Recombinant soluble IFN receptor (sIFNAR2) exhibits intrinsic therapeutic efficacy in a murine model of Multiple Sclerosis.

Endogenous interferon beta (IFNß) is an important cytokine involved in several chronic inflammatory diseases, such as Multiple Sclerosis (MS). In spite of the numerous therapeutic approaches available for MS patients, the administration of recombinant IFNß continues being one of the first line treatment to these patients. The soluble form of IFNß receptor (sIFNAR2) could act as critical regulator of the endogenous and the systemically administered IFNß, but whether it functions as an agonist or antagonist of its ligand is not completely elucidated. Morover, the possible role of sIFNAR2 in autoimmune diseases like MS is still unknown and so far overlooked. Here we evaluated the efficacy of the combined therapy of IFNß and our recombinant protein analogous to human sIFNAR2 as a treatment in a chronic mice model of MS (CP-EAE). We also tested the effect of the sIFNAR2 administered as a monotherapy over these EAE-animals. The results showed that our recombinant sIFNAR2 protein potentiates the immunomodulatory effects of exogenous IFNß in CP-EAE by increasing the reduction of the induced inflammation and the tissue damage. Furthermore, we demonstrate for the first time that sIFNAR2 shows intrinsic properties by modulating the CP-EAE progression and the neuroinflammation processes related to this disease. Another intrinsic activity showed by sIFNAR2 is the inhibition of the T cells proliferation, which increase its potential as therapeutic molecule.

Gene expression in IFNß signalling pathway differs between monocytes, CD4 and CD8 T cells from MS patients.

IFNß exerts its activity through the interaction with IFNAR, through activation of the JAK/STAT pathway. We analyzed the changes in IFNAR1, IFNAR2, STAT1, STAT2, Tyk2, JAK1, IRF9 and MxA gene expressions after prolonged IFNß treatment, in isolated mononuclear-cell subpopulations from MS patients, by real time PCR. The effect of IFNß on gene expression differed depending on the subpopulation assessed. The data suggest that CD8+ T cells are the most influenced by prolonged IFNß therapy as IFNAR2, Tyk2, IRF9 and Jak1 expressions were decreased, whereas MxA expression was increased in these cells.

Neutralizing antibodies against IFN beta in patients with multiple sclerosis: a comparative study of two cytopathic effect tests (CPE) for their detection.

Neutralizing antibodies (NABs) against IFN beta should be measured in specialized laboratories, using a test of inhibition of the cytopathic effect (bioassay or CPE test), based on the capacity of IFNss to block the infection of live monolayer-cultured cells by a virus, depending on the presence or absence of NABs. The European Federation of Neurological Societies (EFNS) considers this assay to be the gold standard. However, the various different ways to perform this assay complicate comparison of the results between laboratories. The World Health Organization (WHO) has published several recommendations to perform this assay using the A549 cell line and the murine encephalomyocarditis virus (EMCV). In order to validate the results previously obtained in our laboratory with HEP2/VSV, we undertook a comparative analysis of the two bioassays, HEP2/VSV and A549/EMCV, to assess whether the use of different cell lines and viruses influences sensitivity. We also calibrated the A549/EMCV assay with a reference IFNss. Our results confirm that the bioassay with HEP2/VSV is as sensitive as the assay with A549/EMCV and that a significant association and correlation exist in the results between both assays. Thus, past results with HEP2/VSV in our laboratory could be comparable with those obtained with A549/EMCV in both our laboratory and others.