Treatment Of Experimental Autoimmune Encephalomyelitis Research Articles

A novel regulatory pathway for autoimmune disease: Binding of partial MHC class II constructs to monocytes reduces CD74 expression and induces both specific and bystander T-cell tolerance

Treatment with partial (p)MHC class II-β1α1 constructs (also referred to as recombinant T-cell receptor ligands – RTL) linked to antigenic peptides can induce T-cell tolerance, inhibit recruitment of inflammatory cells and reverse autoimmune diseases. Here we demonstrate a novel regulatory pathway that involves RTL binding to CD11b+ mononuclear cells through a receptor comprised of MHC class II invariant chain (CD74), cell-surface histones and MHC class II itself for treatment of experimental autoimmune encephalomyelitis (EAE). Binding of RTL constructs with CD74 involved a previously unrecognized MHC class II-α1/CD74 interaction that inhibited CD74 expression, blocked activity of its ligand, macrophage migration inhibitory factor, and reduced EAE severity. These findings implicate binding of RTL constructs to CD74 as a key step in both antigen-driven and bystander T-cell tolerance important in treatment of inflammatory diseases.

Epitope-specific immune tolerization ameliorates experimental autoimmune encephalomyelitis

The availability of glatiramer acetate (GA) for inducing immune tolerance is a significant advancement in the treatment of multiple sclerosis (MS). However, a sizable proportion of patients maintain active disease, regardless of treatment. Another approach to induce T-cell tolerance is therefore still an unmet medical need. We hypothesized that induction of mucosal tolerance toward a pro-inflammatory T-cell epitope derived from a heat shock protein (HSP) (RatP2) could translate into clinical benefit. We found that treatment of experimental autoimmune encephalomyelitis (EAE, a model of MS) with the peptide RatP2 determined a significant clinical improvement, which was comparable to the standard tolerization treatment (an MBP-derived peptide pool) and superior to GA. Histological analysis demonstrated a reduction of brain and spinal cord inflammatory lesions in treated animals. Moreover, with immunological analysis we identified biomarkers associated with clinical response. This work provides proof-of-concept to support the further testing of this approach as a possible complement to currently available therapies for MS.

Estriol preserves synaptic transmission in the hippocampus during autoimmune demyelinating disease

Cognitive deficits occur in over half of multiple sclerosis patients, with hippocampal-dependent learning and memory commonly impaired. Data from in vivo MRI and post-mortem studies in MS indicate that the hippocampus is targeted. However, the relationship between structural pathology and dysfunction of the hippocampus in MS remains unclear. Hippocampal neuropathology also occurs in experimental autoimmune encephalomyelitis (EAE), the most commonly used animal model of MS. Although estrogen treatment of EAE has been shown to be anti-inflammatory and neuroprotective in the spinal cord, it is unknown if estrogen treatment may prevent hippocampal pathology and dysfunction. In the current study we examined excitatory synaptic transmission during EAE and focused on pathological changes in synaptic protein complexes known to orchestrate functional synaptic transmission in the hippocampus. We then determined if estriol, a candidate hormone treatment, was capable of preventing functional changes in synaptic transmission and corresponding hippocampal synaptic pathology. Electrophysiological studies revealed altered excitatory synaptic transmission and paired-pulse facilitation (PPF) during EAE. Neuropathological experiments demonstrated that there were decreased levels of pre- and post-synaptic proteins in the hippocampus, diffuse loss of myelin staining and atrophy of the pyramidal layers of hippocampal cornu ammonis 1 (CA1). Estriol treatment prevented decreases in excitatory synaptic transmission and lessened the effect of EAE on PPF. In addition, estriol treatment prevented several neuropathological alterations that occurred in the hippocampus during EAE. Cross-modality correlations revealed that deficits in excitatory synaptic transmission were significantly correlated with reductions in trans-synaptic protein binding partners known to modulate excitatory synaptic transmission. To our knowledge, this is the first report describing a functional correlate to hippocampal neuropathology in any MS model. Furthermore, a treatment was identified that prevented both deficits in synaptic function and hippocampal neuropathology.

Rolipram promotes remyelination possibly via MEK-ERK signal pathway in cuprizone-induced demyelination mouse

ObjectiveRolipram, a 3′–5′-cyclic adenosine monophosphate (cAMP)-dependent phosphodiesterase 4 (PDE4) inhibitor, has long been studied for its immune modulating effects in the treatment of experimental autoimmune encephalomyelitis (EAE). In the current study, we investigated the effects of rolipram on remyelination after cuprizone- or lysolecithin-induced demyelination and the signal transduction pathways potentially modulating this response. Materials and methodsCuprizone-induced demyelination in mice and lysolecithin (LPC)-induced demyelination in rat cerebellum slice culture were treated with rolipram. Demyelination was evaluated by Luxol fast blue (LFB) or myelin basic protein (MBP) staining and western blot. Oligodendroglial cells were cultured with different concentrations of rolipram, and 2′, 3′-cyclic nucleotide phosphodiesterase (CNPase) activity, MBP expression, and extracellular signal-regulated kinase (ERK) phosphorylation were measured. ResultsRolipram antagonized lysolecithin (LPC)-induced demyelination in rat cerebellar slice cultures and cuprizone-fed mice. In vitro, rolipram treatment promoted oligodendrocyte precursor cell (OPC) maturation, an effect that was partially blocked by the inhibitors of the mitogen activated protein kinase kinase (MEK). ConclusionRolipram promotes the maturation of OPCs, facilitates remyelination, and increases ERK phosphorylation. All of these actions are involved in an action against cuprizone-induced demyelination that may occur partly via the MEK-ERK pathway. Importantly, this may have therapeutic implications for MS.

α-MSH-Stimulated Tolerogenic Dendritic Cells Induce Functional Regulatory T Cells and Ameliorate Ongoing Skin Inflammation

The neuropeptide α-melanocyte-stimulating hormone (α-MSH) is a well-known mediator of skin pigmentation. More recently, it has been shown that α-MSH also exerts a strong anti-inflammatory and immunosuppressive activity. To elucidate the mechanisms underlying α-MSH-induced immunosuppression, we investigated whether α-MSH affects dendritic cell/T cell communication, as especially this interaction has an important role in the regulation of immune responses. Here, we show that α-MSH, by binding to MC-1R, induced tolerogenic dendritic cells, which were capable of expanding CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs) in vitro, as well as in vivo. Notably, those α-MSH-induced Tregs were functional as they efficiently inhibited cutaneous contact allergy and ongoing psoriasis-like skin inflammation in mice. Furthermore, α-MSH induced tolerogenic dendritic cells capable of generating functional Tregs in human blood. Interestingly, human Tregs expanded via α-MSH-stimulated dendritic cells suppressed the proliferation and cytokine secretion of pathogenic T-helper-17 (Th17) cells from individuals with psoriasis. Taken together, these data indicate that α-MSH induced immunosuppressive Tregs in vitro and in vivo, which inhibited disease progression in a mouse model of psoriasis-like skin inflammation and suppressed the activation and proliferation of effector T cells from subjects with psoriasis.

Immunomodulatory synergy by combining atorvastatin and rapamycin in the treatment of experimental autoimmune encephalomyelitis (EAE)

Combination therapies are gaining momentum over monotherapies in the treatment of multiple sclerosis (MS). Suboptimal doses of atorvastatin and rapamycin prevented or reversed clinical and histologic experimental autoimmune encephalomyelitis (EAE). Secretion of proinflammatory Th1 and Th17 cytokines was reduced and Th2 and Treg cytokine secretion was increased in mice. Combination therapy promoted induction of Treg cells and attenuated the infiltration of inflammatory IL-17 cells in EAE. It appeared that rapamycin-reactivated ERK was blunted by addition of atorvastatin. Our results demonstrate that agents with different mechanisms of immune modulation can combine synergistically in treating CNS autoimmunity.

Treatment with 7-O-tetradecanoyl-genistein reduces IFN-γ and IL-17 levels in the brain and ameliorates clinical signs of experimental autoimmune encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is a murine autoimmune disease used to study multiple sclerosis (MS), a human inflammatory demyelinating disease of the central nervous system. Genistein treatment is known to reverse clinical signs of EAE. The present work investigates the use of a genistein analog 7-O-tetradecanoyl-genistein (TDG) in the treatment of EAE. In this study, the genistein analog TDG was obtained by the esterification reaction of genistein. The molecule of TDG was developed based on this previous knowledge, using esterification in vitro to bypass the in vivo processing which favors the biological activity and increasing lipid solubility. The results show that TDG treatment promotes reduction of the clinical signs in EAE animals and it correlates with lower levels of TGF-β, IL-6, IL-17 and IFN-γ in the brain.

Stem Cell Therapy for Multiple Sclerosis: Preclinical Evidence Beyond All Doubt?

Stem cell transplantation holds great promise for restoration of neural function in various neurodegenerative disorders, including multiple sclerosis (MS). However, many questions remain regarding the true efficacy and precise mode of action of stem cell-based therapeutic approaches. Therefore, in this article, we will first discuss the ideal route and/or timing of stem cell-based therapies for experimental autoimmune encephalomyelitis (EAE), the most used preclinical animal model for MS. Next, we will provide an overview of the proposed mechanisms that contribute to the beneficial effects of stem cell transplantation observed during the treatment of rodent EAE. Reviews of current and past literature clearly demonstrate conceptual changes in the development of stem cell-based approaches for EAE/MS, leading to the identification of several major challenges to be tackled before (stem) cell therapy for rodent EAE can be safely and successfully translated to human therapy for MS.

Enhancement of Regulatory T Cell Induction by Intravenous S-sulfonated Immunoglobulin during the Treatment of Experimental Autoimmune Encephalomyelitis

Intravenous immunoglobulin (IVIg) has been shown to be effective for a variety of autoimmune diseases. Despite its widespread use and therapeutic success, the precise mechanisms for the anti-inflammatory therapeutic effects of IVIg are not well understood. In particular, few reports have examined the mechanism of IVIg on regulatory T cells (Treg: CD4(+)CD25(+)FoxP3(+) T cells). In the present study, to clarify the effect of intravenous S-sulfonated immunoglobulin (S-IVIg) on Treg, we investigated experimental autoimmune encephalomyelitis (EAE), the representative animal model of autoimmune disease. First, when we evaluated the effect of S-IVIg in an acute EAE model, the prophylactic treatment of S-IVIg dose-dependently controlled the symptoms of EAE. Next, we measured Treg in EAE mice spleen by flow cytometry. The percentage of Treg in S-IVIg-treated mice was significantly increased compared with Saline-treated mice. Finally, in reinduced EAE, S-IVIg not only prevented EAE progression, but also increased the percentage of Treg in the spleen. The increase in percentage of Treg in S-IVIg-treated EAE might be associated with protection against EAE. These observations provide important evidence that IVIg is effective in T-cell-mediated control of autoimmunity.

The therapeutic effect of mesenchymal stem cell transplantation in experimental autoimmune encephalomyelitis is mediated by peripheral and central mechanisms

Stem cells are currently seen as a treatment for tissue regeneration in neurological diseases such as multiple sclerosis, anticipating that they integrate and differentiate into neural cells. Mesenchymal stem cells (MSCs), a subset of adult progenitor cells, differentiate into cells of the mesodermal lineage but also, under certain experimental circumstances, into cells of the neuronal and glial lineage. Their clinical development, however, has been significantly boosted by the demonstration that MSCs display significant therapeutic plasticity mainly occurring through bystander mechanisms. These features have been exploited in the effective treatment of experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis where the inhibition of the autoimmune response resulted in a significant amelioration of disease and decrease of demyelination, immune infiltrates and axonal loss. Surprisingly, these effects do not require MSCs to engraft in the central nervous system but depend on the cells' ability to inhibit pathogenic immune responses both in the periphery and inside the central nervous system and to release neuroprotective and pro-oligodendrogenic molecules favoring tissue repair. These results paved the road for the utilization of MSCs for the treatment of multiple sclerosis.

Immunomodulatory effects and improved prognosis of experimental autoimmune encephalomyelitis after O-tetradecanoyl-genistein treatment

Experimental autoimmune encephalomyelitis (EAE) is a murine autoimmune disease used to study multiple sclerosis (MS), a human inflammatory demyelinating disease of the central nervous system. Genistein, an isoflavonoid phytoestrogenic compound found in soy, is known to reverse clinical signs of EAE. Although genistein has some potential in clinical application, it has some disadvantages related to its chemical structure, such as rapid in vivo metabolism and a fast decline in serum after oral administration. The present work investigates the treatment of EAE by using 7-O-tetradecanoyl-genistein (TDG), a more lipophilic analog of genistein obtained by esterification. The clinical course of EAE was investigated in C57Bl/6 mice immunized with myelin oligodendrocyte glycoprotein peptide (MOG)35–55 in complete Freund's adjuvant supplemented with Mycobacterium tuberculosis H37RA. After 14days of MOG immunization, mice were treated with TDG for seven days. Numbers of IL-17-producing cells and Foxp3 by CD4+ T cells and CTLA-4 expression by CD3+ T cells from brain were determined by flow cytometry. Levels of IL-6, IFN-γ and IL-10 were evaluated by ELISA. Brain sections were stained by hematoxylin and eosin method. The data obtained indicate that TDG treatment ameliorates the clinical signs of EAE, which correlates with a decrease of IL-17-producing cells and an increase in Foxp3+CD4+ cells in the brain. TDG is also shown to enhance IL-10 production and CTLA-4 expression and to reduce IFN-γ and IL-6. Altogether, these findings suggest an immunomodulatory therapeutic role for TDG in EAE and multiple sclerosis.

Regulatory T cells play a role in T‐cell receptor CDR2 peptide regulation of experimental autoimmune encephalomyelitis

Eliciting T-cell receptor (TCR) -specific responsiveness has been known to provide an effective autoregulatory mechanism for limiting inflammation mediated by T effector cells. Our previous use of TCR peptides derived from the CDR3 regions of a pathogenic TCR effectively reversed ongoing experimental autoimmune encephalomyelitis (EAE) in a humanized TCR transgenic model. In this study, we use the TCR BV8S2 CDR2 peptide in the non-transgenic C57BL/6 EAE model to down-regulate the heterogeneous TCR BV8S2(+) MOG-35-55-specific pathogenic T-cell population and demonstrate successful treatment of EAE after disease onset. Suppression of disease was associated with reduced MOG-35-55-specific and non-specific T-cell production of interleukin-17a and interferon-γ in the central nervous system, as well as reduced numbers of CD4(+) and Foxp3(+) T cells in the central nervous system. With the use of Foxp3-GFP and Foxp3 conditional knockout mice, we demonstrate that the TCR CDR2 peptide treatment effect is dependent on the presence of Foxp3(+) regulatory T cells and that regulatory T cell numbers are significantly expanded in the periphery of treated mice. Hence, TCR CDR2 peptide therapy is effective in regulating heterogeneous, pathogenic T-cell populations through the activity of the Foxp3(+) regulatory T cell population.

GPR30 Forms an Integral Part of E2-Protective Pathway in Experimental Autoimmune Encephalomyelitis

A major focus of our laboratory has been an in-depth evaluation as to how estrogens exert a pronounced protective effect on clinical and histological disease in the animal model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE). An important issue regarding their therapeutic application has been the undesirable estrogenic side effects thought to be mediated primarily through 17β-estradiol (E2) binding to intracellular estrogen receptor alpha (ERα). With the discovery and characterization of GPR30 as the putative membrane estrogen receptor, we sought to study whether signaling through GPR30 was sufficient to mediate protection against EAE without engagement of ERα. Treatment of EAE in WT mice with G-1, a selective GPR30 agonist, retained estradiol's ability to protect against clinical and histological EAE without estrogenic side effects. G-1 treatment deviated cytokine profiles and enhanced suppressive activity of CD4(+)Foxp3(+) Treg cells through a GPR30- and programmed death 1 (PD-1)-dependent mechanism. This novel finding was indicative of the protective effect of GPR30 activation in EAE and provides a strong foundation for the clinical application of GPR30 agonists such as G-1 in MS. However, future studies are needed to elucidate cross-signaling and evaluate possible additive effects of combined signaling through both GPR30 and ER-α. Deciphering the possible mechanism of involvement of GPR30 in estrogen-mediated protection against EAE may result in lowering treatment doses of E2 and GPR30 agonists that could minimize risks and maximize immunoregulation and therapeutic effects in MS. Alternatively, one might envision using E2 derivatives with reduced estrogenic activity alone or in combination with GPR30 agonists as therapies for both male and female MS patients.

Tolerogen-induced interferon-producing killer dendritic cells (IKDCs) protect against EAE

Natural killer (NK) cells and dendritic cells (DCs) have been shown to link the innate and adaptive immune systems. Likewise, a new innate cell subset, interferon-producing killer DCs (IKDCs), shares phenotypic and functional characteristics with both DCs and NK cells. Here, we show IKDCs play an essential role in the resolution of experimental autoimmune encephalomyelitis (EAE) upon treatment with the tolerizing agent, myelin oligodendrocyte glycoprotein (MOG), genetically fused to reovirus protein σ1 (termed MOG-pσ1). Activated IKDCs were recruited subsequent MOG-pσ1 treatment of EAE, and disease resolution was abated upon NK1.1 cell depletion. These IKDCs were able to kill activated CD4 + T cells and mature dendritic DCs, thus, contributing to EAE remission. In addition, IKDCs were responsible for MOG-pσ1-mediated MOG-specific regulatory T cell recruitment to the CNS. The IKDCs induced by MOG-pσ1 expressed elevated levels of HVEM for interactions with cognate ligand-positive cells: LIGHT + NK and T eff cells and BTLA + B cells. Further characterization revealed these activated IKDCs being MHC class II high, and upon their adoptive transfer (CD11c +NK1.1 +MHC class II high), IKDCs, but not CD11c +NK1.1 +MHC class II intermediate/low (unactivated) cells, conferred protection against EAE. These activated IKDCs showed enhanced CD107a, PD-L1, and granzyme B expression and could present OVA, unlike unactivated IKDCs. Thus, these results demonstrate the interventional potency induced HVEM + IKDCs to resolve autoimmune disease.

Liposomal Encapsulation of Glucocorticoids Alters Their Mode of Action in the Treatment of Experimental Autoimmune Encephalomyelitis

Glucocorticoids (GCs) are widely used to treat acute relapses of multiple sclerosis (MS). In this study, we demonstrate that liposomal encapsulation augments the therapeutic potency of GCs as they ameliorate experimental autoimmune encephalomyelitis (EAE) to the same extent as free GC, but at strongly reduced dosage and application frequency. Importantly, this is accompanied by an altered mode of action. Unlike free GCs, which mainly target T lymphocytes during EAE therapy, liposomal GCs only marginally affect T cell apoptosis and function. In contrast, liposomal GCs efficiently repress proinflammatory macrophage functions and upregulate anti-inflammatory genes associated with the alternatively activated M2 phenotype. The GC receptor (GR) per se is indispensable for the therapeutic efficacy of liposomal GC. In contrast to free GCs, however, the individual deletion of the GR either in T cells or myeloid cells has little effect on the efficacy of liposomal GCs in the treatment of EAE. Only the combined deletion of the GR in both cellular compartments markedly compromises the therapeutic effect of liposomal GCs on disease progression. In conclusion, encapsulation of GC does not only enhance their efficacy in the treatment of EAE but also alters their target cell specificity and their mode of action compared with free GCs.

PS1-058 IFN- γ signaling-dependent response to lithium, an inhibitor of GSK3, in the treatment of experimental autoimmune encephalomyelitis (EAE)

PS1-058 IFN- γ signaling-dependent response to lithium, an inhibitor of GSK3, in the treatment of experimental autoimmune encephalomyelitis (EAE)

P4‐285: Treatment of experimental autoimmune encephalomyelitis by antioxidants (experimental study)

P4‐285: Treatment of experimental autoimmune encephalomyelitis by antioxidants (experimental study)

P4‐286: Treatment of experimental autoimmune encephalomyelitis by antioxidants (experimental study)

P4‐286: Treatment of experimental autoimmune encephalomyelitis by antioxidants (experimental study)

Cyclooxygenase expression and prostaglandin levels in central nervous system tissues during the course of chronic relapsing experimental autoimmune encephalomyelitis (EAE)

Multiple sclerosis (MS) and its animal counterpart experimental autoimmune encephalomyelitis (EAE) have a major inflammatory component that drives and orchestrates both diseases. One particular group of mediators are the prostaglandins (PGs), which we have previously shown, through quantitation and pharmacological intervention, to be closely involved in the pathology of MS and EAE. The aim of the current study was to determine the expression of the PG-generating cyclooxygenase (COX) enzymes and the profile of PGE(2) and PGD(2), in selected central nervous system (CNS) tissues, with the development of the chronic relapsing (CR) form of EAE. In particular, the work investigates the possible relationship between the expression of COX isoenzymes and PG levels during the neurological phases of CR EAE. CR EAE was induced in Biozzi mice with inoculum containing lyophilised, syngeneic spinal cord emulsified in complete Freund's adjuvant. The cerebral cortex, cerebellum and spinal cord were dissected from mice during the acute, remission and relapse stages of disease with a minimum of five animals per treatment. The expression of COX-1, COX-1b variant and COX-2, in pooled samples, was determined by Western blotting. PGE(2) and PGD(2) levels in extracted samples were measured using commercial enzyme immunoassay kits. COX-2 expression in spinal cords during acute disease remained unaltered and was in contrast to an enhancement of the enzyme, together with COX-1 and COX-1b, in all other sampled areas. PGE(2) and PGD(2) levels remained unchanged during the acute phase and the subsequent remission of symptoms. COX-1 and COX-1b expression was elevated in tissues during the relapse stage of CR EAE and concentrations of the prostanoids were markedly increased. The study examines the implications of COX isoenzyme expression over the course of CR EAE and discusses the reported relationship between PGE(2) and PGD(2) in the instigation and resolution of CNS inflammation. Consideration is also given to the treatment of CR EAE and suggests that drugs designed to limit the inflammatory effects of the PGs should be administered prior to or during the relapse phase of the disease.

Treatment of experimental autoimmune encephalomyelitis in SJL/J mice with a replicative HSV-1 vector expressing interleukin-5

Experimental autoimmune encephalomyelitis (EAE) is an autoimmune inflammation of the central nervous system and is used as the experimental model of multiple sclerosis (MS). The exact mechanism behind the disease is still unknown, but interleukin (IL)-17 expressing T cells are thought to mediate the disease. Toll-like receptors (TLRs) are known to have a role in the innate immune response against pathogens, and several TLRs have also a role in the disease course of EAE. Here, we show that treatment with a herpes simplex virus type 1 vector expressing the Th2 cytokine IL-5 ameliorates EAE and decreases the numbers of infiltrating lymphocytes in the brain. The effect involves downregulation of TLR 2, 3 and 9 mRNA expression and upregulation of type I interferons (IFNs) in brains during onset of disease. The elevated expression of type I IFNs was also observed during recovery.