interferon beta treatment. A polymorphism located in the NLRP3 gene, rs35829419, was genotyped in 789 multiple sclerosis patients treated with interferon beta. Baseline mRNA expression levels for NLRP3 and IL1B were increased in peripheral blood mononuclear cells from non-responders compared to responders classified according to clinical criteria after 24 months (P = 0.02 and P = 0.001, respectively). No significant differences were observed for other inflammasomes and related cytokines. Differences in NLRP3 and IL1B expression remained significant following a clinical-radiological classification after 12 months (P = 0.007 and P = 0.02, respectively). After treatment with interferon beta, NLRP3 and IL1B expression was increased in responders but unchanged in non-responders. A trend for association was observed between rs35829419 and interferon beta response (pM-H = 0.08). These results point to a role of the NLRP3 inflammasome and its related cytokine IL1B in the response to interferon beta in patients with relapsing-remitting multiple sclerosis.

Multiple sclerosis (MS) is a neurodegenerative, autoimmune disease of the central nervous system. Genome-wide association studies (GWAS) have identified over hundred polymorphisms with modest individual effects in MS susceptibility and they have confirmed the main individual effect of the Major Histocompatibility Complex. Additional risk loci with immunologically relevant genes were found significantly overrepresented. Nonetheless, it is accepted that most of the genetic architecture underlying susceptibility to the disease remains to be defined. Candidate association studies of the leukocyte immunoglobulin-like receptor LILRA3 gene in MS have been repeatedly reported with inconsistent results. Objectives In an attempt to shed some light on these controversial findings, a combined analysis was performed including the previously published datasets and three newly genotyped cohorts. Both wild-type and deleted LILRA3 alleles were discriminated in a single-tube PCR amplification and the resulting products were visualized by their different electrophoretic mobilities. Results and Conclusion Overall, this meta-analysis involved 3200 MS patients and 3069 matched healthy controls and it did not evidence significant association of the LILRA3 deletion [carriers of LILRA3 deletion: p = 0.25, OR (95% CI) = 1.07 (0.95–1.19)], even after stratification by gender and the HLA-DRB1*15:01 risk allele.

Background: Single nucleotide polymorphisms (SNPs) near SOCS1 are associated with multiple sclerosis (MS), but the most important SNPs in the area and mechanisms by which they influence the disease are unknown. Methods: A haplotype-tagging association study was performed covering 60.5kbp around SOCS1, and the index SNP was validated in a total of 2292 individuals. mRNA expression of SOCS1 and nearby genes was measured in MS patients with different disease courses and healthy controls. SOCS1 protein expression was studied by flow cytometry in a separate cohort of patients and controls. Differentiation and maturation of monocyte-derived dendritic cells (moDCs) were also studied. Results: One SNP, rs423674, reached genome-wide significance. No genotype-specific mRNA expression differences were seen, but, by flow cytometry, significant interactions were observed between genotypes for rs423674 and disease activity (relapse or remission) in B cells and regulatory T cells. Furthermore, homozygotes for the risk allele (GG) showed higher levels of CD1a and CD86 than carriers of the protective allele (GT) in immature moDCs and a greater increase of HLA-DR+ cell percentage than GT heterozygotes upon maturation. Conclusions: rs423674, or its genetic proxies, may influence MS risk by modulating SOCS1 expression in a cell-specific manner and by influencing dendritic cell function.

AIM2-like receptors (ALRs) are a family of nucleic acid sensors essential for innate immune responses against viruses and bacteria. We performed an evolutionary analysis of ALR genes (MNDA, PYHIN1, IFI16, and AIM2) by analyzing inter- and intraspecies diversity. Maximum-likelihood analyses indicated that IFI16 and AIM2 evolved adaptively in primates, with branch-specific selection at the catarrhini lineage for IFI16. Application of a population genetics-phylogenetics approach also allowed identification of positive selection events in the human lineage. Positive selection in primates targeted sites located at the DNA-binding interface in both IFI16 and AIM2. In IFI16, several sites positively selected in primates and in the human lineage were located in the PYD domain, which is involved in protein-protein interaction and is bound by a human cytomegalovirus immune evasion protein. Finally, positive selection was found to target nuclear localization signals in IFI16 and the spacer region separating the two HIN domains. Population genetic analysis in humans revealed that an IFI16 genic region has been a target of long-standing balancing selection, possibly acting on two nonsynonymous polymorphisms located in the spacer region. Data herein indicate that ALRs have been repeatedly targeted by natural selection. The balancing selection region in IFI16 carries a variant with opposite risk effect for distinct autoimmune diseases, suggesting antagonistic pleiotropy. We propose that the underlying scenario is the result of an ancestral and still ongoing host-pathogen arms race and that the maintenance of susceptibility alleles for autoimmune diseases at IFI16 represents an evolutionary trade-off.

IFI16 encodes a nucleic acid-sensor which detects latent EBV and triggers inflammasome activation. We analysed IFI16 variants in two multiple sclerosis (MS) case–control cohorts from Italy and Spain; results were combined with a previous study. A risk variant for celiac disease/rheumatoid arthritis, a polymorphic exon 7 duplication, and a copy number variant (CNV) in the 5′ region were genotyped. No significant association was detected, although heterogeneity was noted for the 5′ CNV in the Italian plus GeneMSA cohorts and the Spanish sample. Thus, IFI16 variants do not contribute to MS susceptibility, although some heterogeneity may exist for the 5′ CNV.

A large repertoire of gene-centric data has been generated in the field of zebrafish biology. Although the bulk of these data are available in the public domain, most of them are not readily accessible or available in nonstandard formats. One major challenge is to unify and integrate these widely scattered data sources. We tested the hypothesis that active community participation could be a viable option to address this challenge. We present here our approach to create standards for assimilation and sharing of information and a system of open standards for database intercommunication. We have attempted to address this challenge by creating a community-centric solution for zebrafish gene annotation. The Zebrafish GenomeWiki is a ‘wiki’-based resource, which aims to provide an altruistic shared environment for collective annotation of the zebrafish genes. The Zebrafish GenomeWiki has features that enable users to comment, annotate, edit and rate this gene-centric information. The credits for contributions can be tracked through a transparent microattribution system. In contrast to other wikis, the Zebrafish GenomeWiki is a ‘structured wiki’ or rather a ‘semantic wiki’. The Zebrafish GenomeWiki implements a semantically linked data structure, which in the future would be amenable to semantic search. Database URL: http://genome.igib.res.in/twiki

Malhotra, Sunny et al., [Background and purpose] Ubiquitin specific peptidase 18 (USP18) is a deubiquitinating enzyme that functions as a negative regulator of the type I interferon (IFN) signalling pathway and is specifically induced by type I IFNs. In the present study, previous observations by our group were expanded suggesting an implication of USP18 in multiple sclerosis (MS) based on the finding of a deficient expression of the gene in peripheral blood mononuclear cells from MS patients compared with healthy controls. [Methods] Two polymorphisms, rs2542109 (intronic) and rs9618216 (promoter), were genotyped in a cohort of 691 relapse-onset MS patients and 1028 healthy controls and in 225 MS patients treated with IFNβ and classified into responders and non-responders after 2 years of treatment according to clinical criteria. Correlations between genotypes and expression levels for USP18 and its target ISG15 were performed by real-time polymerase chain reaction. [Results] Two USP18 haplotypes were significantly associated with MS, TG and CG. Additional experiments revealed that CG carriers were characterized by lower USP18 gene expression levels in peripheral blood mononuclear cells and higher clinical disease activity. Finally, AA homozygosis for the intronic polymorphism rs2542109 was associated with the responder phenotype; however, USP18 expression levels induced by IFNβ did not differ amongst MS patients carrying different rs2542109 genotypes. [Conclusions] Altogether, these results point to a role of USP18 in MS pathogenesis and the therapeutic response to IFNβ. © 2013 EFNS., SM is an early stage researcher funded by the European Community's Seventh Framework Programme [FP7/2007–2013 under grant agreement no. 212877 (UEPHA*MS)]. RM and MM are supported by a Juan de la Cierva programme. The authors thank the Red Española de Esclerosis Múltiple (REEM) sponsored by the Fondo de Investigación Sanitaria (FIS), Ministry of Science and Innovation, Spain, and the Ajuts per donar Suport als Grups de Recerca de Catalunya, sponsored by the Agència de Gestió d'Ajuts Universitaris i de Recerca (AGAUR), Generalitat de Catalunya, Spain.

Recent studies have suggested a role of the cation channel TRPM4 in mediating neurodegeneration in experimental autoimmune encephalomyelitis and multiple sclerosis (MS). We aimed to extrapolate central nervous system findings to the blood compartment by determining TRPM4 expression in peripheral blood mononuclear cells from 12 healthy controls (HC) and 64 untreated MS patients. TRPM4 mRNA expression levels were comparable between HC and MS patients with primary progressive MS ( n = 17), secondary progressive MS ( n = 19), and relapsing-remitting MS during clinical remission ( n = 21) and relapses ( n = 7). These findings do not support a role of TRPM4 in the peripheral blood compartment of MS patients.

Objectives: To investigate the roles of 2 polymorphisms of the tumor necrosis factor (TNF) receptor superfamily member 1A ( TNFRSF1A ) gene, rs1800693 (a common variant) and rs4149584 (a coding polymorphism that results in an amino acid substitution—R92Q), as genetic modifiers of multiple sclerosis (MS), and to evaluate their potential functional implications in the disease. Methods: The effects of rs1800693 and rs4149584 on 2 measures of disease severity, age at disease onset and Multiple Sclerosis Severity Score, were analyzed in 2,032 patients with MS. In a subgroup of patients, serum levels of the soluble form of TNF-R1 (sTNF-R1) were measured by ELISA; mRNA expression levels of the full-length TNF-R1 and ∆6-TNF-R1 isoform were investigated in peripheral blood mononuclear cells (PBMC) by real-time PCR; cell surface expression of the TNF-R1 was determined in T cells by flow cytometry. Results: For rs4149584, R92Q carriers were younger at disease onset and progressed slower compared to noncarriers. However, no association with disease severity was observed for rs1800693. Serum levels of sTNF-R1 and mRNA expression levels of the full-length receptor were significantly increased in patients with MS carrying the R92Q mutation ( p = 0.003 and p = 0.011, respectively), but similarly distributed among rs1800693 genotypes; cell surface TNF-R1 expression in T cells did not differ between rs4149584 and rs1800693 genotypes. The truncated soluble ∆6-TNF-R1 isoform was identified in PBMC from patients carrying the risk allele for rs1800693. Conclusions: These findings suggest that both rs1800693 and rs4149584 TNFRSF1A polymorphisms have functional consequences in the TNF-R1.

Background: Sialic acid binding immunoglobulin-like lectins (Siglecs) are cell surface receptors that recognize sialic acids and may attenuate immune responses and reduce inflammation. Objective: The purpose of this study was to investigate the role of two members of the Siglec family, SIGLEC1 and SIGLEC7, in the clinical course and disease activity of patients with multiple sclerosis (MS). Methods: SIGLEC1 and SIGLEC7 expression was determined by flow cytometry in the blood monocytes of 16 healthy controls and 55 untreated MS patients (13 primary progressive MS (PPMS) patients, 13 secondary progressive MS (SPMS) patients and 29 relapsing–remitting MS (RRMS) patients (18 during clinical remission and 11 during relapse)). Results: SIGLEC1 expression by CD14+ monocytes was significantly increased in MS patients compared with controls ( p=0.025 for percentage of positive cells; p=0.007 for mean fluorescence intensity (MFI)). Stratification of patients into different clinical forms revealed increased SIGLEC1 expression in patients with progressive forms of the disease, particularly in those with PPMS ( p=0.003 for percentage of positive cells and p=0.001 for MFI when compared with controls; p=0.031 for percentage of positive cells when compared with RRMS patients). Both inflammatory and resident monocytes contributed to the increase in SIGLEC1 expression observed in PPMS patients. SIGLEC7 expression was significantly up-regulated in blood monocytes from RRMS during relapse compared with patients during clinical remission ( p=0.001 for MFI). Conclusions: These findings suggest roles for SIGLEC1 in the chronic progressive phases of MS and for SIGLEC7 in acute disease activity.

Malhotra, Sunny et al., Recent studies have revealed an association between interleukin 28B (IL28B) and response to IFN-alpha treatment in hepatitis C patients. Here we investigated the influence of IL28B polymorphisms in the response to interferon-beta (IFNβ) in multiple sclerosis (MS) patients. We genotyped two SNPs of the IL28B gene (rs8099917 and rs12979860) in 588 MS patients classified into responders (n = 281) and non-responders (n = 307) to IFNβ. Combined analysis of the study cohorts showed no significant associations between SNPs rs8099917 and rs12979860 and the response to treatment. These findings do not support a role of IL28B polymorphisms in the response to IFNβ in MS patients. © 2011 Elsevier B.V., This study was supported by a grant from the DANA Foundation's Neuroimmunology program. SM is early stage researcher funded by the European Community's Seventh Framework Program ([FP7/2007–2013]) under grant agreement no. 212877 (UEPHA*MS). The authors thank the “Red Española de Esclerosis Múltiple (REEM)” sponsored by the “Fondo de Investigación Sanitaria” (FIS), Ministry of Science and Innovation, Spain, and the “Ajuts per donar Suport als Grups de Recerca de Catalunya (SGR 2005–1081)”, sponsored by the “Agència de Gestió d'Ajuts Universitaris i de Recerca” (AGAUR), Generalitat de Catalunya, Spain. J Drulovic has received research grant support from the Ministry of Education and Science, Republic of Serbia (project no. 175031).

Myxovirus A (MxA), a protein encoded by the MX1 gene with antiviral activity, has proven to be a sensitive measure of IFNβ bioactivity in multiple sclerosis (MS). However, the use of MxA as a biomarker of IFNβ bioactivity has been criticized for the lack of evidence of its role on disease pathogenesis and the clinical response to IFNβ. Here, we aimed to identify specific biomarkers of IFNβ bioactivity in order to compare their gene expression induction by type I IFNs with the MxA, and to investigate their potential role in MS pathogenesis. Gene expression microarrays were performed in PBMC from MS patients who developed neutralizing antibodies (NAB) to IFNβ at 12 and/or 24 months of treatment and patients who remained NAB negative. Nine genes followed patterns in gene expression over time similar to the MX1, which was considered the gold standard gene, and were selected for further experiments: IFI6, IFI27, IFI44L, IFIT1, HERC5, LY6E, RSAD2, SIGLEC1, and USP18. In vitro experiments in PBMC from healthy controls revealed specific induction of selected biomarkers by IFNβ but not IFNγ, and several markers, in particular USP18 and HERC5, were shown to be significantly induced at lower IFNβ concentrations and more selective than the MX1 as biomarkers of IFNβ bioactivity. In addition, USP18 expression was deficient in MS patients compared with healthy controls (p = 0.0004). We propose specific biomarkers that may be considered in addition to the MxA to evaluate IFNβ bioactivity, and to further explore their implication in MS pathogenesis.

OBJECTIVES: We aimed to investigate the association between polymorphisms located in type I interferon (IFN)-induced genes, genes belonging to the toll-like receptor (TLR) pathway, and genes encoding neurotransmitter receptors and the response to IFN-β treatment in patients with multiple sclerosis (MS). METHODS: In a first or screening phase of the study, 384 polymorphisms were genotyped in 830 patients with MS classified into IFN-β responders (n = 416) and nonresponders (n = 414) according to clinical criteria. In a second or validation phase, the most significant polymorphisms associated with IFN-β response were genotyped in an independent validation cohort of 555 patients with MS (281 IFN-β responders and 274 nonresponders). RESULTS: Seven single nucleotide polymorphisms (SNPs) were selected from the screening phase for further validation: rs832032 (GABRR3; p = 0.0006), rs6597 (STUB1; p = 0.019), rs3747517 (IFIH1; p = 0.010), rs2277302 (PELI3; p = 0.017), rs10958713 (IKBKB; p = 0.003), rs2834202 (IFNAR1; p = 0.030), and rs4422395 (CXCL1; p = 0.017). None of these SNPs were significantly associated with IFN-β response when genotyped in an independent cohort of patients. Combined analysis of these SNPs in all patients with MS (N = 1,385) revealed 2 polymorphisms associated with IFN-β response: rs2277302 (PELI3; p = 0.008) and rs832032 (GABRR3; p = 0.006). CONCLUSIONS: These findings do not support an association between polymorphisms located in genes related to the type I IFN or TLR pathways or genes encoding neurotransmitter receptors and the clinical response to IFN-β. Nevertheless, additional genetic and functional studies of PELI3 and GABRR3 are warranted. SM is early stage researcher of the FP7 (2007-2013) Marie Curie Initial Training Network "UEPHA*MS" (2008-2012; Grant Agreement Number 212877). Spanish Ministry of Economy and Competitiveness, SAF/ 2012-34670, MS research, 2013-2015. Ministerio de Economía y Competitividad (MINECO) Convocatoria Proyectos de Investigación 2012 (Madrid, Spain); Funciones intracelulares de tipo-no-citoquina de las subunidades de la familia IL-12; SAF2012-32118. Dirección General de Investigación Científica y Técnica - DGICYT. Spanish Government (BFU2012-38236).