Serena Ruggieri

Increased CD8+ T cell response to Epstein-Barr virus lytic antigens in the active phase of multiple sclerosis

It has long been known that multiple sclerosis (MS) is associated with an increased Epstein-Barr virus (EBV) seroprevalence and high immune reactivity to EBV and that infectious mononucleosis increases MS risk. This evidence led to postulate that EBV infection plays a role in MS etiopathogenesis, although the mechanisms are debated. This study was designed to assess the prevalence and magnitude of CD8+ T-cell responses to EBV latent (EBNA-3A, LMP-2A) and lytic (BZLF-1, BMLF-1) antigens in relapsing-remitting MS patients (n = 113) and healthy donors (HD) (n = 43) and to investigate whether the EBV-specific CD8+ T cell response correlates with disease activity, as defined by clinical evaluation and gadolinium-enhanced magnetic resonance imaging. Using HLA class I pentamers, lytic antigen-specific CD8+ T cell responses were detected in fewer untreated inactive MS patients than in active MS patients and HD while the frequency of CD8+ T cells specific for EBV lytic and latent antigens was higher in active and inactive MS patients, respectively. In contrast, the CD8+ T cell response to cytomegalovirus did not differ between HD and MS patients, irrespective of the disease phase. Marked differences in the prevalence of EBV-specific CD8+ T cell responses were observed in patients treated with interferon-β and natalizumab, two licensed drugs for relapsing-remitting MS. Longitudinal studies revealed expansion of CD8+ T cells specific for EBV lytic antigens during active disease in untreated MS patients but not in relapse-free, natalizumab-treated patients. Analysis of post-mortem MS brain samples showed expression of the EBV lytic protein BZLF-1 and interactions between cytotoxic CD8+ T cells and EBV lytically infected plasma cells in inflammatory white matter lesions and meninges. We therefore propose that inability to control EBV infection during inactive MS could set the stage for intracerebral viral reactivation and disease relapse.

Magnetic resonance imaging correlates of physical disability in relapse onset multiple sclerosis of long disease duration.

Background: Understanding long-term disability in multiple sclerosis (MS) is a key goal of research; it is relevant to how we monitor and treat the disease. Objectives: The Magnetic Imaging in MS (MAGNIMS) collaborative group sought to determine the relationship of brain lesion load, and brain and spinal cord atrophy, with physical disability in patients with long-established MS. Methods: Patients had a magnetic resonance imaging (MRI) scan of their brain and spinal cord, from which we determined brain grey (GMF) and white matter (WMF) fractional volumes, upper cervical spinal cord cross-sectional area (UCCA) and brain T2-lesion volume (T2LV). We assessed patient disability using the Expanded Disability Status Scale (EDSS). We analysed associations between EDSS and MRI measures, using two regression models (dividing cohort by EDSS into two and four sub-groups). Results: In the binary model, UCCA (p < 0.01) and T2LV (p = 0.02) were independently associated with the requirement of a walking aid. In the four-category model UCCA (p < 0.01), T2LV (p = 0.02) and GMF (p = 0.04) were independently associated with disability. Conclusions: Long-term physical disability was independently linked with atrophy of the spinal cord and brain T2 lesion load, and less consistently, with brain grey matter atrophy. Combinations of spinal cord and brain MRI measures may be required to capture clinically-relevant information in people with MS of long disease duration.

Development of oral agent in the treatment of multiple sclerosis: how the first available oral therapy, fingolimod will change therapeutic paradigm approach.

Multiple sclerosis (MS) is a chronic inflammatory disorder of the central nervous system, traditionally considered to be an autoimmune, demyelinating disease. Based on this understanding, the initial therapeutic strategies were directed at immune modulation and inflammation control. At present, there are five licensed first-line disease-modifying drugs and two second-line treatments in MS. Currently available MS therapies have shown significant efficacy throughout many trials, but they produce different side-effect profiles in patients. Since they are well known and safe, they require regular and frequent parenteral administration and are associated with limited long-term treatment adherence. Thus, there is an important need for the development of new therapeutic strategies. Several oral compounds are in late-stage development for treating MS. Fingolimod (FTY720; Novartis, Basel, Switzerland) is an oral sphingosine-1-phosphase receptor modulator which has demonstrated superior efficacy compared with placebo and interferon β-1a in Phase III studies and has been approved in the treatment of MS. We summarily review the oral compounds in study, focusing on the recent development, approval and the clinical experience with FTY720.

Pharmacology and clinical efficacy of dimethyl fumarate (BG-12) for treatment of relapsing–remitting multiple sclerosis

The last two decades have seen the introduction of several therapies for multiple sclerosis (MS). These therapies are intended to work at different levels of the disease, typically targeting direct symptom management, brief corticosteroid administration for acute exacerbations, and the regular use of disease-modifying drugs. Nevertheless, in clinical practice, disease-modifying drugs or immunosuppressive treatments are frequently associated with suboptimal response in terms of efficacy and several side effects leading to poor patient adherence, so the proportion of relapsing–remitting MS patients not adequately responding to disease-modifying therapy have been reported to range from 7% to 49%. Natalizumab and fingolimod are the newest US Food and Drug Administration-approved agents that have been added to the MS treatment armamentarium, but their use is limited by a less known safety profile and recognized specific risk. Thus, there is an important need for new therapeutic strategies, especially those that may offer greater patient satisfaction and safer risk profile in order to optimize therapeutic outcomes. A number of potential therapies for MS are now in late-stage development. Effective, safe, and well-tolerated therapies may improve compliance and empower patients with a level of independence not presently possible. To meet these characteristics, most of these therapies are oral compounds. Herein, we review the pharmacology and efficacy of dimethyl fumarate (BG-12) to date and its role in the evolving marketplace.

New oral drugs for multiple sclerosis

Disease-modifying treatments are now available in relapsing–remitting and secondary progressive multiple sclerosis (MS), and their beneficial effects have been shown in several clinical studies. However, as these treatments are only partially effective in halting the MS disease process and are frequently associated with side effects and suboptimal patient adherence, new oral therapeutic approaches are warranted. This review focuses on advances in current and novel oral treatment approaches for MS. Several pivotal reports have provided promising results for new oral therapies evaluating the safety and efficacy of new agents including fingolimod, fumaric acid, cladribine, teriflunomide and laquinimod.

Pronounced focal and diffuse brain damage predicts short-term disease evolution in patients with clinically isolated syndrome suggestive of multiple sclerosis.

Background: In clinically isolated syndrome (CIS), the role of quantitative magnetic resonance imaging (MRI) in detecting prognostic markers is still debated. Objective: To evaluate measures of diffuse brain damage (such as brain atrophy and the ratio of N-acetylaspartate to creatine (NAA/Cr)) in patients with CIS, in addition to focal lesions, as predictors of 1-year disease evolution. Methods: 49 patients with CIS underwent MRI scans to quantify T2-lesions (T2-L) and gadolinium-enhanced lesion (GEL) number at baseline and after 1 year. Along with 25 healthy volunteers, they also underwent combined MRI/magnetic resonance spectroscopy examination to measure normalized brain volumes (NBVs) and NAA/Cr. Occurrence of relapses and new T2-L was recorded over 1 year to assess disease evolution. Results: Occurrence of relapses and/or new T2-L over 1 year divided patients with CIS into ‘active’ and ‘stable’ groups. Active patients had lower baseline NAA/Cr and NBV. Baseline T2-L number, GEL, NAA/Cr and NBV predicted subsequent disease activity. Multivariable logistic regression models showed that both ‘focal damage’ (based on T2-L number and GEL) and ‘diffuse damage’ (based on NBV and NAA/Cr) models predicted disease activity at 1 year with great sensitivity, specificity and accuracy. This was best when the four MRI measures were combined (80% sensitivity, 89% specificity, 83% accuracy). Conclusions: Quantitative MRI measures of diffuse tissue damage such as brain atrophy and NAA/Cr, in addition to measures of focal demyelinating lesions, may predict short-term disease evolution in patients with CIS, particularly when used in combination. If confirmed in larger studies, these findings may have important clinical and therapeutic implications.

CD28 ligation in the absence of TCR stimulation up-regulates IL-17A and pro-inflammatory cytokines in relapsing-remitting multiple sclerosis T lymphocytes.

CD28 is a crucial costimulatory receptor necessary full T cell activation. The role of CD28 in multiple sclerosis (MS) has been evaluated as the source of costimulatory signals integrating those delivered by TCR. However, CD28 is also able to act as a unique signaling receptor and to deliver TCR-independent autonomous signals, which regulate the expression and production of pro-inflammatory cytokines and chemokines. By comparing the cytokine/chemokine profiles of CD4(+) T cells from relapsing-remitting multiple sclerosis (RRMS) patients and healthy donors (HD), we found that CD28 engagement without TCR strongly up-regulates IL-8 and IL-6 expression in RRMS compared to HD. More interestingly, in RRMS but not in HD, CD28 stimulation selectively induces the expression of IL-17A by cooperating with IL-6-mediated signals. By using specific inhibitory drugs, we also identify the phosphatidylinositol 3 kinase (PI3K) as the critical regulator of CD28 proinflammatory functions in MS.

FAS-ligand regulates differential activation-induced cell death of human T-helper 1 and 17 cells in healthy donors and multiple sclerosis patients

Functionally distinct T-helper (Th) subsets orchestrate immune responses. Maintenance of homeostasis through the tight control of inflammatory Th cells is crucial to avoid autoimmune inflammation. Activation-Induced Cell Death (AICD) regulates homeostasis of T cells, and it has never been investigated in human Th cells. We generated stable clones of inflammatory Th subsets involved in autoimmune diseases, such as Th1, Th17 and Th1/17 cells, from healthy donors (HD) and multiple sclerosis (MS) patients and we measured AICD. We find that human Th1 cells are sensitive, whereas Th17 and Th1/17 are resistant, to AICD. In particular, Th1 cells express high level of FAS-ligand (FASL), which interacts with FAS and leads to caspases’ cleavage and ultimately to cell death. In contrast, low FASL expression in Th17 and Th1/17 cells blunts caspase 8 activation and thus reduces cell death. Interestingly, Th cells obtained from healthy individuals and MS patients behave similarly, suggesting that this mechanism could explain the persistence of inflammatory IL-17-producing cells in autoimmune diseases, such as MS, where their generation is particularly substantial.

Advances in the treatment of relapsing–remitting multiple sclerosis – critical appraisal of fingolimod

Multiple sclerosis (MS) is a chronic inflammatory disorder of the central nervous system, traditionally considered to be an autoimmune, demyelinating disease. Based on this understanding, initial therapeutic strategies were directed at immune modulation and inflammation control. At present, there are five licensed first-line disease-modifying drugs for MS in Europe, and two second-line treatments. Currently available MS therapies have shown significant efficacy throughout many trials, but they produce different side effects. Despite disease-modifying drugs being well known and safe, they require regular and frequent parenteral administration and are associated with limited long-term treatment adherence. Therefore, the development of new therapeutic strategies is warranted. Several oral compounds are in late stages of development for treating MS. fingolimod is an oral sphingosine-1-phosphate receptor modulator that has demonstrated superior efficacy compared with placebo and interferon β-1a in phase III studies. It has already been approved in the treatment of MS. This review focuses on advances in current and novel oral treatment approaches in MS. We summarily review the oral compounds in this study, focusing on the recent development, approval, and the clinical experience with fingolimod.

T helper 9 cells induced by plasmacytoid dendritic cells regulate interleukin-17 in multiple sclerosis

Multiple sclerosis (MS) is a chronic disease of the central nervous system (CNS) characterized by persistent inflammation orchestrated by cluster of differentiation (CD) 4 T helper (Th) cells. In particular, Th1 and Th17 cells amplify, whereas T regulatory (Treg) cells moderate inflammation. The role of other Th subsets in MS is not clear. In the present study, we investigated the generation of different Th responses by human dendritic cells (DCs) in MS. We compared the production of several Th cytokines by naive CD4+ T-cells polarized with myeloid and plasmacytoid DCs (mDCs and pDCs) in healthy donors (HD) and relapsing-remitting (RR)-MS patients. We found that resiquimod-stimulated mDCs were able to activate Th17 differentiation, whereas pDCs induced interleukin (IL)-10-producing Th cells. Surprisingly, resiquimod-stimulated pDCs from MS patients also significantly induced the differentiation of Th9 cells, which produce IL-9 and are known to be involved in allergic diseases. We investigated the potential role of IL-9 in MS. We found that IL-9 activated signal transducer and activator of transcription (STAT) 1 and STAT5 phosphorylation and interfered with IL-17 and interferon (IFN) regulatory transcription factor (IRF)-4 expression in Th17-polarized cells. Moreover, in the cerebrospinal fluid (CSF) of 107 RR-MS patients, IL-9 inversely correlated with indexes of inflammatory activity, neurodegeneration and disability progression of MS. High levels of IL-9 were associated with the absence of IL-17 in the CSF of RR-MS patients. Our results demonstrate a Th9-inducing potential of pDCs in MS, suggesting an immunoregulatory role leading to attenuation of the exaggerated Th17 inflammatory response.