Inhibition of interferon-beta responses in multiple sclerosis immune cells associated with high-dose statins

Pathogenic Role of Fibrinogen in the Neuropathology of Multiple Sclerosis: A Tale of Sorrows and Fears

Multiple sclerosis (MS) is an autoimmune demyelinating neurodegenerative disease of the central nervous system (CNS) due to injury of the myelin sheath by immune cells. The clotting factor fibrinogen is involved in the pathogenesis of MS by triggering microglia and the progress of neuroinflammation. Fibrinogen level is correlated with MS severity; consequently, inhibition of the fibrinogen cascade may reduce MS neuropathology. Thus, this review aimed to clarify the potential role of fibrinogen in the pathogenesis of MS and how targeting of fibrinogen affects MS neuropathology. Accumulation of fibrinogen in the CNS may occur independently or due to disruption of blood-brain barrier (BBB) integrity in MS. Fibrinogen acts as transduction and increases microglia activation which induces the progression of inflammation, oxidative stress, and neuronal injury. Besides, brain fibrinogen impairs the remyelination process by inhibiting the differentiation of oligodendrocyte precursor cells. These findings proposed that fibrinogen is associated with MS neuropathology through interruption of BBB integrity, induction of neuroinflammation, and demyelination with inhibition of the remyelination process by suppressing oligodendrocytes. Therefore, targeting of fibrinogen and/or CD11b/CD18 receptors by metformin and statins might decrease MS neuropathology. In conclusion, inhibiting the expression of CD11b/CD18 receptors by metformin and statins may decrease the pro-inflammatory effect of fibrinogen on microglia which is involved in the progression of MS.

The potential therapeutic effect of statins in multiple sclerosis: beneficial or detrimental effects

Multiple sclerosis (MS) is a chronic progressive disabling disease of the central nervous system (CNS) characterized by demyelination and neuronal injury. Dyslipidemia is observed as one of the imperative risk factors involved in MS neuropathology. Also, chronic inflammation in MS predisposes to the progress of dyslipidemia. Therefore, treatment of dyslipidemia in MS by statins may attenuate dyslipidemia-induced MS and avert MS-induced metabolic changes. Therefore, the present review aimed to elucidate the possible effects of statins on the pathogenesis and outcomes of MS. Statins adversely affect the cognitive function in MS by decreasing brain cholesterol CoQ10, which is necessary for the regulation of neuronal mitochondrial function. However, statins could be beneficial in MS by shifting the immune response from pro-inflammatory Th17 to an anti-inflammatory regulatory T cell (Treg). The protective effect of statins against MS is related to anti-inflammatory and immunomodulatory effects with modulation of fibrinogen and growth factors. In conclusion, the effects of statins on MS neuropathology seem to be conflicting, as statins seem to be protective in the acute phase of MS through anti-inflammatory and antioxidant effects. However, statins lead to detrimental effects in the chronic phase of MS by reducing brain cholesterol and inhibiting the remyelination process.

APOL1 variant-expressing endothelial cells exhibit autophagic dysfunction and mitochondrial stress

Polymorphisms in the Apolipoprotein L1 (APOL1) gene are common in ancestrally African populations, and associate with kidney injury and cardiovascular disease. These risk variants (RV) provide an advantage in resisting Trypanosoma brucei, the causal agent of African trypanosomiasis, and are largely absent from non-African genomes. Clinical associations between the APOL1 high risk genotype (HRG) and disease are stronger in those with comorbid infectious or immune disease. To understand the interaction between cytokine exposure and APOL1 cytotoxicity, we established human umbilical vein endothelial cell (HUVEC) cultures representing each APOL1 genotype. Untreated HUVECs were compared to IFNɣ-exposed; and APOL1 expression, mitochondrial function, lysosome integrity, and autophagic flux were measured. IFNɣ increased median APOL1 expression across all genotypes 22.1 (8.3 to 29.8) fold (p=0.02). Compared to zero risk variant-carrying HUVECs (0RV), HUVECs carrying 2 risk variant copies (2RV) showed both depressed baseline and maximum mitochondrial oxygen consumption (p<0.01), and impaired mitochondrial networking on MitoTracker assays. These cells also demonstrated a contracted lysosomal compartment, and an accumulation of autophagosomes suggesting a defect in autophagic flux. Upon blocking autophagy with non-selective lysosome inhibitor, hydroxychloroquine, autophagosome accumulation between 0RV HUVECs and untreated 2RV HUVECs was similar, implicating lysosomal dysfunction in the HRG-associated autophagy defect. Compared to 0RV and 2RV HUVECs, HUVECs carrying 1 risk variant copy (1RV) demonstrated intermediate mitochondrial respiration and autophagic flux phenotypes, which were exacerbated with IFNɣ exposure. Taken together, our data reveal that IFNɣ induces APOL1 expression, and that each additional RV associates with mitochondrial dysfunction and autophagy inhibition. IFNɣ amplifies this phenotype even in 1RV HUVECs, representing the first description of APOL1 pathobiology in variant heterozygous cell cultures.

Type I interferon detection in autoimmune diseases: challenges and clinical applications

INTRODUCTION

Accumulating data highlights that the dysregulation of type I interferon (IFN) pathways plays a central role in the pathogenesis of several systemic and organ-specific autoimmune diseases. Advances in understanding the role of type I IFNs in these disorders can lead to targeted drug development as well as establishing potential disease biomarkers.

AREAS COVERED

Here, we summarize current knowledge regarding the role of type I IFNs in the major systemic, as well as organ-specific, autoimmune disorders, including prominent inflammatory CNS disorders like multiple sclerosis.

EXPERT OPINION

Type I IFN involvement and its clinical associations in a wide spectrum of autoimmune diseases represents a promising area for research aiming to unveil common pathogenetic pathways in systemic and organ-specific autoimmunity.

Atorvastatin Attenuates Programmed Death Ligand-1 (PD-L1) Induction in Human Hepatocellular Carcinoma Cells

Liver cancer is the sixth most common cancer worldwide with high morbidity and mortality. Programmed death ligand 1 (PD-L1) is a major ligand of programmed death 1 receptor (PD1), and PD1/PD-L1 checkpoint acts as a negative regulator of the immune system. Cancers evade the host’s immune defense via PD-L1 expression. This study aimed to investigate the effects of tumor-related cytokines, interferon gamma (IFNγ), and tumor necrosis factor alpha (TNFα) on PD-L1 expression in human hepatocellular carcinoma cells, HepG2. Furthermore, as atorvastatin, a cholesterol-lowering agent, is documented for its immunomodulatory properties, its effect on PD-L1 expression was investigated. In this study, through real-time RT-PCR, Western blot, and immunocytochemistry methods, PD-L1 expression in both mRNA and protein levels was found to be synergistically upregulated in HepG2 by a combination of IFNγ and TNFα, and STAT1 activation was mainly responsible for that synergistic effect. Next, atorvastatin can inhibit the induction of PD-L1 by either IFNγ alone or IFNγ/TNFα combination treatment in HepG2 cells. In conclusion, in HepG2 cells, expression of PD-L1 was augmented by cytokines in the tumor microenvironment, and the effect of atorvastatin on tumor immune response through inhibition of PD-L1 induction should be taken into consideration in cancer patients who have been prescribed atorvastatin.

Statins act as transient type I interferon inhibitors to enable the antitumor activity of modified vaccinia Ankara viral vectors

BACKGROUND

Modified vaccinia virus Ankara (MVA) are genetically engineered non-replicating viral vectors. Intratumoral administration of MVA induces a cyclic GMP-AMP synthase-mediated type I interferon (IFN) response and the production of high levels of the transgenes engineered into the viral genome such as tumor antigens to construct cancer vaccines. Although type I IFNs are essential for establishing CD8-mediated antitumor responses, this cytokine family may also give rise to immunosuppressive mechanisms.

METHODS

In vitro assays were performed to evaluate the activity of simvastatin and atorvastatin on type I IFN signaling and on antigen presentation. Surface levels of IFN α/β receptor 1, endocytosis of bovine serum albumin-fluorescein 5 (6)-isothiocyanate, signal transducer and activator of transcription (STAT) phosphorylation, and real-time PCR of IFN-stimulated genes were assessed in the murine fibroblast cell line L929. In vivo experiments were performed to characterize the effect of simvastatin on the MVA-induced innate immune response and on the antitumor effect of MVA-based antitumor vaccines in B16 melanoma expressing ovalbumin (OVA) and Lewis lung carcinoma (LLC)-OVA tumor models. RNAseq analysis, depleting monoclonal antibodies, and flow cytometry were used to evaluate the MVA-mediated immune response.

RESULTS

In this work, we identified commonly prescribed statins as potent IFNα pharmacological inhibitors due to their ability to reduce surface expression levels of IFN-α/β receptor 1 and to reduce clathrin-mediated endocytosis. Simvastatin and atorvastatin efficiently abrogated for 8 hours the transcriptomic response to IFNα and enhanced the number of dendritic cells presenting an OVA-derived peptide bound to major histocompatibility complex (MHC) class I. In vivo, intraperitoneal or intramuscular administration of simvastatin reduced the inflammatory response mediated by peritumoral administration of MVA and enhanced the antitumor activity of MVA encoding tumor-associated antigens. The synergistic antitumor effects critically depend on CD8⁺ cells, whereas they were markedly improved by depletion of CD4⁺ lymphocytes, T regulatory cells, or NK cells. Either MVA-OVA alone or combined with simvastatin augmented B cells, CD4⁺ lymphocytes, CD8⁺ lymphocytes, and tumor-specific CD8⁺ in the tumor-draining lymph nodes. However, only the treatment combination increased the numbers of these lymphocyte populations in the tumor microenvironment and in the spleen.

CONCLUSION

In conclusion, blockade of IFNα functions by simvastatin markedly enhances lymphocyte infiltration and the antitumor activity of MVA, prompting a feasible drug repurposing.

Distinct Single Cell Gene Expression in Peripheral Blood Monocytes Correlates With Tumor Necrosis Factor Inhibitor Treatment Response Groups Defined by Type I Interferon in Rheumatoid Arthritis

Previously, we demonstrated in test and validation cohorts that type I IFN (T1IFN) activity can predict non-response to tumor necrosis factor inhibitors (TNFi) in rheumatoid arthritis (RA). In this study, we examine the biology of non-classical and classical monocytes from RA patients defined by their pre-biologic treatment T1IFN activity. We compared single cell gene expression in purified classical (CL, n = 342) and non-classical (NC, n = 359) monocytes. In our previous work, RA patients who had either high IFNβ/α activity (>1.3) or undetectable T1IFN were likely to have EULAR non-response to TNFi. In this study comparisons were made among patients grouped according to their pre-biologic treatment T1IFN activity as clinically relevant: “T1IFN undetectable (T1IFN ND) or IFNβ/α >1.3” (n = 9) and “T1IFN detectable but IFNβ/α ≤ 1.3” (n = 6). In addition, comparisons were made among patients grouped according to their T1IFN activity itself: “T1IFN ND,” “T1IFN detected and IFNβ/α ≤ 1.3,” and “IFNβ/α >1.3.” Major differences in gene expression were apparent in principal component and unsupervised cluster analyses. CL monocytes from the T1IFN ND or IFNβ/α >1.3 group were unlikely to express JAK1 and IFI27 (p < 0.0001 and p 0.0005, respectively). In NC monocytes from the same group, expression of IFNAR1, IRF1, TNFA, TLR4 (p ≤ 0.0001 for each) and others was enriched. Interestingly, JAK1 expression was absent in CL and NC monocytes from nine patients. This pattern most strongly associated with the IFNβ/α>1.3 group. Differences in gene expression in monocytes among the groups suggest differential IFN pathway activation in RA patients who are either likely to respond or to have no response to TNFi. Additional transcripts enriched in NC cells of those in the T1IFN ND and IFNβ/α >1.3 groups included MYD88, CD86, IRF1, and IL8. This work could suggest key pathways active in biologically defined groups of patients, and potential therapeutic strategies for those patients unlikely to respond to TNFi.

Statins and autoimmunity: State-of-the-art

HMG-CoA reductase inhibitors, or statins, are potent plasma LDL-cholesterol (LDL-c) lowering agents. Since the introduction of the first statin, lovastatin, in 1987, accumulating evidence showed that non-cholesterol lowering effects play an important role in their efficacy to reduce atherosclerotic cardiovascular disease (ASCVD). Thus, these non-LDL-c lowering properties could benefit patients with immune-mediated diseases. Statins and their associated immune-modulating roles have recently received much attention. Different statins have been administered in various experimental and clinical studies focused on autoimmunity. The results indicate that statins can modulate immune responses through mevalonate pathway-dependent and -independent mechanisms. The anti-inflammatory and immune-modulating effects include cell adhesion, migration of antigen presenting cells, and differentiation, as well as activation, of T-cells. In various autoimmune diseases (e.g. rheumatoid arthritis, lupus, and multiple sclerosis), promising results have been obtained to date.

Lessons from precision medicine in rheumatology

Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) are two common autoimmune rheumatic diseases that vary in severity, clinical presentation, and disease course between individuals. Molecular and genetic studies of both diseases have identified candidate genes and molecular pathways that are linked to various disease outcomes and treatment responses. Currently, patients can be grouped into molecular subsets in each disease, and these molecular categories should enable precision medicine approaches to be applied in rheumatic diseases. In this article, we will review key lessons learned about disease heterogeneity and molecular characterization in rheumatology, which we hope will lead to personalized therapeutic strategies.

Interferon-β corrects massive gene dysregulation in multiple sclerosis: Short-term and long-term effects on immune regulation and neuroprotection

Background

In multiple sclerosis (MS), immune up-regulation is coupled to subnormal immune response to interferon-β (IFN-β) and low serum IFN-β levels. The relationship between the defect in IFN signalling and acute and long-term effects of IFN-β on gene expression in MS is inadequately understood.

Methods

We profiled IFN-β-induced transcriptome shifts, using high-resolution microarrays on 227 mononuclear cell samples from IFN-β-treated MS Complete Responders (CR) stable for five years, and stable and active Partial Responders (PR), stable and active untreated MS, and healthy controls.

Findings

IFN-β injection induced short-term changes in 1,200 genes compared to baseline expression after 4-day IFN washout. Pre-injection after washout, and in response to IFN-β injections, PR more frequently had abnormal gene expression than CR. Surprisingly, short-term IFN-β induced little shift in Th1/Th17/Th2 gene expression, but up-regulated immune-inhibitory genes (ILT, IDO1, PD-L1). Expression of 8,800 genes was dysregulated in therapy-naïve compared to IFN-β-treated patients. These long-term changes in protein-coding and long non-coding RNAs affect immunity, synaptic transmission, and CNS cell survival, and correct the disordered therapy-naïve transcriptome to near-normal. In keeping with its impact on clinical course and brain repair in MS, long-term IFN-β treatment reversed the overexpression of proinflammatory and MMP genes, while enhancing genes involved in the oligodendroglia-protective integrated stress response, neuroprotection, and immunoregulation. In the rectified long-term signature, 277 transcripts differed between stable PR and CR patients.

Interpretation

IFN-β had minimal short-term effects on Th1 and Th2 pathways, but long-term it corrected gene dysregulation and induced immunoregulatory and neuroprotective genes. These data offer new biomarkers for IFN-β responsiveness.

Funding

Unrestricted grants from the US National MS Society, NMSS RG#4509A, and Bayer Pharmaceuticals

Vitamin D enhances responses to interferon-β in MS

Objective

To determine the effect of vitamin D3 on interferon-β (IFN-β) response and immune regulation in MS mononuclear cells (MNCs).

Methods

MNCs from 126 subjects, including therapy-naive patients with different forms of MS, plus patients with MS receiving IFN-β or glatiramer treatment, plus healthy controls were incubated in vitro with IFN-β-1b ± vitamin D3 (calcitriol). Activation of the IFN-β–induced transcription factor, p-Y-STAT1, and antiviral myxovirus A (MxA) protein was measured with flow cytometry and Western blots; serum proteins were measured with a customized 31-protein multiplex assay.

Results

Vitamin D enhanced in vitro IFN responses, as measured by induction of p-Y-STAT1 and MxA in MNCs, T cells, and monocytes. Vitamin D augmentation of IFN responses was seen in untreated and in IFN-β-1b–treated MS. The combination of vitamin D plus IFN-β reduced Th1 and Th17 cytokines, and increased Th2 responses, reversing the effect of IFN-β alone. Exacerbations and progression in untreated patients reduced the vitamin D enhancement of IFN responses. Vitamin D had less effect on IFN response in clinically stable glatiramer-treated than in IFN-β–treated patients.

Conclusion

Vitamin D enhances IFN-β induction of multiple proteins and also reverses the Th1/Th2 bias in MS seen with IFN-β alone. The combination of vitamin D and IFN-β has potential benefit in ameliorating MS.

Novel genetic associations with interferon in systemic lupus erythematosus identified by replication and fine-mapping of trait-stratified genome-wide screen

BACKGROUND/PURPOSE

High serum interferon alpha (IFN-α) is an important heritable phenotype in systemic lupus erythematosus (SLE) which is involved in primary disease pathogenesis. High vs. low levels of IFN-α are associated with disease severity and account for some of the biological heterogeneity between SLE patients. The aim of the study was to replicate and fine-map previously detected genetic associations with serum IFN-α in SLE.

METHODS

We previously undertook a case-case genome-wide association study of SLE patients stratified by ancestry and extremes of phenotype in serum IFN-α. Single nucleotide polymorphisms (SNPs) in seven loci identified in this screen were selected for follow up in a large independent cohort of 1370 SLE patients (703 European-ancestry, 432 African ancestry, and 235 Amerindian ancestry). Each ancestral background was analyzed separately, and ancestry-informative markers were used to control for ancestry and admixture.

RESULTS

We find a rare haplotype spanning the promoter region of EFNA5 that is strongly associated with serum IFN-α in both African-American and European-American SLE patients (OR = 3.0, p = 3.7 × 10^-6). We also find SNPs in the PPM1H, PTPRM, and NRGN regions associated with IFN-α levels in European-American, Amerindian, and African-American SLE patients respectively. Many of these associations are within regulatory regions of the gene, suggesting an impact on transcription.

CONCLUSION

This study demonstrates the power of molecular sub-phenotypes to reveal genetic factors involved in complex autoimmune disease. The distinct associations observed in different ancestral backgrounds emphasize the heterogeneity of molecular pathogenesis in SLE.

Zika Virus as an Emerging Neuropathogen: Mechanisms of Neurovirulence and Neuro-Immune Interactions

Zika virus (ZIKV) is an emerging arbovirus of the genus Flaviviridae, which causes a febrile illness and has spread from across the Pacific to the Americas in a short timeframe. Convincing evidence has implicated the ZIKV to incident cases of neonatal microcephaly and a set of neurodevelopmental abnormalities referred to as the congenital Zika virus syndrome. In addition, emerging data points to an association with the ZIKV and the development of the so-called Guillain-Barre syndrome, an acute autoimmune polyneuropathy. Accumulating knowledge suggests that neurovirulent strains of the ZIKV have evolved from less pathogenic lineages of the virus. Nevertheless, mechanisms of neurovirulence and host-pathogen neuro-immune interactions remain incompletely elucidated. This review provides a critical discussion of genetic and structural alterations in the ZIKV which could have contributed to the emergence of neurovirulent strains. In addition, a mechanistic framework of neuro-immune mechanisms related to the emergence of neuropathology after ZIKV infection is discussed. Recent advances in knowledge point to avenues for the development of a putative vaccine as well as novel therapeutic strategies. Nevertheless, there are unique unmet challenges that need to be addressed in this regard. Finally, a research agenda is proposed.

Statin treatment in multiple sclerosis: a systematic review and meta-analysis

BACKGROUND

Multiple sclerosis (MS) is a chronic inflammatory disease that leads to progressive disability. Statins [hydroxymethylglutaryl-CoA (HMG-CoA) reductase inhibitors] are widely prescribed drugs in hypercholesterolemia. They exert immunomodulatory and neurotrophic effects and are attractive candidates for MS treatment due to reliable safety profiles and favorable costs. Studies of statins in a murine MS model and in open-label trials in MS have shown decreased disease severity.

OBJECTIVE

Our objective was to assess current evidence to support statin treatment in MS and clinically isolated syndrome (CIS).

METHODS

We conducted a systematic literature review of EMBASE, PubMed, and CINAHL databases, clinical trials registries, and unpublished conference meeting abstracts as well as reference lists between 1 and 8 June 2014 and repeated it on 1 December 2014. Randomized controlled trials (RCTs) of statins, in any form or dosage, as monotherapy or add-on to established therapy in relapsing-remitting MS (RRMS), progressive MS, and CIS were included. Data were extracted using pre-defined fields to measure study quality. Meta-analysis was performed with regards to pre-defined outcome measures of relapse activity, magnetic resonance imaging (MRI) activity, Expanded Disability Status Scale (EDSS) progression, and adverse events using a fixed-effects model due to low heterogeneity between studies.

RESULTS

Eight trials were included in the review [five of statin add-on to interferon (IFN)-β treatment in RRMS, one of statin monotherapy in CIS, one of statin monotherapy in optic neuritis (ON)/CIS, and one of statin monotherapy in secondary progressive MS (SPMS)]. Three trials with eligible characteristics had not been published in peer-reviewed journals and were therefore not included. Due to the low number of trials in CIS and SPMS, meta-analysis of primary outcomes was only performed for RRMS studies. Meta-analysis showed no significant effect of statin add-on to IFNβ therapy. Indeed, a trend towards an increase in disease activity was shown in the statin group with regards to new T2 lesions, proportion of patients with relapse, and whole brain atrophy but not for EDSS progression. In SPMS, statin monotherapy showed significant reduction in brain atrophy and disability progression but no effect on relapse rate. In CIS, a phase II trial showed no difference in relapse activity, MRI activity or risk of MS between statin monotherapy and placebo. In acute ON, statin monotherapy produced better visual outcome but no difference in relapse activity, MRI activity, or risk of MS.

CONCLUSIONS

The pleiotropic effects and effects in the murine model of MS could not be converted to a proven effect in relapsing MS and hence statin therapy either as a monotherapy or in combination with IFNβ treatment for RRMS, and statin monotherapy for CIS cannot at present be recommended. However, indications are that statins may be beneficial in SPMS. The benefit thereof and whether this is due to a direct immunomodulatory and neuroprotective effect warrant further studies.

Interferon regulatory factors: critical mediators of human lupus

The pathogenesis of systemic lupus erythematosus (SLE) is multifactorial, and the interferon regulatory factors (IRFs) play an important role. Autoantibodies formed in SLE target nuclear antigens, and immune complexes formed by these antibodies contain nucleic acid. These immune complexes can activate antiviral pattern recognition receptors (PRRs), resulting in the downstream activation of IRFs, which can induce type I interferon (IFN-I) and other inflammatory mediators. Genetic variations in IRFs have been associated with susceptibility to SLE, and current evidence supports the idea that these polymorphisms are gain of function in humans. Recent studies suggest that these genetic variations contribute to the break in humoral tolerance that allows for nucleic acid binding autoantibodies, and that the same polymorphisms also augment IFN-I production in the presence of these autoantibody immune complexes, forming a feed-forward loop. In this review, we will outline major features of the PRR/IRF systems and describe the role of the IRFs in human SLE pathogenesis.

Genetic analysis of the pathogenic molecular sub-phenotype interferon-alpha identifies multiple novel loci involved in systemic lupus erythematosus

Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disorder characterized by inflammation of multiple organ systems and dysregulated interferon responses. SLE is both genetically and phenotypically heterogeneous, greatly reducing the power of case-control studies in SLE. Elevated circulating interferon alpha (IFN-α) is a stable, heritable trait in SLE, which has been implicated in primary disease pathogenesis. 40–50% of patients have high IFN-α, and high levels correspond with clinical differences. To study genetic heterogeneity in SLE, we performed a case-case study comparing patients with high vs. low IFN-α in over 1550 SLE cases, including GWAS and replication cohorts. In meta-analysis, the top associations in European ancestry were PRKG1 rs7897633 (P_Meta=2.75 × 10⁻⁸) and PNP rs1049564 (P_Meta=1.24 × 10⁻⁷). We also found evidence for cross-ancestral background associations with the ANKRD44 and PLEKHF2 loci. These loci have not been previously identified in case-control SLE genetic studies. Bioinformatic analyses implicated these loci functionally in dendritic cells and natural killer cells, both of which are involved in IFN-α production in SLE. As case-control studies of heterogeneous diseases reach a limit of feasibility with respect to subject number and detectable effect size, the study of informative pathogenic subphenotypes becomes an attractive strategy for genetic discovery in complex disease.

How type I interferons work in multiple sclerosis and other diseases: some unexpected mechanisms

Type I interferons (IFNs) are important in innate and adaptive immunity. They are used to treat virus infections, cancer, and multiple sclerosis (MS). There are 5 type I IFN families in humans-IFN-α with 13 subtypes, plus IFN-β, ɛ, κ, and ω. Because their receptor binding affinities vary, these IFNs have different gene induction profiles and quite variable therapeutic effects. IFN-α subtypes may each be specific for certain viruses, but can be neurotoxic. IFN-β induces IFN-α, plus has additional direct effects on target cells. IFN-β was the first therapy approved that could change the course of MS. It has broader specificity than IFN-α, enhances cognition in MS, and may be neuroprotective and can potentially enhance fertility in women. Priming the IFN signaling system with an injection of IFN-β can enhance subnormal type I IFN signals in MS. Many other commonly used drugs and vitamins may potentiate clinical benefits of IFN-β.

MxA mRNA quantification and disability progression in interferon beta-treated multiple sclerosis patients

Even though anti-interferon beta (IFNβ) antibodies are the main determinants of IFNβ bioactivity loss and Myxovirus-resistance protein A (MxA) is the most established marker of IFNβ biological activity in IFNβ-treated multiple sclerosis patients, their usefulness in the routine clinical practice is still debated. Therefore, 118 multiple sclerosis patients naïve for treatment were enrolled for a 3-year longitudinal observational study mimicking the conditions of a real-world setting. In order to evaluate the kinetics of bioactivity loss in blood samples obtained every 6 months after therapy initiation, MxA and interferon receptor isoform/subunit mRNA were quantified by real-time PCR, anti-IFNβ binding antibodies were detected by radioimmunoprecipitation, and neutralizing antibodies by cytopathic effect inhibition assay. Clinical measures of disease activity and disability progression were also obtained at all time points. We found that, at the individual-patient level, the response to IFNβ therapy was extremely heterogeneous, including patients with stable or transitory, early or late loss of IFNβ bioactivity, and patients with samples lacking MxA mRNA induction in spite of absence of antibodies. No interferon receptor isoform alterations that could explain these findings were found. At the group level, none of these biological features correlated with the measures of clinical disease activity or progression. However, when MxA mRNA was evaluated not at the single time point as a dichotomic marker (induced vs. non-induced), but as the mean of its values measured over the 6-to-24 month period, the increasing average MxA predicted a decreasing risk of short-term disability progression, independently from the presence of relapses. Therefore, a more bioactive treatment, even if unable to suppress relapses, reduces their severity by an amount that is proportional to MxA levels. Together with its feasibility in the routine laboratory setting, these data warrant the quantification of MxA mRNA as a primary tool for a routine monitoring of IFNβ therapy.

Role of statins in the treatment of multiple sclerosis

Statins as inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase are widely prescribed for hypercholesterolemia treatment. In the last years, statins have also been shown to exert immunomodulatory and anti-inflammatory effects which appear to be related to inhibition of isoprenylation of small GTP-binding proteins and, at least in part, independent of their cholesterol-lowering effects. These "pleiotropic" effects make statins an attractive treatment option for immune-mediated disorders such as multiple sclerosis. Studies in vitro and in experimental autoimmune encephalomyelitis animal model seem to support not only the efficacy of statins as immunomodulatory agents but also their potential neuroprotective properties, although the exact mechanism with which statins exert these effects has not yet been fully understood. The immunomodulatory, anti-inflammatory and neuroprotective properties of statins provided the incentive for several clinical trials in multiple sclerosis, in which they were tested not only as mono-therapy but also in combination with interferon-β. However, the attempt to translate the results of animal model studies in humans produced conflicting results. Further large, prospective, randomized, double-blind, placebo-controlled trials, designed to evaluate the long-term effects of statins alone or in add-on to other disease-modifying therapies, are needed to support their routine clinical use in multiple sclerosis.

Simvastatin attenuates rhinovirus-induced interferon and CXCL10 secretion from monocytic cells in vitro

RV infections frequently trigger exacerbations of respiratory diseases, such as asthma, yet treatment and intervention options remain limited. Statin drugs are the treatment of choice for dyslipidemia and can also modulate immune cell function. To determine whether statin drugs modify antiviral responses of human monocytic cells, we obtained blood monocytes from donors with allergies and/or asthma and treated the cells with sim prior to challenge with RV. RV-induced secretion of CXCL10 was attenuated significantly, irrespective of RV type (RV-16, -14, or -1A), which corresponded with decreases in IFN-α secretion and pSTAT1. Sim pretreatment also reduced RV-induced CXCL10 secretion from human alveolar macrophages. The addition of mev and GGPP-two intermediates of the cholesterol biosynthesis pathway-was able to rescue CXCL10 release fully, demonstrating that effects of sim were related to inhibition of cholesterol biosynthesis and not to an off-target effect. In addition, sim pretreatment attenuated IFN-α-induced pSTAT1 and CXCL10 secretion, providing evidence that sim additionally can affect type I IFNR signaling. SOCS1 and 3 mRNA are both induced with RV stimulation, but sim did not elevate SOCS1 or SOCS3 mRNA expression basally or in the presence of RV. Our findings suggest that sim inhibition of the cholesterol biosynthesis pathway leads to decreased RV-induced chemokine secretion in monocytes and macrophages. These findings suggest that statin drugs have the potential to curb the inflammatory response to RV infection.

Atorvastatin added to interferon beta for relapsing multiple sclerosis: 12-month treatment extension of the randomized multicenter SWABIMS trial

Background

Statins have anti-inflammatory and immunomodulatory properties in addition to lipid-lowering effects.

Objectives

To report the 12-month extension of a phase II trial evaluating the efficacy, safety and tolerability of atorvastatin 40 mg/d added to interferon beta-1b (IFNB-1b) in relapsing-remitting multiple sclerosis (RRMS).

Methods

In the randomized, multicenter, parallel-group, rater-blinded core study, 77 RRMS patients started IFNB-1b. At month three they were randomized 1∶1 to receive atorvastatin 40 mg/d or not in addition to IFNB-1b until month 15. In the subsequent extension study, patients continued with unchanged medication for another 12 months. Data at study end were compared to data at month three of the core study.

Results

27 of 72 patients that finished the core study entered the extension study. 45 patients were lost mainly due to a safety analysis during the core study including a recruitment stop for the extension study. The primary end point, the proportion of patients with new lesions on T2-weighted images was equal in both groups (odds ratio 1.926; 95% CI 0.265–14.0007; p = 0.51). All secondary endpoints including number of new lesions and total lesion volume on T2-weighted images, total number of Gd-enhancing lesions on T1-weighted images, volume of grey and white matter, EDSS, MSFC, relapse rate, number of relapse-free patients and neutralizing antibodies did not show significant differences either. The combination therapy was well tolerated.

Conclusions

Atorvastatin 40 mg/day in addition to IFNB-1b did not have any beneficial effects on RRMS compared to IFNB-1b monotherapy over a period of 24 months.

Trial Registration

ClinicalTrials.gov NCT01111656

Aberrant Type I Interferon Regulation in Autoimmunity: Opposite Directions in MS and SLE, Shaped by Evolution and Body Ecology

Studying the action of mechanisms of type I interferon (IFN) provides the insight to elucidate the cause and therapy for autoimmune diseases. There are high IFN responses in some diseases such as connective tissue diseases, but low responses in multiple sclerosis. Distinct IFN features lead us to understand pathology of a spectrum of autoimmune diseases and help us to search genetic changes, gene expression, and biomarkers for diagnosis, disease progression, and treatment response.

Genetic variation near IRF8 is associated with serologic and cytokine profiles in systemic lupus erythematosus and multiple sclerosis

Alleles of IRF8 are associated with susceptibility to both systemic lupus erythematosus (SLE) and multiple sclerosis (MS). While high type I interferon (IFN) is thought to be causal in SLE, type I IFN is used as a therapy in MS. We investigated whether IRF8 alleles were associated with type I IFN levels or serologic profiles in SLE and MS. Alleles which have been previously associated with SLE or MS were genotyped in SLE and MS patients. The MS-associated rs17445836G allele was associated with anti-dsDNA autoantibodies in SLE patients (meta-analysis OR=1.92). The same allele was associated with decreased serum IFN activity in SLE patients with anti-dsDNA antibodies, and with decreased type I IFN-induced gene expression in PBMC from anti-dsDNA negative SLE patients. In secondary progressive MS patients, rs17445836G was associated with decreased serum type I IFN. Rs17445836G was associated with increased IRF8 expression in SLE patient B cells. In summary, IRF8 rs17445836G is associated with human autoimmune disease characterized by low type I IFN levels, and this may have pharmacogenetic relevance as type I IFN is modulated in SLE and MS. The association with autoantibodies and increased IRF8 expression in B cells supports a role for rs17445836G in humoral tolerance.

Combinatorial Effect of Metformin and Lovastatin Impedes T-cell Autoimmunity and Neurodegeneration in Experimental Autoimmune Encephalomyelitis

Multiple Sclerosis (MS) is an incurable central nervous system (CNS) demyelinating disease affecting several million people worldwide. Due to the multifactorial and complex pathology of MS, FDA approved drugs often show limited efficacy inpatients. We earlier documented that both lovastatin (cholesterol lowering drug) and metformin (anti-diabetic drug) attenuate experimental autoimmune encephalomyelitis (EAE), a widely used model of MS via different mechanisms of action. Since combination therapy of two or more agents has advantage over monotherapy, we here assessed the therapeutic efficacy of metformin and lovastatin combination in EAE. We found that suboptimal doses of these drugs in combination had additive effect to attenuate established EAE in treated animals than their individual treatments. Histological, immunohistochemistry and western blotting analyses revealed that the observed demyelination and axonal loss as evident from reduced levels of myelin and neurofilament proteins in the spinal cords of EAE animals were attenuated by treatment with these drugs in combination. Accordingly, the observed infiltration of myelin reactive T cells (CD4 and CD8) and macrophages (CD68) as well as the increased expression of their signatory cytokines in the spinal cords of EAE animals were attenuated by this regimen as revealed by enzyme-linked immune-sorbent assay and real-time PCR analyses. In the periphery, this regimen biased the class of elicited anti-myelin basic protein immunoglobulins from IgG2a to IgG1 and IgG2b, suggesting a Th1 to Th2 shift which was further supported by the increased expression of their signatory cytokines in EAE animals. Taken together, these data imply that metformin and lovastatin combination attenuates T-cell autoimmunity and neurodegeneration in treated EAE animals thereby suggesting that the oral administration of these FDA approved drugs in combination has potential to limit MS pathogenesis.