Immunomodulatory Effects of IFN-β and Lovastatin on Immunophenotype of Monocyte-Derived Dendritic Cells in Multiple Sclerosis

CLADIN- CLADribine and INnate immune response in multiple sclerosis - A phase IV prospective study

Cladribine (Mavenclad®) is an oral treatment for relapsing remitting MS (RRMS), but its mechanism of action and its effects on innate immune responses in unknown. This study is a prospective Phase IV study of 41 patients with RRMS, and aims to investigate the mechanism of action of cladribine on peripheral monocytes, and its impact on the P2X7 receptor. There was a significant reduction in monocyte count in vivo at week 1 post cladribine administration, and the subset of cells being most impacted were the CD14lo CD16+ 'non-classical' monocytes. Of the 14 cytokines measured in serum, CCL2 levels increased at week 1. In vitro, cladrabine induced a reduction in P2X7R pore as well as channel activity. This study demonstrates a novel mechanism of action for cladribine. It calls for studying potential benefits of cladribine in progressive forms of MS and other neurodegenerative diseases where innate immune related inflammation is implicated in disease pathogenesis.

Statins and autoimmunity: State-of-the-art

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

Pigments from Filamentous Ascomycetes for Combination Therapy

Filamentous ascomycetes (Neurospora and Monascus) have been studied for a long time because of their production of secondary metabolites such as microbial pigments. The ascomycetes represent an interesting group of compounds with high potential for medicinal applications. Many recent studies have shown their efficacy in the treatment of serious pathological states such as oncological diseases, neurodegenerative diseases and hyperlipidaemia. Nevertheless, the clinical usability of ascomycetes is still limited. However, this problem can be solved by the use of these compounds with combinations of other therapeutic agents. This strategy can suppress their side effects and improve their therapeutic efficacy. Moreover, their co-application can significantly enhance conventional therapies that are used. This review summarizes and discusses the general principles of this approach, introduced and supported by numerous examples. In addition, the prediction of the future potential application of this methodology is included.

Role of statins in the treatment of multiple sclerosis

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

2-Chlorodeoxyadenosine (cladribine) induces apoptosis in human monocyte-derived dendritic cells

2-Chlorodeoxyadenosine (cladribine, CdA) is an immunosuppressive drug that is licensed to treat hairy cell leukaemia, and has been shown recently to have beneficial effects in patients with multiple sclerosis (MS). The therapeutic effects of CdA have been suggested to be mediated partly through its potent toxicity towards lymphocytes. However, the effects of CdA on other immune cells are poorly understood. In the present study, we investigated the effects of CdA on the induction of apoptosis in human monocytes, monocyte-derived immature (ImDC) and mature (mDC) dendritic cells. Treatment of monocytes with CdA strongly induced apoptosis after 24 h, while apoptosis induction in DC was evident after 72 h. Furthermore, CdA treatment strongly induced caspase-3 and caspase-9 in monocytes, whereas activation of caspases was undetected in DC. The mitochondrial membrane potential in DC was reduced significantly after CdA treatment. DNA hypodiploid assessment showed fragmented nuclei in DC after CdA treatment together with activation of p53 protein. These results revealed that CdA induces caspase-independent apoptosis in DC and suggest cell type specific effects of CdA. This mechanism may contribute to the effect of CdA in autoimmune diseases.

Simvastatin as add-on therapy to interferon β-1a for relapsing-remitting multiple sclerosis (SIMCOMBIN study): a placebo-controlled randomised phase 4 trial

BACKGROUND

Treatment of relapsing-remitting multiple sclerosis with interferon beta is only partly effective. We aimed to establish whether add-on of simvastatin, a statin with anti-inflammatory properties, improves this efficacy.

METHODS

We enrolled treatment-naive patients with relapsing-remitting multiple sclerosis in a multicentre, placebo-controlled, double-blind, randomised, parallel-group trial of simvastatin (80 mg daily) as add-on treatment to intramuscular interferon beta-1a (30 μg weekly). After starting treatment with interferon beta, patients were randomly assigned (in computer-generated blocks of four patients) to simvastatin 80 mg per day or placebo for 1-3 years. Patients and treating and evaluating physicians were masked to treatment allocation. The primary outcome measure was annual rate of documented relapses; analysis was by intention to treat. This trial is registered at ClinicalTrials.gov, NCT00492765.

FINDINGS

We randomly assigned 307 patients to interferon beta plus simvastatin (n=151) or plus placebo (n=156). Annual rate of documented relapses was 0·19 (95% CI 0·13 to 0·28) in the simvastatin group and 0·14 (95% CI 0·09 to 0·23) in the placebo group (absolute difference 0·059, 95% CI -0·21 to 0·09; p=0·35). Time to first documented relapse (20th percentile) was 18·1 months in patients on simvastatin and 21·5 months in those on placebo (hazard ratio 1·21, 95% CI 0·74 to 1·99; p=0·51). Mean number of new or enlarging T2 lesions was 2·96 in the simvastatin group and 2·52 in the placebo group (ratio of new lesions, 1·17, 95% CI 8·89 to 1·55; p=0·25). Eight (6%) patients on simvastatin and 17 (13%) on placebo had no disease activity (odds ratio 0·42, 95% CI 0·17 to 1·00; p=0·05). No unexpected adverse events were seen. Generally, adverse events were mild and there were no group differences in infections or musculoskeletal disorders, including myalgia (five [3%] patients on simvastatin and nine [6%] on placebo). Rhabdomyolysis and myoglobinuria were not reported and there were no differences in serum creatine phosphokinase.

INTERPRETATION

We found no beneficial effect of simvastatin as add-on therapy to interferon beta-1a. Although unlikely, we can not exclude that combination of other statins with other disease-modifying drugs still could be beneficial.

FUNDING

Biogen Idec.

Exogenous control of the expression of Group I CD1 molecules competent for presentation of microbial nonpeptide antigens to human T lymphocytes

Group I CD1 (CD1a, CD1b, and CD1c) glycoproteins expressed on immature and mature dendritic cells present nonpeptide antigens (i.e., lipid or glycolipid molecules mainly of microbial origin) to T cells. Cytotoxic CD1-restricted T lymphocytes recognizing mycobacterial lipid antigens were found in tuberculosis patients. However, thanks to a complex interplay between mycobacteria and CD1 system, M. tuberculosis possesses a successful tactic based, at least in part, on CD1 downregulation to evade CD1-dependent immunity. On the ground of these findings, it is reasonable to hypothesize that modulation of CD1 protein expression by chemical, biological, or infectious agents could influence host's immune reactivity against M. tuberculosis-associated lipids, possibly affecting antitubercular resistance. This scenario prompted us to perform a detailed analysis of the literature concerning the effect of external agents on Group I CD1 expression in order to obtain valuable information on the possible strategies to be adopted for driving properly CD1-dependent immune functions in human pathology and in particular, in human tuberculosis.