A comparison of the mechanisms of action of interferon beta and glatiramer acetate in the treatment of multiple sclerosis

EBNA1 Inhibitors Block Proliferation of Spontaneous Lymphoblastoid Cell Lines From Patients With Multiple Sclerosis and Healthy Controls

BACKGROUND AND OBJECTIVES

Epstein-Barr virus (EBV) is a ubiquitous herpesvirus that establishes lifelong latency in memory B cells and has been identified as a major risk factor of multiple sclerosis (MS). B cell depletion therapies have disease-modifying benefit in MS. However, it is unclear whether this benefit is partly attributable to the elimination of EBV+ B cells. Currently, there are no EBV-specific antiviral therapies available for targeting EBV latent infection in MS and limited experimental models to study EBV in MS.

METHODS

In this study, we describe the establishment of spontaneous lymphoblastoid cell lines (SLCLs) generated ex vivo with the endogenous EBV of patients with MS and controls and treated with either an Epstein-Barr virus nuclear antigen 1 (EBNA1) inhibitor (VK-1727) or cladribine, a nucleoside analog that eliminates B cells.

RESULTS

We showed that a small molecule inhibitor of EBNA1, a critical regulator of the EBV life cycle, blocks the proliferation and metabolic activity of these SLCLs. In contrast to cladribine, a highly cytotoxic B cell depleting therapy currently used in MS, the EBNA1 inhibitor VK-1727 was cytostatic rather than cytotoxic and selective for EBV+ cells, while having no discernible effects on EBV- cells. We validate that VK-1727 reduces EBNA1 DNA binding at known viral and cellular sites by ChIP-qPCR.

DISCUSSION

This study shows that patient-derived SLCLs provide a useful tool for interrogating the role of EBV+ B cells in MS and suggests that a clinical trial testing the effect of EBNA1 inhibitors in MS may be warranted.

Lymphocyte Counts and Multiple Sclerosis Therapeutics: Between Mechanisms of Action and Treatment-Limiting Side Effects

Although the detailed pathogenesis of multiple sclerosis (MS) is not completely understood, a broad range of disease-modifying therapies (DMTs) are available. A common side effect of nearly every MS therapeutic agent is lymphopenia, which can be both beneficial and, in some cases, treatment-limiting. A sound knowledge of the underlying mechanism of action of the selected agent is required in order to understand treatment-associated changes in white blood cell counts, as well as monitoring consequences. This review is a comprehensive summary of the currently available DMTs with regard to their effects on lymphocyte count. In the first part, we describe important general information about the role of lymphocytes in the course of MS and the essentials of lymphopenic states. In the second part, we introduce the different DMTs according to their underlying mechanism of action, summarizing recommendations for lymphocyte monitoring and definitions of lymphocyte thresholds for different therapeutic regimens.

Immunological Aspects of Approved MS Therapeutics

Multiple sclerosis (MS) is the most common neurological immune-mediated disease leading to disability in young adults. The outcome of the disease is unpredictable, and over time, neurological disabilities accumulate. Interferon beta-1b was the first drug to be approved in the 1990s for relapsing-remitting MS to modulate the course of the disease. Over the past two decades, the treatment landscape has changed tremendously. Currently, more than a dozen drugs representing 1 substances with different mechanisms of action have been approved (interferon beta preparations, glatiramer acetate, fingolimod, siponimod, mitoxantrone, teriflunomide, dimethyl fumarate, cladribine, alemtuzumab, ocrelizumab, and natalizumab). Ocrelizumab was the first medication to be approved for primary progressive MS. The objective of this review is to present the modes of action of these drugs and their effects on the immunopathogenesis of MS. Each agent's clinical development and potential side effects are discussed.

Clinical effectiveness and cost-effectiveness of beta-interferon and glatiramer acetate for treating multiple sclerosis: systematic review and economic evaluation

BACKGROUND

At the time of publication of the most recent National Institute for Health and Care Excellence (NICE) guidance [technology appraisal (TA) 32] in 2002 on beta-interferon (IFN-β) and glatiramer acetate (GA) for multiple sclerosis, there was insufficient evidence of their clinical effectiveness and cost-effectiveness.

OBJECTIVES

To undertake (1) systematic reviews of the clinical effectiveness and cost-effectiveness of IFN-β and GA in relapsing-remitting multiple sclerosis (RRMS), secondary progressive multiple sclerosis (SPMS) and clinically isolated syndrome (CIS) compared with best supportive care (BSC) and each other, investigating annualised relapse rate (ARR) and time to disability progression confirmed at 3 months and 6 months and (2) cost-effectiveness assessments of disease-modifying therapies (DMTs) for CIS and RRMS compared with BSC and each other.

REVIEW METHODS

Searches were undertaken in January and February 2016 in databases including The Cochrane Library, MEDLINE and the Science Citation Index. We limited some database searches to specific start dates based on previous, relevant systematic reviews. Two reviewers screened titles and abstracts with recourse to a third when needed. The Cochrane tool and the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) and Philips checklists were used for appraisal. Narrative synthesis and, when possible, random-effects meta-analysis and network meta-analysis (NMA) were performed. Cost-effectiveness analysis used published literature, findings from the Department of Health's risk-sharing scheme (RSS) and expert opinion. A de novo economic model was built for CIS. The base case used updated RSS data, a NHS and Personal Social Services perspective, a 50-year time horizon, 2014/15 prices and a discount rate of 3.5%. Outcomes are reported as incremental cost-effectiveness ratios (ICERs). We undertook probabilistic sensitivity analysis.

RESULTS

In total, 6420 publications were identified, of which 63 relating to 35 randomised controlled trials (RCTs) were included. In total, 86% had a high risk of bias. There was very little difference between drugs in reducing moderate or severe relapse rates in RRMS. All were beneficial compared with BSC, giving a pooled rate ratio of 0.65 [95% confidence interval (CI) 0.56 to 0.76] for ARR and a hazard ratio of 0.70 (95% CI, 0.55 to 0.87) for time to disability progression confirmed at 3 months. NMA suggested that 20 mg of GA given subcutaneously had the highest probability of being the best at reducing ARR. Three separate cost-effectiveness searches identified > 2500 publications, with 26 included studies informing the narrative synthesis and model inputs. In the base case using a modified RSS the mean incremental cost was £31,900 for pooled DMTs compared with BSC and the mean incremental quality-adjusted life-years (QALYs) were 0.943, giving an ICER of £33,800 per QALY gained for people with RRMS. In probabilistic sensitivity analysis the ICER was £34,000 per QALY gained. In sensitivity analysis, using the assessment group inputs gave an ICER of £12,800 per QALY gained for pooled DMTs compared with BSC. Pegylated IFN-β-1 (125 µg) was the most cost-effective option of the individual DMTs compared with BSC (ICER £7000 per QALY gained); GA (20 mg) was the most cost-effective treatment for CIS (ICER £16,500 per QALY gained).

LIMITATIONS

Although we built a de novo model for CIS that incorporated evidence from our systematic review of clinical effectiveness, our findings relied on a population diagnosed with CIS before implementation of the revised 2010 McDonald criteria.

CONCLUSIONS

DMTs were clinically effective for RRMS and CIS but cost-effective only for CIS. Both RCT evidence and RSS data are at high risk of bias. Research priorities include comparative studies with longer follow-up and systematic review and meta-synthesis of qualitative studies.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016043278.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Regulation of differentiation and functional properties of monocytes and monocyte-derived dendritic cells by interferon beta in multiple sclerosis

Interferon beta (IFN beta) has complex immune regulatory properties that contribute to its treatment effect on multiple sclerosis (MS). In this study, we investigated the role of IFN beta in differentiation and functional properties of monocytes and monocyte-derived dendritic cells that are critical to the inflammatory process in MS. The results revealed that IFN beta inhibited intracellular production of interleukin (IL)-1b (PB/0.01) in both monocytes exposed toin vitro treatment of IFN beta and monocytes analysedex vivo from MS patients treated with IFN beta. IFN beta was shown to modulate differentiation of monocytes into dendritic cells in the presence of IL-4 and GM-CSF, which resulted in a delayed differentiation process. Furthermore, it characteristically altered the phenotypic features of differentiated dendritic cells by inhibiting the expression of CD1a, CD11b, CD11c, CD123 and CD209 while upregulating costimulatory molecules, such as CD86. The selective regulatory properties of IFN beta appeared to render the function of differentiated dendritic cells to produce an increased amount (PB/0.01) while their ability to secrete proinflammatory IL-12 and TGF beta was significantly reduced. The observed collective effects of IFN beta seemed to correlate with Th2 immune deviation. The study has provided new insights into the regulatory mechanisms of IFN beta in the treatment of MS.

Interferon-β suppresses murine Th1 cell function in the absence of antigen-presenting cells

Interferon (IFN)-β is a front-line therapy for the treatment of the relapsing-remitting form of multiple sclerosis. However, its immunosuppressive mechanism of function remains incompletely understood. While it has been proposed that IFN-β suppresses the function of inflammatory myelin antigen-reactive T cells by promoting the release of immunomodulatory cytokines such as IL-27 from antigen-presenting cells (APCs), its direct effects on inflammatory CD4⁺ Th1 cells are less clear. Here, we establish that IFN-β inhibits mouse IFN-γ⁺ Th1 cell function in the absence of APCs. CD4⁺ T cells express the type I interferon receptor, and IFN-β can suppress Th1 cell proliferation under APC-free stimulation conditions. IFN-β-treated myelin antigen-specific Th1 cells are impaired in their ability to induce severe experimental autoimmune encephalomyelitis (EAE) upon transfer to lymphocyte-deficient Rag1^-/- mice. Polarized Th1 cells downregulate IFN-γ and IL-2, and upregulate the negative regulatory receptor Tim-3, when treated with IFN-β in the absence of APCs. Further, IFN-β treatment of Th1 cells upregulates phosphorylation of Stat1, and downregulates phosphorylation of Stat4. Our data indicate that IFN-γ-producing Th1 cells are directly responsive to IFN-β and point to a novel mechanism of IFN-β-mediated T cell suppression that is independent of APC-derived signals.

Interferon-β1bin multiple sclerosis

In 1993, interferon (IFN)-beta(1b) for subcutaneous injection became the first US FDA-approved immunomodulatory treatment for multiple sclerosis, a chronic inflammatory disease of the CNS. In this review of IFN-beta(1b), we first present a short introduction to multiple sclerosis and currently available therapeutics. We then summarize current knowledge about the biochemical structure of IFN-beta(1b), as well as pharmacokinetics and pharmacodynamics, including data on putative mechanisms underlying therapeutic as well as adverse effects. Furthermore, a critical review of ongoing and recently published clinical trials investigating IFN-beta(1b) in multiple sclerosis will be provided. Main topics are: trials investigating IFN-beta(1b) after a first clinical event, at higher dosages or in comparison to once-weekly subcutaneous IFN-beta(1a) injections, 16 years of long-term follow-up, IFN-beta(1b) in Japanese patients, the role of neutralizing antibodies, biomarkers for the prediction of therapy response, IFN-beta(1b) and pregnancy, and IFN-beta(1b) treatment of children with multiple sclerosis. Finally, we discuss how novel drugs, especially monoclonal antibodies and orally administered immunosuppressants, might soon challenge the position of this well-established agent on the multiple sclerosis therapeutics market.

Regulatory effects of IFN-beta on production of osteopontin and IL-17 by CD4+ T Cells in MS

IFN-beta currently serves as one of the major treatments for MS. Its anti-inflammatory mechanism has been reported as involving a shift in cytokine balance from Th1 to Th2 in the T-cell response against elements of the myelin sheath. In addition to the Th1 and Th2 groups, two other important pro-inflammatory cytokines, IL-17 and osteopontin (OPN), are believed to play important roles in CNS inflammation in the pathogenesis of MS. In this study, we examined the potential effects of IFN-beta on the regulation of OPN and IL-17 in MS patients. We found that IFN-beta used in vitro at 0.5-3 ng/mL significantly inhibited the production of OPN in primary T cells derived from PBMC. The inhibition of OPN was determined to occur at the CD4(+) T-cell level. In addition, IFN-beta inhibited the production of IL-17 and IL-21 in CD4(+) T cells. It has been described that IFN-beta suppresses IL-17 production through the inhibition of a monocytic cytokine, the intracellular translational isoform of OPN. Our further investigation demonstrated that IFN-beta also acted directly on the CD4(+) T cells to regulate OPN and IL-17 expression through the type I IFN receptor-mediated activation of STAT1 and suppression of STAT3 activity. Administration of IFN-beta to EAE mice ameliorated the disease severity. Furthermore, spinal cord infiltration of OPN(+) and IL-17(+) cells decreased in IFN-beta-treated EAE mice along with decreases in serum levels of OPN and IL-21. Importantly, decreased OPN production by IFN-beta treatment contributes to the reduced migratory activity of T cells. Taken together, the results from both in vitro and in vivo experiments indicate that IFN-beta treatment can down-regulate the OPN and IL-17 production in MS. This study provides new insights into the mechanism of action of IFN-beta in the treatment of MS.

GLANCE: results of a phase 2, randomized, double-blind, placebo-controlled study

OBJECTIVE

To evaluate the safety and tolerability of natalizumab when added to glatiramer acetate (GA) in patients with relapsing multiple sclerosis. The primary outcome assessed whether this combination would increase the rate of development of new active lesions on cranial MRI scans vs GA alone.

METHODS

This phase 2, randomized, double-blind, placebo-controlled study included patients aged 19 to 55 years who were treated with GA for at least 1 year before randomization and experienced at least one relapse during the previous year. Patients received IV natalizumab 300 mg (n = 55) or placebo (n = 55) once every 4 weeks plus GA 20 mg subcutaneously once daily for < or = 20 weeks.

RESULTS

The mean rate of development of new active lesions was 0.03 with combination therapy vs 0.11 with GA alone (p = 0.031). Combination therapy resulted in lower mean numbers of new gadolinium-enhancing lesions (0.6 vs 2.3 for GA alone, p = 0.020) and new/newly enlarging T2-hyperintense lesions (0.5 vs 1.3, p = 0.029). The incidence of infection and infusion reactions was similar in both groups; no hypersensitivity reactions were observed. One serious adverse event occurred with combination therapy (elective hip surgery). With the exception of an increase in anti-natalizumab antibodies with combination therapy, laboratory data were consistent with previous clinical studies of natalizumab alone.

CONCLUSION

The combination of natalizumab and glatiramer acetate seemed safe and well tolerated during 6 months of therapy.

High-dose cyclophosphamide in the treatment of multiple sclerosis

High dose cyclophosphamide (HDC) has been successfully used for the treatment of a variety of autoimmune diseases. In this study, we sought to determine whether the use of high dose cyclophosphamide provided stabilization of relapsing remitting MS (RRMS), secondary progressive MS (SPMS), or primary progressive MS (PPMS). The parameters evaluated were EDSS scores, lesion load and brain volumes by MRI and frequency of relapses. Twenty-three patients underwent immunoablative therapy with HDC and were followed for 3.5 years. Nine were relapsing remitting (RRMS), 11 secondary progressive (SPMS), and 3 primary progressive (PPMS). Four of 9 RRMS have had no clinical progression up to 3.5 years following treatment. Three of 9 patients maintained a normal neurologic examination with improved EDSS scores. Seven of the nine RRMS patients had reduction in flare frequency which was maintained for 3.5 years following treatment or no immunomodulating agents. Subgroup analysis in the RRMS patients of lesion load and brain parenchymal volume revealed a favorable trend in these parameters which did not reach statistical significance. The treatment was generally ineffective for SPMS and failed in the 2 PPMS patients. HDC was well tolerated, demonstrated a good safety profile and had minimal adverse effects. These results along with previous reports suggest that early use of HDC therapy in RRMS is promising.

Interferon-beta induces brain-derived neurotrophic factor in peripheral blood mononuclear cells of multiple sclerosis patients

Interferon-beta (IFN-beta) achieves its beneficial effect on multiple sclerosis (MS) via anti-inflammatory properties. In this study, we assessed the expression of the brain-derived neurotrophic factor (BDNF) in peripheral blood mononuclear cells (PBMC) from relapsing-remitting multiple sclerosis (RRMS) patients treated or not with IFN-beta. Intracellular BDNF was measured by Western blot and ELISA and compared with serum BDNF. We found higher levels of BDNF in PBMC of IFN-beta-treated versus non-treated patients, whereas serum levels of BDNF were similar. We hypothesize that the increased intracellular BDNF secondary to IFN-beta is not released in the periphery. This release is probably not tissue specific but in MS patients, BDNF could be specifically delivered by PBMC at the site of re-activation, i.e. within the central nervous system.

Therapeutic potential of statins in multiple sclerosis: immune modulation, neuroprotection and neurorepair

Statins as inhibitors of 3-hydroxy-3-methyl glutaryl coenzyme A reductase are widely used as cholesterol-lowering drugs. Recent studies provide evidence that the anti-inflammatory activity of statins, which is independent of their cholesterol-lowering effects, may have potential therapeutic implications for neuroinflammatory diseases such as multiple sclerosis (MS), Alzheimer's disease and brain tumors, as well as traumatic spinal cord and brain injuries. Studies with animal models of MS suggest that, in addition to immunomodulatory activities similar to the ones observed with approved MS medications, statin treatment also protects the BBB, protects against neurodegeneration and may also promote neurorepair. Although the initial human studies on statin treatment for MS are encouraging, prospective randomized clinical studies will be required to evaluate their efficacy in the larger patient population.

Beta-interferon protects multiple sclerosis patients against enhanced susceptibility to infections caused by poor air quality

BACKGROUND

The monthly multiple sclerosis relapse rate was studied from January 1995 to March 2001 from hospital records in Southwestern Finland as a retrospective open-label study.

METHODS

The relapse rates of beta-interferon users and nonusers were compared to ambient air inhalable particle levels and viral infections in the population with logistic regression.

RESULTS

In the non-user group, relapses were more frequent 1 month following the episodes when PM(10) was in the highest quartile [logistic regression odds ratio = 1.196 (95% CI = 1.019-1.404), p = 0.028] and following adenovirus epidemics in the general population [logistic regression odds ratio = 2.234 (95% CI = 1.013-4.926), p = 0.046]. PM(10) and virus infections had no significant effects in interferon users.

CONCLUSION

In addition to being antiviral, interferon also protected multiple sclerosis patients against an enhanced susceptibility to infections caused by PM(10).

Prevalence of newly generated naive regulatory T cells (Treg) is critical for Treg suppressive function and determines Treg dysfunction in multiple sclerosis

The suppressive function of regulatory T cells (T(reg)) is impaired in multiple sclerosis (MS) patients. The mechanism underlying the T(reg) functional defect is unknown. T(reg) mature in the thymus and the majority of cells circulating in the periphery rapidly adopt a memory phenotype. Because our own previous findings suggest that the thymic output of T cells is impaired in MS, we hypothesized that an altered T(reg) generation may contribute to the suppressive deficiency. We therefore determined the role of T(reg) that enter the circulation as recent thymic emigrants (RTE) and, unlike their CD45RO(+) memory counterparts, express CD31 as typical surface marker. We show that the numbers of CD31(+)-coexpressing CD4(+)CD25(+)CD45RA(+)CD45RO(-)FOXP3(+) T(reg) (RTE-T(reg)) within peripheral blood decline with age and are significantly reduced in MS patients. The reduced de novo generation of RTE-T(reg) is compensated by higher proportions of memory T(reg), resulting in a stable cell count of the total T(reg) population. Depletion of CD31(+) cells from T(reg) diminishes the suppressive capacity of donor but not patient T(reg) and neutralizes the difference in inhibitory potencies between the two groups. Overall, there was a clear correlation between T(reg)-mediated suppression and the prevalence of RTE-T(reg), indicating that CD31-expressing naive T(reg) contribute to the functional properties of the entire T(reg) population. Furthermore, patient-derived T(reg), but not healthy T(reg), exhibit a contracted TCR Vbeta repertoire. These observations suggest that a shift in the homeostatic composition of T(reg) subsets related to a reduced thymic-dependent de novo generation of RTE-T(reg) with a compensatory expansion of memory T(reg) may contribute to the T(reg) defect associated with MS.

Human mesenchymal stem cells constitutively express chemokines and chemokine receptors that can be upregulated by cytokines, IFN-beta, and Copaxone

The factors associated with the migration of marrow-derived mesenchymal stem cells (MSCs) when transplanted into the diseased central nervous system (CNS) are unclear. Chemokines are key mediators of selective cell migration in neurodegenerative diseases and related inflammatory processes. We hypothesized that chemokines are likely to be the chief determinants of MSC migration. We, therefore, systematically assessed the expression and modulating factors for chemokines and chemokine receptors in human MSCs (HuMSCs). The present study demonstrates that unstimulated HuMSCs express a broad range of mRNAs encoding cytokines, chemokines, and their receptors. Using chemotaxis assays, we also assessed the functionality of the receptor expression in HuMSC and we show that CXCL12/stromal cell-derived factor-lalpha (SDF-lalpha), CX3CL1/fractalkine, and CXCL10/interferon-gamma (IFN-gamma)-inducible protein (IP-10) lead to significant HuMSC migration. Moreover, we provide evidence that tumor necrosis factor-alpha (TNF-alpha) and IFN-gamma act as major regulators of the expression of chemokines and their receptors in HuMSCs. Correspondingly, we demonstrate for the first time that current multiple sclerosis (MS) therapies, namely, IFN-beta and Copaxone, influence the expression of chemokines and their receptors in HuMSCs at both mRNA and protein levels. Administration of cytokines, including IFN-beta and Copaxone, may be important in stem cell transplantation therapies and perhaps important in the efficacy of existing MS therapies.

IL-10 is essential for disease protection following intranasal peptide administration in the C57BL/6 model of EAE

We have shown previously that intranasal administration of encephalitogenic peptides in soluble form to H-2u and H-2s mice affords protection from experimental autoimmune encephalomyelitis (EAE). Here we demonstrate that this method of disease protection can be induced in C57BL/6 mice by administration of the soluble peptide 35-55 from myelin oligodendrocyte glycoprotein. This protective effect was demonstrated by the evaluation of both clinical EAE scores and central nervous system histopathology; the latter showing minimal inflammatory infiltrates in treated mice. The employment of an IL-10-/- congenic strain allowed an appraisal of the involvement of IL-10 in this process. The lack of disease protection in these mice clearly demonstrates the non-redundant role of IL-10 in this process.

Chlamydia pneumoniae infection of microglial cells in vitro: a model of microbial infection for neurological disease

Chlamydia pneumoniae is the aetiological cause of a wide variety of chronic inflammatory diseases and may be associated with neurological disease. Microbiological and immunological aspects of the interaction between C. pneumoniae and the central nervous system (CNS) are not well understood because of the lack of a suitable infection model for neuronal studies. In the present study, an in vitro C. pneumoniae infection model was developed in the established microglial cell line EOC 20. Infection of the cells resulted in obvious induction of proinflammatory cytokines. The infection also selectively induced matrix metalloproteinase-9 (MMP-9) but not MMP-2. Moreover, beta interferon, which is known to modulate CNS disease, inhibited induction of MMP-9 following C. pneumoniae infection. These results support the view that C. pneumoniae infection may be associated with marked alteration of the ability of microglial cells to enhance cytokine production as well as induction of an MMP.

Neurotrophic factors in relapsing remitting and secondary progressive multiple sclerosis patients during interferon beta therapy

Although interferon (IFN) beta is a widely used disease-modifying therapy in multiple sclerosis (MS), the mechanisms responsible for its effects are not fully understood. Some studies demonstrated that IFNbeta induces nerve growth factor (NGF) secretion by astrocytes and by brain endothelial cells. In this study, we determined the production of various neurotrophins (brain-derived neurotrophic factor, BDNF; NGF; glial cell line-derived neurotrophic factor; neurotrophin 3; neurotrophin 4) by peripheral blood mononuclear cells (PBMCs) in relapsing-remitting (RR) and secondary progressive (SP) MS patients during IFNbeta treatment. There were no main variations in neurotrophin production either among all MS patients globally considered or in the group of SPMS subjects. Instead, in the group of RRMS patients who did not present clinical exacerbation of disease up to the end of the study, we found a significant increase in BDNF production as from 6 months after starting therapy.

Evidence of involvement of leptin and IL-6 peptides in the action of interferon-beta in secondary progressive multiple sclerosis

Leptin is a peptide hormone which acts on cells of immune system by influencing the production of cytokines. Serum leptin levels and cytokine production by peripheral blood mononuclear cells (PBMC) were measured in 18 secondary progressive multiple sclerosis (SPMS) patients under IFN-beta-1b treatment. There were no overall effects on leptin, interleukin-6 (IL-6), IL-10 and IL-12 p40 after 2, 6 and 12 months of treatment. However, leptin and IL-6 decreased after 6 and 12 months of treatment in 12 patients who did not show progression of disability. Thus, our pilot data show that the beneficial effect of IFN-beta on some SPMS patients might be associated with the reduced levels of leptin and reduced IL-6 production by PBMC.

Increased disability and MRI lesions after discontinuation of IFN-beta-1a in secondary progressive MS

OBJECTIVE

To examine neurological and magnetic resonance imaging (MRI) changes following discontinuation of interferon (IFN)-beta-1a treatment in secondary progressive multiple sclerosis (SPMS).

METHODS

The study involved 21 SPMS patients who received subcutaneous (s.c.) IFN-beta-1a 44 microg three times weekly (t.i.w.) for 12 months and were thereafter followed up without treatment for a further 12 months. The number of relapses, disability on the Expanded Disability Status Scale (EDSS) and MRI were recorded at baseline, at 12 months of IFN-beta-1a 44 microg t.i.w. and 1 year after discontinuation of treatment.

RESULTS

During the 12-month treatment EDSS score and volumes of brain T2- and T1-weighted lesions remained without significant progression, but at 12 months after treatment discontinuation both EDSS score and the volumes of cerebral lesions increased significantly. Cerebrospinal fluid fraction increased significantly both during the treatment and during follow-up.

CONCLUSIONS

Discontinuation of IFN-beta-1a 44 microg t.i.w. in SPMS may be associated with an increase in neurological disability and brain lesions on MRI.

Role of Magnetic Resonance Imaging and Immunotherapy in Treating Multiple Sclerosis

Significant advances in magnetic resonance imaging (MRI) technology and treatment of multiple sclerosis (MS) have been made during the past decade. These advances have revealed evidence of profound heterogeneity in MS. There is a clear need to revisit the key issues in MS pathogenesis and treatment strategies, taking new data into consideration. This paper provides an overview of recent progress in MS research, including (a) a review of clinical, pathologic, and immunologic aspects of MS, (b) a discussion of the mechanism of action of currently available disease-modifying drugs for MS, (c) an account of the role of MRI in clinical management and clinical trials in MS, and (d) an overview of some emerging treatments for MS.

Subcutaneous Recombinant Interferon-??-1a (Rebif??)

Subcutaneous recombinant interferon-beta-1a (Rebif) 22 or 44 microg three times weekly is a valuable option in the first-line treatment in patients with relapsing-remitting multiple sclerosis (RRMS). It has shown benefits on outcome measures related to relapses, progression of disability and magnetic resonance imaging (MRI) in clinical trials. A significant efficacy advantage for subcutaneous interferon-beta-1a three times weekly over intramuscular interferon-beta-1a 30 microg once weekly was shown at 24 and 48 weeks. The most common adverse events are generally mild and clinically manageable. Considering both direct and indirect comparative clinical trial data, an assessment suggests that subcutaneous interferon-beta-1a 44 microg three times weekly has the best benefit-to-risk values of the available disease-modifying drugs used to treat RRMS.

Differential Activation of ERK, p38, and JNK Required for Th1 and Th2 Deviation in Myelin-Reactive T Cells Induced by Altered Peptide Ligand

Autoreactive T cells can be induced by altered peptide ligands to switch Th1 and Th2 phenotypes. The underlying molecular mechanism is critical for understanding of activation of autoreactive T cells and development of novel therapeutic strategies for autoimmune conditions. In this study, we demonstrated that analog peptides of an immunodominant epitope of myelin basic protein (residues 83-99) with alanine substitution at Val(86) and His(88) had a unique partial agonistic property in the induction of Th1 or Th2 deviation in MBP(83-99)-reactive T cell clones typical of Th0 phenotype. The observed phenotypic switch involved differential activation of ERK, p38, and JNK MAPKs. More specifically, Th1 deviation induced by peptide 86V-->A (86A) correlated with enhanced p38 and JNK activities, while Th2 deviation by peptide 88H-->A (88A) was associated with up-regulated ERK activity and a basal level of p38 and JNK activity. Further characterization revealed that a specific inhibitor for ERK selectively prevented Th2 deviation of MBP(83-99)-specific T cells. Conversely, specific inhibitors for p38 and JNK blocked Th1 deviation in the same T cell preparations induced by peptide 86A. The findings have important implications in our understanding of regulation of ERK, p38, and JNK by altered peptide ligands and their role in cytokine regulation and phenotype switch of autoreactive T cells.

Gene expression profiling of relevant biomarkers for treatment evaluation in multiple sclerosis

Multiple sclerosis (MS) is thought to correlate with an array of clinically relevant biomarkers produced during inflammatory process. In this study, a novel gene expression profiling technology was developed and characterized to quantitatively measure the expression profiles of 34 genes selected based on their role in inflammation and their susceptibility to regulation by current MS treatment agents, beta-interferon (IFN) and glatiramer acetate (GA). Potential clinical applications of the technology were evaluated by in vitro and ex vivo analyses in peripheral blood mononuclear cells (PBMC) obtained from MS patients and controls. Interferon-inducible genes were universally up-regulated after in vitro treatment with beta-IFN while the expression of other selected genes encoding cytokines and molecules related to T cell trafficking, activation and apoptosis was variably affected. Beta-IFN and GA exhibited distinctive and characteristic regulatory effects on the expression of the selected genes. Similar regulatory properties of beta-IFN and GA were seen by ex vivo analysis of PBMC specimens in a self-paired study by comparing specific changes induced by beta-IFN or GA treatment in the same patients as well as in a group study by measuring specific profiles in treatment groups compared with an untreated group. Furthermore, the technology served as a simple and sensitive assay for detection of beta-IFN neutralizing antibody based on the blocking effect of serum antibodies on the known regulatory properties of beta-IFN on PBMC. The findings provide important information on the immunoregulatory properties of beta-IFN and GA and support potential clinical applications of this technology in detection of neutralizing antibody (NAB) and evaluation of treatment responses in MS patients.

Ex vivo detection of myelin basic protein-reactive T cells in multiple sclerosis and controls using specific TCR oligonucleotide probes

T cell reactivity to candidate myelin autoantigens, such as myelin basic protein (MBP), may play an important role in the pathogenesis of multiple sclerosis (MS). Although MBP-reactive T cells have been found to undergo in vivo activation in patients with MS, their true precursor frequency in MS is unknown as current frequency analysis is commonly based on the T cell functional responses to MBP. In this study, we developed a TCR sequence-based ex vivo detection system using colony hybridization with oligonucleotide probes specific for CDR3 of selected T cell clones for the analysis of true T cell precursor frequency in PBMC. The results revealed that the precursor frequency of five independent T cell clones recognizing the immunodominant MBP(83-99) region was found to be in the range of 1.6 x 10(-4) in total T cells in three HLA-DR2 patients with MS compared to that of 0.25 x 10(-4) in HLA-DR2 healthy individuals. The observed frequency of MBP(83-99)-reactive T cells in MS patients was considerably higher than those measured in parallel by cell culture-based analysis (2.3 x 10(-6)) or by enzyme-linked immunospot assay (3.9 x 10(-5)) in the same peripheral blood mononuclear cell specimens. Furthermore, the study showed that MBP(83-99)-reactive T cells detected ex vivo belonged to CD45RA+, CD25+ and CD95- T cell subsets as evidenced by preferential expression of specific TCR transcripts in these cell fractions.

Regulation of gene expression associated with acute experimental autoimmune encephalomyelitis by Lovastatin

The attenuation of experimental autoimmune encephalomyelitis (EAE) by Lovastatin (LOV) has now been well established. The present study was designed to explore the global effect of LOV treatment on expression of immune-related genes in lumbar spinal cord (LSC) during acute EAE by using Affymetrix DNA microarrays. LOV treatment demonstrated the limited infiltration of inflammatory cells into the LSC, and microarray analysis further validated those interpretations by demonstrating relatively less alteration in expression of immune response genes in LOV-treated EAE rats on peak clinical day and recovery vs. untreated EAE counterparts. There was significant change in expression of about 158 immune-related genes (including 127 genes reported earlier) in LOV-treated vs. untreated EAE (>1.5 or <-1.5 fold change; P </=.05), of which 140 genes were suppressed and only 18 genes were up-regulated. These altered genes encode for leukocyte-specific markers and receptors, histocompatibility complex, cytokines/receptors, chemokines/receptors, adhesion molecules, components of the complement cascade, cellular activation, and transcription factors and signal transduction-related molecules. Interestingly, T(H)2 phenotype cytokines such as interleukin-4, interleukin-10, and transforming growth factor-beta1 and transcription factors such as peroxisome proliferator-activated receptor (PPAR)-gamma were up-regulated in LSC by LOV treatment as further revealed by real-time PCR and immunoblotting. These findings indicate that PPARs may be mediating the antiinflammatory and immunomodulatory effects of LOV. Together, these findings provide new insight into the molecular events associated with the protection provided by statins during treatment of demyelinating diseases such as multiple sclerosis.