Objective
Accumulating evidence supports a role for exosomes in immune regulation. In this study, we investigated the total circulating exosome transcriptome in relapsing–remitting multiple sclerosis ...(RRMS) patients and healthy controls (HC).
Methods
Next generation sequencing (NGS) was used to define the global RNA profile of serum exosomes in 19 RRMS patients (9 in relapse, 10 in remission) and 10 HC. We analyzed 5 million reads and >50,000 transcripts per sample, including a detailed analysis of microRNAs (miRNAs) differentially expressed in RRMS. The discovery set data were validated by quantification using digital quantitative polymerase chain reaction with an independent cohort of 63 RRMS patients (33 in relapse, 30 in remission) and 32 HC.
Results
Exosomal RNA NGS revealed that of 15 different classes of transcripts detected, 4 circulating exosomal sequences within the miRNA category were differentially expressed in RRMS patients versus HC: hsa‐miR‐122‐5p, hsa‐miR‐196b‐5p, hsa‐miR‐301a‐3p, and hsa‐miR‐532‐5p. Serum exosomal expression of these miRNAs was significantly decreased during relapse in RRMS. These miRNAs were also decreased in patients with a gadolinium enhancement on brain magnetic resonance imaging. In vitro secretion of these miRNAs by peripheral blood mononuclear cells was also significantly impaired in RRMS.
Interpretation
These data show that circulating exosomes have a distinct RNA profile in RRMS. Because putative targets for these miRNAs include the signal transducer and activator of transcription 3 and the cell cycle regulator aryl hydrocarbon receptor, the data suggest a disturbed cell‐to‐cell communication in this disease. Thus, exosomal miRNAs might represent a useful biomarker to distinguish multiple sclerosis relapse. Ann Neurol 2017;81:703–717
In this randomized trial involving patients with multiple sclerosis, BG-12 (dimethyl fumarate) reduced clinical relapses, disability progression, and MRI lesions. BG-12 treatment resulted in reduced ...lymphocyte counts and elevated liver aminotransferase levels.
Oral BG-12 (dimethyl fumarate) is being investigated for the treatment of multiple sclerosis. Inflammation and oxidative stress are central pathologic factors in multiple sclerosis.
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Immune cell activation and infiltration into the central nervous system are thought to result in widespread cellular damage, potentially owing to the dysregulated production and release of reactive oxygen and nitrogen species, such as hydrogen peroxide and peroxynitrite, and proinflammatory stimuli.
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This combination of toxic factors ultimately results in demyelination and neurodegeneration, causing disease activity and progression of disability.
BG-12 has been shown to have beneficial effects in preclinical models of neuroinflammation, neurodegeneration, and toxic . . .
Abstract Multiple sclerosis (MS) is a putative autoimmune disease of the central nervous system (CNS) in which autoreactive immune cells recognizing myelin antigens lead to demyelination and axonal ...injury. Mechanisms relevant to the pathogenesis of MS have not been fully elucidated, particularly those underlying initiation of immune system dysfunction. For example, it is not known how reactivity against CNS components is generated within the peripheral immune system. In this review, we propose that a significant contribution to the immunoregulatory events may derive from a cell-to-cell communication system involving the production, secretion and transfer of extracellular vesicles known as exosomes. Herein, we discuss in detail the biogenesis and roles of these cell surface-generated vesicles from the standpoint of receptors and their cargo, microRNA. It is well known that exosomes can cross the blood–brain barrier and thus may contribute to the spread of brain antigens to the periphery. Further understanding of exosome-dependent mechanisms in MS should provide a novel angle to the analysis of the pathogenesis of this disease. Finally, we launch the idea that exosomes and their contents may serve as biomarkers in MS.
microRNA-155 (miR-155) plays an important role in posttranscriptional gene regulation of the immune system. We and others have described miR-155 upregulation in T helper cells (Th) during the ...development of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. We have shown that mice in which the miR-155 host gene (MIR155HG) has been deactivated are resistant to EAE. MIR155HG produces two different miRNA strands, miR-155-5p and miR-155-3p, and miR-155-5p has been considered the only functional miR-155 form. Surprisingly, we found that miR-155-3p is also strongly upregulated in Th cells infiltrating the brain in EAE. Functional manipulation of miR-155-3p expression revealed its particular role in regulation of Th17 development. The search for miRNA-155-3p target genes highlighted transcripts of two heat shock protein 40 genes, Dnaja2 and Dnajb1. These two genes negatively regulated Th17 differentiation, leading to decreased EAE. Therefore, our findings provide new insights into a previously unknown mechanism by which miR-155-3p controls Th17 cell differentiation and autoimmune demyelination.
Multiple sclerosis (MS) is brain-specific autoimmune disease mediated by T helper (Th) cells autoreactive to myelin. The mechanisms leading to MS are not fully understood and microRNAs (miRNAs) emerge as important regulators of the process. We report that, in an MS murine model of experimental autoimmune encephalomyelitis, miR-155 controls Th cell function by an unusual mechanism involving a rare form, miR-155-3p. miR-155-3p is specifically found in brain-infiltrating myelin-autoreactive CD4(+) T cells and contributes to the development of an encephalitogenic Th17 population. miR-155-3p promotes Th17 by inhibiting two heat shock protein 40 genes, Dnaja2 and Dnajb1. Our findings indicate a unique miRNA function in the brain-infiltrating Th cells and suggest Dnaja2 and Dnajb1 as targets for intervention in autoimmune demyelination.
Multiple sclerosis (MS) is believed to be an autoimmune disease of the central nervous system (CNS) in which autoreactive immune cells recognizing myelin antigens lead to demyelination and axonal ...injury. Mechanisms inducing and controlling the pathogenesis of MS have not been fully elucidated. Recent studies suggest an important role of epigenetic processes during the development of MS. One of the most significant discoveries in the field of epigenetic contribution to immune response has been the recognition of a group of microRNAs (miRNAs). These single-stranded non-coding RNA molecules regulate the expression of genes encoding proteins and have already been shown to be involved in pathogenesis of MS. Some miRNAs enhance generation of pro-inflammatory immune cells by promoting Th1 and Th17 pathways and others contribute to regulatory and tissue repair processes. The miRNA-dependent controlling process of autoimmune reactions is highly complex because of miRNA redundancy and multitarget nature of most of these molecules. Recently it was discovered that circular RNAs (circRNA) representing a new class of RNA possess a unique ability to control miRNAs by blocking their activity. CircRNAs are called natural miRNA “sponges” as the single circRNA molecule is able to neutralize several miRNAs and thus might determine the availability of miRNAs for their posttranscription regulation. Thus, circRNAs emerged as critical factors in epigenetic regulation of many human diseases including MS. In addition, in contrary to other RNA species they are very stable in the blood and other biological fluids and thus might be considered as a candidate for a biomarker of MS.
•Recognition of circular RNA as a new mechanism for gene expression regulation in MS.•CircRNA particular impact on the inhibition of microRNA.•circular RNA may provide a new source for biomarkers in multiple sclerosis.
In two trials involving patients with relapsing multiple sclerosis, the anti-CD20+ monoclonal antibody ocrelizumab was associated with lower annualized relapse rates, lower risk of disability ...progression, and better MRI features than interferon beta-1a.
Despite the availability of several disease-modifying treatments for relapsing forms of multiple sclerosis, patients often continue to have clinical and subclinical disease activity, and neurologic disability continues to accrue. Thus, there is a need for more effective treatments with acceptable safety profiles.
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B cells are thought to influence the underlying pathogenesis of multiple sclerosis by means of antigen presentation,
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autoantibody production,
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cytokine regulation,
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and the formation of ectopic lymphoid aggregates in the meninges, which possibly contribute to cortical demyelination and neurodegeneration.
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Ocrelizumab is a humanized monoclonal antibody that selectively targets CD20, a cell-surface antigen that is expressed . . .
Patients with primary progressive MS who received the anti-CD20+ humanized antibody ocrelizumab were less likely to have clinical deterioration that was sustained for 12 weeks than those who received ...placebo. The drug was associated with decreased lesion activity on MRI.
Primary progressive multiple sclerosis accounts for 10 to 15% of the overall population with multiple sclerosis.
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The course of this disease differs from those of relapsing–remitting and secondary progressive forms of multiple sclerosis in that progression consists mainly of gradual worsening of neurologic disability from symptom onset, although relapses may occur.
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Phase 3 trials in primary progressive multiple sclerosis have been unsuccessful,
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and no disease-modifying treatments have been approved.
B cells contribute to the pathogenesis of multiple sclerosis, including the primary progressive form.
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Although the mechanisms of tissue injury in multiple sclerosis are uncertain, B cells may influence pathogenesis . . .
Summary Background The anti-CD52 monoclonal antibody alemtuzumab reduced disease activity in a phase 2 trial of previously untreated patients with relapsing-remitting multiple sclerosis. We aimed to ...assess efficacy and safety of first-line alemtuzumab compared with interferon beta 1a in a phase 3 trial. Methods In our 2 year, rater-masked, randomised controlled phase 3 trial, we enrolled adults aged 18–50 years with previously untreated relapsing-remitting multiple sclerosis. Eligible participants were randomly allocated in a 2:1 ratio by an interactive voice response system, stratified by site, to receive intravenous alemtuzumab 12 mg per day or subcutaneous interferon beta 1a 44 μg. Interferon beta 1a was given three-times per week and alemtuzumab was given once per day for 5 days at baseline and once per day for 3 days at 12 months. Coprimary endpoints were relapse rate and time to 6 month sustained accumulation of disability in all patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov , number NCT00530348. Findings 187 (96%) of 195 patients randomly allocated interferon beta 1a and 376 (97%) of 386 patients randomly allocated alemtuzumab were included in the primary analyses. 75 (40%) patients in the interferon beta 1a group relapsed (122 events) compared with 82 (22%) patients in the alemtuzumab group (119 events; rate ratio 0·45 95% CI 0·32–0·63; p<0.0001), corresponding to a 54·9% improvement with alemtuzumab. Based on Kaplan-Meier estimates, 59% of patients in the interferon beta 1a group were relapse-free at 2 years compared with 78% of patients in the alemtuzumab group (p<0·0001). 20 (11%) of patients in the interferon beta 1a group had sustained accumulation of disability compared with 30 (8%) in the alemtuzumab group (hazard ratio 0·70 95% CI 0·40–1·23; p=0·22). 338 (90%) of patients in the alemtuzumab group had infusion-associated reactions; 12 (3%) of which were regarded as serious. Infections, predominantly of mild or moderate severity, occurred in 253 (67%) patients treated with alemtuzumab versus 85 (45%) patients treated with interferon beta 1a. 62 (16%) patients treated with alemtuzumab had herpes infections (predominantly cutaneous) compared with three (2%) patients treated with interferon beta 1a. By 24 months, 68 (18%) patients in the alemtuzumab group had thyroid-associated adverse events compared with 12 (6%) in the interferon beta 1a group, and three (1%) had immune thrombocytopenia compared with none in the interferon beta 1a group. Two patients in the alemtuzumab group developed thyroid papillary carcinoma. Interpretation Alemtuzumab's consistent safety profile and benefit in terms of reductions of relapse support its use for patients with previously untreated relapsing-remitting multiple sclerosis; however, benefit in terms of disability endpoints noted in previous trials was not observed here. Funding Genzyme (Sanofi) and Bayer Schering Pharma.
Summary Background The anti-CD52 monoclonal antibody alemtuzumab reduces disease activity in previously untreated patients with relapsing-remitting multiple sclerosis. We aimed to assess efficacy and ...safety of alemtuzumab compared with interferon beta 1a in patients who have relapsed despite first-line treatment. Methods In our 2 year, rater-masked, randomised controlled phase 3 trial, we enrolled adults aged 18–55 years with relapsing-remitting multiple sclerosis and at least one relapse on interferon beta or glatiramer. Eligible participants were randomly allocated in a 1:2:2 ratio by an interactive voice response system, stratified by site, to receive subcutaneous interferon beta 1a 44 μg, intravenous alemtuzumab 12 mg per day, or intravenous alemtuzumab 24 mg per day. Interferon beta 1a was given three-times per week and alemtuzumab was given once per day for 5 days at baseline and for 3 days at 12 months. The 24 mg per day group was discontinued to aid recruitment, but data are included for safety assessments. Coprimary endpoints were relapse rate and time to 6 month sustained accumulation of disability, comparing alemtuzumab 12 mg and interferon beta 1a in all patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov , number NCT00548405. Findings 202 (87%) of 231 patients randomly allocated interferon beta 1a and 426 (98%) of 436 patients randomly allocated alemtuzumab 12 mg were included in the primary analyses. 104 (51%) patients in the interferon beta 1a group relapsed (201 events) compared with 147 (35%) patients in the alemtuzumab group (236 events; rate ratio 0·51 95% CI 0·39–0·65; p<0·0001), corresponding to a 49·4% improvement with alemtuzumab. 94 (47%) patients in the interferon beta 1a group were relapse-free at 2 years compared with 278 (65%) patients in the alemtuzumab group (p<0·0001). 40 (20%) patients in the interferon beta 1a group had sustained accumulation of disability compared with 54 (13%) in the alemtuzumab group (hazard ratio 0·58 95% CI 0·38–0·87; p=0·008), corresponding to a 42% improvement in the alemtuzumab group. For 435 patients allocated alemtuzumab 12 mg, 393 (90%) had infusion-associated reactions, 334 (77%) had infections (compared with 134 66% of 202 patients in the interferon beta 1a group) that were mostly mild-moderate with none fatal, 69 (16%) had thyroid disorders, and three (1%) had immune thrombocytopenia. Interpretation For patients with first-line treatment-refractory relapsing-remitting multiple sclerosis, alemtuzumab could be used to reduce relapse rates and sustained accumulation of disability. Suitable risk management strategies allow for early identification of alemtuzumab's main adverse effect of secondary autoimmunity. Funding Genzyme (Sanofi) and Bayer Schering Pharma.
Ozanimod is a sphingosine 1-phosphate receptor modulator, which selectively binds to sphingosine 1-phosphate receptor subtypes 1 and 5 with high affinity. In the RADIANCE phase 2 study in ...participants with relapsing multiple sclerosis, ozanimod was associated with better efficacy than placebo on MRI measures and was well tolerated. The RADIANCE phase 3 study aimed to confirm the safety and efficacy of ozanimod versus interferon beta-1a in individuals with relapsing multiple sclerosis.
We did a 24-month, multicentre, double-blind, double-dummy phase 3 trial in participants with relapsing multiple sclerosis at 147 medical centres and clinical practices in 21 countries. Participants were aged 18–55 years, had multiple sclerosis according to 2010 McDonald criteria, a relapsing clinical course, brain MRI lesions consistent with multiple sclerosis, an expanded disability status scale score of 0·0–5·0, and either at least one relapse within 12 months before screening or at least one relapse within 24 months before screening plus at least one gadolinium-enhancing lesion within the 12 months before randomisation. Participants were randomly assigned (1:1:1) via an interactive voice response system to daily oral ozanimod 1·0 mg or 0·5 mg or weekly intramuscular interferon beta-1a 30 μg. Participants, investigators, and study staff were masked to treatment allocation. The primary endpoint was annualised relapse rate (ARR) over 24 months. The primary analysis was done in the intention-to-treat population of all participants who received study drug and safety was assessed in all randomly assigned participants who received study drug, grouped by highest dose of ozanimod received. This trial is registered at ClinicalTrials.gov, NCT02047734, and EudraCT, 2012-002714-40.
Between Dec 27, 2013, and March 31, 2015, we screened 1695 participants, of which 375 did not meet inclusion criteria. 1320 participants were enrolled and randomly assigned to a group, of whom 1313 received study drug (433 assigned to ozanimod 1·0 mg, 439 assigned to ozanimod 0·5 mg, and 441 assigned to interferon beta-1a) and 1138 (86·7%) completed 24 months of treatment. Adjusted ARRs were 0·17 (95% CI 0·14–0·21) with ozanimod 1·0 mg, 0·22 (0·18–0·26) with ozanimod 0·5 mg, and 0·28 (0·23–0·32) with interferon beta-1a, with rate ratios versus interferon beta-1a of 0·62 (95% CI 0·51–0·77; p<0·0001) for ozanimod 1·0 mg and 0·79 (0·65 to 0·96; p=0·0167) for ozanimod 0·5 mg. The incidence of treatment-emergent adverse events was higher in the interferon beta-1a group (365 83·0% of 440 participants) than in the ozanimod 1·0 mg group (324 74·7% of 434) or the ozanimod 0·5 mg group (326 74·3% of 439). More participants in the interferon beta-1a group had treatment-emergent adverse events leading to treatment discontinuation than in the ozanimod groups. Incidences of infections and serious treatment-emergent adverse events were similar across treatment groups. No cases of ozanimod-related symptomatic reduction in heart rate and no second-degree or third-degree cases of atrioventricular block were reported.
In this 24-month phase 3 study in participants with relapsing multiple sclerosis, ozanimod was well tolerated and associated with a significantly lower rate of clinical relapses than intramuscular interferon beta-1a. These findings show the potential of ozanimod as an effective oral therapy for individuals with relapsing multiple sclerosis.
Celgene International II.
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