VLA-4 expression on peripheral blood lymphocytes is downregulated after treatment of multiple sclerosis with interferon beta

The role of type I IFN in autoimmune and autoinflammatory diseases with CNS involvement

Type I interferons (IFNs) are major mediators of innate immunity, with well-known antiviral, antiproliferative, and immunomodulatory properties. A growing body of evidence suggests the involvement of type I IFNs in the pathogenesis of central nervous system (CNS) manifestations in the setting of chronic autoimmune and autoinflammatory disorders, while IFN-β has been for years, a well-established therapeutic modality for multiple sclerosis (MS). In the present review, we summarize the current evidence on the mechanisms of type I IFN production by CNS cellular populations as well as its local effects on the CNS. Additionally, the beneficial effects of IFN-β in the pathophysiology of MS are discussed, along with the contributory role of type I IFNs in the pathogenesis of neuropsychiatric lupus erythematosus and type I interferonopathies.

Antisense Oligonucleotide Therapy for the Nervous System: From Bench to Bedside with Emphasis on Pediatric Neurology

Antisense oligonucleotides (ASOs) are disease-modifying agents affecting protein-coding and noncoding ribonucleic acids. Depending on the chemical modification and the location of hybridization, ASOs are able to reduce the level of toxic proteins, increase the level of functional protein, or modify the structure of impaired protein to improve function. There are multiple challenges in delivering ASOs to their site of action. Chemical modifications in the phosphodiester bond, nucleotide sugar, and nucleobase can increase structural thermodynamic stability and prevent ASO degradation. Furthermore, different particles, including viral vectors, conjugated peptides, conjugated antibodies, and nanocarriers, may improve ASO delivery. To date, six ASOs have been approved by the US Food and Drug Administration (FDA) in three neurological disorders: spinal muscular atrophy, Duchenne muscular dystrophy, and polyneuropathy caused by hereditary transthyretin amyloidosis. Ongoing preclinical and clinical studies are assessing the safety and efficacy of ASOs in multiple genetic and acquired neurological conditions. The current review provides an update on underlying mechanisms, design, chemical modifications, and delivery of ASOs. The administration of FDA-approved ASOs in neurological disorders is described, and current evidence on the safety and efficacy of ASOs in other neurological conditions, including pediatric neurological disorders, is reviewed.

The Role of Distinct Subsets of Macrophages in the Pathogenesis of MS and the Impact of Different Therapeutic Agents on These Populations

Multiple sclerosis (MS) is a demyelinating inflammatory disorder of the central nervous system (CNS). Besides the vital role of T cells, other immune cells, including B cells, innate immune cells, and macrophages (MФs), also play a critical role in MS pathogenesis. Tissue-resident MФs in the brain’s parenchyma, known as microglia and monocyte-derived MФs, enter into the CNS following alterations in CNS homeostasis that induce inflammatory responses in MS. Although the neuroprotective and anti-inflammatory actions of monocyte-derived MФs and resident MФs are required to maintain CNS tolerance, they can release inflammatory cytokines and reactivate primed T cells during neuroinflammation. In the CNS of MS patients, elevated myeloid cells and activated MФs have been found and associated with demyelination and axonal loss. Thus, according to the role of MФs in neuroinflammation, they have attracted attention as a therapeutic target. Also, due to their different origin, location, and turnover, other strategies may require to target the various myeloid cell populations. Here we review the role of distinct subsets of MФs in the pathogenesis of MS and different therapeutic agents that target these cells.

Preferential Targeting Cerebral Ischemic Lesions with Cancer Cell-Inspired Nanovehicle for Ischemic Stroke Treatment

The poor drug delivery to cerebral ischemic regions is a key challenge of ischemic stroke treatment. Inspired by the intriguing blood-brain barrier (BBB)-penetrating ability of 4T1 cancer cells upon their brain metastasis, we herein designed a promising biomimetic nanoplatform by camouflaging a succinobucol-loaded pH-sensitive polymeric nanovehicle with a 4T1 cell membrane (MPP/SCB), aiming to promote the preferential targeting of cerebral ischemic lesions to attenuate the ischemia/reperfusion injury. In transient middle cerebral artery occlusion (tMCAO) rat models, MPP/SCB could be preferentially delivered to the ischemic hemisphere with a 4.79-fold higher than that in the normal hemisphere. Moreover, MPP/SCB produced notable enhancement of microvascular reperfusion in the ischemic hemisphere, resulting in a 69.9% reduction of infarct volume and showing remarkable neuroprotective effects of tMCAO rats, which was superior to the counterpart uncamouflaged nanovehicles (PP/SCB). Therefore, this design provides a promising nanoplatform to target the cerebral ischemic lesions for ischemic stroke therapy.

Differential Effects of MS Therapeutics on B Cells-Implications for Their Use and Failure in AQP4-Positive NMOSD Patients

B cells are considered major contributors to multiple sclerosis (MS) pathophysiology. While lately approved disease-modifying drugs like ocrelizumab deplete B cells directly, most MS medications were not primarily designed to target B cells. Here, we review the current understanding how approved MS medications affect peripheral B lymphocytes in humans. These highly contrasting effects are of substantial importance when considering these drugs as therapy for neuromyelitis optica spectrum disorders (NMOSD), a frequent differential diagnosis to MS, which is considered being a primarily B cell- and antibody-driven diseases. Data indicates that MS medications, which deplete B cells or induce an anti-inflammatory phenotype of the remaining ones, were effective and safe in aquaporin-4 antibody positive NMOSD. In contrast, drugs such as natalizumab and interferon-β, which lead to activation and accumulation of B cells in the peripheral blood, lack efficacy or even induce catastrophic disease activity in NMOSD. Hence, we conclude that the differential effect of MS drugs on B cells is one potential parameter determining the therapeutic efficacy or failure in antibody-dependent diseases like seropositive NMOSD.

The Interaction between Viral and Environmental Risk Factors in the Pathogenesis of Multiple Sclerosis

Multiple sclerosis (MS) is a chronic debilitating inflammatory disease of unknown ethology targeting the central nervous system (CNS). MS has a polysymptomatic onset and is usually first diagnosed between the ages of 20–40 years. The pathology of the disease is characterized by immune mediated demyelination in the CNS. Although there is no clinical finding unique to MS, characteristic symptoms include sensory symptoms visual and motor impairment. No definitive trigger for the development of MS has been identified but large-scale population studies have described several epidemiological risk factors for the disease. This list is a confusing one including latitude, vitamin D (vitD) levels, genetics, infection with Epstein Barr Virus (EBV) and endogenous retrovirus (ERV) reactivation. This review will look at the evidence for each of these and the potential links between these disparate risk factors and the known molecular disease pathogenesis to describe potential hypotheses for the triggering of MS pathology.

Interferon β-Mediated Protective Functions of Microglia in Central Nervous System Autoimmunity

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) leading to demyelination and axonal damage. It often affects young adults and can lead to neurological disability. Interferon β (IFNβ) preparations represent widely used treatment regimens for patients with relapsing-remitting MS (RRMS) with therapeutic efficacy in reducing disease progression and frequency of acute exacerbations. In mice, IFNβ therapy has been shown to ameliorate experimental autoimmune encephalomyelitis (EAE), an animal model of MS while genetic deletion of IFNβ or its receptor augments clinical severity of disease. However, the complex mechanism of action of IFNβ in CNS autoimmunity has not been fully elucidated. Here, we review our current understanding of the origin, phenotype, and function of microglia and CNS immigrating macrophages in the pathogenesis of MS and EAE. In addition, we highlight the emerging roles of microglia as IFNβ-producing cells and vice versa the impact of IFNβ on microglia in CNS autoimmunity. We finally discuss recent progress in unraveling the underlying molecular mechanisms of IFNβ-mediated effects in EAE.

Clinical significance of glatiramer acetate antibodies

Glatiramer acetate is a mixture of synthetic peptides that are cross-reactive with MBP. The antigen-based therapy induces a shift to an anti-inflammatory Th2 bias and is used in the treatment of relapsing-remitting multiple sclerosis. Like other peptide antigens, GA induces an antibody response in all patients. In contrast to biologically active agents, such as the recombinant interferon beta drugs, GA is a peptide antigen that lacks intrinsic biological activity. In vitro and in vivo data have shown that GA-reactive antibodies are not neutralizing. Antibodies do not alter the principal immunological effects of GA, including binding to MHC Class II molecules, activation and proliferation of GA-reactive T cells, and the release of anti-inflammatory Th2 cytokines. Higher antibody titres do not appear to be associated with a deterioration in clinical endpoints, such as relapse rate, EDSS progression or the occurrence of side effects in MS patients treated with GA. The presence of GA-reactive antibodies may promote remyelination and enhance the immunological and clinical effects of GA, indicating that they may be part of GA's mechanism of action. Multiple Sclerosis 2007; 13: S28—S35. http://msj.sagepub.com

Advances in the treatment of relapsing-remitting multiple sclerosis: the role of pegylated interferon β-1a

Multiple sclerosis (MS) is a progressive, neurodegenerative disease with unpredictable phases of relapse and remission. The cause of MS is unknown, but the pathology is characterized by infiltration of auto-reactive immune cells into the central nervous system (CNS) resulting in widespread neuroinflammation and neurodegeneration. Immunomodulatory-based therapies emerged in the 1990s and have been a cornerstone of disease management ever since. Interferon β (IFNβ) was the first biologic approved after demonstrating decreased relapse rates, disease activity and progression of disability in clinical trials. However, frequent dosing schedules have limited patient acceptance for long-term therapy. Pegylation, the process by which molecules of polyethylene glycol are covalently linked to a compound, has been utilized to increase the half-life of IFNβ and decrease the frequency of administration required. To date, there has been one clinical trial evaluating the efficacy of pegylated IFN. The purpose of this article is to provide an overview of the role of IFN in the treatment of MS and evaluate the available evidence for pegylated IFN therapy in MS.

Serum immunologic markers in multiple sclerosis patients on continuous combined therapy with beta-interferon 1a, prednisone and azathioprine

Break-through symptoms (BTS) in multiple sclerosis (MS) patients on beta-interferon (beta-IFN) monotherapy are most frequently treated with a brief administration of steroids. Here, we report the results of monitoring serum immunologic markers recorded at three-month intervals for 1.5 years in responders to beta-INF 1a (Avonex) monotherapy ( n = 21) and MS patients placed on Avonex with prednisone ( n = 83) and Avonex, prednisone and azathioprine (AZA) ( n = 21) because of BTS. Compared to 23 healthy controls, patients on Avonex monotherapy and Avonex with prednisone, in individuals on Avonex, prednisone and AZA, a significant decrease in serum concentration of soluble intercellular adhesion molecule-1 (sICAM-1) ( P = 0.001) was established. Combined therapy with Avonex, prednisone and AZA was associated with a significant increase in the serum level of interleukin (IL)10 ( P < 0.001). Compared to Avonex monotherapy, combined therapy suppressed the serum level of IL12p40, antagonized elevation in the serum concentration of soluble IL2 receptor (sIL2R) and inhibited an increase in the serum soluble CD95 (sCD95) molecule. In patients studied, no significant differences in the serum level of IL18 and tumor necrosis factor-α (TNF-α) were established. These findings are important in understanding some of the immunoregulatory mechanisms induced by combined therapy in MS.

Pharmacokinetic considerations in the treatment of multiple sclerosis with interferon-β

INTRODUCTION

Interferon-β (IFNβ) is well established as a disease-modifying treatment for patients with multiple sclerosis. Several preparations of the biopharmaceutical are available differing in protein structure, formulation, dose as well as frequency and route of administration. Recently, a pegylated form of IFNβ has been marketed.

AREAS COVERED

Following a PubMed database search, we provide an overview of what is presently known about the pharmacokinetics (PK) of IFNβ including its absorption, distribution, metabolism and elimination. Also, we discuss the association with clinically relevant issues such as treatment efficacy, adverse events and anti-drug antibodies.

EXPERT OPINION

IFNβ has a bioavailability of ∼ 30% after subcutaneous or intramuscular administration, shows peak serum concentrations within several hours, has a half-life of < 1 day and is eliminated by a renal and hepatic pathway. PK parameters do not substantially differ between the types of IFNβ and routes of administration; only pegylation of IFNβ results in substantially increased and prolonged PK. Although no clinical dose-effect relationship could be established, there is an association of IFNβ dose with magnetic resonance imaging outcome parameters. Furthermore, there is an association of IFNβ serum levels with the occurrence of adverse events and anti-drug antibodies.

IFNβ secreted by microglia mediates clearance of myelin debris in CNS autoimmunity

Introduction

Multiple sclerosis (MS) is a chronic demyelinating disorder of the central nervous system (CNS) leading to progressive neurological disability. Interferon β (IFNβ) represents a standard treatment for relapsing-remitting MS and exogenous administration of IFNβ exhibits protective effects in experimentally induced CNS autoimmunity. Also, genetic deletion of IFNβ in mice leads to an aggravation of disease symptoms in the MS model of experimental autoimmune encephalomyelitis (EAE). However, neither the underlying mechanisms mediating the beneficial effects nor the cellular source of IFNβ have been fully elucidated.

Results

In this report, a subpopulation of activated microglia was identified as the major producers of IFNβ in the CNS at the peak of EAE using an IFNβ-fluorescence reporter mouse model. These IFNβ expressing microglia specifically localized to active CNS lesions and were associated with myelin debris in demyelinated cerebellar organotypic slice cultures (OSCs). In response to IFNβ microglia showed an enhanced capacity to phagocytose myelin in vitro and up-regulated the expression of phagocytosis-associated genes. IFNβ treatment was further sufficient to stimulate association of microglia with myelin debris in OSCs. Moreover, IFNβ-producing microglia mediated an enhanced removal of myelin debris when co-transplanted onto demyelinated OSCs as compared to IFNβ non-producing microglia.

Conclusions

These data identify activated microglia as the major producers of protective IFNβ at the peak of EAE and as orchestrators of IFNβ-induced clearance of myelin debris.

Electronic supplementary material

The online version of this article (doi:10.1186/s40478-015-0192-4) contains supplementary material, which is available to authorized users.

CD49d antisense drug ATL1102 reduces disease activity in patients with relapsing-remitting MS

Objective:

This study evaluated the efficacy and safety of ATL1102, an antisense oligonucleotide that selectively targets the RNA for human CD49d, the α subunit of very late antigen 4, in patients with relapsing-remitting multiple sclerosis (RRMS).

Methods:

In a multicenter, double-blind, placebo-controlled randomized phase II trial, 77 patients with RRMS were treated with 200 mg of ATL1102 subcutaneously injected 3 times in the first week and twice weekly for 7 weeks or placebo and monitored for a further 8 weeks. MRI scans were taken at baseline and weeks 4, 8, 12, and 16. The primary endpoint was the cumulative number of new active lesions (either new gadolinium-enhancing T1 lesions or nonenhancing new or enlarging T2 lesions) at weeks 4, 8, and 12.

Results:

A total of 72 patients completed the study and 74 intention-to-treat patients were assessed. ATL1102 significantly reduced the cumulative number of new active lesions by 54.4% compared to placebo (mean 3.0 [SD 6.12] vs 6.2 [9.89], p = 0.01). The cumulative number of new gadolinium-enhancing T1 lesions was reduced by 67.9% compared to placebo (p = 0.002). Treatment-emergent adverse events included mild to moderate injection site erythema and decrease in platelet counts that returned to within the normal range after dosing.

Conclusions:

In patients with RRMS, ATL1102 significantly reduced disease activity after 8 weeks of treatment and was generally well-tolerated. This trial provides evidence for the first time that antisense oligonucleotides may be used as a therapeutic approach in neuroimmunologic disorders.

Classification:

This study provides Class I evidence that for patients with RRMS, the antisense oligonucleotide ATL1102 reduces the number of new active head MRI lesions.

Glatiramer acetate attenuates the pro-migratory profile of adhesion molecules on various immune cell subsets in multiple sclerosis

An altered expression pattern of adhesion molecules (AM) on the surface of immune cells is a premise for their extravasation into the central nervous system (CNS) and the formation of acute brain lesions in multiple sclerosis (MS). We evaluated the impact of glatiramer acetate (GA) on cell-bound and soluble AM in the peripheral blood of patients with relapsing-remitting MS (RRMS). Fifteen patients treated de novo with GA were studied on four occasions over a period of 12 months. Surface levels of intracellular cell adhesion molecule (ICAM)-1, ICAM-3, lymphocyte function-associated antigen (LFA)-1 and very late activation antigen (VLA)-4 were assessed in T cells (CD3(+) CD8(+) , CD3(+) CD4(+) ), B cells, natural killer (NK) cells, natural killer T cells (NK T) and monocytes by five-colour flow cytometry. Soluble E-selectin, ICAM-1, ICAM-3, platelet endothelial cell adhesion molecule (PECAM)-1, P-selectin and vascular cell adhesion molecule (VCAM)-1 were determined with a fluorescent bead-based immunoassay. The pro-migratory pattern in RRMS was verified by comparison with healthy controls and was characterized by up-regulation of LFA-1 (CD3(+) CD4(+) T cells, B cells), VLA-4 (CD3(+) CD8(+) T cells, NK cells), ICAM-1 (B cells) and ICAM-3 (NK cells). Effects of GA treatment were most pronounced after 6 months and included attenuated levels of LFA-1 (CD3(+) CD4(+) ) and VLA-4 (CD3(+) CD4(+) , CD3(+) CD8(+) , NK, NK T, monocytes). Further effects included lowering of ICAM-1 and ICAM-3 levels in almost all immune cell subsets. Soluble AM levels in RRMS did not differ from healthy controls and remained unaltered after GA treatment. The deregulated pro-migratory expression profile of cell-bound AM is altered by GA treatment. While this alteration may contribute to the beneficial action of the drug, the protracted development and unselective changes indicate more secondary immune regulatory phenomena related to these effects.

Endogenous and recombinant type I interferons and disease activity in multiple sclerosis

Although treatment of multiple sclerosis (MS) with the type I interferon (IFN) IFN-β lowers disease activity, the role of endogenous type I IFN in MS remains controversial. We studied CD4+ T cells and CD4+ T cell subsets, monocytes and dendritic cells by flow cytometry and analysed the relationship with endogenous type I IFN-like activity, the effect of IFN-β therapy, and clinical and magnetic resonance imaging (MRI) disease activity in MS patients. Endogenous type I IFN activity was associated with decreased expression of the integrin subunit CD49d (VLA-4) on CD4+CD26(high) T cells (Th1 helper cells), and this effect was associated with less MRI disease activity. IFN-β therapy reduced CD49d expression on CD4+CD26(high) T cells, and the percentage of CD4+CD26(high) T cells that were CD49d(high) correlated with clinical and MRI disease activity in patients treated with IFN-β. Treatment with IFN-β also increased the percentage of CD4+ T cells expressing CD71 and HLA-DR (activated T cells), and this was associated with an increased risk of clinical disease activity. In contrast, induction of CD71 and HLA-DR was not observed in untreated MS patients with evidence of endogenous type IFN I activity. In conclusion, the effects of IFN-β treatment and endogenous type I IFN activity on VLA-4 expression are similar and associated with control of disease activity. However, immune-activating effects of treatment with IFN-β may counteract the beneficial effects of treatment and cause an insufficient response to therapy.

Interferon-beta increases systemic BAFF levels in multiple sclerosis without increasing autoantibody production

BACKGROUND

Treatment with interferon-beta (IFN-beta) increases B-cell activating factor of the TNF family (BAFF) expression in multiple sclerosis (MS), raising the concern that treatment of MS patients with IFN-beta may activate autoimmune B cells and stimulate the production of MS-associated autoantibodies.

OBJECTIVE

To investigate whether BAFF levels are associated with disease severity/activity in untreated MS patients, and to assess the effect of IFN-beta therapy on circulating BAFF and anti-myelin basic protein (MBP) autoantibody levels.

RESULTS

Twenty-three patients with relapsing-remitting MS (RRMS) were followed longitudinally from initiation of IFN-beta therapy. Their blood levels of BAFF correlated positively at baseline with the expanded disability status scale (p<0.009) and MS severity score (p<0.05), but not with disease activity as determined by the number of gadolinium-enhanced lesions. The patients were followed for up to 26 months, during which the BAFF levels remained elevated without association to increased disease activity. IFN-beta therapy caused an increase in plasma BAFF levels after both 3 and 6 months of therapy (p<0.002). However, an 11% decrease in IgM and a 33% decrease in IgG anti-MBP autoantibodies (p<0.09 and p<0.009, respectively) was observed after 6 months.

CONCLUSION

Pre-treatment BAFF levels correlate with high disability scores in MS, suggesting that high BAFF expression is a negative prognostic marker. Despite its known beneficial effects, IFN-beta therapy causes a sustained increase in plasma BAFF levels, which does not translate into increased levels of anti-MBP autoantibodies.

Type I interferon in organ-targeted autoimmune and inflammatory diseases

A significant role for IFNα in the pathogenesis of systemic lupus erythematosus is well supported, and clinical trials of anti-IFNα monoclonal antibodies are in progress in this disease. In other autoimmune diseases characterized by substantial inflammation and tissue destruction, the role of type I interferons is less clear. Gene expression analysis of peripheral blood cells from patients with rheumatoid arthritis and multiple sclerosis demonstrate an interferon signature similar to but less intense than that seen in patients with lupus. In both of those diseases, presence of the interferon signature has been associated with more significant clinical manifestations. At the same time, evidence supports an anti-inflammatory and beneficial role of IFNβ locally in the joints of patients with rheumatoid arthritis and in murine arthritis models, and many patients with multiple sclerosis show a clinical response to recombinant IFNβ. As can also be proposed for type I diabetes mellitus, type I interferon appears to contribute to the development of autoimmunity and disease progression in multiple autoimmune diseases, while maintaining some capacity to control established disease - particularly at local sites of inflammation. Recent studies in both rheumatoid arthritis and multiple sclerosis suggest that quantification of type I interferon activity or target gene expression might be informative in predicting responses to distinct classes of therapeutic agents.

Natalizumab treatment reduces endothelial activity in MS patients

Vascular cell adhesion molecule-1 a ligand for leukocyte very late activating antigen-4 is a key player in leukocyte extravasation in MS lesions. Natalizumab a monoclonal antibody against VLA-4 blocks this interaction. VCAM-1 and its soluble form are up-regulated during endothelial activation in MS. We investigated the effect of Natalizumab on sVCAM-1 and VLA-4 on circulating leukocytes in MS patients. Natalizumab reduced levels of sVCAM-1 compared to controls (256 vs. 597 ng/mL). This effect was sustained and only reversed in patients with neutralizing antibodies against Natalizumab. Correspondingly Natalizumab diminished VLA-4 on leukocyte subsets. Our findings indicate that Natalizumab reduces transmigration not only by blocking VLA-4 but also by down-regulating VCAM-1.

A role for interferon-beta in Guillain-Barré Syndrome?

Guillain-Barré syndrome (GBS) is an acute inflammatory demyelinating neuropathy that is associated with long-lasting morbidity and a substantial risk of mortality. The 2 reference treatments, plasma exchange and intravenous immunoglobulins (IVIg), do not change the functional prognosis for the most severely ill patients. The pathogenesis of GBS involves humoral and cellular immune dysfunctions that have only recently been characterised. Antibodies to nerve antigens may participate in complement activation, antibody-dependent macrophage cytotoxicity and reversible conduction failure. The cellular immune reaction is associated with increases in pro-inflammatory cytokines [such as tumour necrosis factor-alpha (TNFalpha)] and matrix metalloproteinases (MMPs; e.g. MMP-9), and a decrease in anti-inflammatory cytokines [such as transforming growth factor-beta1 (TGFbeta1)]. All the changes favour adhesion to and transmigration across the endothelium of immune cells, a key phenomenon associated with GBS. Recovery from GBS is characterised by the normalisation of these changes. Experimental allergic neuritis (EAN), the experimental model of GBS, has strikingly similar immunological characteristics. The usual treatment options for patients with GBS (plasma exchange and IVIg) mainly target the humoral component of the immune response. Interferon-beta (IFNbeta) is a cellular immunomodulator that inhibits antigen presentation and TNFalpha production and binding, and modulates macrophage properties. IFNbeta increases anti-inflammatory T cell functions and the production of anti-inflammatory cytokines, such as TGFbeta1. IFNbeta has important effects on leukodiapedesis, caused by modulating the expression of cell adhesion molecules and the MMP-9 proteinases. It has been used with success in EAN, in some patients with acute exacerbation of chronic inflammatory demyelinating polyneuropathy, and in 1 patient with GBS. The pathophysiology of patients with GBS, an understanding of IFNbeta properties and results of experimental studies support the investigation of IFNbeta in trials of patients with GBS.

Association of the response to tumor necrosis factor antagonists with plasma type I interferon activity and interferon-beta/alpha ratios in rheumatoid arthritis patients: a post hoc analysis of a predominantly Hispanic cohort

OBJECTIVE

Despite the substantial clinical efficacy of tumor necrosis factor alpha (TNFalpha) antagonist therapy in patients with rheumatoid arthritis (RA), some patients respond poorly to such agents. Since an interferon (IFN) signature is variably expressed among RA patients, we investigated whether plasma type I IFN activity might predict the response to TNF antagonist therapy.

METHODS

RA patients (n = 35), the majority of whom were Hispanic, from a single center were evaluated before and after initiation of TNF antagonist therapy. As controls, 12 RA patients from the same center who were not treated with a TNF antagonist were studied. Plasma type I IFN activity was measured using a reporter cell assay, and disease status was assessed using the Disease Activity Score in 28 joints (DAS28). Levels of interleukin-1 receptor antagonist (IL-1Ra) were determined in baseline plasma samples using a commercial enzyme-linked immunosorbent assay. The clinical response was classified according to the European League Against Rheumatism criteria for improvement in RA.

RESULTS

Plasma type I IFN activity at baseline was significantly associated with clinical response (odds ratio 1.36 [95% confidence interval 1.05-1.76], P = 0.020), with high baseline IFN activity associated with a good response. Changes in DAS28 scores were greater among patients with a baseline plasma IFNbeta/alpha ratio >0.8 (indicating elevated plasma IFNbeta levels). Consistent with the capacity of IFNbeta to induce IL-1Ra, elevated baseline IL-1Ra levels were associated with better therapeutic outcomes (odds ratio 1.82 [95% confidence interval 1.1-3.29], P = 0.027).

CONCLUSION

The plasma type I IFN activity, the IFNbeta/alpha ratio, and the IL-1Ra level were predictive of the therapeutic response in TNF antagonist-treated RA patients, indicating that these parameters might define clinically meaningful subgroups of RA patients with distinct responses to therapeutic agents.

Identification of two major types of age-associated CD8 clonal expansions with highly divergent properties

CD8 memory T cells are tightly regulated in young, healthy individuals but are often perturbed in aged animals by the appearance of large CD8 T cell clones. These clones are associated with impaired immunity in the aged. The molecular basis of this phenomenon remains unclear. Here, it is shown that the issue is confused by the fact that the clones are heterogeneous. Some clones bear high, and others, low levels of integrin alpha(4) (itgalpha4). These subtypes differ by multiple criteria. They appear in mice of different ages, concentrate in different tissues, and have different stabilities in vivo and responses to stimulation in vitro. itgalpha4(high), but not itgalpha4(low), CD8 clonal expansions have several characteristics consistent with a chronically stimulated phenotype. These properties include lowered levels of CD8, decreased expression of some cytokine receptors, and elevated expression of various inhibitory receptors, including the programmed death-1 (PD1) receptor and the killer cell lectin-like receptor G1 (KLRG1). The characteristics of itgalpha4(high) clonal expansions suggest that they may arise from age-dependent alterations in antigen expression and tolerance. These data redefine CD8 clonal expansions into at least two distinct entities and indicate that there are multiple mechanisms that drive age-related alterations of CD8 T cell homeostasis.

The effect of beta-interferon therapy on myelin basic protein-elicited CD4+ T cell proliferation and cytokine production in multiple sclerosis

Interferon (IFN)-beta therapy has well-established clinical benefits in multiple sclerosis (MS), but the underlying modulation of cytokine responses to myelin self-antigens remains poorly understood. We analysed the CD4+ T cell proliferation and cytokine responses elicited by myelin basic protein (MBP) and a foreign recall antigen, tetanus toxoid (TT), in mononuclear cell cultures from fourteen MS patients undergoing IFN-beta therapy. The MBP-elicited IFN-gamma-, TNF-alpha- and IL-10 production decreased during therapy (p<0.007-0.03), while the IL-6 production increased (p<0.03). No significant change was observed in the MBP-induced CD4+ T cell proliferation, or in the production of IL-4, IL-5 and brain-derived neurotrophic factor. In comparison, IFN-beta therapy reduced IFN-gamma and IL-4 responses to TT (p<0.003 and p<0.04). Thus, IFN-beta inhibits IFN-gamma production in general, presumably alleviating the detrimental influence of IFN-gamma in MS. However, the increase in proinflammatory IL-6 and the decrease in anti-inflammatory IL-10 responses suggest that IFN-beta has more diverse effects than previously assumed.

CCR7 expression on peripheral blood lymphocytes is up-regulated following treatment of multiple sclerosis with interferon-beta

A prospective study of the expression of the chemokine receptor CCR7 was performed in 11 relapsing-remitting multiple sclerosis (MS) patients during 12 months of interferon-beta (IFNbeta) treatment. The results show increased expression of CCR7 on peripheral blood lymphocytes (PBL) of MS patients receiving IFNbeta treatment as well as lymphocytes from healthy subjects treated with IFNbeta in vitro. Our results suggest that in addition to modulating the expression of adhesion molecules, the mode of action of IFNbeta also involves the control of the chemokine receptor CCR7. The net effect is a key change in the control of lymphocyte traffic between immune organs and the central nervous system (CNS) and a shift from CCR7 negative effector T cells to CCR7 positive central memory T cells.

Lack of interferon-beta leads to accelerated remyelination in a toxic model of central nervous system demyelination

Interferon-beta (IFN-beta) is a pleiotropic cytokine that is known to modulate the immune response in multiple sclerosis (MS), an inflammatory demyelinating disease of the central nervous system (CNS). Spontaneous remyelination and repair mechanisms in MS are mostly insufficient and contribute to clinical disability. Here, we investigated whether IFN-beta has a potential in modifying the extent of de- and remyelination in a toxic model of CNS demyelination induced by the copper chelator cuprizone. IFN-beta deficient (k/o) mice showed an accelerated spontaneous remyelination. However, the amount of remyelination after 6 weeks did not differ between the two groups. Demyelination in IFN-beta k/o mice was paralleled by a diminished astrocytic and microglia response as compared with wildtype controls, whereas the accelerated remyelination was paralleled by an increased number of oligodendrocyte precursor cells (OPC) within the demyelinated lesion at the beginning of the remyelination phase. We hypothesize that the absence of IFN-beta leads to more efficient recruitment and proliferation of OPC already during demyelination, thus allowing early remyelination. These results demonstrate that IFN-beta is able to alter remyelination in the absence of an immune-mediated demyelination.

Interferon-β is neuroprotective against the toxicity induced by activated microglia

Multiple sclerosis (MS) is a chronic inflammatory disorder of the central nervous system characterized by demyelination, T lymphocyte infiltration, and neuronal degeneration. Interferon-beta (IFN)-beta reduces symptoms of the relapsing-remitting form of MS. In this study, we investigated whether IFN-beta is neuroprotective against the toxicity induced by activated microglia in cortical neurons and microglia co-cultures. IFN-beta suppressed the production of glutamate and superoxide by activated microglia to 70% and 75% of lipopolysaccharide stimulation, respectively, and prevented microglial-induced neuronal cell death. Although IFN-beta enhanced the production of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and nitric oxide (NO) by activated microglia, these molecules did not directly induce neurotoxicity in cultured cortical neurons. IFN-beta did not prevent neuronal cell death induced by the peroxynitrite donor 3-morpholinosydnonimine (SIN-1) or ionotropic glutamate receptor agonists such as N-methyl-D-aspartic acid (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA). These results suggest that IFN-beta may be a useful agent counteracting neurotoxicity associated with activated microglia.

Pharmacokinetics and pharmacodynamics of the interferon-betas, glatiramer acetate, and mitoxantrone in multiple sclerosis

Five disease-modifying agents are currently approved for long-term treatment of multiple sclerosis (MS), namely three interferon-beta preparations, glatiramer acetate, and mitoxantrone(1). Pharmacokinetics describes the fate of drugs in the human body by studying their absorption, distribution, metabolism and excretion. Pharmacodynamics is dedicated to the mechanisms of action of drugs. The understanding of the pharmacokinetics and pharmacodynamics of the approved disease-modifying agents against MS is of importance as it might contribute to the development of future derivatives with a potentially higher efficacy and a more favourable safety profile. This article reviews data thus far present both on the pharmacokinetics as well as on the putative mechanisms of action of the interferon-betas, glatiramer acetate, and mitoxantrone in the immunopathogenesis of MS.

Gene expression changes in peripheral blood mononuclear cells from multiple sclerosis patients undergoing β-interferon therapy

OBJECTIVE

Multiple sclerosis (MS) is a disabling idiopathic inflammatory disorder with evidence of immune dysfunction. Current therapies for MS include preparations of beta-interferon (beta IFN). We studied the gene expression patterns in peripheral blood mononuclear cells from relapsing-remitting MS patients undergoing weekly beta IFN-1a therapy (Avonex; 30 mg intramuscular) to identify biomarkers for beta IFN responsiveness.

METHODS

Oligonucleotide microarrays were used for the comparative analysis of gene expression patterns from longitudinal PBMC samples taken from five patients undergoing beta IFN therapy.

RESULTS

On the basis of two-fold changes in expression levels and statistical analyses we selected a candidate diagnostic set of 136 genes that were differentially expressed between pretreatment and IFN-beta-1a-treated MS patients. When we applied this gene set to cluster the specimens according to their expression profiles, the pretreatment samples clustered in one branch, and acute and chronic samples following treatment clustered in another branch. However, the chronic samples from the single clinical non-responder clustered with the pretreatment branch, suggesting that a possible reversal of beta IFN-induced gene expression may be contributing to the poor clinical response.

CONCLUSIONS

These 136 genes represent potential targets for new MS therapeutics and the basis for lack of beta IFN response.

The blood-brain-barrier in multiple sclerosis: functional roles and therapeutic targeting

In most regions of the central nervous system (CNS), the composition of the neuronal microenvironment is maintained by virtue of particular blood-brain-barrier (BBB) characteristics, to which vascular endothelial cells (ECs) contribute an important role. Multiple sclerosis (MS) is an inflammatory demyelinating disease of the CNS, characterized at tissue level by multifocal perivascular infiltrates, predominantly of lymphocytes and macrophages. Thus, lymphocyte recruitment into the brain across ECs of the BBB represents a critical event in disease pathogenesis, which is highly restricted and carefully regulated. In recent years, different investigations have identified the crucial components involved in leukocyte migration, providing new insights into mechanisms modulating neuroinflammatory reactions. In this review, several topics relating to these events are discussed, namely: (1) cellular and molecular characteristics of the BBB regulating permeability, as well as signals inducing EC differentiation in the brain and specific cell properties; (2) pathogenic mechanisms guiding the migration of different leukocyte populations through the BBB in MS; and (3) current knowledge on how different MS therapies targeting leukocytes migration across the BBB function. Furthermore, because the BBB has proven to be an important retaining wall preventing drug passage into the CNS, novel strategies directed at successful delivery of large molecules for effective treatment of various inflammatory conditions of the brain, both currently available or still under development, are discussed.

Interferon-β1afor the treatment of multiple sclerosis

At present, two types of recombinant human interferon (IFN)-beta are in clinical use. IFN-beta1a is produced in genetically engineered Chinese hamster ovary cells, and its amino acid sequence and glycosylation pattern are identical to those of endogenous human IFN-beta. The beneficial effect of IFN-beta in multiple sclerosis (MS) probably results from different mechanisms of action, such as a direct effect on plasma cells modulating IgG synthesis, an increase of interleukin (IL)-10 levels, the inhibition of IL-1beta and tumour necrosis factor alpha, the stimulation of IL-1 receptor antagonist production, the inhibition of proliferation of leukocytes, a decreased antigen presentation in microglia, a reduction of T cell migration into the brain by inhibition of the activity of T cell matrix metalloproteinases, and a downregulation of adhesion molecules. IFN-beta1a has been shown by several multicenter controlled trials to be effective in relapsing-remitting MS. It reduces relapse rate by 30-50%, magnetic resonance imaging signs of disease activity in 30-80% and disability progression by 30%. It is also effective in preventing conversion to clinically definite MS when given at the time of a first demyelinating event (i.e., at the very beginning of the clinical disease). No clear evidence of the persistence of the efficacy over the long-term has stood out from a systematic analysis of published trials. A Cochrane review concluded that, in fact, the clinical effect beyond the first year of treatment is not clear. Finally, no efficacy has been shown in secondary progressive or primary progressive MS. However, IFN-beta1a is very well tolerated and the most frequent side effects are mild (local skin reaction and flu-like symptoms) and decline in frequency or disappear after the first 3-6 months of treatment. Although the optimal frequency between once weekly or multiple weekly administrations is still controversial, all protocols require multiple monthly injections. Some patients might find it hard to cope with such a treatment regimen over the long term. Ongoing trials with new powerful immunomodulatory drugs, such as monoclonal antibodies, that require only monthly or bimonthly parenteral administrations will probably offer a better tolerated treatment option in the near future.

Cell surface adhesion molecules and cytokine profiles in primary progressive multiple sclerosis

OBJECTIVE

We evaluated the utility of adhesion molecule (AM) and cytokine/chemokine expressions in blood and cerebrospinal fluid (CSF) as markers of disease activity in primary progressive multiple sclerosis (PPMS).

METHODS

The expressions of AMs and the levels of 17 cytokines in patients with PPMS (n = 25) were compared with those in secondary progressive MS (SPMS) (n = 18) and controls (n =11) and correlated with the volumes of focal and atrophic changes on MRI.

RESULTS

The expressions of very late activation antigen 4 (VLA-4), lymphocyte function-associated antigen 1 (LFA-1) and intercellular adhesion molecule 1 (ICAM-1) in blood and CSF were higher in PPMS than in controls. Comparison between PPMS and SPMS showed higher levels of ICAM-1 in blood and CSF in PPMS, while the level of the vascular adhesion molecule (VCAM-1) was higher only in blood. There was no difference in the levels of cytokines in serum or CSF between PPMS and SPMS or controls, but evidence suggesting intrathecal synthesis of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) was found in PPMS. The expressions of CSF VLA-4 in PPMS correlated with the total volume of cerebral lesions and the number of diffuse brain lesions in MRI, while the amount of LFA-1 in CSF correlated with the number of spinal T2 lesions. The level of serum MIP-1beta correlated with the T2 lesion load and EDSS score in PPMS.

CONCLUSIONS

The upregulated expressions of AMs in blood and CSF and evidence for intrathecal synthesis of MCP-1 and IL-8 in PPMS indicate the importance of inflammatory changes in the pathogenesis of PPMS.

Novel insights in the immune function of the vitamin D system: synergism with interferon-beta

The 1,25(OH)(2)D(3) analog, TX527 (19-nor-14,20-bisepi-23-yne-1,25(OH)(2)D(3)), has an interesting dissociation profile between its potent immunomodulatory and its calcemic effects in vivo. The strong immunomodulatory potency of TX527 is reflected by its ability to attenuate experimental autoimmune encephalomyelitis (EAE), a murine model of multiple sclerosis (MS). At present most MS patients are being treated with systemic IFN-beta administration. The aim of this study was to investigate whether combining IFN-beta with TX527 could empower its EAE-protective effects. We evaluated also combinations with the standard immunosuppressant cyclosporin A (CsA). EAE was induced in SJL mice by PLP immunization, treatment was started 3 days before disease induction. The TX527+IFN-beta combination resulted in significant disease protection which was superior to the effect of both treatment separately. No disease amelioration, even aggravation, was obtained with the IFN-beta+CsA combination. By adding TX527 to the IFN-beta+CsA combination near complete protection from EAE was achieved (100% protection from paralysis, mean maximal score of 1.8+/-1.5, both p<0.05 versus controls and all individual treatments). From these data we conclude that adding TX527 to an IFN-beta and/or CsA treatment results in clear additional immunomodulatory effects in EAE prevention and is therefore a potentially interesting candidate to be considered in clinical intervention trials in MS.

The clinical response to minocycline in multiple sclerosis is accompanied by beneficial immune changes: a pilot study

Minocycline has immunomodulatory and neuroprotective activities in vitro and in an animal model of multiple sclerosis (MS). We have previously reported that minocycline decreased gadolinium-enhancing activity over six months in a small trial of patients with active relapsing-remitting MS (RRMS). Here we report the impact of oral minocycline on clinical and magnetic resonance imaging (MRI) outcomes and serum immune molecules in this cohort over 24 months of open-label minocycline treatment. Despite a moderately high pretreatment annualized relapse rate (1.3/year pre-enrolment; 1.2/year during a three-month baseline period) prior to treatment, no relapses occurred between months 6 and 24. Also, despite very active MRI activity pretreatment (19/40 scans had gadolinium-enhancing activity during a three-month run-in), the only patient with gadolinium-enhancing lesions on MRI at 12 and 24 months was on half-dose minocycline. Levels of the p40 subunit of interleukin (IL)-12, which at high levels might antagonize the proinflammatory IL-12 receptor, were elevated over 18 months of treatment, as were levels of soluble vascular cell adhesion molecule-1. The activity of matrix metalloproteinase-9 was decreased by treatment. Thus, clinical and MRI outcomes are supported by systemic immunological changes and call for further investigation of minocycline in MS.

IFN-beta inhibits T cell activation capacity of central nervous system APCs

We have previously investigated the physiological effects of IFN-beta on chronic CNS inflammation and shown that IFN-beta(-/-) mice develop a more severe experimental autoimmune encephalomyelitis than their IFN-beta(+/-) littermates. This result was shown to be associated with a higher activation state of the glial cells and a higher T cell cytokine production in the CNS. Because this state suggested a down-regulatory effect of IFN-beta on CNS-specific APCs, these results were investigated further. We report that IFN-beta pretreatment of astrocytes and microglia (glial cells) indeed down-modulate their capacity to activate autoreactive Th1 cells. First, we investigated the intrinsic ability of glial cells as APCs and report that glial cells prevent autoreactive Th1 cells expansion while maintaining Ag-specific T cell effector functions. However, when the glial cells are treated with IFN-beta before coculture with T cells, the effector functions of T cells are impaired as IFN-gamma, TNF-alpha, and NO productions are decreased. Induction of the T cell activation marker, CD25 is also reduced. This suppression of T cell response is cell-cell dependent, but it is not dependent on a decrease in glial expression of MHC class II or costimulatory molecules. We propose that IFN-beta might exert its beneficial effects mainly by reducing the Ag-presenting capacity of CNS-specific APCs, which in turn inhibits the effector functions of encephalitogenic T cells. This affect is of importance because activation of encephalitogenic T cells within the CNS is a prerequisite for the development of a chronic progressive CNS inflammation.

Anti-inflammatory properties of Type I interferons

The notion that Type I interferons (interferon-alpha and -beta) possess anti-inflammatory potential is supported by data from clinical application in multiple sclerosis, by studies on cultured immune-competent cells and by investigation of experimental diseases in whole animals. These observations deserve the attention of virologists for their potential role in the pathogenesis and clinical management of virus infections.

Natalizumab plus interferon beta-1a for relapsing multiple sclerosis

BACKGROUND

Interferon beta is used to modify the course of relapsing multiple sclerosis. Despite interferon beta therapy, many patients have relapses. Natalizumab, an alpha4 integrin antagonist, appeared to be safe and effective alone and when added to interferon beta-1a in preliminary studies.

METHODS

We randomly assigned 1171 patients who, despite interferon beta-1a therapy, had had at least one relapse during the 12-month period before randomization to receive continued interferon beta-1a in combination with 300 mg of natalizumab (589 patients) or placebo (582 patients) intravenously every 4 weeks for up to 116 weeks. The primary end points were the rate of clinical relapse at 1 year and the cumulative probability of disability progression sustained for 12 weeks, as measured by the Expanded Disability Status Scale, at 2 years.

RESULTS

Combination therapy resulted in a 24 percent reduction in the relative risk of sustained disability progression (hazard ratio, 0.76; 95 percent confidence interval, 0.61 to 0.96; P=0.02). Kaplan-Meier estimates of the cumulative probability of progression at two years were 23 percent with combination therapy and 29 percent with interferon beta-1a alone. Combination therapy was associated with a lower annualized rate of relapse over a two-year period than was interferon beta-1a alone (0.34 vs. 0.75, P<0.001) and with fewer new or enlarging lesions on T(2)-weighted magnetic resonance imaging (0.9 vs. 5.4, P<0.001). Adverse events associated with combination therapy were anxiety, pharyngitis, sinus congestion, and peripheral edema. Two cases of progressive multifocal leukoencephalopathy, one of which was fatal, were diagnosed in natalizumab-treated patients.

CONCLUSIONS

Natalizumab added to interferon beta-1a was significantly more effective than interferon beta-1a alone in patients with relapsing multiple sclerosis. Additional research is needed to elucidate the benefits and risks of this combination treatment. (ClinicalTrials.gov number, NCT00030966.).

Mechanisms of action for treatments in multiple sclerosis: Does a heterogeneous disease demand a multi-targeted therapeutic approach?

The etiology of multiple sclerosis (MS) is incompletely understood, and evidence suggests there may be more than one underlying cause in this disorder. Furthermore, this complex and heterogeneous autoimmune disease shows a high degree of clinical variability between patients. Therefore, in the absence of a single therapeutic target for MS, it is difficult to apply conventional drug design strategies in the search for new treatments. We review the potential mechanisms of action of several effective therapies for MS that are currently available or in development. The effects of each treatment are described in terms of their actions on key processes in a five-step model of MS pathogenesis. Conventional immunosuppressants targeting intracellular ligands (e.g. mitoxantrone) have broad cytotoxic effects on B cells, T cells, and macrophages. This suppresses the pathogenic immune response in MS with high efficacy but is also associated with high toxicity, limiting the long-term use of these agents. Monoclonal antibodies (e.g. natalizumab and alemtuzumab) are a new generation of immunosuppressants that act on immune-cell surface ligands. These agents have narrower immunosuppressive actions and different safety profiles compared with conventional immunosuppressants. Immunomodulators (interferon-beta and glatiramer acetate), which shift the immune balance toward an anti-inflammatory response, are at the frontline of treatments for MS. Immunomodulators have targeted actions on the immune system, but affect a greater number of immunopathogenic processes than monoclonal antibodies. Given the inherent heterogeneity of MS, such treatments, which act at many levels of the disease, may achieve the best clinical results. Using our understanding of the interplay between mechanism of action and clinical effects in MS therapies may help us to better design and select new treatments for the future.

The role of alpha-4 integrin in the aetiology of multiple sclerosis: current knowledge and therapeutic implications

Multiple sclerosis (MS) has been recognised as a disease since the mid-19th century. The delineation of its CNS pathology, revealing the presence of inflammatory demyelination and relative sparing of axons, was originally interpreted as evidence of infection. Despite many studies, a primary infectious aetiology of MS has not been found. However, the occurrence of acute demyelinating disease following a variety of infections and vaccinations, leading to MS in about a third of cases, provides evidence for the existence of an auto-allergic pathogenesis for the disease. Improved understanding of the role of the blood-brain barrier in protecting the CNS, and the mechanisms by which cells gain entry into the brain and spinal cord has advanced the understanding of MS. Evidence of the central role of the adhesion molecule alpha4beta1-integrin (very late activation antigen-4 [VLA-4]) for lymphocytes in endothelial transmigration into the CNS specifically, has provided a major insight into the pathogenesis of human demyelinating disease and its experimental model, experimental autoimmune encephalomyelitis (EAE). This finding has led to a new window of therapeutic opportunity in MS. Monoclonal antibodies to VLA-4 abrogate the development of EAE in sensitised animals and may actually reverse its clinical and pathological findings in manifest disease. Natalizumab, one such monoclonal antibody, which is administered intravenously, has been found to be a promising agent in the treatment of MS. Although single doses produced no improvement in the speed or quality of recovery from acute exacerbations of MS in a phase II trial, long-term administration (in phase II and phase III trials) have produced significant benefits with results showing both a marked reduction in the risk of new magnetic resonance imaging lesions and a significant reduction in the risk of exacerbations within 2 months of the initiation of therapy. Phase III double-blinded controlled trials have provided additional evidence of safety and a favourable impact on exacerbation rates over the 1 year of administration. Unfortunately, the success of natalizumab has been curtailed by three cases of progressive multifocal leukoencephalopathy, which have prompted the manufacturer to voluntary withdraw the drug from the market. An independent review board is currently investigating the safety of the drug to determine whether it should return to the market. The demonstration that selective modulation (blocking) of the adhesion molecule VLA-4 by natalizumab in MS, resembling that observed in experimental disease, represents a major advance in rational therapy.

Downregulation of VLA-4 on T cells as a marker of long term treatment response to interferon beta-1a in MS

We determined longitudinally the expression of a panel of adhesion molecules on T cells and soluble ICAM-1, VCAM-1 and tumor necrosis factor apoptosis inducing ligand (TRAIL) in serum during first year of the PRISMS Study with IFNbeta1a in MS. Clinical data and quantitative MRI data were available for 4 years. VLA-4 was down-regulated on T cells and VCAM-1 was up-regulated in serum during the first 3 to 6 months of therapy in patients with favorable long-term treatment response (EDSS progression </=1.0 in 4 years). Short disease duration and low EDSS were clinical pre-treatment characteristics related to good long-term response to therapy.

Hyaluronate receptor (CD44) and integrin alpha4 (CD49d) are up-regulated on T cells during MS relapses

A longitudinal study of peripheral blood T cell adhesion molecule expression was performed in 24 relapsing-remitting MS patients. There were 15 relapses in 11 patients during 15 months of observation. In comparison with remission, expression of hyaluronate receptor (CD44) was highly significant, and expression of integrin alpha4 (CD49d, VLA-4) significantly up-regulated during relapses. CD44 and CD49d are putative activity markers and CD44 a potential novel therapeutic target in MS.

Microarray analysis identifies an aberrant expression of apoptosis and DNA damage-regulatory genes in multiple sclerosis

To clarify the molecular mechanisms underlying multiple sclerosis (MS)-promoting autoimmune process, we have investigated a comprehensive gene expression profile of T cell and non-T cell fractions of peripheral blood mononuclear cells (PBMC) isolated from 72 MS patients and 22 age- and sex-matched healthy control (CN) subjects by using a cDNA microarray. Among 1258 genes examined, 173 genes in T cells and 50 genes in non-T cells were expressed differentially between MS and CN groups. Downregulated genes greatly outnumbered upregulated genes in MS. More than 80% of the top 30 most significant genes were categorized into apoptosis signaling-related genes of both proapoptotic and antiapoptotic classes. They included upregulation in MS of orphan nuclear receptor Nurr1 (NR4A2), receptor-interacting serine/threonine kinase 2 (RIPK2), and silencer of death domains (SODD), and downregulation in MS of TNF-related apoptosis-inducing ligand (TRAIL), B-cell CLL/lymphoma 2 (BCL2), and death-associated protein 6 (DAXX). Furthermore, a set of the genes involved in DNA repair, replication, and chromatin remodeling was downregulated in MS. These results suggest that MS lymphocytes show a complex pattern of gene regulation that represents a counterbalance between promoting and preventing apoptosis and DNA damage of lymphocytes.

Interferons in relapsing-remitting multiple sclerosis: are there benefits from long-term use?

Multiple sclerosis (MS) is one of the most common chronic neurological diseases in young adults in western countries. An important aspect of treatment of this disease is the use of interferons (IFNs). These are molecules with antiviral, immunomodulatory, antiproliferative and hormonal activities. IFNbeta, a class I IFN, has been used extensively in the therapy of MS, particularly in its relapsing-remitting (RRMS) phase, the most frequent clinical form of the disease. Although the available evidence from published clinical trials is difficult to evaluate because of methodological differences, an unbiased review of the data reveals sufficient evidence to conclude that treatment with IFNbeta in RRMS is both efficacious and safe, at least over the periods so far investigated (up to 4-6 years). While there is no reason to suspect that IFNbeta should not continue to be efficacious and safe over the longer term, studies investigating these questions over longer periods and including greater numbers of patients are needed.

Interferon-beta-1a induces increases in vascular cell adhesion molecule: implications for its mode of action in multiple sclerosis

We investigated soluble vascular cell adhesion molecule-1 (sVCAM) levels and MRI lesions over 24 weeks in 15 Relapsing Remitting MS (RRMS) patients randomized prospectively to receive once-weekly (qw) IFN-beta-1a 30 mug intramuscularly (IM) (Group I, 8 patients) or three-times-weekly (tiw) IFN-beta-1a 44 mug subcutaneously (SC) (Group II, 7 patients). Both groups demonstrated a significant increase in sVCAM during treatment when compared to pre-treatment levels. Patients on IFN-beta-1a 44 mug SC tiw had a significant (p<0.0001) mean increase in sVCAM of 321.9 ng/ml which was significantly greater (p<0.0001) than with IFN-beta-1a 30 mug IM qw (68.6 ng/ml). There was a negative correlation between combined unique (CU) MRI lesions and sVCAM levels within the IFN-beta-1a 44 mug SC tiw group (slope=-0.00106, p=0.009). We postulate that the mode of action of IFN-beta therapy in MS may involve the induction of an increase in sVCAM. sVCAM could bind VLA-4 on T-cells and intercept their adhesion to the blood brain barrier (BBB). This mechanism is consistent with the observed clinical effect of IFN-beta in reducing MRI contrast enhancing lesions.

CD45RA+ ICAM-3+ lymphocytes in interferon-beta1b-treated and -untreated patients with relapsing-remitting multiple sclerosis

OBJECTIVES

Multiple sclerosis (MS) is believed to be an autoimmune disease of the human central nervous system mediated by autoreactive T cells. Interferon-beta1b (IFN-beta1b) has been shown to be effective in reducing disease activity defined by clinical and magnetic resonance imaging (MRI) criteria in relapsing-remitting MS (RRMS). Yet, the exact mechanisms by which these benefits are achieved remain unknown. CD45RA is a marker for naive T lymphocytes and intercellular adhesion molecule-3 (ICAM-3) is expressed on resting lymphocytes.

MATERIAL AND METHODS

Forty-eight patients with RRMS, 24 of them treated with recombinant IFN-beta1b and 24 untreated, were enrolled in this prospective study over 18 months. We investigated the percentage of CD45RA+ ICAM-3+ cells within the total lymphocyte subset in the peripheral blood serially every 3 months and in CSF once at baseline. Detailed clinical examination including Expanded Disability Status Scale (EDSS) score was performed every 3 months and cranial MRI scans were assessed every 6 months.

RESULTS

We found a temporary increase in the CD45RA+ ICAM-3+ lymphocyte ratio in peripheral blood of both untreated and IFN-beta1b-treated RRMS patients. Moreover, we determined a significant negative correlation (r = -0.5874; P < 0.01) between age as well as the EDSS score (r = -0.3629; P < 0.05) and the percentages of CD45RA+ ICAM-3+ lymphocytes in peripheral blood but a positive correlation between EDSS score and the CD45RA+ ICAM-3+ ratio (r = 0.3913; P < 0.05) in the CSF at baseline.

CONCLUSION

CD45RA+ ICAM-3+ lymphocyte ratio in peripheral blood might indicate immunosenescence in MS. However, from our data it cannot be finally concluded whether it is also influenced by IFN-beta1b treatment.

Interferon beta-1b modulates serum sVCAM-1 levels in primary progressive multiple sclerosis

Endothelial activation is a key feature of multiple sclerosis (MS) pathogenesis. It is modulated by interferon beta-1b (IFNB-1b) treatment in relapsing-remitting MS (RRMS) patients. This particular pharmacodynamic effect still has to be proven in primary progressive MS (PPMS). In the current study, serum concentrations of soluble vascular cell adhesion molecule-1 (sVCAM-1) and sE-selectin were analyzed longitudinally in 18 PPMS patients before, during and after 12 months of treatment with IFNB-1b. During drug therapy there was a significant early and sustained increase of sVCAM-1 (overall P < 0.0001). Flu-like symptoms induced by IFNB-1b and also concomitant infections were associated with higher sVCAM-1 levels. Neutralizing antibodies to IFNB-1b were associated with lower sVCAM-1 levels. In conclusion, IFNB-1b modulates the adhesion cascade in patients with PPMS in a similar way it does in RRMS. Nevertheless, a clinical effect of IFNB in PPMS still has to be proven in a randomized controlled clinical trial.