Nov 22, 2017 Last Updated 4:46 PM, Nov 21, 2017

Published by AINI members

RANTES correlates with inflammatory activity and synaptic excitability in multiple sclerosis
Mori et al.
Mult Scler.; October 2016

Background: Alterations of synaptic transmission induced by inflammatory activity have been linked to the pathogenic mechanisms of multiple sclerosis (MS). Regulated upon activation, normal T-cell expressed, and secreted (RANTES) is a pro-inflammatory chemokine involved in MS pathophysiology,
potentially able to regulate glutamate release and plasticity in MS brains, with relevant consequences on the clinical manifestations of the disease.
Objective: To assess the role of RANTES in the regulation of cortical excitability.
Methods: We explored the association of RANTES levels in the cerebrospinal fluid (CSF) of newly diagnosed MS patients with magnetic resonance imaging (MRI) and laboratory measures of inflammatory activity, as well its role in the control of cortical excitability and plasticity explored by means of transcranial magnetic stimulation (TMS), and in hippocampal mouse slices in vitro.
Results: CSF levels of RANTES were remarkably high only in active MS patients and were correlated with the concentrations of interleukin-1β. RANTES levels were associated with TMS measures of cortical synaptic excitability, but not with long-term potentiation (LTP)-like plasticity. Similar findings were
obtained in mouse hippocampal slices in vitro, where we observed that RANTES enhanced basal excitatory synaptic transmission with no effect on LTP.
Conclusion: RANTES correlates with inflammation and synaptic excitability in MS brains.

Keywords: Chemokines, CSF, glutamate, LTP, synaptic plasticity, TMS

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Astrocytes: Key Regulators of Neuroinflammation
Colombo et al.
Trends Immunol.; September 2016

Astrocytes are crucial regulators of innate and adaptive immune responses in the injured central nervous system. Depending on timing and context, astrocyte activity may exacerbate inflammatory reactions and tissue damage, or promote immunosuppression and tissue repair. Recent literature has unveiled key factors and intracellular signaling pathways that govern astrocyte behavior during neuroinflammation. Here we have re-visited in vivo studies on astrocyte signaling in neuroinflammatory models focusing on evidences obtained from the analysis of transgenic mice where distinct genes involved in ligand binding, transcriptional regulation and cell communication have been manipulated in astrocytes. The integration of in vivo observations with in vitro data clarifies precise signaling steps, highlights the crosstalk among pathways and identifies shared effector mechanisms in neuroinflammation.

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Interaction between interleukin-1β and type-1 cannabinoid receptor is involved in anxiety-like behavior in experimental autoimmune encephalomyelitis
Gentile et al.
J Neuroinflammation; September 2016

Background: Mood disorders, including anxiety and depression, are frequently diagnosed in multiple sclerosis (MS) patients, even independently of the disabling symptoms associated with the disease. Anatomical, biochemical, and pharmacological evidence indicates that type-1 cannabinoid receptor (CB1R) is implicated in the control of emotional behavior and is modulated during inflammatory neurodegenerative diseases such as MS and experimental autoimmune encephalomyelitis (EAE).
Methods: We investigated whether CB1R could exert a role in anxiety-like behavior in mice with EAE. We performed behavioral, pharmacological, and electrophysiological experiments to explore the link between central inflammation, mood, and CB1R function in EAE.
Results: We observed that EAE-induced anxiety was associated with the downregulation of CB1R-mediated control of striatal GABA synaptic transmission and was exacerbated in mice lacking CB1R (CB1R-KO mice). Central blockade of interleukin-1β (IL-1β) reversed the anxiety-like phenotype of EAE mice, an effect associated with the concomitant rescue of dopamine (DA)-regulated spontaneous behavior, and DA-CB1R neurotransmission, leading to the rescue of striatal CB1R sensitivity.
Conclusions: Overall, results of the present investigation indicate that synaptic dysfunction linked to CB1R is involved in EAE-related anxiety and motivation-based behavior and contribute to clarify the complex neurobiological mechanisms underlying mood disorders associated to MS.

Keywords: Type-1 cannabinoid receptor, Striatum, Interleukin-1β, Anxiety, Experimental autoimmune encephalomyelitis

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IFNγ orchestrates mesenchymal stem cells plasticity through STAT1, STAT3 and mTOR pathways
Vigo et al.
J Allergy Clin Immunol.; September 2016

BACKGROUND: Mesenchymal stem cells (MSC) display a therapeutic plasticity, due to their ability to modulate immunity, foster tissue repair and differentiate into mesodermal cells. IFNγ has been described to differently affect human and mouse MSC immunomodulation and differentiation, depending on the inflammatory milieu.
OBJECTIVE: We aimed at dissecting the relevant intracellular pathways through which IFNγ affects MSC plasticity and the consequence of their manipulation on MSC functions.
METHODS: Modification of relevant IFNγ-dependent pathways in mouse MSC was carried out in vitro through gene silencing or chemical inhibition of key components. Functional outcomes were assessed by western blotting, real-time PCR, differentiation and proliferation assays on MSC. The impact on T cells was addressed by T-cell proliferation assays; the effect of mTOR manipulation in MSC was studied in vivo in a mouse model of delayed-type hypersensitivity assay (DTH). To address whether similar mechanisms are involved also in human MSC upon IFNγ stimulation, the effect of chemical inhibition on the same intracellular pathways was assessed by western blotting and the final outcome on immunomodulatory properties evaluated by real-time PCR and on T-cell proliferation.
RESULTS: We revealed that, in mouse MSC, IFNγ-induced immunoregulation is mediated by an early phosphorylation of STAT1 and STAT3, significantly enhanced by an ERK1/2-dependent mTOR inhibition, thereby promoting pSTAT1 nuclear translocation. Accordingly, following intracellular mTOR inhibition, MSC augmented their ability to inhibit T cell proliferation and control DTH in vivo. Similarly, upon mTOR blockade, human MSC also enhanced their immunoregulatory features. A sustained exposure to IFNγ lead to inhibition of STAT3 activity, which, in mouse MSC resulted in an impaired proliferation and differentiation.
CONCLUSION: These results provide new insights about MSC intracellular pathways affected by IFNγ, demonstrating that pharmacological or genetic manipulation of MSC may enhance their immunomodulatory functions, which could be translated into novel therapeutic approaches.

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Siponimod (BAF312) prevents synaptic neurodegeneration in experimental multiple sclerosis.
Gentile et al.
J Neuroinflammation.; August 2016

BACKGROUND: Data from multiple sclerosis (MS) and the MS rodent model, experimental autoimmune encephalomyelitis (EAE), highlighted an inflammation-dependent synaptopathy at the basis of the neurodegenerative damage causing irreversible disability in these disorders. This synaptopathy is characterized by an imbalance between glutamatergic and GABAergic transmission and has been proposed to be a potential therapeutic target. Siponimod (BAF312), a selective sphingosine 1-phosphate1,5 receptor modulator, is currently under investigation in a clinical trial in secondary progressive MS patients. We investigated whether siponimod, in addition to its peripheral immune modulation, may exert direct neuroprotective effects in the central nervous system (CNS) of mice with chronic progressive EAE.
METHODS: Minipumps allowing continuous intracerebroventricular (icv) infusion of siponimod for 4 weeks were implanted into C57BL/6 mice subjected to MOG35-55-induced EAE. Electrophysiology, immunohistochemistry, western blot, qPCR experiments, and peripheral lymphocyte counts were performed. In addition, the effect of siponimod on activated microglia was assessed in vitro to confirm the direct effect of the drug on CNS-resident immune cells.
RESULTS: Siponimod administration (0.45 μg/day) induced a significant beneficial effect on EAE clinical scores with minimal effect on peripheral lymphocyte counts. Siponimod rescued defective GABAergic transmission in the striatum of EAE, without correcting the EAE-induced alterations of glutamatergic transmission. We observed a significant attenuation of astrogliosis and microgliosis together with reduced lymphocyte infiltration in the striatum of EAE mice treated with siponimod. Interestingly, siponimod reduced the release of IL-6 and RANTES from activated microglial cells in vitro, which might explain the reduced lymphocyte infiltration. Furthermore, the loss of parvalbumin-positive (PV+) GABAergic interneurons typical of EAE brains was rescued by siponimod treatment, providing a plausible explanation of the selective effects of this drug on inhibitory synaptic transmission.
CONCLUSIONS: Altogether, our results show that siponimod has neuroprotective effects in the CNS of EAE mice, which are likely independent of its peripheral immune effect, suggesting that this drug could be effective in limiting neurodegenerative pathological processes in MS

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Dysregulation of regulatory CD56bright NK cells/T cells interactions in multiple sclerosis
Laroni et al.
J Autoimm.; August 2016

Recent evidence has shown that CD56bright NK cells, a subset of NK cells abundant in lymph nodes, may have an immunoregulatory function. In multiple sclerosis (MS), expansion of CD56bright NK cells has been associated to successful response to different treatments and to remission of disease during pregnancy; how whether they exert immunoregulation in physiologic conditions and whether this is impaired in MS is not known.We dissected the  immunoregulatory role of CD56bright NK cells function in healthy subjects (HS) and compared it with that of untreated MS subjects or patients with clinically isolated syndrome suggestive of MS (CIS). We found that CD56bright NK cells from HS acquire, upon inflammatory cues, the capability of suppressing autologous CD4þT cell proliferation through direct cytotoxicity requiring engagement of natural cytotoxicity receptors (NCRs) and secretion of granzyme B. CD56bright NK cells from patients with MS/CIS did not differ in frequency and share a similar phenotype but displayed a significantly lower ability to inhibit autologous T cell proliferation. This impairment was not related to deficient expression of NCRs or granzyme B by CD56bright NK cells, but to increased HLA-E expression on T cells from MS/CIS subjects, which could enhance the inhibitory effect mediated by NKG2A that is homogeneously expressed on CD56bright NK cells. The defect in controlling autologous T cells by CD56bright NK cells in MS/CIS might contribute to the excess of autoimmune response that is associated to disease development.

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Histamine Regulates Actin Cytoskeleton in Human Toll-like Receptor 4-activated Monocyte-derived Dendritic Cells Tuning CD4 T Lymphocyte Response
Aldinucci et al.
J Biol Chem; July 2016

Histamine, a major mediator in allergic diseases, differentially regulates the polarizing ability of dendritic cells after Tolllike receptor (TLR) stimulation, by not completely explained mechanisms. In this study we investigated the effects of histamine on innate immune reaction during the response of human monocyte-derived DCs (mDCs) to different TLR stimuli: LPS, specific for TLR4, and Pam3Cys, specific for heterodimer molecule TLR1/TLR2. We investigated actin remodeling induced by histamine together with mDCs phenotype, cytokine production, and the stimulatory and polarizing ability of Th0. By confocal microscopy and RT-PCR expression of Rac1/CdC42 Rho GTPases, responsible for actin remodeling, we show that histamine selectively modifies actin cytoskeleton organization induced by TLR4, but not TLR2 and this correlates with increased IL4 production and decreased IFN by primedTcells. We also demonstrate that histamine-induced cytoskeleton organization is at least in part mediated by down-regulation of small Rho GTPase CdC42 and the protein target PAK1, but not by down-regulation of Rac1. The presence and relative expression of histamine receptors HR1–4 and TLRs were determined as well. Independently of actin remodeling, histamine downregulates IL12p70 and CXCL10 production in mDCs after TLR2 and TLR4 stimulation.Wealso observed a trend of IL10 up-regulation that, despite previous reports, did not reach statistical significance.

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NG2, a common denominator for neuroinflammation, blood–brain barrier alteration, and oligodendrocyte precursor response in EAE, plays a role in dendritic cell activation
Ferarra et al.
Acta Neuropathol; July 2016

In adult CNS, nerve/glial-antigen 2 (NG2) is expressed by oligodendrocyte progenitor cells (OPCs) and is an early marker of pericyte activation in pathological conditions. NG2 could, therefore, play a role in experimental autoimmune encephalomyelitis (EAE), a disease associated with increased blood–brain barrier (BBB) permeability, inflammatory infiltrates, and CNS damage. We induced EAE in NG2 knock-out (NG2KO) mice and used laser confocal microscopy immunofluorescence and morphometry to dissect the effect of NG2 KO on CNS pathology. NG2KO mice developed milder EAE than their wild-type (WT) counterparts, with less intense neuropathology associated with a significant improvement in BBB stability. In contrast to WT mice, OPC numbers
did not change in NG2KO mice during EAE. Through FACS and confocal microscopy, we found that NG2 was also expressed by immune cells, including T cells, macrophages, and dendritic cells (DCs). Assessment of recall T cell responses to the encephalitogen by proliferation assays and ELISA showed that, while WT and NG2KO T cells proliferated equally to the encephalitogenic peptide MOG35-55, NG2KO T cells were skewed towards a Th2- type response. Because DCs could be responsible for this effect, we assessed their expression of IL-12 by PCR and intracellular FACS. IL-12-expressing CD11c+ cells were
significantly decreased in MOG35-55-primed NG2KO lymph node cells. Importantly, in WT mice, the proportion of IL-12-expressing cells was significantly lower in CD11c+ NG2- cells than in CD11c+ NG2+ cells. To assess the relevance of NG2 at immune system and CNS levels, we induced EAE in bone- marrow chimeric mice, generated with WT recipients of NG2KO bone marrow cells and vice versa. Regardless of their original phenotype, mice receiving NG2KO bone marrow developed milder EAE than those receiving WT bone marrow. Our data suggest that NG2 plays a role in EAE not only at CNS/BBB level, but also at immune response level, impacting on DC activation and thereby their stimulation of reactive T cells, through controlling IL-12 expression.

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Toll-like receptor 2 Mediates In Vivo Pro- and anti-inflammatory effects of Mycobacterium Tuberculosis and Modulates autoimmune encephalomyelitis
Piermattei et al.
Front Immunol.; May 2016

Mycobacteria display pro- and anti-inflammatory effects in human and experimental pathology. We show here that both effects are mediated by Toll-like receptor 2 (Tlr2), by exploiting a previously characterized Tlr2 variant (Met82Ile). Tlr2 82ile promoted self-specific proinflammatory polarization as well as expansion of ag-specific FoxP3+ Tregs, while Tlr2 82met impairs the expansion of Tregs and reduces the production of IFN-γ and IL-17 proinflammatory cytokines. Preferential dimerization with Tlr1 or Tlr6 could not explain these differences. In silico, we showed that Tlr2 variant Met82Ile modified the binding pocket for peptidoglycans and participated directly to a putative binding pocket for sugars and cadherins. The distinct pro- and anti-inflammatory actions impacted severity, extent of remission, and distribution of the lesions within the central nervous system of experimental autoimmune encephalomyelitis. Thus, Tlr2 has a janus function in vivo as mediator of the role of bacterial products in balancing pro- and anti-inflammatory immune responses.

Keywords: TLR2, EAE/MS, host–pathogen interactions, inflammation, Foxp3

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Animal models of myasthenia gravis: utility and limitations.
Mantegazza et al.
Int J Gen Med; March 2016

Abstract: Myasthenia gravis (MG) is a chronic autoimmune disease caused by the immune attack of the neuromuscular junction. Antibodies directed against the acetylcholine receptor (AChR) induce receptor degradation, complement cascade activation, and postsynaptic membrane destruction, resulting in functional reduction in AChR availability. Besides anti-AChR antibodies, other autoantibodies are known to play pathogenic roles in MG. The experimental autoimmune MG (EAMG) models have been of great help over the years in understanding the pathophysiological role of specific autoantibodies and T helper lymphocytes and in suggesting new therapies for prevention and modulation of the ongoing disease. EAMG can be induced in mice and rats of susceptible strains that show clinical symptoms mimicking the human disease. EAMG models are helpful for studying both the muscle and the immune compartments to evaluate new treatment perspectives. In this review, we concentrate on recent findings on EAMG models, focusing on their utility and limitations.
Keywords: myasthenia gravis, autoimmunity, neuroimmunology, AChR

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Cerebrospinal fluid lactate is associated with multiple sclerosis disease progression
Albanese et al.
J Neuroinflammation.; February 2016

Background: Altered cerebrospinal fluid (CSF) levels of lactate have been described in neurodegenerative diseases and related to mitochondrial dysfunction and neuronal degeneration. We investigated the relationship between CSF lactate levels, disease severity, and biomarkers associated with neuroaxonal damage in patients with multiple sclerosis (MS).
Methods: One-hundred eighteen subjects with relapsing-remitting multiple sclerosis (RRMS) were included, along with one-hundred fifty seven matched controls. CSF levels of lactate, tau protein, and neurofilament light were detected at the time of diagnosis. Patients were followed-up for a mean of 5 years. Progression index (PI), multiple sclerosis severity scale (MSSS), and Bayesian risk estimate for multiple sclerosis (BREMS) were assessed as clinical measures of disease severity and progression. Differences between groups and correlation between CSF lactate, disease severity and CSF biomarkers of neuronal damage were explored.
Results: CSF lactate was higher in RRMS patients compared to controls. A negative correlation was found between lactate levels and disease duration. Patients with higher CSF lactate concentration had significantly higher PI, MSSS, and BREMS scores at long-term follow-up. Furthermore, CSF lactate correlated positively and significantly with CSF levels of both tau protein and neurofilament light protein.
Conclusions: Measurement of CSF lactate may be helpful, in conjunction with other biomarkers of tissue damage, as an early predictor of disease severity in RRMS patients. A better understanding of the alterations of mitochondrial metabolic pathways associated to RRMS severity may pave the way to new therapeutic targets to contrast axonal damage and disease severity.

Keywords: CSF, EDSS, Inflammation, Mitochondrial damage, MS, Neurofilaments, Neurodegeneration, Tau protein

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The immune response in the CNS in Theiler’s virus induced demyelinating disease switches from an early adaptive response to a chronic innate-like response
Gilli et al.
J. Neurovirol.; February 2016
 
Theiler’s murine encephalomyelitis virus-induced demyelinating disease (TMEV-IDD) is an important model of the progressive disability caused by irreversible CNS tissue injury, and provides an example of how a CNS pathogen can cause inflammation, demyelination, and neuronal damage. We were interested in which molecules, especially inflammatory mediators, might be upregulated in the CNS throughout TMEV-IDD. We quantitated by a real-time RT-PCR multigene system the expression of a pathway-focused panel of genes at 30 and 165 days post infection, characterizing both the early inflammatory and the late neurodegenerative stages of TMEV-IDD. Also, we measured 32 cytokines/chemokines by multiplex Luminex analysis in CSF specimens from early and late TMEV-IDD as well as sham-treated mice. Results indicate that, in the later stage of TMEV-IDD, activation of the innate immune response is most prominent: TLRs, type I IFN response genes, and innate immunity-associated cytokines were highly expressed in late TMEV-IDD compared to sham (p≤0.0001) and early TMEV-IDD (p<0.05). Conversely, several molecular mediators of adaptive immune response were highly expressed in early TMEV-IDD (all p≤0.001). Protein detection in the CSF was broadly concordant with mRNA abundance of the corresponding gene measured by real-time RT-PCR in the spinal cord, since several cytokines/ chemokines were increased in the CSF of TMEV-IDD mice. Results show a clear shift from adaptive to innate immunity from early to late TMEV-IDD, indicating that adaptive and innate immune pathways are likely involved in the development and progression of the disease to different extents. CSF provides an optimal source of biomarkers of CNS neuroinflammation.

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Cerebrospinal fluid soluble TREM2 is higher in Alzheimer disease and associated with mutation status
Piccio et al.
Acta Neuropathol; January 2016
 
Low frequency coding variants in TREM2 are associated with increased Alzheimer disease (AD) risk, while loss of functions mutations in the gene lead to an autosomal recessive early-onset dementia, named Nasu- Hakola disease (NHD). TREM2 can be detected as a soluble protein in cerebrospinal fluid (CSF) and plasma, and its CSF levels are elevated in inflammatory CNS diseases. We measured soluble TREM2 (sTREM2) in the CSF of a large AD case–control dataset (n = 180) and 40 TREM2 risk variant carriers to determine whether CSF sTREM2 levels are associated with AD status or mutation status. We also performed genetic studies to identify genetic variants associated with CSF sTREM2 levels. CSF, but not plasma, sTREM2 was highly correlated with CSF total tau and phosphorylated-tau levels (r = 0.35, P < 1×10−4; r = 0.40, P < 1×10−4, respectively), but not with CSF Aβ42. AD cases presented higher CSF sTREM2 levels than controls (P = 0.01). Carriers of NHD-associated TREM2 variants presented significantly lower CSF sTREM2 levels, supporting the hypothesis that these mutations lead to reduced protein production/function (R136Q, D87N, Q33X or T66M; P = 1×10−3). In contrast, CSF sTREM2 levels were significantly higher in R47H carriers compared to non-carriers (P = 6×10−3), suggesting that this variant does not impact protein expression and increases AD risk through a different pathogenic mechanism than NHD variants. In GWAS analyses for CSF sTREM2 levels the most significant signal was located on the MS4A gene locus (P = 5.45 × 10−07) corresponding to one of the SNPs reported to be associated with AD risk in this locus. Furthermore, SNPs involved in pathways related to virus cellular entry and vesicular trafficking were overrepresented, suggesting that CSF sTREM2 levels could be an informative phenotype for AD.

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Immunometabolic biomarkers of inflammation in Behçet’s disease: relationship with epidemiological profile, disease activity and therapeutic regimes
Cantarini et al.
Clinical Experimental Immunology; January 2016
 
Behcet's disease (BD) is a systemic inflammatory disease with a still unclear pathogenesis. Although several inflammatory molecules have been studied current biomarkers are largely insensitive in BD and unable to predict disease progression and response to treatment. Our primary aim was to explore serum levels of soluble CD40 L (sCD40L), soluble intracellular adhesion molecule (sICAM-1), monocyte chemoattractant protein-1 (MCP-1), myeloperoxidase (MPO), leptin, resistin, osteoprotegerin (OPG), soluble type 1 tumour necrosis factor receptor (sTNFR) and interleukin 6 (IL-6) and SAA serum concentration in a cohort of 27 BD patients. The secondary aim was to evaluate potential correlations between the putative circulating biomarkers, demographic profile of patients, the status of disease activity, the specific organ involvement at the time of sample collection and different therapeutic regimes. Serum concentrations of sTNFR (p=0.008), leptin (p=0.0011), sCD40L (<0.0001), and IL-6 (p=0.0154), were significantly higher in BD patients than in HC, while no difference was found in MCP-1, MPO and resistin serum levels. Moreover, we observed significantly higher sTNFR serum concentrations in BD patients presenting inactive disease than HC (p=0.0108). A correlation between sTNFR and age was also found, with higher levels in patients over 40 years than HC (p=0.0329). Although further research is warranted to elucidate the role of circulating biomarkers, some of that may contribute to the understanding of the physiopathology processes underlying BD activity and damage as well as to provide useful tools for prognostic purposes and a personalized treatment approach.

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Advances in T Helper 17 Cell Biology: Pathogenic Role and Potential Therapy in Multiple Sclerosis
Volpe et al.
Mediators of Inflammation; December 2015
 
The discovery of the T helper (Th) 17 lineage, involved in the protection against fungal and extracellular bacterial infections, has profoundly revolutionized our current understanding of T cell-mediated responses in autoimmune diseases, including multiple sclerosis (MS). Indeed, recent data demonstrate the pathogenic role of Th17 cells in autoimmune disorders. In particular, studies in MS and in its animal model (EAE, experimental autoimmune encephalomyelitis) have revealed a crucial role of Th17 cells in the pathogenesis of autoimmune demyelinating diseases in both mice and humans. Over the past years, several important aspects concerning Th17 cells have been elucidated, such as the factors which promote or inhibit their differentiation and the effector cytokines which mediate their responses.The identification of the features endowing Th17 cells with high pathogenicity inMS is of particular interest, and discoveries inTh17 cell biology and function could lead to the design of new strategies aimed at modulating the immune response inMS.Here, we will discuss recent advances in this field, with particular focus on themechanisms conferring pathogenicity in MS and their potential modulation.

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Synaptopathy connects inflammation and neurodegeneration in multiple sclerosis
Mandolesi et al.
Nat Rev Neurol.; December 2015

Multiple sclerosis (MS) has long been regarded as a chronic inflammatory disease of the white matter that leads to demyelination and eventually to neurodegeneration. In the past decade, several aspects of MS pathogenesis have been challenged, and degenerative changes of the grey matter, which are independent of demyelination, have become a topic of interest. CNS inflammation in MS and experimental autoimmune encephalomyelitis (EAE; a disease model used to study MS in rodents) causes a marked imbalance between GABAergic and glutamatergic transmission, and a loss of synapses, all of which leads to a diffuse ‘synaptopathy’. Altered synaptic transmission can occur early in MS and EAE, independently of demyelination and axonal loss, and subsequently causes excitotoxic damage. Inflammation-driven synaptic abnormalities are emerging as a prominent pathogenic mechanism in MS—importantly, they are potentially reversible and, therefore, represent attractive therapeutic targets. In this Review, we focus on the connection between inflammation and synaptopathy in MS and EAE, which sheds light not only on the pathophysiology of MS but also on that of primary neurodegenerative disorders in which inflammatory processes contribute to disease progression.

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The effect of B-cell depletion in the Theiler's model of multiple sclerosis
Gilli et al.
Journal of the Neurological Sciences; December 2015
 
B cell depletion (BCD) is being considered as a treatment for multiple sclerosis (MS), but there are many uncertainties surrounding the use of this therapy, such as its potential effect in individuals with concurrent viral infections. We sought to discover what effect BCD, induced by an anti-CD20 monoclonal antibody, would have on Theiler's murine encephalomyelitis virus-induced demyelinating disease (TMEV-IDD). Mice were injected with the anti-CD20 monoclonal antibody 5D2, 14 days before or 14 days after infection with TMEV. Efficacy of depletion of B cells was assessed by flow cytometry of CD19+ cells. Mouse disability was measured by Rotarod, viral load was measured by real time PCR for TMEV RNA. Binding and neutralizing antibody levels were determined in sera and CSF by ELISA, and in CNS by real time PCR for IgG RNA. Inflammation, microglial activation, axonal damage and demyelination were assessed using immunohistochemistry. 5D2-induced BCD was confirmed by demonstration of nearly absent CD19+ cells in the blood and lymphoid tissue. Systemic and CNS antibody responses were suppressed during 5D2 treatment. Higher viral loads were detected in 5D2-treated mice than in controls, and the viral levels correlated negatively with IgG production in the brain. Overall, 5D2 caused worsening of the early encephalitis and faster progression of disability, as well as exacerbation of the pathology of TMEV-IDD at the end stage of the disease. These data indicate that BCD in humans might worsen CNS viral infections and might not improve disability accrual in MS.

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Progressive MS: from pathophysiology to drug discovery
Salvetti et al.
Mult Scler.; October 2015

Progressive multiple sclerosis (MS) will be a major area of research interest for years to come. No treatments exist and success in the field will generalise to other neurological conditions where neurodegeneration coexists with neuroinflammation. The issue is complex, and interdisciplinary approaches– uniting scientists with different competences (neurobiology, immunogenetics, etc.) and ‘mindsets’ (academia and industry) – will be decisive. The International Progressive MS Alliance is catalysing this process through various initiatives, the most recent of which was a meeting where scientists from academia (also outside the MS field) and from industry reviewed data and strategies to determine the next steps towards the translation of current knowledge into effective therapies.

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Glycolysis controls the induction of human regulatory T cells by modulating the expression of FOXP3 exon 2 splicing variants
De Rosa et al.
Nature Immunology; November 2015
 
Human regulatory T cells (Treg cells) that develop from conventional T cells (Tconv cells) following suboptimal stimulation via the T cell antigen receptor (TCR) (induced Treg cells ( iTreg cells)) express the transcription factor Foxp3, are suppressive, and display an active proliferative and metabolic state. Here we found that the induction and suppressive function of iTreg cells tightly depended on glycolysis, which controlled Foxpoxpoxp3 splicing variants containing exon 2 (Foxp3-E2) through the glycolytic enzyme enolase-1. The Foxp3-E2–related suppressive activity of iTreg cells was altered in human autoimmune diseases, including multiple sclerosis and type 1 diabetes, and was associated with impaired glycolysis and signaling via interleukin 2. This link between glycolysis and Foxp3-E2 variants via enolase-1 shows a previously unknown mechanism for controlling the induction and function of Treg cells in health and in autoimmunity.

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Myeloid cells as target of fingolimod action in multiple sclerosis
Di Dario et al.
Neurology: Neuroimmunology & Neuroinflammation; November 2015
 
Objective
To track the effects of fingolimod, an approved drug for multiple sclerosis (MS), on the activation of myeloid cells from the periphery to the CNS.
Methods
In vitro and ex vivo immunologic studies coupled with flow cytometry were performed to evaluate the action of fingolimod on lipopolysaccharide (LPS)–induced expression of activation markers in human monocytes from healthy participants, participants with untreated MS, and participants with fingolimod-treated MS. In vivo administration of fingolimod during experimental autoimmune encephalomyelitis (EAE) was established to verify the activation state of splenic, CNS infiltrating, and CNS resident myeloid cells ex vivo at flow cytometer.
Results
We found that in vitro exposure of human monocytes to fingolimod inhibited LPS-induced CD25 and CD150 expression and tumor necrosis factor–a (TNF-a) secretion without altering immune cell survival. Further, EAE treatment with fingolimod led to reduced amounts of TNF-a produced by myeloid cells in vivo in the spleen and CNS. Finally, while displaying normal induction of CD25 and CD150 levels at high LPS concentration, monocytes from patients with fingolimodtreated MS showed significantly higher activation threshold at suboptimal LPS stimulation than controls.
Conclusions
The inhibition of myeloid cell activation may be part of the immunosuppressive action of fingolimod and take place in the periphery and in the CNS.

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Impact of Mycobacterium tuberculosis RD1-locus on human primary dendritic cell immune functions
Etna et al.
Scientific Reports; November 2015
 
Modern strategies to develop vaccines against Mycobacterium tuberculosis (Mtb) aim to improve the current Bacillus Calmette-Guerin (BCG) vaccine or to attenuate the virulence of Mtb vaccine candidates. In the present study, the impact of wild type or mutated region of difference 1 (RD1) variants on the immunogenicity of Mtb and BCG recombinants was investigated in human primary dendritic cells (DC). A comparative analysis of transcriptome, signalling pathway activation, maturation, apoptosis, cytokine production and capacity to promote Th1 responses demonstrated that DC sense quantitative and qualitative differences in the expression of RD1-encoded factors— ESAT6 and CFP10—within BCG or Mtb backgrounds. Expansion of IFN-γ producing T cells was promoted by BCG::RD1-challenged DC, as compared to their BCG-infected counterparts. Although Mtb recombinants acted as a strong Th-1 promoting stimulus, even with RD1 deletion, the attenuated Mtb strain carrying a C-terminus truncated ESAT-6 elicited a robust Th1 promoting phenotype in DC. Collectively, these studies indicate a necessary but not sufficient role for the RD1 locus in promoting DC immune-regulatory functions. Additional mycobacterial factors are likely required to endow DC with a high Th1 polarizing capacity, a desirable attribute for a successful control of Mtb infection.

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Patient and parent preferences for characteristics of prophylactic treatment in hemophilia
Furlan et al.
Dovepress; November 2015
 
Introduction
New longer-acting factor products will potentially allow for less frequent infusion in prophylactic treatment of hemophilia. However, the role of administration frequency relative to other treatment attributes in determining preferences for prophylactic hemophilia treatment regimens is not well understood.
Aim
To identify the relative importance of frequency of administration, efficacy, and other treatment characteristics among candidates for prophylactic treatment for hemophilia A and B.
Method
An Internet survey was conducted among hemophilia patients and the parents of pediatric hemophilia patients in Australia, Canada, and the US. A monadic conjoint task was included in the survey, which varied frequency of administration (three, two, or one time per week for hemophilia A; twice weekly, weekly, or biweekly for hemophilia B), efficacy (no bleeding or breakthrough bleeding once every 4 months, 6 months, or 12 months), diluent volume (3 mL vs 2.5 mL for hemophilia A; 5 mL vs 3 mL for hemophilia B), vials per infusion (2 vs 1), reconstitution device (assembly required vs not), and manufacturer (established in hemophilia vs not). Respondents were asked their likelihood to switch from their current regimen to the presented treatment. Respondents were told to assume that other aspects of treatment, such as risk of inhibitor development, cost, and method of distribution, would remain the same.
Results
A total of 89 patients and/or parents of children with hemophilia A participated; another 32 were included in the exercise for hemophilia B. Relative importance was 47%, 24%, and 18% for frequency of administration, efficacy, and manufacturer, respectively, in hemophilia A; analogous values were 48%, 26%, and 21% in hemophilia B. The remaining attributes had little impact on preferences.
Conclusion
Patients who are candidates for prophylaxis and their caregivers indicate a preference for reduced frequency of administration and high efficacy, but preferences were more sensitive to administration frequency than small changes in annual bleeding rate.

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Differential impact of high and low penetrance TNFRSF1A gene mutations on conventional and regulatory CD4+ T cell functions in TNFR1-associated periodic syndrome
Pucino et al.
JLB; November 2015
 
TNFR-associated periodic syndrome is an autoinflammatory disorder caused by autosomal-dominant mutations in TNFRSF1A, the gene encoding for TNFR superfamily 1A. The lack of knowledge in the field of TNFR-associated periodic syndrome biology is clear, particularly in the context of control of immune selftolerance. We investigated how TNF-a/TNFR superfamily 1A signaling can affect T cell biology, focusing on conventional CD4+CD252 and regulatory CD4+CD25+ T cell functions in patients with TNFR-associated periodic syndrome carrying either high or low penetrance TNFRSF1A mutations. Specifically, we observed that in high penetrance TNFR-associated periodic syndrome, at the molecular level, these alterations were secondary to a hyperactivation of the ERK1/2, STAT1/3/5, mammalian target of rapamycin, and NF-kB pathways in conventional T cells. In addition, these patients had a lower frequency of peripheral regulatory T cells, which also displayed a defective suppressive phenotype. These alterations were partially found in low penetrance TNFRassociated periodic syndrome, suggesting a specific link between the penetrance of the TNFRSF1A mutation and the observed T cell phenotype. Taken together, our data envision a novel role for adaptive immunity in the pathogenesis of TNFR-associated periodic syndrome involving both CD4+ conventional T cells and Tregs, suggesting a novel mechanism of inflammation in the context of autoinflammatory disorders.

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Dimethyl fumarate selectively reduces memory T cells in multiple sclerosis patients
Longbrake et al.
MSJ; October 2015
 
Background
Dimethyl fumarate (DMF) alters the phenotype of circulating immune cells and causes lymphopenia in a subpopulation of treated multiple sclerosis (MS) patients.
Objective
To phenotypically characterize circulating leukocytes in DMF-treated MS patients.
Methods
Cross-sectional observational comparisons of peripheral blood from DMF-treated MS patients (n = 17 lymphopenic and n = 24 non-lymphopenic), untreated MS patients (n = 17) and healthy controls (n = 23); immunophenotyped using flow cytometry. Longitudinal samples were analyzed for 13 DMF-treated patients.
Results
Lymphopenic DMF-treated patients had significantly fewer circulating CD8+ and CD4+ T cells, CD56dim natural killer (NK) cells, CD19+ B cells and plasmacytoid dendritic cells when compared to controls. CXCR3+ and CCR6+ expression was disproportionately reduced among CD4+ T cells, while the proportion of T-regulatory (T-reg) cells was unchanged. DMF did not affect circulating CD56hi NK cells, monocytes or myeloid dendritic cells. Whether lymphopenic or not, DMF-treated patients had a lower proportion of circulating central and effector memory T cells and concomitant expansion of naïve T cells compared to the controls.
Conclusions
DMF shifts the immunophenotypes of circulating T cells, causing a reduction of memory cells and a relative expansion of naïve cells, regardless of the absolute lymphocyte count. This may represent one mechanism of action of the drug. Lymphopenic patients had a disproportionate loss of CD8+ T-cells, which may affect their immunocompetence.

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Influence of dopamine receptor gene polymorphisms on circulating T lymphocytes: A pilot study in healthy subjects
Cosentino et al.
Human Immunology; October 2015
 
Dopamine is a key transmitter in the neuroimmune network, acting through five dopaminergic receptors (DR): the D1-like D1 and D5 and the D2-like D2, D3 and D4. Several DR gene variants exist and may affect DR expression and activity. We assessed total lymphocytes, CD3+, CD4+ and CD8+ T lymphocytes in peripheral blood of healthy subjects and their association with selected DR gene variants (DRD1 rs4532 and rs686, DRD5 rs6283, DRD2 rs1800497 and rs6277, DRD3 rs6280 and rs1800828, DRD4 rs747302 and 7 48-base pair VNTR). DRD1 rs4532 and rs686 and DRD5 rs6283 were associated with total lymphocytes, and with CD3+ and CD4+ (but not CD8+) T lymphocytes, while none of the D2-like DR gene variants showed any association with lymphocyte counts. An arbitrary score based on the activity of D1- like vs D2-like DR correlated with total lymphocytes, CD3+ and CD4+ T cells (but not with CD8+ T cells). The association between D1-like DR gene variants and lymphocyte count, and in particular with CD4+ (but not CD8+) T lymphocytes, may imply a functional prevalence of D1-like over D2-like DR in CD4+ T cells. This is the first study showing an influence of DR gene polymorphisms on lymphocyte count, and in particular on CD4+ T cells. Future studies should address the possible association between DR gene variants and the immune function in health and disease. The relevance of these findings for the immune effects of dopaminergic agents should be also carefully examined.

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Nutritional control of immunity: Balancing the metabolic requirements with an appropriate immune function
De Rosa et al.
Semin Immunol.; September 2015

The immune system is a highly integrated network of cells sensitive to a number of environmental factors. Interestingly, recent years have seen a dramatic increase in our understanding of how diet makes a crucial contribution to human health, affecting the immune system, secretion of adipocytokines and metabolic pathways. Recent experimental evidence indicates that diet and its components are able to profoundly influence immune responses, thus affecting the development of inflammatory and autoimmune diseases. This review aims to discuss some of the main topics concerning the impact of nutrients and their relative composition on immune cell development and function that may be particularly important for regulating the balance between inflammatory and tolerogenic processes. We also highlight the effects of diet on commensal bacteria and how changes in the composition of the microbiota alter intestinal and systemic immune homeostasis. Finally, we summarize the effects of dietary compounds on epigenetic mechanisms involved in the regulation of several immune related genes.

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IFN-b Therapy Regulates TLR7-Mediated Response in Plasmacytoid Dendritic Cells of Multiple Sclerosis Patients Influencing an Anti-Inflammatory Status
Severa et al.
Journal of interferon & Cytokine research.; September 2015
 
Plasmacytoid dendritic cells (pDCs) display altered immune-phenotype in multiple sclerosis (MS) patients and are found actively recruited in postmortem MS brain lesions, implying that their immune regulation may represent an important aspect of MS pathogenesis. Because of the reported Toll-like receptor 7 (TLR7) implication in autoimmunity, in this study we characterized how IFN-b therapy impacts on pDC activation to TLR7 triggering in MS patients, aspect only poorly investigated so far. In vivo IFN-b administration regulates pDC functions in TLR7-treated peripheral blood mononuclear cell (PBMC) cultures differently from what is observed in isolated cells, suggesting that IFN-b may activate inhibitory mechanisms in MS peripheral blood involved in turning off pDC response to dampen the ongoing inflammation. Indeed, IL-10, a key regulatory cytokine found increased upon TLR7 stimulation in in vivo IFN-b-exposed PBMCs, directly reduced pDCmediated IFN-a production. IFN-b therapy also shaped T-cell responses by decreasing TLR7-induced pDC maturation and inducing T-cell inhibitory molecules. Accordingly, raised pDC-induced IL-27 and decreased IL- 23 expression, together with high IL-10 level, contribute to inhibit Th17 cell differentiation. Our study uncovered a role for IFN-b in the regulation of TLR7-mediated pDC responses in MS toward an anti-inflammatory phenotype opening new opportunities to better understand mechanisms of action of this drug in controlling MS immunopathogenesis.

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Nurr1 reduction influences the onset of chronic EAE in mice
Montarolo et al.
Inflamm. Res.; September 2015

Objective
Nurr1 plays anti-inflammatory functions in astrocytes/ microglia. Gene expression analysis revealsNurr1 downregulation in PBMCs of MS patients that negatively correlates with disease aggressiveness. This study assesses the consequences ofNurr1 reduction in aMSmodel represented by EAE.
Methods
EAE was induced in heterozygous Nurr1 knockout mice. Clinical course was evaluated during presymptomatic, acute, and chronic phases. Neurohistopathological state was analyzed in spinal cord.
Results and conclusions
Nurr1 defect induces early EAE onset and increases inflammatory infiltrates in spinal cord suggesting a Nurr1 role in the early phase of EAE.

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Fingolimod versus interferon beta/glatiramer acetate after natalizumab suspension in multiple sclerosis
Iaffaldano et al.
Brain; September 2015

The comparative effectiveness of fingolimod versus interferon beta/glatiramer acetate was assessed in a multicentre, observational, prospectively acquired cohort study including 613 patients with relapsing multiple sclerosis discontinuing natalizumab in the Italian iMedWeb registry. First, after natalizumab suspension, the relapse risk during the untreated wash-out period and during the course of switch therapies was estimated through Poisson regression analyses in separated models. During the wash-out period an increased risk of relapses was found in patients with a higher number of relapses before natalizumab treatment (incidence rate ratio = 1.31, P = 0.0014) and in patients discontinuing natalizumab due to lack of efficacy (incidence rate ratio = 2.33, P = 0.0288), patient’s choice (incidence rate ratio = 2.18, P = 0.0064) and adverse events (incidence rate ratio = 2.09, P = 0.0084). The strongest independent factors influencing the relapse risk after the start of switch therapies were a wash-out duration longer than 3 months (incidence rate ratio = 1.78, P50.0001), the number of relapses experienced during and before natalizumab treatment (incidence rate ratio = 1.61, P50.0001; incidence rate ratio = 1.13, P = 0.0118, respectively) and the presence of comorbidities (incidence rate ratio = 1.4, P = 0.0097). Switching to fingolimod was associated with a 64% reduction of the adjusted-risk for relapse in comparison with switching to interferon beta/glatiramer acetate (incidence rate ratio = 0.36, P50.0001). Secondly, patients who switched to fingolimod or to interferon beta/glatiramer acetate were propensity score-matched on a 1-to-1 basis at the switching date. In the propensity score-matched sample a Poisson model showed a significant lower incidence of relapses in patients treated with fingolimod in comparison with those treated with interferon beta/glatiramer acetate (incidence rate ratio = 0.52, P = 0.0003) during a 12-month follow-up. The cumulative probability of a first relapse after the treatment switch was significantly lower in patients receiving fingolimod than in those receiving interferon beta/glatiramer acetate (P = 0.028). The robustness of this result was also confirmed by sensitivity analyses in subgroups with different wash-out durations (less or more than 3 months). Time to 3- month confirmed disability progression was not significantly different between the two groups (Hazard ratio = 0.58; P = 0.1931). Our results indicate a superiority of fingolimod in comparison to interferon beta/glatiramer acetate in controlling disease reactivation after natalizumab discontinuation in the real life setting.

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Longitudinal assessment of immuno-metabolic parameters in multiple sclerosis patients during treatment with glatiramer acetate
Carrieri et al.
Metabolism; September 2015

Objective
We investigated the effect of glatiramer acetate (GA) on the modulation of immune cell subpopulations and serum levels of multiple immune/metabolic markers in patients with relapsing–remitting multiple sclerosis (RRMS) to understand whether the treatment with GA could induce a specific change in the immunometabolic asset of patients with RRMS.
Material and methods
We performed an extensive peripheral blood immunophenotyping and measured serum levels of several parameters involved in the pathogenesis of RRMS and also relevant in the pathogenesis of metabolic syndrome and obesity such as leptin, soluble leptin-receptor (sLep-R), myeloperoxidase (MPO), soluble CD40 ligand (sCD40-L), soluble tumor necrosis factor-receptor (sTNF-R), monocyte chemoattractant protein 1 (MCP-1), soluble Inter-Cellular Adhesion Molecule-1 (sICAM-1) and osteoprotegerin (OPG), in 20 naïve-to-treatment RRMS patients and 20 healthy controls. We repeated these analyses over time at 6 and 12 months after starting GA treatment.
Results
Our analysis showed that naïve-to-treatment RRMS patients had a lower number of CD16+CD56+ NK cells, CD19+ B cells, CD4+ T cells co-expressing the MHC class II activation marker HLA-DR (CD4+DR+) and naïve CD4+CD45RA+ T cells in basal conditions. GA treatment induced a specific and significant decrease of circulating CD19+ B cells. Naïve-to-treatment RRMS patients also showed a significantly higher number of CD4+ T cells with a memory phenotype (CD4+CD45RO+) whose peripheral frequency was not affected by GA treatment. These changes over time associated with a higher serum concentration of leptin and lower levels of MPO. GA treatment also reduced significantly the circulating levels of sCD40-L and sTNF-R overtime.
Conclusions
Our data suggest that the clinical outcome of GA treatment is associated with changes in immune cell subpopulations and modulation of specific immunometabolic markers. These data add substantial evidence of the immune modulating effect of GA during RRMS and could be of relevance in understanding the pathogenesis of disease and its follow-up.

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Natalizumab treatment reduces L-selectin (CD62L) in CD4+ T cells
Spadaro et al.
JNI; August 2015

Background
The purpose of this research was to validate the low expression of L-selectin (CD62L) in natalizumab (NTZ)-treated patients. CD62L is involved in rolling and transmigration of leukocyte cells. A correlation between CD62LCD4+ T cells low expression and progressive multifocal leukoencephalopathy (PML) development has been suggested in multiple sclerosis (MS) patients treated with NTZ.
Methods
We performed a flow cytometric analysis on peripheral blood mononuclear cells (PBMC); we collected from 23 healthy donors and 225 MS patients: untreated (n = 19) or treated with NTZ (n = 113), interferon-beta (n = 26), glatiramer acetate (n = 26), fingolimod (n = 23) and rituximab (n = 18). We have also analysed two PML/IRIS (immune reconstitution inflammatory syndrome) patients and four longitudinal samples of a NTZ-treated patients before and during the development of a clinical asymptomatic magnetic resonance imaging (MRI) lesion confirmed as PML by cerebrospinal fluid (CSF) examination. Thirty-five NTZ-treated patients were studied longitudinally with three samples taken 4 months apart.
Results
The NTZ-treated patients showed a lower percentage of CD62L (33.68 %, n = 113) than first-line treated patients (44.24 %, n = 52, p = 0.0004). NTZ effect was already clear during the first year of treatment (34.68 %; p = 0.0184); it persisted in the following years and disappeared after drug withdrawal (44.08 %). Three percent of longitudinally analysed patients showed a percentage of CD62LCD4+ T cells under a hypothetical threshold and one patient with asymptomatic PML belongs to a group which expressed low percentage of CD62LCD4+ T cells.
Conclusions
Our research confirms that NTZ has a specific effect on CD62LCD4+ T cells consisting in decreasing of the number of positive cells. The low level of CD62L found in a clinically asymptomatic PML patient strengthens its potential usefulness as a biomarker of high PML risk in NTZ-treated patients. A larger study is required to better confirm the data.

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Neutrophils promote Alzheimer’s disease–like pathology and cognitive decline via LFA-1 integrin
Zenaro et al.
Nature Medicine; August 2015

Inflammation is a pathological hallmark of Alzheimer’s disease, and innate immune cells have been shown to contribute to disease pathogenesis. In two transgenic models of Alzheimer’s disease (5xFAD and 3xTg-AD mice), neutrophils extravasated and were present in areas with amyloid-β (Aβ) deposits, where they released neutrophil extracellular traps (NETs) and IL-17. Aβ42 peptide triggered the LFA-1 integrin high-affinity state and rapid neutrophil adhesion to integrin ligands. In vivo, LFA-1 integrin controlled neutrophil extravasation into the CNS and intraparenchymal motility. In transgenic Alzheimer’s disease models, neutrophil depletion or inhibition of neutrophil trafficking via LFA-1 blockade reduced Alzheimer’s disease–like neuropathology and improved memory in mice already showing cognitive dysfunction. Temporary depletion of neutrophils for 1 month at early stages of disease led to sustained improvements in memory. Transgenic Alzheimer’s disease model mice lacking LFA-1 were protected from cognitive decline and had reduced gliosis. In humans with Alzheimer’s disease, neutrophils adhered to and spread inside brain venules and were present in the parenchyma, along with NETs. Our results demonstrate that neutrophils contribute to Alzheimer’s disease pathogenesis and cognitive impairment and suggest that the inhibition of neutrophil trafficking may be beneficial in Alzheimer’s disease.

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Fumarates modulate microglia activation through a novel HCAR2 signaling pathway and rescue synaptic dysregulation in inflamed CNS
Parodi et al.
Nature Medicine; August 2015

Dimethyl fumarate (DMF), recently approved as an oral immunomodulatory treatment for relapsingremitting multiple sclerosis (MS), metabolizes to monomethyl fumarate (MMF) which crosses the blood–brain barrier and has demonstrated neuroprotective effects in experimental studies. We postulated that MMF exerts neuroprotective effects through modulation of microglia activation, a critical component of the neuroinflammatory cascade that occurs in neurodegenerative diseases such as MS. To ascertain our hypothesis and define the mechanistic pathways involved in the modulating effect of fumarates, we used real-time PCR and biochemical assays to assess changes in the molecular and functional phenotype of microglia, quantitative Western blotting to monitor activation of postulated pathway components, and ex vivo wholecell patch clamp recording of excitatory post-synaptic currents in corticostriatal slices from mice with experimental autoimmune encephalomyelitis (EAE), a model for MS,to study synaptic transmission. We show that exposure to MMF switches the molecular and functional phenotype of activated microglia from classically activated, pro-inflammatory type to alternatively activated, neuroprotective one, through activation of the hydroxycarboxylic acid receptor 2 (HCAR2). We validate a downstream pathway mediated through the AMPK–Sirt1 axis resulting in deacetylation, and thereby inhibition, of NF-κB and, consequently, of secretion of pro-inflammatory molecules. We demonstrate through ex vivo monitoring of spontaneous glutamate- mediated excitatory post-synaptic currents of single neurons in corticostriatal slices from EAE mice that the neuroprotective effect of DMF was exerted on neurons at pre-synaptic terminals by modulating glutamate release. By exposing control slices to untreated and MMF-treated activated microglia, we confirm the modulating effect of MMF on microglia function and, thereby, its indirect neuroprotective effect at post-synaptic level. These findings, whereby DMF-induced activation of a new HCAR2-dependent pathway on microglia leads to the modulation of neuroinflammation and restores synaptic alterations occurring in EAE, represent a possible novel mechanism of action for DMF in MS.

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Flow Cytofluorimetric Analysis of Anti-LRP4 (LDL Receptor-Related Protein 4) Autoantibodies in Italian Patients with Myasthenia Gravis
Marino et al.
Plos One; August 2015

Background
Myasthenia gravis (MG) is an autoimmune disease in which 90% of patients have autoantibodies against the muscle nicotinic acetylcholine receptor (AChR), while autoantibodies to muscle-specific tyrosine kinase (MuSK) have been detected in half (5%) of the remaining 10%. Recently, the low-density lipoprotein receptor-related protein 4 (LRP4), identified as the agrin receptor, has been recognized as a third autoimmune target in a significant portion of the double sero-negative (dSN) myasthenic individuals, with variable frequency depending on different methods and origin countries of the tested population. There is also convincing experimental evidence that anti-LRP4 autoantibodies may cause MG.
Methods
The aim of this study was to test the presence and diagnostic significance of anti-LRP4 autoantibodies in an Italian population of 101 myasthenic patients (55 dSN, 23 AChR positive and 23 MuSK positive), 45 healthy blood donors and 40 patients with other neurological diseases as controls. All sera were analyzed by a cell-based antigen assay employing LRP4-transfected HEK293T cells, along with a flow cytofluorimetric detection system.
Results
We found a 14.5%(8/55) frequency of positivity in the dSN-MG group and a 13% frequency of co-occurrence (3/23) in both AChR and MuSK positive patients; moreover, we report a younger female prevalence with a mild form of disease in LRP4-positive dSN-MG individuals.
Conclusion
Our data confirm LRP4 as a new autoimmune target, supporting the value of including anti- LRP4 antibodies in further studies on Myasthenia gravis.

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Conferences & Courses

XXVII AINI Congress

May 7-10, 2018 
Trieste

 

Workshop Sclerosi Multipla: dall'immunologia all'innovazione …

December 15-16, 2017 
Modena (Baggiovara) - UNA Hotel Modena


Scientific Program

Nature Conferences REGENERATION

November 16-18, 2017
Aula Caravella Santa Maria, San Raffaele Congress Centre, Milan, Itlay

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2nd Americas Schools of Neuroimmunology (ASNI)

October 3-6, 2017
Charlottesville (VA) - USA 

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JNIInternational Brain Research Organization
Bringing Neuroscience to the World
JNIJournal of Neuroimmunology
Studies on all branches of neurosciences covering both research and clinical problems of neuroscientific interest.

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