Interferon-beta treatment of experimental autoimmune encephalomyelitis leads to rapid nonapoptotic termination of T cell infiltration

Anti-inflammatory mechanisms and pharmacological actions of phycocyanobilin in a mouse model of experimental autoimmune encephalomyelitis: A therapeutic promise for multiple sclerosis

Cytokines, demyelination and neuroaxonal degeneration in the central nervous system are pivotal elements implicated in the pathogenesis of multiple sclerosis (MS) and its nonclinical model of experimental autoimmune encephalomyelitis (EAE). Phycocyanobilin (PCB), a chromophore of the biliprotein C-Phycocyanin (C-PC) from Spirulina platensis, has antioxidant, immunoregulatory and anti-inflammatory effects in this disease, and it could complement the effect of other Disease Modifying Treatments (DMT), such as Interferon-β (IFN-β). Here, our main goal was to evaluate the potential PCB benefits and its mechanisms of action to counteract the chronic EAE in mice. MOG_35-55-induced EAE was implemented in C57BL/6 female mice. Clinical signs, pro-inflammatory cytokines levels by ELISA, qPCR in the brain and immunohistochemistry using precursor/mature oligodendrocytes cells antibodies in the spinal cord, were assessed. PCB enhanced the neurological condition, and waned the brain concentrations of IL-17A and IL-6, pro-inflammatory cytokines, in a dose-dependent manner. A down- or up-regulating activity of PCB at 1 mg/kg was identified in the brain on three (LINGO1, NOTCH1, and TNF-α), and five genes (MAL, CXCL12, MOG, OLIG1, and NKX2-2), respectively. Interestingly, a reduction of demyelination, active microglia/macrophages density, and axonal damage was detected along with an increase in oligodendrocyte precursor cells and mature oligodendrocytes, when assessed the spinal cords of EAE mice that took up PCB. The studies in vitro in rodent encephalitogenic T cells and in vivo in the EAE mouse model with the PCB/IFN-β combination, showed an enhanced positive effect of this combined therapy. Overall, these results demonstrate the anti-inflammatory activity and the protective properties of PCB on the myelin and support its use with IFN-β as an improved DMT combination for MS.

A comparative study of melatonin and immunomodulatory therapy with interferon beta and glatiramer acetate in a mouse model of multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is a chronic, demyelinating, autoimmune disease of the central nervous system causing neuroinflammation. Experimental autoimmune encephalitis (EAE) is a model of the disease. MS is classically treated with interferon beta (IFN-β) and glatiramer acetate (GA). Melatonin (MLT) has been reported to modulate immune system responses. The aim of the present study is to analyse the effects of MLT administration in comparison with the first-line treatments for MS (IFN-β and GA).

METHODS

EAE was induced in male Sprague-Dawley rats; the animals subsequently received either IFN-β, GA, or MLT. Cerebrospinal fluid (CSF) samples were analysed by multiplex assay to determine the levels of proinflammatory cytokines. The neurological evaluation of EAE was also recorded.

RESULTS

All immunised animals developed EAE. We evaluated the first relapse-remission cycle, observing that IFN-β and GA had better results than MLT in the clinical evaluation. Neither EAE nor any of the treatments administered modified CSF IL-1β and IL-12p70 concentrations. However, IFN-β and MLT did decrease CSF TNF-α concentrations.

CONCLUSIONS

Further studies are needed to evaluate the molecular mechanisms involved in the behaviour of MLT in EAE, and to quantify other cytokines in different biological media in order for MLT to be considered an anti-inflammatory agent capable of regulating MS.

Animal models of multiple sclerosis: From rodents to zebrafish

Multiple sclerosis (MS) is a chronic, immune-mediated demyelinating disease of the central nervous system. Animal models of MS have been critical for elucidating MS pathological mechanisms and how they may be targeted for therapeutic intervention. Here we review the most commonly used animal models of MS. Although these animal models cannot fully replicate the MS disease course, a number of models have been developed to recapitulate certain stages. Experimental autoimmune encephalomyelitis (EAE) has been used to explore neuroinflammatory mechanisms and toxin-induced demyelinating models to further our understanding of oligodendrocyte biology, demyelination and remyelination. Zebrafish models of MS are emerging as a useful research tool to validate potential therapeutic candidates due to their rapid development and amenability to genetic manipulation.

Effects of Systemic and Local Interferon Beta-1a on Epidural Fibrosis

Study Design

Level 1 randomized controlled study.

Purpose

To investigate the effects of systemic and local interferon-beta-1a (IFN-β-1a) on prevention of epidural fibrosis using histopathological parameters.

Overview of Literature

Epidural fibrosis involves fibroblastic invasion of nerve roots into the epidural space. Formation of dense fibrous tissue causes lumbar and radicular pain. Many surgical techniques and several materials have been proposed in the literature, but no study has assessed the effect of IFN-β-1a on prevention of epidural fibrosis.

Methods

Forty-eight adult female Sprague-Dawley rats were divided into six groups of eight: sham group, control group, systemic 44 μg IFN-β-1a group and 22 μg IFN-β-1a group (after laminectomy and discectomy, 0.28 mL and 0.14 mL IFN-β-1a applied subcutaneously three times for a week, respectively), local 44 μg IFN-β-1a group (laminectomy and discectomy, followed by 0.28 mL IFN-β-1a on the surgical area), and local 22 μg IFN-β-1a group (laminectomy and discectomy, followed by 0.14 mL IFN-β-1a on the surgical area). All rats were sacrificed after 4 weeks and groups were evaluated histopathologically.

Results

Compared with sham and control groups, significantly less epidural fibrosis, dural adhesion, and fibroblast cell density were observed in the local and systemic 44 μg IFN-β-1a groups. No other differences were evident between the local and systemic groups.

Conclusions

IFN-β-1a is effective in preventing epidural fibrosis with systemic and local application.

Neuroprotective dimethyl fumarate synergizes with immunomodulatory interferon beta to provide enhanced axon protection in autoimmune neuroinflammation

INTRODUCTION

Despite recent advances in development of treatments for multiple sclerosis, there is still an unmet need for more effective and also safe therapies. Based on the modes of action of interferon-beta (IFN-β) and dimethyl fumarate (DMF), we hypothesized that anti-inflammatory and neuroprotective effects may synergize in experimental autoimmune encephalomyelitis (EAE).

METHODS

EAE was induced in C57BL/6 mice by immunization with MOG35-55-peptide. Murine IFN-β was injected s.c. every other day at 10.000IU, and DMF was provided at 15mg/kg by oral gavage twice daily. Control mice received PBS injections and were treated by oral gavage with the vehicle methylcellulose. Mice were scored daily by blinded observers and histological, FACS and cytokine studies were performed to further elucidate the underlying mechanism of action.

RESULTS

Combination therapy significantly ameliorated EAE disease course in comparison to controls and monotherapy with IFN-β. Histological analyses showed a significant effect on axon preservation with almost twice as much axons present in inflamed lesions as compared to control. Remarkably, the effect on axonal preservation was more pronounced under combination therapy than with both monotherapies. Neither monotherapy nor combination therapy demonstrated modulation of cytokines and frequency of antigen presenting cells.

DISCUSSION

Combination of IFN-β and DMF resulted in greater beneficial effects with improved tissue protection as compared to the respective monotherapies. Further combination studies of these safe therapies in human disease are warranted.

Cell-based delivery of brain-derived neurotrophic factor in experimental allergic encephalomyelitis

Brain-derived neurotrophic factor (BDNF) is a pleiotropic cytokine with neuroprotective properties that has been identified as a potential therapeutic agent for diseases of the central nervous system (CNS). The use of BDNF has been limited by a short serum half-life and poor penetration of the blood-brain barrier. To address this limitation we have explored cell-based approaches to delivery. We have used experimental allergic encephalomyelitis (EAE), an inflammatory disease of the CNS, as a model system. We engineered hematopoietic stem cells to produce BDNF to determine the feasibility and effectiveness of cell-based delivery of BDNF into the CNS in EAE. We review those studies here.

Role of interleukin 10 transcriptional regulation in inflammation and autoimmune disease

Interleukin 10 (IL-10) is a cytokine with potent anti-inflammatory properties that plays a central role in limiting host immune response to pathogens, thereby preventing damage to the host and maintaining normal tissue homeostasis. Dysregulation of IL-10 is associated with enhanced immunopathology in response to infection as well as increased risk for development of many autoimmune diseases. Thus a fundamental understanding of IL-10 gene expression is critical for our comprehension of disease progression and resolution of host inflammatory response. In this review, we discuss modes of regulation of IL-10 gene expression in immune effector cell types, including signal transduction, epigenetics, promoter architecture, and post-transcriptional regulation, and how aberrant regulation contributes to immunopathology and disease progression.

Additive effects of combination treatment with anti-inflammatory and neuroprotective agents in experimental autoimmune encephalomyelitis

We studied the effects of combination treatment with an anti-inflammatory agent, interferon (IFN)-beta, and a putative neuroprotective agent, an estrogen receptor (ER)-beta ligand, during EAE. Combination treatment significantly attenuated EAE disease severity, preserved axonal densities in spinal cord, and reduced CNS inflammation. Combining ERbeta treatment with IFNbeta reduced IL-17, while it abrogated IFNbeta-mediated increases in Th1 and Th2 cytokines from splenocytes. Additionally, combination treatment reduced VLA-4 expression on CD4+ T cells, while it abrogated IFNbeta-mediated decreases in MMP-9. Our data demonstrate that combination treatments can result in complex effects that could not have been predicted based on monotherapy data alone.

High-dose, high-frequency recombinant interferon beta-1a in the treatment of multiple sclerosis

BACKGROUND

There is at present no cure for multiple sclerosis (MS), and existing therapies are designed primarily to prevent lesion formation, decrease the rate and severity of relapses and delay the resulting disability by reducing levels of inflammation.

OBJECTIVE

The aim of this review was to assess the treatment of relapsing MS with particular focus on subcutaneous (s.c.) interferon (IFN) beta-1a.

METHOD

The literature on IFN beta-1a therapy of MS was reviewed based on a PubMed search (English-language publications from 1990) including its pharmacodynamics and pharmacokinetics, clinical efficacy in relapsing MS as shown in placebo-controlled studies and in comparative trials, efficacy in secondary progressive MS, safety and tolerability, and the impact of neutralizing antibodies.

CONCLUSION

The literature suggests that high-dose, high-frequency s.c. IFN beta-1a offers an effective option for treating patients with relapsing MS, with proven long-term safety and tolerability, and has a favourable benefit-to-risk ratio compared with other forms of IFN beta.

Beta-interferon unbalances the peripheral T cell proinflammatory response in experimental autoimmune encephalomyelitis

Interferon beta (IFNbeta) is a widespread therapy for multiple sclerosis (MS). We have analyzed some critical features of the T cell activation process in lymph nodes after IFNbeta treatment of experimental autoimmune encephalomyelitis (EAE) in SJL mice. Prevention of clinical signs and drastic reduction of perivascular infiltrates in the central nervous system (CNS) were accompanied by alterations in nuclear DNA binding activity levels of NFkappaB and Stat6 transcription factors in lymph node cells (LNC). A decrease of active NFkappaB subunits in treated animals correlated with lower levels of the cytoplasmic phosphorylated form of IkappaBalpha. Results also showed that nuclear DNA binding activity of Stat6 was increased by IFNbeta treatment, as were the cytoplasmic levels of phosphorilated Stat6 (P-Stat6). These high levels of P-Stat6 in IFNbeta-treated animals were accompanied by an increase of IL-4 expression levels measured by real time PCR. In vitro experiments with the IL-4 producing clone D10.G4.1 indicates that the IFNbeta-mediated IL-4 induction is not an effect exclusive to MBP-reactive cells, and suggest that it could be mediated by mRNA stability enlargement. On the other hand, IFNbeta treatment of EAE produced no significant changes in peripheral IFNgamma expression and a striking decrease of IL-17. These findings suggest that the inhibition of NFkappaB activity, the increase of IL-4 expression and its signaling transduction, and the decrease of IL-17 may cooperate to some of the antiinflammatory effects of IFNbeta on EAE.

Effects of interferon-beta-1a on neuronal survival under autoimmune inflammatory conditions

Interferon-beta-1a (IFN-beta-1a) is an approved treatment for multiple sclerosis (MS). It improves the disease course by reducing the relapse rate as well as the persistent neurological deficits. Recent MRI and post-mortem studies revealed that neuronal and axonal damage are most relevant for chronic disability in MS patients. We have characterized previously time course and mechanisms of neuronal apoptosis in a rat model of myelin oligodendrocyte glycoprotein (MOG)-induced optic neuritis. In this animal model, application of IFN-beta-1a three times per week slightly decreases the loss of retinal ganglion cells (RGCs), the neurons that form the axons within the optic nerve. In contrast to neurotrophic factors, this cytokine does not directly protect cultured RGCs from apoptosis. We conclude that IFN-beta-1a is a suitable candidate to be combined with a directly neuroprotective agent in order to further decrease axonal and neuronal degeneration in MS patients.

Apoptotic Cell Death in Experimental Autoimmune Encephalomyelitis

Particularly in the vulnerable CNS with a low capacity for regeneration specialized mechanisms must be active for the fast and gentle elimination of dysregulated autoaggressive immune cells. In EAE, local apoptosis of autoimmune T-cells has been identified as a safe means for the removal of these unwanted cells. T-cell apoptosis in situ followed by phagocytic clearance of apoptotic remnants by glia assures a minimum of detrimental bystander damage to the local parenchyma and down-regulates the local inflammatory reaction. The pharmacological augmentation of local apoptosis of inflammatory effector cells might gain therapeutic importance also in human neuroimmunological diseases such as multiple sclerosis.

Early pregnancy factor suppresses the infiltration of lymphocytes and macrophages in the spinal cord of rats during experimental autoimmune encephalomyelitis but has no effect on apoptosis

Early pregnancy factor (EPF) is a secreted protein with immunosuppressive and growth factor properties that has been shown to suppress acute experimental autoimmune encephalomyelitis (EAE) induced with myelin basic protein (MBP) in Lewis rats. EAE is associated with infiltration of the central nervous system (CNS) with inflammatory cells. Spontaneous recovery involves the loss of T lymphocytes from the CNS and the selective apoptosis of Vbeta8.2+ cells. In the present study, T cell, macrophage (CD11b/c+) and B cell (CD45RA+) populations in spinal cord and popliteal lymph nodes (LN) of Lewis rats with EAE were quantitated and apoptosis was studied. Rats were treated with EPF or vehicle. Following treatment on day 14 after inoculation with MBP, neither 1 x 100 microg nor 2 x 100 microg doses of EPF affected the total number of cells infiltrating the spinal cord on day 15, although the higher dose caused a decrease in the number of CD5+ and CD11b/c+ cells. Treatment with 2 x 100 microg/day from days 10 to 14 decreased the total number of infiltrating cells, and the numbers of CD5+, CD11b/c+ and CD45RA+ cells. Apoptosis was unaffected. No alteration on the number or type of inflammatory cells in the popliteal LN was observed after treatment on days 10-14. However, treatment with EPF from days 0 to 11 increased the total number of T and B cells and CD5+ T cells found on day 12 in the LN. Similarly, there was an increase in the frequency of MBP-reactive cells in the LN as determined by limiting dilution analysis. These results suggest that EPF treatment reduces the numbers of lymphocytes and macrophages in the CNS, possibly through an effect on cell trafficking.

Phagocytosis of apoptotic inflammatory cells by microglia and its therapeutic implications: termination of CNS autoimmune inflammation and modulation by interferon-beta

Apoptosis of autoaggressive T-cells in the CNS is an effective, noninflammatory mechanism for the resolution of T-cell infiltrates, contributing to clinical recovery in T-cell-mediated neuroinflammatory diseases. The clearance of apoptotic leukocytes by tissue-specific phagocytes is critical in the resolution of the inflammatory infiltrate and leads to a profound downregulation of phagocyte immune functions. Adult human microglia from surgically removed normal brain tissue was used in a standardized, light-microscopic in vitro phagocytosis assay of apoptotic autologous peripheral blood-derived mononuclear cells (MNCs). Microglia from five different patients had a high capacity for the uptake of apoptotic MNCs in contrast to nonapoptotic target cells with the phagocytosis rate for nonapoptotic MNCs amounting to only 61.6% of the apoptotic MNCs. A newly described phosphatidylserine receptor, critical in the phagocytosis of apoptotic cells by macrophages, is also expressed at similar levels on human microglia. The effects of the therapeutically used immunomodulatory agent interferon-beta (IFNbeta) were investigated using Lewis rat microglia and apoptotic, encephalitogenic, myelin basic protein-specific autologous T-cells. Also, rat microglia had a high capacity to phagocytose apoptotic T-cells specifically. IFNbeta increased the phagocytosis of apoptotic T-cells to 36.8% above the untreated controls. The enhanced phagocytic activity was selective for apoptotic T-cells and was not mediated by increased IL-10 secretion. Apoptotic inflammatory cells may be efficiently and rapidly removed by microglial cells in the autoimmune-inflamed human CNS. The in vitro increase of phagocytosis by IFNbeta merits further investigations whether this mechanism could also be therapeutically exploited.

Drug targeting by long-circulating liposomal glucocorticosteroids increases therapeutic efficacy in a model of multiple sclerosis

High-dose glucocorticosteroid hormones are a mainstay in the treatment of relapses in multiple sclerosis. We searched for a way to deliver ultra high doses of glucocorticosteroids to the CNS of rats with experimental autoimmune encephalomyelitis (EAE) using a novel formulation of polyethylene glycol (PEG)-coated long-circulating liposomes encapsulating prednisolone (predni solone liposomes, PL). 3H-labelled PL showed selective targeting to the inflamed CNS, where up to 4.5-fold higher radioactivity was achieved than in healthy control animals. HPLC revealed much higher and more persistent levels of prednisolone in spinal cord after PL compared with an equal dose of free prednisolone. Gold-labelled liposomes could be detected in the target tissue, mostly taken up by macrophages (Mphi), microglial cells and astrocytes. Blood-brain barrier disruption was greatly reduced by 10 mg/kg PL, which was superior to a 5-fold higher dose of free methylprednisolone (MP). PL was also superior to MP in diminishing T-cell infiltration by induction of T-cell apoptosis in spinal cord. Mphi infiltration was clearly decreased only by PL. The percentage of tumour necrosis factor-alpha (TNF-alpha)-positive T cells or Mphi was greatly reduced by PL and by MP. No adverse effects on glial cells were detected. A single injection of PL clearly ameliorated the course of adoptive transfer EAE and EAE induced by immunization. In conclusion, PL is a highly effective drug in treatment of EAE, and is superior to a 5-fold higher dose of free MP, possibly by means of drug targeting. These findings may have implications for future therapy of autoimmune disorders such as multiple sclerosis.

Immunotherapy in autoimmune neuromuscular disorders

Important progress has been made in our understanding of the cellular and molecular processes underlying autoimmune neuromuscular diseases that has led us to identify targets for rational therapeutic intervention. Although antigen-specific immunotherapy is not yet available, old and new immunomodulatory treatments, alone or in combination, provide effective immunotherapy for most autoimmune disorders. In parallel, the achievements of molecular medicine provide more specific yet largely experimental therapeutic tools that need to be tested in the human diseases. Here we review the principles and targets of immunotherapy for autoimmune neuromuscular disorders, address applications and practical guidelines, and give an outlook on future developments.