MOG-induced Experimental Autoimmune Encephalomyelitis Research Articles

Circulating Picomolar Levels of CCL2 Downregulate Ongoing Chronic Experimental Autoimmune Encephalomyelitis by Induction of Regulatory Mechanisms.

Multiple sclerosis is an inflammatory disease of the CNS characterized by neurologic impairment resulting from primary demyelination and axonal damage. The pathogenic mechanisms of disease development include Ag-specific T cell activation and Th1 differentiation, followed by T cell and macrophage migration into the CNS. CCL2 is a chemokine that induces migration of monocytes, memory T cells, and dendritic cells. We previously demonstrated that picomolar levels of CCL2 strongly restrict the development of inflammation in models of inflammatory bowel disease. Moreover, CCR2 deficiency in T cells promotes a program inducing the accumulation of Foxp3+ regulatory T cells while decreasing the levels of Th17 cells in vivo. In the current study, the effect of picomolar levels of CCL2 on the autoimmune inflammatory response associated with a multiple sclerosis-like disease in mice was analyzed. We found that low dosages of CCL2 were effective in suppressing MOG-induced experimental autoimmune encephalomyelitis (EAE), and they downregulated chronic EAE. The modulation of EAE by CCL2 was associated with downregulation of Th1/Th17 cells and upregulation of TGF-β and induction of regulatory CD4+Foxp3 T cells. Most strikingly, these low levels of CCL2 induced formation of highly functional regulatory T cells. Thus, this study strongly supports the potential use of CCL2 as a regulatory mediator for treating inflammatory autoimmune diseases.

Repetitive intrathecal injection of human NMO-IgG with complement exacerbates disease severity with NMO pathology in experimental allergic encephalomyelitis mice

Neuromyelitis optica (NMO) is recognized as a different CNS autoimmune disease from multiple sclerosis (MS). Whether NMO-IgG contributes directly to the pathogenesis of NMO or is just a serologic marker of autoimmune responses of the disease needs to be clarified. We created MOG-induced experimental autoimmune encephalomyelitis (EAE) mice by passively transferring NMO-IgG to model the pathogenic findings in NMO patients. The mice were divided into three groups and administered intrathecal PBS, human complement with IgG from normal subjects, or IgG from AQP4(+) patients on days 8 and 11 after immunization. The EAE scores of EAE mice with intrathecal NMO-IgG injection were significantly elevated 14 days post-immunization. All of the mice were sacrificed for brain and spinal cord pathology analysis on day 21 post-immunization. Compared to mice given normal human IgG, EAE mice injected with NMO-IgG had markedly decreased AQP4 and glial fibrillary acidic protein (GFAP) expression and fluorescent intensity in the brain and spinal cord but more scattered deposition of complement (C9neo). Thus, our studies not only support the pathogenic role of NMO-IgG with complement in NMO disease but also provide a platform for the development of future therapeutics.

Immune Thymic Profile of the MOG-Induced Experimental Autoimmune Encephalomyelitis Mouse Model.

Multiple sclerosis (MS) is a chronic, immune-mediated, demyelinating disease that affects the neurons of the central nervous system. Activated T cells, specific for myelin epitopes, cross the brain barriers, and react against the myelin sheath, leading to demyelination. Since T cells are generated within the thymus, here we explored, in mice, the alterations occurring in this organ throughout the different phases of the disease. We induced experimental autoimmune encephalomyelitis (EAE) in C57BL/6 females and sacrifice them at the onset (day 16) and chronic phases of disease (day 23), along with non-induced controls. We observed thymic atrophy in EAE mice at the onset that remained until the chronic phase of disease. This atrophy was associated with a preferential loss of the CD4+CD8+ double positive thymocytes, an intermediate population between the more immature CD4−CD8− double negative and the most mature single positive thymocytes. This was accompanied by an increase in the thymic medullary/cortical ratio and by an altered expression levels of genes important for T cell survival. During the chronic phase, the thymi remained atrophic, but reacquired the normal proportion of the main four thymocyte populations and the normal medullary/cortical ratio. Importantly, at the onset phase, and accompanying these thymic alterations, EAE animals presented an increased percentage of demyelinating lesion area in the cerebellum, and an increased expression of interferon gamma (Ifng), interleukin (Il) 12a, and Il17a. This study suggests dynamic thymic alterations occurring in response to EAE, from the induction to the chronic phase, that might help to elucidate the MS pathophysiology.

Immunomodulatory effects of a rationally designed peptide mimetic of human IFNβ in EAE model of multiple sclerosis

The efficiency of interferon beta (IFNβ)-based drugs is considerably limited due to their undesirable properties, especially high immunogenicity. In this study, for the first time we investigated the impact of a computationally designed peptide mimetic of IFNβ, called MSPEP27, in the animal model of MS.A peptide library was constructed using the Rosetta program based on the predominant IFNAR1-binding site of IFNβ. Molecular docking studies were carried out using ClusPro and HADDOCK tools. The GROMACS package was subsequently used for molecular dynamics (MD) simulations. Validation of peptide-receptor interaction was carried out using intrinsic fluorescence measurements. To explore in silico findings further, experimental autoimmune encephalomyelitis (EAE) was induced by subcutaneous immunization of myelin oligodendrocyte glycoprotein (MOG35-55). Mice were then separated into distinct groups and intravenously received 10 or 20mgkg−1 of MSPEP27 or IFNβ. The inflammatory mediators were monitored by immunohistochemistry (IL17, CD11b, CD45), quantitative real-time PCR (MMP2, MMP9, TIMP-1) and enzyme-linked immunosorbent assay (IL1β, TNFα) methods.Among the library of tolerated peptides, MSPEP27, a peptide with favorable physicochemical properties, was chosen for further experiments. This peptide was shown to significantly interact with IFNAR1 in a dose-dependent manner. Like IFNβ, MSPEP27 could efficiently bind to IFNAR1 and form a stable peptide-receptor complex during 30ns MD simulations. In vivo analyses revealed that MSPEP27 could lessen inflammation by modulating the levels of inflammatory mediators.According to our results, MSPEP27 peptide could efficiently bind to IFNAR1 and suppress neuroinflammation in vivo. We conclude that MSPEP27 has protective effects against MOG-induced EAE via reduction of immune dysfunction and inflammation.

Erythropoietin reduces experimental autoimmune encephalomyelitis severity via neuroprotective mechanisms

BackgroundTreatment with erythropoietin (Epo) in experimental autoimmune encephalomyelitis (EAE), the rodent model of multiple sclerosis (MS), has consistently been shown to ameliorate disease progression and improve overall outcome. The effect has been attributed to modulation of the immune response and/or preservation of the central nervous system (CNS) tissue integrity. It remains unclear, however, if (a) Epo acts primarily in the CNS or the periphery and if (b) Epo’s beneficial effect in EAE is mainly due to maintaining CNS tissue integrity or to modulation of the immune response. If Epo acts primarily by modulating the immune system, where is this modulation required? In the periphery, the CNS or both?MethodsTo address these questions, we used two well-characterized transgenic mouse strains that constitutively overexpress recombinant human Epo (rhEpo) either systemically (tg6) or in CNS only (tg21) in a MOG-induced EAE model. We assessed clinical severity, disease progression, immunomodulation, and CNS tissue integrity, including neuronal survival.ResultsAlthough disease onset remained unaffected, EAE progression was alleviated in transgenic animals compared to controls with both lines performing equally well showing that expression of Epo in the periphery is not required; Epo expression in the CNS is sufficient. Immunomodulation was observed in both strains but surprisingly the profile of modulation differed substantially between strains. Modulation in the tg21 strain was limited to a reduction in macrophages in the CNS, with no peripheral immunomodulatory effects observed. In contrast, in the tg6 strain, macrophages were upregulated in the CNS, and, in the periphery of this strain, T cells and macrophages were downregulated. The lack of a consistent immunomodulatory profile across both transgenic species suggests that immunomodulation by Epo is unlikely to be the primary mechanism driving amelioration of EAE. Finally, CNS tissue integrity was affected in all strains. Although myelin appeared equally damaged in all strains, neuronal survival was significantly improved in the spinal cord of tg21 mice, indicating that Epo may ameliorate EAE predominantly by protecting neurons.ConclusionsOur data suggests that moderate elevated brain Epo levels provide clinically significant neuroprotection in EAE without modulation of the immune response making a significant contribution.

Essential role for CCR6 in certain inflammatory diseases demonstrated using specific antagonist and knockin mice.

The chemokine receptor CCR6 marks subsets of T cells and innate lymphoid cells that produce IL-17 and IL-22, and as such may play a role in the recruitment of these cells to certain inflammatory sites. However, the precise role of CCR6 has been controversial, in part because no effective monoclonal antibody (mAb) inhibitors against this receptor exist for use in mouse models of inflammation. We circumvented this problem using transgenic mice expressing human CCR6 (hCCR6) under control of its native promoter (hCCR6-Tg/mCCR6-/-). We also developed a fully humanized mAb against hCCR6 with antagonistic activity. The expression pattern of hCCR6 in hCCR6-Tg/mCCR6-/- mice was consistent with the pattern observed in humans. In mouse models of experimental autoimmune encephalomyelitis (EAE) and psoriasis, treatment with anti-hCCR6 mAb was remarkably effective in both preventive and therapeutic regimens. For instance, in the imiquimod model of psoriasis, anti-CCR6 completely abolished all signs of inflammation. Moreover, anti-hCCR6 attenuated clinical symptoms of myelin oligodendrocyte glycoprotein-induced (MOG-induced) EAE and reduced infiltration of inflammatory cells in the central nervous system. CCR6 plays a critical role in Th17 type inflammatory reactions, and CCR6 inhibition may offer an alternative approach for the treatment of these lesions.

Chemokine CCL17 is expressed by dendritic cells in the CNS during experimental autoimmune encephalomyelitis and promotes pathogenesis of disease

The CC chemokine ligand 17 (CCL17) and its cognate CC chemokine receptor 4 (CCR4) are known to control leukocyte migration, maintenance of TH17 cells, and regulatory T cell (Treg) expansion in vivo. In this study we characterized the expression and functional role of CCL17 in the pathogenesis of experimental autoimmune encephalomyelitis (EAE). Using a CCL17/EGFP reporter mouse model, we could show that CCL17 expression in the CNS can be found in a subset of classical dendritic cells (DCs) that immigrate into the CNS during the effector phase of MOG-induced EAE. CCL17 deficient (CCL17−/−) mice exhibited an ameliorated disease course upon MOG-immunization, associated with reduced immigration of IL-17 producing CD4+ T cells and peripheral DCs into the CNS. CCL17−/− DCs further showed equivalent MHC class II and costimulatory molecule expression and an equivalent capacity to secrete IL-23 and induce myelin-reactive TH17 cells when compared to wildtype DCs. In contrast, their transmigration in an in vitro model of the blood-brain barrier was markedly impaired. In addition, peripheral Treg cells were enhanced in CCL17−/− mice at peak of disease pointing towards an immunoregulatory function of CCL17 in EAE. Our study identifies CCL17 as a unique modulator of EAE pathogenesis regulating DC trafficking as well as peripheral Treg cell expansion in EAE. Thus, CCL17 operates at distinct levels and on different cell subsets during immune response in EAE, a property harboring therapeutic potential for the treatment of CNS autoimmunity.

Treatment with a recombinant human IgM that recognizes PSA-NCAM preserves brain pathology in MOG-induced experimental autoimmune encephalomyelitis.

A single peripheral dose of CNS-binding IgMs promote remyelination and preserve axons in a number of animal models of neurologic disease. A myelin-binding recombinant human IgM (rHIgM22) is presently in a safety trial in MS patients following an acute MS exacerbation. rHIgM22 (directed against oligodendrocytes) or rHIgM12 (directed against neurons) were administered to mice with MOG-induced experimental autoimmune encephalomyelitis (EAE) with study endpoints: clinical deficits and brain and spinal cord pathology. IgMs were administered at a therapeutic dose of 100 μ g intra peritoneal at the time of immunization (day -1, 0, +$1), disease onset (15 days) or peak of the disease (28 days). Disease course was not worsened by either human IgM regardless of the time of treatment. Of note, the human IgM that recognizes a carbohydrate epitope on gangliosides and NCAM, rHIgM12, reduced brain pathology when given at time of immunization or at onset of disease, but did not reduce clinical deficits or spinal cord disease burden. Hence, treatment with rHIgM12 resulted in marked reduction in meningeal inflammation. Data consistent with the hypothesis that in the EAE model this molecule has an immune-modulatory effect. Treatment with an anti-CD4 blocking IgG prevented both clinical course and CNS pathology. This pre-clinical study further supports the safety of therapeutic CNS-binding human IgMs in the presence of autoimmunity and clearly differentiates them from IgGs directed against MOG or aquaporin-4 that worsen neurologic disease.

Neutralization of Interleukin-9 Decreasing Mast Cells Infiltration in Experimental Autoimmune Encephalomyelitis.

Background:Th9 cells are a newly discovered CD4+ T helper cell subtype, characterized by high interleukin (IL)-9 secretion. Growing evidences suggest that Th9 cells are involved in the pathogenic mechanism of multiple sclerosis (MS). Mast cells are multifunctional innate immune cells, which are perhaps best known for their role as dominant effector cells in allergies and asthma. Several lines of evidence point to an important role for mast cells in MS and its animal models. Simultaneously, there is dynamic “cross-talk” between Th9 and mast cells. The aim of the present study was to examine the IL-9-mast cell axis in experimental autoimmune encephalomyelitis (EAE) and determine its interaction after neutralizing anti-IL-9 antibody treatment.Methods:Female C57BL/6 mice were randomly divided into three groups (n = 5 in each group): mice with myelin oligodendrocyte glycoprotein (MOG)-induced EAE (EAE group), EAE mice treated with anti-IL-9 antibody (anti-IL-9 Abs group), and EAE mice treated with IgG isotype control (IgG group). EAE clinical score was evaluated. Mast cells from central nervous system (CNS) were detected by flow cytometry. The production of chemokine recruiting mast cells in the CNS was explored by reverse transcription-polymerase chain reaction (RT-PCR). In mice with MOG-induced EAE, the expression of IL-9 receptor (IL-9R) complexes in CNS and spleen mast cells was also explored by RT-PCR, and then was repeating validated by immunocytochemistry. In vitro, spleen cells from EAE mice were cultured with anti-IL-9 antibody, and quantity of mast cells was counted by flow cytometry after co-culture.Results:Compared with IgG group, IL-9 blockade delayed clinical disease onset and ameliorated EAE severity (t = −2.217, P = 0.031), accompany with mast cells infiltration decreases (day 5: t = −8.005, P < 0.001; day 15: t = −11.857, P < 0.001; day 20: t = −5.243, P = 0.001) in anti-IL-9 Abs group. The messenger RNA expressions of C-C motif chemokine ligand 5 (t = −5.932, P = 0.003) and vascular cell adhesion molecule-1 (t = −4.029, P = 0.004) were significantly decreased after IL-9 neutralization in anti-IL-9 Abs group, compared with IgG group. In MOG-induced EAE, the IL-9R complexes were expressed in CNS and spleen mast cells. In vitro, splenocytes cultured with anti-IL-9 antibody showed significantly lower levels of mast cells in a dose-dependent manner, compared with splenocytes cultured with anti-mouse IgG (5 μg/ml: t = −0.894, P = 0.397; 10 μg/ml: t = −3.348, P = 0.019; 20 μg/ml: t = −7.639, P < 0.001).Conclusions:This study revealed that IL-9 neutralization reduced mast cell infiltration in CNS and ameliorated EAE, which might be relate to the interaction between IL-9 and mast cells.

NDR1 protein kinase promotes IL-17- and TNF-α-mediated inflammation by competitively binding TRAF3.

Interleukin 17 (IL-17) is an important inducer of tissue inflammation and is involved in numerous autoimmune diseases. However, how its signal transduction is regulated is not well understood. Here, we report that nuclear Dbf2-related kinase 1 (NDR1) functions as a positive regulator of IL-17 signal transduction and IL-17-induced inflammation. NDR1 deficiency or knockdown inhibits the IL-17-induced phosphorylation of p38, ERK1/2, and p65 and the expression of chemokines and cytokines, whereas the overexpression of NDR1 promotes IL-17-induced signaling independent of its kinase activity. Mechanistically, NDR1 interacts with TRAF3 and prevents its binding to IL-17R, which promotes the formation of an IL-17R-Act1-TRAF6 complex and downstream signaling. Consistent with this, IL-17-induced inflammation is significantly reduced in NDR1-deficient mice, and NDR1 deficiency significantly protects mice from MOG-induced experimental autoimmune encephalomyelitis (EAE) and 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis likely by its inhibition of IL-17-mediated signaling pathway. NDR1 expression is increased in the colons of ulcerative colitis (UC) patients. Taken together, these findings suggest that NDR1 is involved in the development of autoimmune diseases.

UCP2 up-regulation within the course of autoimmune encephalomyelitis correlates with T-lymphocyte activation

Multiple sclerosis (MS) is an inflammatory demyelinating autoimmune disorder of the central nervous system (CNS) associated with severe neurological disability. Reactive oxygen species (ROS) and mitochondrial dysfunction play a pivotal role in the pathogenesis of this disease. Several members of the mitochondrial uncoupling protein subfamily (UCP2–UCP5) were suggested to regulate ROS by diminishing the mitochondrial membrane potential and constitute therefore a promising pharmacological target for MS. To evaluate the role of different uncoupling proteins in neuroinflammation, we have investigated their expression patterns in murine brain and spinal cord (SC) during different stages of experimental autoimmune encephalomyelitis (EAE), an animal model for MS. At mRNA and protein levels we found that only UCP2 is up-regulated in the SC, but not in brain. The increase in UCP2 expression was antigen-independent, reached its maximum between 14 and 21days in both OVA and MOG immunized animals and correlated with an augmented number of CD3+ T-lymphocytes in SC parenchyma. The decrease in abundance of UCP4 was due to neuronal injury and was only detected in CNS of MOG-induced EAE animals. The results provide evidence that the involvement of mitochondrial UCP2 in CNS inflammation during EAE may be mainly explained by the invasion of activated T-lymphocytes. This conclusion coincides with our previous observation that UCP2 is up-regulated in activated and rapidly proliferating T-cells and participates in fast metabolic re-programming of cells during proliferation.

Piperlongumine attenuates experimental autoimmune encephalomyelitis through inhibition of NF-kappaB activity

Multiple sclerosis (MS) is a chronic, autoimmune and neurodegenerative disease in which demyelination sporadically and repeatedly occurs in the central nervous system (CNS). The activity of nuclear factor kappa B (NF-κB), a family of transcription factors, was increased in the cerebrospinal fluid (CSF) and/or the serum and brain and/or spinal cord of MS patients than in a healthy donors. In our study, we investigated whether piperlongumine (PL), which is known to have inhibitory effect on activity of NF-κB, can alleviate an experimental autoimmune encephalomyelitis (EAE). The mice were immunized with myelin oligodendrocyte glycoprotein 35–55 (MOG35–55), and then we injected PL (1.5mg/kg/day or 3.0mg/kg/day) into the mice intraperitoneally on every second day from days 2 to 28. For in vitro study, we treated PL (0.5, 1 and 2.5μM) to RAW 264.7 and Jurkat cells with each stimulator. We observed that the paralytic severity and neuropathology of EAE in PL-treated group were decreased compared with the EAE group. PL showed a suppressed effect on demyelination, immune cells infiltration, astrocytes/microglials activation, level of inflammatory cytokines and proteins as well as NF-κB activity. Production of inflammatory cytokines and proteins as well as translocation of NF-κB into nucleus by treatment stimulators in RAW 264.7 and Jurkat cells were reduced by PL. Moreover, treatment of NF-κB inhibitor further inhibited production of inflammatory cytokines and proteins. These results suggest that PL can mitigate MOG-induced EAE symptoms and activation of macrophages and T cells by inhibiting NF-κB signaling. Therefore, PL could be useful for the treatment for MS.

Neuroendothelial NMDA receptors as therapeutic targets in experimental autoimmune encephalomyelitis.

Multiple sclerosis is among the most common causes of neurological disability in young adults. Here we provide the preclinical proof of concept of the benefit of a novel strategy of treatment for multiple sclerosis targeting neuroendothelial N-methyl-D-aspartate glutamate receptors. We designed a monoclonal antibody against N-methyl-D-aspartate receptors, which targets a regulatory site of the GluN1 subunit of N-methyl-D-aspartate receptor sensitive to the protease tissue plasminogen activator. This antibody reverted the effect of tissue plasminogen activator on N-methyl-D-aspartate receptor function without affecting basal N-methyl-D-aspartate receptor activity (n = 21, P < 0.01). This antibody bound N-methyl-D-aspartate receptors on the luminal surface of neurovascular endothelium in human tissues and in mouse, at the vicinity of tight junctions of the blood-spinal cord barrier. Noteworthy, it reduced human leucocyte transmigration in an in vitro model of the blood-brain barrier (n = 12, P < 0.05). When injected during the effector phase of MOG-induced experimental autoimmune encephalomyelitis (n = 24), it blocked the progression of neurological impairments, reducing cumulative clinical score (P < 0.001) and mean peak score (P < 0.001). This effect was observed in wild-type animals but not in tissue plasminogen activator knock-out animals (n = 10). This therapeutic effect was associated to a preservation of the blood-spinal cord barrier (n = 6, P < 0.001), leading to reduced leucocyte infiltration (n = 6, P < 0.001). Overall, this study unveils a critical function of endothelial N-methyl-D-aspartate receptor in multiple sclerosis, and highlights the therapeutic potential of strategies targeting the protease-regulated site of N-methyl-D-aspartate receptor.

Your nose knows how to target brain inflammation

Your nose knows how to target brain inflammation

Extra-cellular Matrix protein 1 (ECM1) Ameliorates Experimental Autoimmune Encephalomyelitis (EAE) through Inhibition of MMP9 Activity

Abstract Multiple sclerosis (MS) is the most common inflammatory demyelinating disease of the central nervous system (CNS). Experimental autoimmune encephalomyelitis (EAE), an animal model representing human multiple sclerosis (MS), is mainly mediated by Th1 and Th17 cells. Matrix metalloproteinase-9 (MMP9), a zinc bound protease, plays an important role in the invasion or infiltration of pathogenic Th cells into CNS during MS/EAE. In current study, we find that ECM1 could inhibit MMP9 activity through protein/protein interaction in vitro and ameliorate MOG-induced EAE via blocking MMP9-mediated invasion/infiltration of pathogenic Th cells into CNS in vivo. Giving ECM1 protein treatment on the late periods of pathogenic T cell migration in EAE model, the EAE disease is significantly attenuated. This treatment functions by reduction of infiltrating pathogenic Th cells into CNS, but had no impact on Th1/Th17 cell development in the peripheral lymphoid tissues. Our results suggest that ECM1 is potential an inhibitor to treat EAE disease.

CLIC1 regulates dendritic cell antigen processing and presentation by modulating phagosome acidification and proteolysis.

ABSTRACTIntracellular chloride channel protein 1 (CLIC1) participates in inflammatory processes by regulating macrophage phagosomal functions such as pH and proteolysis. Here, we sought to determine if CLIC1 can regulate adaptive immunity by actions on dendritic cells (DCs), the key professional antigen presenting cells. To do this, we first generated bone marrow-derived DCs (BMDCs) from germline CLIC1 gene-deleted (CLIC1−/−) and wild-type (CLIC1+/+) mice, then studied them in vitro and in vivo. We found phagocytosis triggered cytoplasmic CLIC1 translocation to the phagosomal membrane where it regulated phagosomal pH and proteolysis. Phagosomes from CLIC1−/− BMDCs displayed impaired acidification and proteolysis, which could be reproduced if CLIC1+/+, but not CLIC1−/− cells, were treated with IAA94, a CLIC family ion channel blocker. CLIC1−/− BMDC displayed reduced in vitro antigen processing and presentation of full-length myelin oligodendrocyte glycoprotein (MOG) and reduced MOG-induced experimental autoimmune encephalomyelitis. These data suggest that CLIC1 regulates DC phagosomal pH to ensure optimal processing of antigen for presentation to antigen-specific T-cells. Further, they indicate that CLIC1 is a novel therapeutic target to help reduce the adaptive immune response in autoimmune diseases.

EphrinB1 and EphrinB2 regulate T cell chemotaxis and migration in experimental autoimmune encephalomyelitis and multiple sclerosis

T cells are believed to be key effector cells in multiple sclerosis (MS). In this study, we examined the roles of T cell ephrinB1 (EFNB1) and ephrinB2 (EFNB2) in the pathogenesis of experimental autoimmune encephalomyelitis (EAE) and MS. We provide evidence that animals with T cell specific double deletion of EFNB1 and EFNB2 (dKO) have reduced proliferation in response to MOG35–55, defective Th1 and Th17 differentiations and significantly lower scores of MOG-induced EAE. We further demonstrate that dKO T cells are compromised in their ability to migrate into the CNS of EAE animals in vivo and towards multiple chemokines in vitro. Using deletion mutations, we identified a critical 11-aa EFNB1 intracellular domain segment that controls T cell chemotaxis towards CCL21. In humans, EFNB1 and EFNB2 are highly expressed in Th1 and Th17 cells and EFNB1- and EFNB2-expressing T cells are found among immune cell infiltrates in MS lesions. Reverse signaling through EFNB1 and EFNB2 in human Th17 cells enhances their migration through a monolayer of blood brain barrier endothelial cells. Our study demonstrates that expression of EFNB1 and EFNB2 is implicated in Th cell differentiation and migration to inflammatory sites in both EAE and MS.

Salvianolic acid B ameliorates CNS autoimmunity by suppressing Th1 responses

Experimental autoimmune encephalomyelitis (EAE), the animal model of multiple sclerosis (MS), is a Th1 and Th17 cell-mediated CNS autoimmune disease. Therefore, immune regulation is a key target for therapy. Salvianolic acid B (Sal B) is a major water-soluble bioactive component of the famous traditional Chinese medicine Salvia miltiorrhiza, which is notable for its anti-oxidative and anti-inflammatory effects. Thus Sal B, by impairing Th1 or Th17 responses in EAE/MS, might ameliorate the crippling symptoms. Here we show that the intraperitoneal administration of 30mg/kg Sal B daily for 14 days after the onset of MOG-induced EAE in mice effectively reduced its severity. Additionally, Sal B treatment downgraded the infiltration of inflammatory cells, limited astrogliosis and blocked Th1 responses other than that of Th17. These results indicated that Sal B may serve as an effective therapeutic agent for MS/EAE by inhibiting Th1 cell responses.

Arg Deficiency Does not Influence the Course of Myelin Oligodendrocyte Glycoprotein (MOG35-55)-induced Experimental Autoimmune Encephalomyelitis.

Background:Inhibition of Abl kinases has an ameliorating effect on the rodent model for multiple sclerosis, experimental autoimmune encephalomyelitis, and arrests lymphocyte activation. The family of Abl kinases consists of the Abl1/Abl and Abl2/Arg tyrosine kinases. While the Abl kinase has been extensively studied in immune activation, roles for Arg are incompletely characterized. To investigate the role for Arg in experimental autoimmune encephalomyelitis, we studied disease development in Arg−/− mice.Methods:Arg−/− and Arg+/+ mice were generated from breeding of Arg+/− mice on the C57BL/6 background. Mice were immunized with the myelin oligodendrocyte glycoprotein (MOG)35–55 peptide and disease development recorded. Lymphocyte phenotypes of wild type Arg+/+ and Arg−/− mice were studied by in vitro stimulation assays and flow cytometry.Results:The breeding of Arg+/+ and Arg−/− mice showed skewing in the frequency of born Arg−/− mice. Loss of Arg function did not affect development of experimental autoimmune encephalomyelitis, but reduced the number of splenic B-cells in Arg−/− mice following immunization with MOG peptide.Conclusions:Development of MOG-induced experimental autoimmune encephalomyelitis is not dependent on Arg, but Arg plays a role for the number of B cells in immunized mice. This might suggest a novel role for the Arg kinase in B-cell trafficking or regulation. Furthermore, the results suggest that Arg is important for normal embryonic development.

MOG-induced experimental autoimmune encephalomyelitis in the rat species triggers anti-neurofascin antibody response that is genetically regulated.

BackgroundΙn multiple sclerosis (MS), axonal damage leads to permanent neurological disabilities and the spreading of the autoimmune response to axonal antigens is implicated in disease progression. Experimental autoimmune encephalomyelitis (EAE) provides an animal model that mimics MS. Using different EAE models, we investigated the pathophysiological basis of epitope spreading to neurofascin, a protein localized at the node of Ranvier and its regulation by non-MHC genes.MethodsWe used two different EAE models in DA rat; one which is induced with myelin oligodendrocyte glycoprotein (MOG) which leads to disease characterized by profound demyelination, and the second which is induced with myelin basic protein (MBP) peptide 63–88 which results in severe central nervous system (CNS) inflammation but little or no demyelination. We determined anti-neurofascin antibody levels during the course of disease. Furthermore, the anti-neurofascin IgG response was correlated with clinical parameters in 333 (DAxPVG.1AV1) x DA rats on which we performed linkage analysis to determine if epitope spreading to neurofascin was affected by non-MHC genes.ResultsSpreading of the antibody response to neurofascin occurred in demyelinating MOG-induced EAE but not in EAE induced with MBP peptide 63–88. Anti-neurofascin IgG levels correlated with disease severity in (DAxPVG.1AV1) x DA rats, and a genomic region on chromosome 3 was found to influence this response.ConclusionsInter-molecular epitope spreading to neurofascin correlates with disease severity in MOG-EAE is dependent on extensive demyelination and is influenced by non-MHC genes. The findings presented here may shed light on factors involved in the severity of MS and its genetics.Electronic supplementary materialThe online version of this article (doi:10.1186/s12974-015-0417-2) contains supplementary material, which is available to authorized users.