Immunology of multiple sclerosis

Putative Roles and Therapeutic Potential of the Chaperone System in Amyotrophic Lateral Sclerosis and Multiple Sclerosis

The putative pathogenic roles and therapeutic potential of the chaperone system (CS) in amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS) are reviewed to provide a bibliographic and conceptual platform for launching research on the diagnostic and therapeutic applications of CS components. Various studies suggest that dysfunction of the CS contributes to the pathogenesis of ALS and MS, and here, we identify some of the implicated CS members. The physiology and pathophysiology of the CS members can be properly understood if they are studied or experimentally or clinically manipulated for diagnostic or therapeutic purposes, bearing in mind that they belong to a physiological system with multiple interacting and dynamic components, widespread throughout the body, intra- and extracellularly. Molecular chaperones, some called heat shock protein (Hsp), are the chief components of the CS, whose canonical functions are cytoprotective. However, abnormal chaperones can be etiopathogenic factors in a wide range of disorders, chaperonopathies, including ALS and MS, according to the data reviewed. Chaperones typically form teams, and these build functional networks to maintain protein homeostasis, the canonical role of the CS. However, members of the CS also display non-canonical functions unrelated to protein homeostasis. Therefore, chaperones and other members of the CS, if abnormal, may disturb not only protein synthesis, maturation, and migration but also other physiological processes. Thus, in elucidating the role of CS components in ALS and MS, one must look at protein homeostasis abnormalities and beyond, following the clues emerging from the works discussed here.

Neutrophil Nanovesicle Protects against Experimental Autoimmune Encephalomyelitis through Enhancing Myelin Clearance by Microglia

Timely clearance of myelin debris is the premise of neuroinflammation termination and tissue regeneration in multiple sclerosis (MS). Microglia are the main scavengers of myelin debris in MS lesions, but its phagocytic capability is limited in MS patients. Here, we develop neutrophil-derived nanovesicles (NNVs) to enhance the efficiency of myelin debris clearance in microglia for MS therapy. RNA sequencing (RNAseq) results demonstrate that NNVs treatment ameliorates lesional neuroinflammation of experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. Consequently, EAE mice exhibit favorable neurological functions and white matter integrity after NNVs treatment. Specifically, NNVs treatment upregulates the expression of nuclear factor E2-related factor 2 (NRF2) in microglia, as revealed by Assay for Transposase Accessible Chromatin using sequencing (ATACseq). We also demonstrate that NRF2 can activate the transcription of RUBCN (RUN domain and cysteine-rich domain containing Beclin 1-interacting protein), which in turn enhances LC3-associated phagocytosis (LAP) in microglia. As a result, myelin debris engulfed by microglia can be efficiently catabolized in NNVs-treated EAE mice without obvious side effects. Together, this study proves that NNVs can modulate neuroinflammation by clearing myelin debris and is a promising MS treatment strategy.

New Insights into the Gut Microbiota in Neurodegenerative Diseases from the Perspective of Redox Homeostasis

An imbalance between oxidants and antioxidants in the body can lead to oxidative stress, which is one of the major causes of neurodegenerative diseases. The gut microbiota contains trillions of beneficial bacteria that play an important role in maintaining redox homeostasis. In the last decade, the microbiota-gut-brain axis has emerged as a new field that has revolutionized the study of the pathology, diagnosis, and treatment of neurodegenerative diseases. Indeed, a growing number of studies have found that communication between the brain and the gut microbiota can be accomplished through the endocrine, immune, and nervous systems. Importantly, dysregulation of the gut microbiota has been strongly associated with the development of oxidative stress-mediated neurodegenerative diseases. Therefore, a deeper understanding of the relationship between the gut microbiota and redox homeostasis will help explain the pathogenesis of neurodegenerative diseases from a new perspective and provide a theoretical basis for proposing new therapeutic strategies for neurodegenerative diseases. In this review, we will describe the role of oxidative stress and the gut microbiota in neurodegenerative diseases and the underlying mechanisms by which the gut microbiota affects redox homeostasis in the brain, leading to neurodegenerative diseases. In addition, we will discuss the potential applications of maintaining redox homeostasis by modulating the gut microbiota to treat neurodegenerative diseases, which could open the door for new therapeutic approaches to combat neurodegenerative diseases.

Serum levels of IgM to phosphatidylcholine predict the response of multiple sclerosis patients to natalizumab or IFN-β

We developed an ELISA assay demonstrating the high prevalence of serum IgM to phosphatidylcholine (IgM-PC) in the first stages of multiple sclerosis (MS). We aimed to analyze the role of serum IgM-PC as a biomarker of response to treatment. Paired serum samples from 95 MS patients were obtained before (b.t) and after (a.t) treatment with disease modifying therapies. Patients were classified as non-responders or responders to treatment, according to classical criteria. Serum IgM-PC concentration was analyzed using our house ELISA assay. The level of serum IgM-PC b.t was higher in patients treated later with natalizumab than in those treated with Copaxone (p = 0.011) or interferon-β (p = 0.009). Responders to natalizumab showed higher concentration of serum IgM-PC b.t than those who did not respond to it (p = 0.019). The 73.3% of patients with the highest level of serum IgM-PC b.t responded to natalizumab. IgM-PC level decreased a.t in both cases, non-responders and responders to natalizumab. IgM-PC levels a.t did not decrease in non-responders to interferon-β, but in responders to it the IgM-PC level decreased (p = 0.007). Serum IgM-PC could be a biomarker of response to natalizumab or interferon-β treatment. Further studies would be necessary to validate these results.

Reduced IκB-α Protein Levels in Peripheral Blood Cells of Patients with Multiple Sclerosis-A Possible Cause of Constitutive NF-κB Activation

NF-κB signaling pathways are dysregulated in both the central nervous system (CNS) and peripheral blood cells in multiple sclerosis (MS), but the cause of this is unknown. We have recently reported that peripheral blood mononuclear cells (PBMC) of patients with MS have increased constitutive activation and translocation of the transcription factor NF-κB to the nucleus compared to healthy subjects. NF-κB can be activated through either canonical or non-canonical pathways. In the canonical pathway, activation of NF-κB is normally negatively regulated by the inhibitor IκB. We therefore hypothesized that the increased activation of NF-κB could be caused by reduced IκB-α in the cells of patients with MS, possibly due to increased activity of the IκB kinase (IKK) complex, which regulates IκB-α. Alternatively, changes to the activity of key molecules in the non-canonical pathway, such as IKKα, could also lead to increased NF-κB activation. We therefore used Western blotting to detect IκB-α levels and ELISA to investigate NF-κB DNA binding activity and phosphorylation of IKKα and IKKβ in samples from PBMC of MS patients and controls. The level of full-length IκB-α protein in the cytosolic fraction of PBMC of MS patients was significantly reduced compared to healthy subjects, with significantly more evidence of multiple low molecular weight putative degradation products of IκB-α present in MS patients compared to healthy subjects. Conversely, the level of NF-κB DNA binding activity was increased in whole cell lysates from MS patients. Both IKKα and IKKβ showed increased overall activity in MS compared to healthy subjects, although not all of the MS patients showed increased activity compared to the healthy subjects, suggesting that there may be several different mechanisms underlying the constitutive activation of NF-κB in MS. Taken together, these findings suggest that there may be multiple points at which the NF-κB pathway is dysregulated in MS and that decreased levels of the full-length IκB-α protein are a major component in this.

Identification of key target genes and biological pathways in multiple sclerosis brains using microarray data obtained from the Gene Expression Omnibus database

OBJECTIVE

The purpose of this study was to investigate critical genes in multiple sclerosis (MS) using microarray data from brain tissue in MS.

MATERIALS

The expression profile data set of MS (GSE38010) downloaded from the Gene Expression Omnibus database contained gene information from five plaque tissues from MS brains and two white matter tissues from healthy controls. An R package was applied to process these raw chip data. Gene Ontology (GO) functional analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and protein-protein interaction (PPI) network analysis were performed to investigate interactions between differentially expressed genes (DEGs) in MS brain tissues.

RESULTS

This study identified a total of 1065 DEGs, including 530 up-regulated genes and 535 down-regulated genes, in MS brain tissue samples compared to those in normal white matter tissue samples. GO and KEGG pathway enrichment analyses showed that the up-regulated DEGs were mainly related to neuron development, neuron projection morphogenesis and neuron differentiation. Furthermore, the down-regulated DEGs were largely related to axon ensheathment, ensheathment of neurons and nervous system development. Seven key genes were found as hub genes in the maintenance of the PPI network.

CONCLUSION

Several key target genes and their GO and KEGG pathway enrichment identified in the present study may serve as feasible targets for MS therapies.

Association of AIRE Polymorphism and the Susceptibility to Multiple Sclerosis in Iranian Population

Background:

Multiple Sclerosis (MS) is the most common cause of neurologic disability in young adults. Recently, the AIRE gene was identified as a genetic risk factor for several autoimmune diseases in genome wide association studies. The aim of this study was to further investigate the possible role of the AIRE gene in susceptibility to MS in Iranian population.

Methods:

A total of 112 MS patients and 94 ethnically matched controls were included in the study. The Single-Nucleotide Polymorphism (SNP) (rs1800520, C>G) with a global MAF=0.2282/1143 was selected and genotyped using HRM real-time PCR method.

Results:

Results showed that AIRE SNP rs1800520 was significantly less common in the MS patients than in healthy controls (17.8 vs. 28.7%, pc=0.032, OR=0.54,95% CI 0.279, 1.042). Also, the frequency of allele G was significantly higher among the control group than in the case group (37.77 vs. 25%, pc=0.014). Interestingly, mRNA transcribed on the rs1800520 SNP showed decreased free energy than the wild type suggesting that its increased stability may be responsible for the different activities of the polymorphic AIRE molecule.

Conclusions:

This is the first study investigating the relationship between AIRE gene and the susceptibility to MS. These results indicated that the rs1800520 SNP is not a susceptibility gene variant for the development of MS in Iranian population.

Investigation of Endogenous Retrovirus Sequences in the Neighborhood of Genes Up-regulated in a Neuroblastoma Model after Treatment with Hypoxia-Mimetic Cobalt Chloride

Human endogenous retroviruses (ERVs) have been found to be associated with different diseases, e.g., multiple sclerosis (MS). Most human ERVs integrated in our genome are not competent to replicate and these sequences are presumably silent. However, transcription of human ERVs can be reactivated, e.g., by hypoxia. Interestingly, MS has been linked to hypoxia since decades. As some patterns of demyelination are similar to white matter ischemia, hypoxic damage is discussed. Therefore, we are interested in the association between hypoxia and ERVs. As a model, we used human SH-SY5Y neuroblastoma cells after treatment with the hypoxia-mimetic cobalt chloride and analyzed differences in the gene expression profiles in comparison to untreated cells. The vicinity of up-regulated genes was scanned for endogenous retrovirus-derived sequences. Five genes were found to be strongly up-regulated in SH-SY5Y cells after treatment with cobalt chloride: clusterin, glutathione peroxidase 3, insulin-like growth factor 2, solute carrier family 7 member 11, and neural precursor cell expressed developmentally down-regulated protein 9. In the vicinity of these genes we identified large (>1,000 bp) open reading frames (ORFs). Most of these ORFs showed only low similarities to proteins from retro-transcribing viruses. However, we found very high similarity between retrovirus envelope sequences and a sequence in the vicinity of neural precursor cell expressed developmentally down-regulated protein 9. This sequence encodes the human endogenous retrovirus group FRD member 1, the encoded protein product is called syncytin 2. Transfection of syncytin 2 into the well-characterized Ewing sarcoma cell line A673 was not able to modulate the low immunostimulatory activity of this cell line. Future research is needed to determine whether the identified genes and the human endogenous retrovirus group FRD member 1 might play a role in the etiology of MS.

Effects of Intron 1 Sequences on Human PLP1 Expression: Implications for PLP1-Related Disorders

Alterations in the myelin proteolipid protein gene ( PLP1) may result in rare X-linked disorders in humans such as Pelizaeus-Merzbacher disease and spastic paraplegia type 2. PLP1 expression must be tightly regulated since null mutations, as well as elevated PLP1 copy number, both lead to disease. Previous studies with Plp1-lacZ transgenic mice have demonstrated that mouse Plp1 ( mPlp1) intron 1 DNA (which accounts for slightly more than half of the gene) is required for the mPlp1 promoter to drive significant levels of reporter gene expression in brain. However not much is known about the mechanisms that control expression of the human PLP1 gene ( hPLP1). Therefore this review will focus on sequences in hPLP1 intron 1 DNA deemed important for hPLP1 gene activity as well as a couple of "human-specific" supplementary exons within the first intron which are utilized to generate novel splice variants, and the potential role that these sequences may play in PLP1-linked disorders.

Nutrition and fasting mimicking diets in the prevention and treatment of autoimmune diseases and immunosenescence

Complex and coordinated signals are necessary to initiate and sustain the activation, proliferation, and differentiation of lymphocytes. These signals, which are known to determine T-cell fate and function, also depend on the metabolic state of the organism. Recent studies indicate that both the type and levels of nutrients can influence the generation, survival and function of lymphocytes and therefore can affect several autoimmune diseases. Here, we review the dysregulation of lymphocytes during autoimmunity and aging, the mechanisms associated with loss of immune function, and how fasting mimicking diets and other dietary interventions affect autoimmunity and immunosenescence.

Preliminary Study on the Role of TMEM39A Gene in Multiple Sclerosis

Genome-wide association studies (GWAS) have identified hundreds of new potential genetic risk loci associated with numerous complex diseases such as multiple sclerosis (MS). Genes which have been discovered by GWAS are now the focus of numerous ongoing studies. The goal of this study was to confirm and understand the potential role of one of such genes—transmembrane protein 39A gene (TMEM39A)—in multiple sclerosis.

We showed the difference in TMEM39A messenger RNA (mRNA) expression between MS patients and controls (T²_2;74 = 5.429; p = 0.0063). In our study, the lower mRNA expression of TMEM39A gene in patients did not correlate with a higher methylation level of the TMEM39A promoter. Moreover, a decreased level of TMEM39A mRNA was associated neither with rs1132200 nor with rs17281647. Additionally, we did not find an association between these two TMEM39A polymorphisms and the risk and progression of multiple sclerosis.

Our investigation is the first which indicates that TMEM39A mRNA expression may be associated with the development and/or course of multiple sclerosis.

Cooccurrences of Putative Endogenous Retrovirus-Associated Diseases

At least 8% of the human genome is composed of endogenous retrovirus (ERV) sequences. ERVs play a role in placental morphogenesis and can sometimes protect the host against exogenous viruses. On the other hand, ERV reactivation has been found to be associated with different diseases, for example, multiple sclerosis (MS), schizophrenia, type 1 diabetes mellitus (T1D), or amyotrophic lateral sclerosis (ALS). Little is known about the cooccurrence of these diseases. If all these diseases are caused by ERV, antiretroviral therapy should perhaps also show some effects in the other diseases. Here, we summarize literature demonstrating that some ERV-associated diseases seem to appear together more often than expected, for example, MS and ALS, MS and T1D, MS and schizophrenia, or ALS and T1D. In contrast, some ERV-associated diseases seem to appear together less frequently than expected, for example, schizophrenia and T1D. Besides, some reports demonstrate amelioration of MS, ALS, or schizophrenia under antiretroviral therapy in human immunodeficiency virus-infected patients. If such results could be confirmed in larger studies, alternative therapy strategies for ERV-associated diseases like MS and schizophrenia might be possible.

Multiple Sclerosis - A Vascular Etiology?

From the earliest pathological studies the perivenular localization of the demyelination in multiple sclerosis (MS) has been observed. It has recently been suggested that obstructions to venous flow or inadequate venous valves in the great veins in the neck, thorax and abdomen can cause damaging backflow into the cerebral and spinal cord circulations. Paolo Zamboni and colleagues have demonstrated abnormal venous circulation in some multiple sclerosis patients using non-invasive sonography and invasive venography. Furthermore, they have obtained apparent clinical improvement or stabilization by endovascular ballooning of points of obstruction in the great veins in some, at least temporarily. If non-invasive observations by others validate their initial observations of a significantly increased prevalence of venous obstructions in MS then trials of angioplasty/stenting would be justified in selected cases in view of the biological plausibility of the concept.

NF-κB Pathways in the Pathogenesis of Multiple Sclerosis and the Therapeutic Implications

Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathways are involved in cell immune responses, apoptosis and infections. In multiple sclerosis (MS), NF-κB pathways are changed, leading to increased levels of NF-κB activation in cells. This may indicate a key role for NF-κB in MS pathogenesis. NF-κB signaling is complex, with many elements involved in its activation and regulation. Interestingly, current MS treatments are found to be directly or indirectly linked to NF-κB pathways and act to adjust the innate and adaptive immune system in patients. In this review, we will first focus on the intricacies of NF-κB signaling, including the activating pathways and regulatory elements. Next, we will theorize about the role of NF-κB in MS pathogenesis, based on current research findings, and discuss some of the associated therapeutic implications. Lastly, we will review four new MS treatments which interrupt NF-κB pathways—fingolimod, teriflunomide, dimethyl fumarate (DMF) and laquinimod (LAQ)—and explain their mechanisms, and the possible strategy for MS treatments in the future.

Prevalence of Cytomegalovirus in Patients With Multiple Sclerosis: A Case-Control Study in Northern Iran

BACKGROUND

Multiple sclerosis (MS) is a chronic debilitating disease known as one of the most common neurological dysfunctions in young adults. Recent studies suggest that infections with herpesviruses play a critical role in the pathogenesis of MS.

OBJECTIVES

The present investigation aimed to detect the presence of cytomegalovirus (CMV) in patients with MS using polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) methods.

PATIENTS AND METHODS

Plasma and peripheral blood mononuclear cells (PBMCs) were collected from MS patients (n = 82) and from blood donors as control group (n = 89). They were tested for the presence of CMV antibodies and DNA by ELISA and PCR, respectively.

RESULTS

Anti-CMV was positive in 65 (79.3%) and 69 (77.5%) of the MS patients and healthy subjects, respectively (P= 0.853). Similarly, 23 (28%) and 2 (2.2%) patients were positive for CMV DNA among the MS and control groups, respectively. Statistical analysis showed that the frequency of CMV DNA in the MS patients was significantly higher than in the healthy controls (P < 0.001).

CONCLUSIONS

The results of this study showed a possible association between CMV infection and MS. Further experimental and epidemiological studies using case-control approaches are needed to confirm this association.

A Diet Mimicking Fasting Promotes Regeneration and Reduces Autoimmunity and Multiple Sclerosis Symptoms

Dietary interventions have not been effective in the treatment of multiple sclerosis (MS). Here, we show that periodic 3-day cycles of a fasting mimicking diet (FMD) are effective in ameliorating demyelination and symptoms in a murine experimental autoimmune encephalomyelitis (EAE) model. The FMD reduced clinical severity in all mice and completely reversed symptoms in 20% of animals. These improvements were associated with increased corticosterone levels and regulatory T (Treg) cell numbers and reduced levels of pro-inflammatory cytokines, TH1 and TH17 cells, and antigen-presenting cells (APCs). Moreover, the FMD promoted oligodendrocyte precursor cell regeneration and remyelination in axons in both EAE and cuprizone MS models, supporting its effects on both suppression of autoimmunity and remyelination. We also report preliminary data suggesting that an FMD or a chronic ketogenic diet are safe, feasible, and potentially effective in the treatment of relapsing-remitting multiple sclerosis (RRMS) patients (NCT01538355).

A survey of endogenous retrovirus (ERV) sequences in the vicinity of multiple sclerosis (MS)-associated single nucleotide polymorphisms (SNPs)

Although multiple sclerosis (MS) is one of the most common central nervous system diseases in young adults, little is known about its etiology. Several human endogenous retroviruses (ERVs) are considered to play a role in MS. We are interested in which ERVs can be identified in the vicinity of MS associated genetic marker to find potential initiators of MS. We analysed the chromosomal regions surrounding 58 single nucleotide polymorphisms (SNPs) that are associated with MS identified in one of the last major genome wide association studies. We scanned these regions for putative endogenous retrovirus sequences with large open reading frames (ORFs). We observed that more retrovirus-related putative ORFs exist in the relatively close vicinity of SNP marker indices in multiple sclerosis compared to control SNPs. We found very high homologies to HERV-K, HCML-ARV, XMRV, Galidia ERV, HERV-H/env62 and XMRV-like mouse endogenous retrovirus mERV-XL. The associated genes (CYP27B1, CD6, CD58, MPV17L2, IL12RB1, CXCR5, PTGER4, TAGAP, TYK2, ICAM3, CD86, GALC, GPR65 as well as the HLA DRB1*1501) are mainly involved in the immune system, but also in vitamin D regulation. The most frequently detected ERV sequences are related to the multiple sclerosis-associated retrovirus, the human immunodeficiency virus 1, HERV-K, and the Simian foamy virus. Our data shows that there is a relation between MS associated SNPs and the number of retroviral elements compared to control. Our data identifies new ERV sequences that have not been associated with MS, so far.

Interleukin 7 receptor polymorphisms and the risk of multiple sclerosis: A meta-analysis

BACKGROUND

Multiple sclerosis (MS) is considered as the most common chronic inflammatory neurologic disorder diagnosed in young adults. Both environmental and genetic factors may influence risk of MS development. Interleukin 7 receptor (IL7R) is one of the most studied gene polymorphism on MS that may play a possible role in MS development. The most studied polymorphism of IL7R gene is "rs6897932" polymorphism on IL7Rα gene (IL7RA).

METHODS

PubMed, Scopus, and Google scholar databases were searched for all of related studies on the association of IL7RA polymorphism with single nucleotide polymorphism (SNP) ID of "rs6897932" and the risk of MS through August 07, 2015. After exclusion of irrelevant articles, 11 eligible studies were selected, which were analyzed to determine an association between the MS and IL7R T244I polymorphism (rs6897932). For identification of this association, odds ratios (ORs) and 95% confidence interval (95% CI) were calculated. Four models of allelic (T vs. C), co-dominant genotype (TT vs. CC), dominant (TT+CT vs. CC), and recessive genotypes (TT vs. CT+CC) were considered to check the possible role of rs6897932 polymorphism in MS. A sensitivity analysis was conducted to find the reliability of this study. Furthermore, funnel plots were used to evaluate publication bias.

RESULTS

A total of 11 case-control studies were identified through this meta-analysis, which containing 6752 cases and 7349 controls. In overall, the frequency of the C allele was found to be higher in patients with MS compared to healthy controls (75.66% vs. 72.19%). T allele was significantly associated with the decreased risk of MS in a random effect model (T vs. C: OR=0.84, 95% CI=0.77-0.92, P-value <0.001). In the co-dominant, dominant, and recessive genotypes models, a significant association between the IL7R T244I polymorphism and MS risk was demonstrated (TT vs. CC: OR=0.70, 95% CI=0.61-0.80, P-value <0.001; TT+CT vs. CC: OR=0.82, 95% CI=0.73-0.92, P-value <0.001; TT vs. CT+CC: OR=0.76, 95% CI=0.66-0.87, P-value <0.001). Sensitivity analysis revealed that this study is reliable. There was no evidence of publication bias.

CONCLUSION

It was demonstrated that the IL7R T244I polymorphism was associated with susceptibility to MS. However, more well-designed studies with large sample size are needed to validate this association between this single nucleotide polymorphism and MS.

Disparate Effects of Mesenchymal Stem Cells in Experimental Autoimmune Encephalomyelitis and Cuprizone-Induced Demyelination

Mesenchymal stem cells (MSCs) are pleiotropic cells with potential therapeutic benefits for a wide range of diseases. Because of their immunomodulatory properties they have been utilized to treat autoimmune diseases such as multiple sclerosis (MS), which is characterized by demyelination. The microenvironment surrounding MSCs is thought to affect their differentiation and phenotype, which could in turn affect the efficacy. We thus sought to dissect the potential for differential impact of MSCs on central nervous system (CNS) disease in T cell mediated and non-T cell mediated settings using the MOG_35–55 experimental autoimmune encephalomyelitis (EAE) and cuprizone-mediated demyelination models, respectively. As the pathogeneses of MS and EAE are thought to be mediated by IFNγ-producing (T_H1) and IL-17A-producing (T_H17) effector CD4+ T cells, we investigated the effect of MSCs on the development of these two key pathogenic cell groups. Although MSCs suppressed the activation and effector function of T_H17 cells, they did not affect T_H1 activation, but enhanced T_H1 effector function and ultimately produced no effect on EAE. In the non- T cell mediated cuprizone model of demyelination, MSC administration had a positive effect, with an overall increase in myelin abundance in the brain of MSC-treated mice compared to controls. These results highlight the potential variability of MSCs as a biologic therapeutic tool in the treatment of autoimmune disease and the need for further investigation into the multifaceted functions of MSCs in diverse microenvironments and the mechanisms behind the diversity.

Th17-biased RORγt transgenic mice become susceptible to a viral model for multiple sclerosis

In a viral model for multiple sclerosis (MS), Theiler's murine encephalomyelitis virus-induced demyelinating disease (TMEV-IDD), both immune-mediated tissue damage (immunopathology) and virus persistence have been shown to cause pathology. T helper (Th) 17 cells are a Th cell subset, whose differentiation requires the transcription factor retinoic acid-related orphan receptor (ROR) γt, secrete pro-inflammatory cytokines, including IL-17, and can antagonize Th1 cells. Although Th17 cells have been shown to play a pathogenic role in immune-mediated diseases or a protective role in bacterial and fungal infections, their role in viral infections is unclear. Using newly established Th17-biased RORγt Tg mice, we tested whether Th17 cells could play a pathogenic or protective role in TMEV-IDD by contributing to immunopathology and/or by modulating anti-viral Th1 immune responses. While TMEV-infected wild-type littermate C57BL/6 mice are resistant to TMEV-IDD, RORγt Tg mice developed inflammatory demyelinating lesions with virus persistence in the spinal cord. TMEV-infected RORγt Tg mice had higher levels of IL-17, lower levels of interferon-γ, and fewer CD8(+) T cells, without alteration in overall levels of anti-viral lymphoproliferative and antibody responses, compared with TMEV-infected wild-type mice. This suggests that a Th17-biased "gain-of-function" mutation could increase susceptibility to virus-mediated demyelinating diseases.

Epstein-Barr virus and multiple sclerosis: potential opportunities for immunotherapy

Multiple sclerosis (MS) is a common chronic inflammatory demyelinating disease of the central nervous system (CNS) causing progressive disability. Many observations implicate Epstein–Barr virus (EBV) in the pathogenesis of MS, namely universal EBV seropositivity, high anti-EBV antibody levels, alterations in EBV-specific CD8⁺ T-cell immunity, increased spontaneous EBV-induced transformation of peripheral blood B cells, increased shedding of EBV from saliva and accumulation of EBV-infected B cells and plasma cells in the brain. Several mechanisms have been postulated to explain the role of EBV in the development of MS including cross-reactivity between EBV and CNS antigens, bystander damage to the CNS by EBV-specific CD8⁺ T cells, activation of innate immunity by EBV-encoded small RNA molecules in the CNS, expression of αB-crystallin in EBV-infected B cells leading to a CD4⁺ T-cell response against oligodendrocyte-derived αB-crystallin and EBV infection of autoreactive B cells, which produce pathogenic autoantibodies and provide costimulatory survival signals to autoreactive T cells in the CNS. The rapidly accumulating evidence for a pathogenic role of EBV in MS provides ground for optimism that it might be possible to prevent and cure MS by effectively controlling EBV infection through vaccination, antiviral drugs or treatment with EBV-specific cytotoxic CD8⁺ T cells. Adoptive immunotherapy with in vitro-expanded autologous EBV-specific CD8⁺ T cells directed against viral latent proteins was recently used to treat a patient with secondary progressive MS. Following the therapy, there was clinical improvement, decreased disease activity on magnetic resonance imaging and reduced intrathecal immunoglobulin production.

Protein 4.1R attenuates autoreactivity in experimental autoimmune encephalomyelitis by suppressing CD4(+) T cell activation

Immune synapse components contribute to multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE) pathogenesis as they play important role in autoreactive T cell activation. Protein 4.1R, a red cell membrane cytoskeletal protein, recently was identified as an important component of immunological synapse (IS) and acted as the negative regulator of CD4(+) T cell activation. However, the pathological role of 4.1R in the MS/EAE pathogenesis is still not elucidated. In this study, we investigated the potential role of protein 4.1R in pathologic processes of EAE by using 4.1R knockout mouse model. Our results suggest that 4.1R can prevent pathogenic autoimmunity in MS/EAE progression by suppressing the CD4(+) T cell activation.

The retrovirus/superantigen hypothesis of multiple sclerosis

The pathogenesis of multiple sclerosis (MS) is as yet unknown. Commonly, MS is assumed to be due to an autoimmune inflammation of the central nervous system (CNS). Neurodegeneration is regarded to be a secondary reaction. This concept is increasingly being challenged. Human endogenous retroviruses (HERV) that could be locally activated in the CNS have been proposed as an alternative concept. HERV-encoded envelope proteins (env) can act as strong immune stimulators (superantigens). Thus, slow disease progression following neurodegeneration might be induced by re-activation of HERV expression directly, while relapses in parallel to inflammation might be secondary to the expression of HERV-encoded superantigens. It has been shown previously that T-cell superantigens are capable to induce a cellular inflammatory reaction in the CNS of experimental animals similar to that in MS. Furthermore, B-cell superantigens have been shown to activate blood leucocytes in vitro to produce immunoglobulin in an oligoclonal manner. It remains to be established, whether the outlined hypothesis accords with all known features of MS. Furthermore, anti-HERV agents may be taken into consideration to enrich and improve MS therapy.

Gender differences in autoimmune disease

Autoimmune diseases are a range of diseases in which the immune response to self-antigens results in damage or dysfunction of tissues. Autoimmune diseases can be systemic or can affect specific organs or body systems. For most autoimmune diseases there is a clear sex difference in prevalence, whereby females are generally more frequently affected than males. In this review, we consider gender differences in systemic and organ-specific autoimmune diseases, and we summarize human data that outlines the prevalence of common autoimmune diseases specific to adult males and females in countries commonly surveyed. We discuss possible mechanisms for sex specific differences including gender differences in immune response and organ vulnerability, reproductive capacity including pregnancy, sex hormones, genetic predisposition, parental inheritance, and epigenetics. Evidence demonstrates that gender has a significant influence on the development of autoimmune disease. Thus, considerations of gender should be at the forefront of all studies that attempt to define mechanisms that underpin autoimmune disease.

T Follicular Helper Cells in Transplantation: The Target to Attenuate Antibody-Mediated Allogeneic Responses?

Antibody-mediated, humoral rejection has been recognized as a common cause of transplant dysfunction and is responsible for 30-50 % of failed allografts. The production of antibody is dependent on instructions from memory CD4+ T helper cells that interact with antigen-specific B cells. Recently, a specialized T-cell subset has been identified-T follicular helper (Tfh) cells-which support activated B cells via interleukin (IL)-21 after binding to the IL-21 receptor expressed by these B cells. Therefore, neutralizing the IL-21 pathway will selectively inhibit the allogeneic IL-21-driven Tfh- and B-cell functions. However, little is known of the role of Tfh cells in alloreactivity. In this review, we debate the role of Tfh cells in B-cell-mediated allogeneic responses by discussing their mechanisms of actions. In addition, we speculate about the use of agents that intervene in Tfh-B-cell interaction and consequently prevent or treat antibody-mediated rejection in patients after transplantation.

Association between IL-6-174G/C polymorphism and risk of multiple sclerosis: a meta-analysis

OBJECTIVE

Interleukin-6 (IL-6) is a pleiotropic cytokine and important mediator of many inflammatory processes, which might affect susceptibility to multiple sclerosis (MS). The aim of this study was to assess the effect of IL-6-174G/C polymorphism on the risk of MS using a meta-analysis.

MATERIALS AND METHODS

The Pubmed, ISI Web of Science, Wanfang, VIP, and China National Knowledge Infrastructure databases were screened and six studies were included in the meta-analysis. Pooled odds ratios (ORs) with corresponding 95% confidence intervals (CI) were calculated to evaluate the association between the IL-6-174G/C polymorphism and risk of MS.

RESULTS

No significant association between the IL-6-174G/C polymorphism and risk of MS was observed in overall analyses. With stratification according to ethnicity, we found that carriers with the IL-6-174CC genotype had a 1.87-fold increased risk for the development of MS in Asians (recessive model: OR=1.87, 95% CI, 1.08-3.24), but not in Caucasians.

CONCLUSION

This meta-analysis provides evidence that the IL-6-174G/C polymorphism may be a risk factor for the development of MS in Asians. Further association studies with a larger sample size are required to confirm the result in different populations.

[A case of chronic active Epstein-Barr virus infection associated with recurrent cerebellar ataxia and skin eruptions]

A 62-year-old woman presented with subacute cerebellar ataxia, lymph node swelling and skin eruption. Laboratory tests revealed elevated titers of anti-VCA-IgG antibody and anti-EADR-IgG antibody, with Epstein-Barr virus (EBV) DNA detected from the blood and CSF by PCR. Since these data were highlighted with the diagnosis of chronic active EBV infection (CAEBV) and her ataxia improved concomitantly with the remission of other infectious mononucleosis-like symptoms, we supposed her ataxia is associated with CAEBV. Five years later, at the age of 67, her ataxia relapsed concurrently with skin eruptions, whereas MRI demonstrated progression of cerebellar atrophy. After high-dose intravenous methylprednisolone treatment, the clinical symptoms resolved. Initial infection of EBV in childhood often causes autoimmune acute cerebellitis but cerebellar ataxia has rarely been described in CAEBV. Furthermore, immunohistochemical analysis revealed a reactivity of the patient's serum and CSF on rat cerebellum, suggesting an autoimmune pathomechanism for the ataxia.

Multiple sclerosis and the blood-central nervous system barrier

The central nervous system (CNS) is isolated from the blood system by a physical barrier that contains efflux transporters and catabolic enzymes. This blood-CNS barrier (BCNSB) plays a pivotal role in the pathophysiology of multiple sclerosis (MS). It binds and anchors activated leukocytes to permit their movement across the BCNSB and into the CNS. Once there, these immune cells target particular self-epitopes and initiate a cascade of neuroinflammation, which leads to the breakdown of the BCNSB and the formation of perivascular plaques, one of the hallmarks of MS. Immunomodulatory drugs for MS are either biologics or small molecules, with only the latter having the capacity to cross the BCNSB and thus have a propensity to cause CNS side effects. However, BCNSB penetration is a desirable feature of MS drugs that have molecular targets within the CNS. These are nabiximols and dalfampridine, which target cannabinoid receptors and potassium channels, respectively. Vascular cell adhesion molecule-1, present on endothelial cells of the BCNSB, also serves as a drug discovery target since it interacts with α4-β1-integrin on leucocytes. The MS drug natalizumab, a humanized monoclonal antibody against α4-β1-integrin, blocks this interaction and thus reduces the movement of immune cells into the CNS. This paper further elaborates on the role of the BCNSB in the pathophysiology and pharmacotherapy of MS.

Interleukin-6 gene promoter-572 C allele may play a role in rate of disease progression in multiple sclerosis

Multiple sclerosis (MS) is an inflammatory demyelinating disease affecting the central nervous system. Although the exact pathogenesis of MS is unknown, it is generally considered to be an autoimmune disease, with numerous genetic and environmental factors determining disease susceptibility and severity. One important mediator of immune responses and inflammation is interleukin-6 (IL-6). Previously, elevated levels of IL-6 in mononuclear cells in blood and in brain tissue from MS patients have been reported. Various polymorphisms in the promoter region of the IL6 gene have also been linked with IL-6 protein levels. In MS, several small studies have investigated whether two IL6 promoter polymorphisms (−597 G>A and −174 G>C) correlate with MS susceptibility, but with varying results. In the present study, we analyzed these polymorphisms, together with an additional polymorphism (−572 G>C) in 279 healthy controls and 509 patients with MS. We found no significant differences between MS patients and healthy controls for the different −597 or −174 IL6 promoter alleles or genotypes. There was a slight reduction in the percentage of individuals with MS who carried a C allele at position −572, although this was not significant after correction for multiple comparisons. Interestingly, however, the −572 C allele showed a significant correlation with the MS severity score, suggesting a possible role in disease progression.

Pharmacotherapeuetic Options for the Treatment of Multiple Sclerosis

Multiple sclerosis is the most common progressive and disabling neurological condition in young adults. Neuro-inflammation is an early and persistent change and forms the basis of most pharmacotherapy for this disease. Immunomodulatory drugs are mainly biologies (β-interferons, a four amino acid peptide, and a monoclonal antibody to a cell adhesion molecule on the blood-CNS barrier) that either attenuate the inflammatory response or block the movement of immune cells into the CNS. They reduce the rate of relapse, but have little or no effect on the progression of disability. The market landscape for MS drugs is in the midst of major change because the patent life of many of these medicines will soon expire, which will lead to the emergence of biosimilars. In addition, new small molecule immunomodulatory and palliative drugs have entered the market, with more in the pipeline; a number of monoclonal antibodies and other immunomodulatory drugs are also in clinical development.

Immunopathological patterns from EAE and Theiler's virus infection: Is multiple sclerosis a homogenous 1-stage or heterogenous 2-stage disease?

Multiple sclerosis (MS) is a disease which can presents in different clinical courses. The most common form of MS is the relapsing-remitting (RR) course, which in many cases evolves into secondary progressive (SP) disease. Autoimmune models such as experimental autoimmune encephalomyelitis (EAE) have been developed to represent the various clinical forms of MS. These models along with clinico-pathological evidence obtained from MS patients have allowed us to propose '1-stage' and '2-stage' disease theories to explain the transition in the clinical course of MS from RR to SP. Relapses in MS are associated with pro-inflammatory T helper (Th) 1/Th17 immune responses, while remissions are associated with anti-inflammatory Th2/regulatory T (Treg) immune responses. Based on the '1-stage disease' theory, the transition from RR to SP disease occurs when the inflammatory immune response overwhelms the anti-inflammatory immune response. The '2-stage disease' theory proposes that the transition from RR to SP-MS occurs when the Th2 response or some other responses overwhelm the inflammatory response resulting in the sustained production of anti-myelin antibodies, which cause continuing demyelination, neurodegeneration, and axonal loss. The Theiler's virus model is also a 2-stage disease, where axonal degeneration precedes demyelination during the first stage, followed by inflammatory demyelination during the second stage.

Updated assessment of the prevalence, spectrum and case definition of autoimmune disease

Autoimmune diseases are heterogeneous with regard to prevalence, manifestations, and pathogenesis. The classification of autoimmune diseases has varied over time. Here, we have compiled a comprehensive up-to-date list of the autoimmune diseases, and have reviewed published literature to estimate their prevalence. We identified 81 autoimmune diseases. The overall estimated prevalence is 4.5%, with 2.7% for males and 6.4% for females. For specific diseases, prevalence ranges from 1% to <1/10(6). Considering all diseases in the class, the most common mean age-of-onset was 40-50 years. This list of autoimmune diseases has also yielded information about autoantigens. Forty-five autoimmune diseases have been associated with well-defined autoantigens. Of the diseases with known autoantigens, 33.3% had highly repetitive sequences, 35.6% had coiled-coil arrangements and 57.8% were associated with cellular membranes, which means that based on these structural motifs alone, autoantigens do not appear to be a random sample of the human proteome. Finally, we identified 19 autoimmune diseases that phenocopy diseases arising from germline mutations in the corresponding autoantigen. Collectively, our findings lead to a tentative proposal for criteria for assigning autoimmune pathogenesis to a particular disease.

Combinatorial antibody library from multiple sclerosis patients reveals antibodies that cross-react with myelin basic protein and EBV antigen

Multiple sclerosis (MS) is a widespread neurodegenerative autoimmune disease with unknown etiology. It is increasingly evident that, together with pathogenic T cells, autoreactive B cells are among the major players in MS development. The analysis of myelin neuroantigen-specific antibody repertoires and their possible cross-reactivity against environmental antigens, including viral proteins, could shed light on the mechanism of MS induction and progression. A phage display library of single-chain variable fragments (scFvs) was constructed from blood lymphocytes of patients with MS as a potential source of representative MS autoantibodies. Structural alignment of 13 clones selected toward myelin basic protein (MBP), one of the major myelin antigens, showed high homology within variable regions with cerebrospinal fluid MS-associated antibodies as well as with antibodies toward Epstein-Barr latent membrane protein 1 (LMP1). Three scFv clones showed pronounced specificity to MBP fragments 65-92 and 130-156, similar to the serum MS antibodies. One of these clones, designated E2, in both scFv and full-size human antibody constructs, was shown to react with both MBP and LMP1 proteins in vitro, suggesting natural cross-reactivity. Thus, antibodies induced against LMP1 during Epstein-Barr virus infection might act as inflammatory trigger by reacting with MBP, suggesting molecular mimicry in the mechanism of MS pathogenesis.

Genetics of rheumatoid arthritis: GWAS and beyond

The study of complex genetics in autoimmune diseases has progressed at a tremendous pace over the last 4 years, as a direct result of the enormous gains made by genome wide association studies (GWAS). Novel genetic findings are continuously being reported alongside the rapid development of genetic technologies, sophisticated statistical analysis, and larger sample collections. It is now becoming clear that multiple genes contribute to disease risk in many complex genetic disorders including rheumatoid arthritis (RA) and that there are common genetic risk factors that underlie a spectrum of autoimmune diseases. This review details the current genetic landscape of RA, and describes what GWAS has taught us in terms of missing heritability, subsets of disease, existence of genetic heterogeneity, and shared autoimmune risk loci. Finally, this review addresses the initial challenges faced in translating the wealth of genetic findings into determining the biological mechanisms that contribute to the relationship between genotype and phenotype. Unraveling the mechanism of how genes directly influence the cause of RA will lead to a better understanding of the disease and will ultimately have a direct clinical impact, informing the development of new therapies that can be utilized in the treatment of RA.

The mechanism of sesame oil in ameliorating experimental autoimmune encephalomyelitis in C57BL/6 mice

Experimental autoimmune encephalomyelitis (EAE) is a Th1 cell-mediated autoimmune disease of the CNS that serves as an animal model for multiple sclerosis (MS). The study investigated the effectiveness of treatment with sesame oil on the development of EAE. EAE was induced in 8 week old C57BL/6 mice with an emulsion of MOG35-55. Therapy with sesame oil (4 mL/kg/day as oral gavage) was started on day 3 before the immunization. IFN-gamma and IL-10 production from cultured spleen supernatants were determined by the ELISA method. The results showed that daily oral gavage of sesame oil significantly reduced the clinical symptoms of EAE in C57BL/6 mice. In addition, sesame oil-treated mice displayed a significantly delayed disease onset. Mononuclear cells isolated from spleen of sesame oil-treated mice showed a significant decrease in the production of IFN-gamma compared with control mice (p = 0.001). IL-10 production was also enhanced in splenic mononuclear cells in sesame oil-treated mice. The ratio of IFN-gamma to IL-10 in sesame oil-treated EAE mice was significantly less than in non-treated EAE mice (p = 0.01). This report indicates that sesame oil therapy protected mice from developing EAE by reducing IFN-gamma secretion. Thus, sesame oil treatment may be effective in MS patients by immunomodulating the Th1 immune response.

Role of gender in multiple sclerosis: clinical effects and potential molecular mechanisms

Multiple sclerosis (MS) is more prevalent in females than males, and this female predominance is increasing as time goes by. Additionally, gender appears to play critical roles in development, progression and treatment of MS, and is therefore an aspect that should always be considered in the design and interpretation of research and clinical trials for MS. In this review, factors that could potentially explain the gender-biased observations in MS are discussed. These include sex-specific differences between the male and female immune systems and nervous systems, genetic and epigenetic or environmental-related effects, the effects of gonadal hormones, and materno-fetal interactions.

Current and future role of interferon beta in the therapy of multiple sclerosis

Interferon beta was the first specific disease-modifying therapy licensed for multiple sclerosis (MS) and in its many forms remains the most commonly prescribed agent worldwide. It, however, has a modest effect in reducing relapse rates, magnetic resonance imaging activity, and disability, and many patients are unable to tolerate it because of the associated side effects or mode of administration. With the licensing of glatiramer acetate, natalizumab and mitoxantrone as disease-modifying therapies for MS alternative options are available to people with MS. Many exciting new therapies are also in the pipeline, namely, the monoclonal antibodies alemtuzumab, rituximab, and daclizumab and the promising oral agents BG00012, cladribine, fingolimod, laquinimod, and teriflunomide. In this article we review the immunopathology of MS and the proposed mechanisms of action of currently available and anticipated treatments. We also review the efficacy of each drug, use of combination therapy strategies, and the potential role of the interferon beta preparations in the future.

The essential role of Epstein-Barr virus in the pathogenesis of multiple sclerosis

There is increasing evidence that infection with the Epstein-Barr virus (EBV) plays a role in the development of multiple sclerosis (MS), a chronic inflammatory demyelinating disease of the CNS. This article provides a four-tier hypothesis proposing (1) EBV infection is essential for the development of MS; (2) EBV causes MS in genetically susceptible individuals by infecting autoreactive B cells, which seed the CNS where they produce pathogenic autoantibodies and provide costimulatory survival signals to autoreactive T cells that would otherwise die in the CNS by apoptosis; (3) the susceptibility to develop MS after EBV infection is dependent on a genetically determined quantitative deficiency of the cytotoxic CD8+ T cells that normally keep EBV infection under tight control; and (4) sunlight and vitamin D protect against MS by increasing the number of CD8+ T cells available to control EBV infection. The hypothesis makes predictions that can be tested, including the prevention and successful treatment of MS by controlling EBV infection.

Dynamics and fate of USPIO in the central nervous system in experimental autoimmune encephalomyelitis

Signal loss observed in the brain by MRI following the administration of ultrasmall superparamagnetic particles of iron oxide (USPIO) has been correlated with immune cell activity in inflammatory areas during multiple sclerosis. Uptake of USPIO by circulating monocytes and their migration towards inflammatory areas have been considered as the most important mechanism for USPIO uptake by the brain parenchyma. However, the involvement of a damaged blood-brain barrier is also debated as a possible mechanism for cerebral USPIO uptake. Compared with these uptake-associated issues, little is known about the clearance of USPIO from the brain. The acute uptake and chronic clearance of USPIO in the brain were therefore studied with MRI in an animal model of multiple sclerosis. Lewis Hannover rats with acute experimental autoimmune encephalomyelitis received a single intravenous injection of USPIO (300 µmol Fe/kg), and repetitive MRI of the brain and cervical lymph nodes, a possible drainage pathway, was performed. USPIO were detected in the brain within 1 h after injection independent of the severity of experimental autoimmune encephalomyelitis, and histological analysis revealed extracellular iron clusters colocalising with a leaky blood-brain barrier. Loss of signal was not present 72 h after USPIO injection, irrespective of the disease state. MR images of cervical lymph nodes showed USPIO accumulation at 24 h after administration, which stabilised at 72 h. Histological analyses revealed that USPIO accumulated in infiltrated macrophages in the medulla and subcapsular sinus. The current study demonstrates that USPIO enter the central nervous system directly after administration, pointing to the involvement of a damaged blood-brain barrier in the appearance of USPIO-associated MR abnormalities. Furthermore, a possible role of the cervical lymph nodes as a drainage pathway of USPIO is suggested. These data shed new light on the use of USPIO in neuroinflammatory diseases, identifying USPIO as a marker for both cellular infiltration and blood-brain barrier damage.

Potential triggers of MS

MS is an immune mediated disease of the central nervous system (CNS) characterized by demyelination, axonal damage and neurologic disability. The primary cause of this CNS disease remains elusive. Here we will address our current understanding of the role of viruses as potential environmental triggers for MS. Virus infections can act peripherally (outside the CNS) or within the CNS. The association of viral infections with demyelinating disease, in both animals and humans, will be discussed, as will the potential contributions of peripheral infection with Torque Teno virus, infection outside of and/or within the CNS with Epstein-Barr virus and infection within the CNS with Human Herpesvirus 6 to MS. An experimental animal model, Theiler's murine encephalomyelitis virus infection of susceptible strains of mice is an example of viral infections of the CNS as a prerequisite for demyelination. Finally, the proposition that multiple virus infections are required, which first prime the immune system and then trigger the disease, as a model where infections outside of the CNS lead to inflammatory changes within the CNS, for the development of a MS-like disease is explored.

TLR3 ligand polyinosinic:polycytidylic acid induces IL-17A and IL-21 synthesis in human Th cells

TLR3 and TLR9 recognize the pathogen-associated microbial patterns dsRNA and unmethylated DNA, respectively. The recent discovery that these receptors also recognize endogenous ligands from necrotic material has drawn increased attention to their involvement in autoimmunity. Th cell cytokines IL-17A and IL-21 have been assigned with pivotal roles in the regulation of such autoimmune diseases. IL-17A is the hallmark cytokine of the recently discovered proinflammatory Th cell subset T(H)17. By contrast, the expression of IL-21 does not seem to be limited to a single distinct Th cell subset. We investigated the expression of IL-17A and IL-21 in human CD4+ T cells in response to stimulation with the TLR3 ligand polyinosinic:polycytidylic acid (poly(I:C)) and the TLR9 ligand CpG. We discovered that poly(I:C) induced synthesis of both IL-17A and IL-21. Moreover, we found that poly(I:C) was able to drive the differentiation of naive Th cells into an IL-21 but not into an IL-17A-producing phenotype and did this without affecting the levels of transcription factors T-bet, GATA-3, or retinoic acid receptor-related orphan receptor C. Finally, we found that the IL-21-producing cells that were differentiated in response to poly(I:C) expressed the chemokine receptor CXCR3, which is important in the recruitment of T cells into inflamed joints in rheumatoid arthritis. This is the first report to show that the TLR3 ligand poly(I:C) can directly induce the synthesis of IL-17A and IL-21 and drive differentiation of human naive CD4+ T cells.

Review: Treatment of early multiple sclerosis: the value of treatment initiation after a first clinical episode

Multiple sclerosis is a chronic, demyelinating disorder of the central nervous system. It is characterised by progressive neurological disability, which is likely to occur as a result of permanent axonal damage. Such damage may be reflected by brain atrophy, which can be identified early in the course of the disease. Patients who present with an initial episode of inflammatory demyelination, commonly referred to as a clinically isolated syndrome, are at high risk of developing clinically definite multiple sclerosis, especially if their magnetic resonance imaging studies suggest the presence of multi-focal disease. Treatment with disease-modifying therapies at the initial episode of demyelination may postpone this development. In this review we present an overview of evidence supporting early treatment initiation. We focus on three large placebo-controlled trials of interferon beta therapy: Controlled High-Risk Avonex® Multiple Sclerosis Prevention Study, Early Treatment of Multiple Sclerosis and Betaferon ® in Newly Emerging Multiple Sclerosis for Initial Treatment. Results from these early treatment studies are presented, and the impact of using interferon beta treatment in the early stages of disease is discussed with the aim of considering optimal therapeutic strategies to improve long-term patient outcome.

Prominent brainstem and cerebellar involvement in multiple sclerosis with psoriasis

INTRODUCTION

We identified a subgroup of 20 patients with multiple sclerosis (MS) and psoriasis within a total group of 692 patients with MS.

RESULTS

There was a high (80%) incidence of brainstem and/or cerebellar involvement and a high mean (+/-SD) Multiple Sclerosis Severity Score (6.06 +/- 2.88) in this subgroup. Of the patients who were human leukocyte antigen typed, 53% carried the MS-associated allele, DRB1*1501, and 27% carried the psoriasis-associated DRB1*07 allele.

CONCLUSION

The high incidence of brainstem and cerebellar involvement might be explained by the greater severity of MS and the high frequency (60%) of carriage of DRB1*04, DRB1*07, and/or DRB1*13 alleles, which are associated with brainstem and cerebellar involvement in MS.