Decreased interferon-β induced STAT-4 activation in immune cells and clinical outcome in multiple sclerosis

Beta interferons as immunotherapy in multiple sclerosis: a new outlook on a classic drug during the COVID-19 pandemic

Beta interferons (IFN-β) are pleiotropic cytokines with antiviral properties. They play important roles in the pathogenesis of multiple sclerosis (MS), an incurable immune-mediated disorder of the central nervous system. The clinical expression of MS is heterogeneous, with relapses of neuroinflammation and with disability accrual in considerable part unrelated to the attacks. The injectable recombinant IFN-β preparations are the first approved disease-modifying treatments for MS. They have moderate efficacy in reducing the frequency of relapses, but good long-term cost-efficacy and safety profiles, so are still widely used. They have some tolerability and adherence issues, partly mitigated in recent years by the introduction of a PEGylated formulation and use of 'smart' autoinjector devices. Their general impact on long-term disability is modest but could be further improved by developing accurate tools for identifying the patient profile of best responders to IFN-β. Here, we present the IFN-β-based immunomodulatory therapeutic approaches in MS, highlighting their place in the current coronavirus disease (COVID-19) pandemic. The potential role of IFN-β in the treatment of COVID-19 is also briefly discussed.

PAF-R on activated T cells: Role in the IL-23/Th17 pathway and relevance to multiple sclerosis

IL-23 is a potent stimulus for Th17 cells. These cells have a distinct developmental pathway from Th1 cells induced by IL-12 and are implicated in autoimmune and inflammatory disorders including multiple sclerosis (MS). TGF-β, IL-6, and IL-1, the transcriptional regulator RORγt (RORC) and IL-23 are implicated in Th17 development and maintenance. In human polyclonally activated T cells, IL-23 enhances IL-17 production. The aims of our study were: 1). To validate microarray results showing preferential expression of platelet activating factor receptor (PAF-R) on IL-23 stimulated T cells. 2). To determine whether PAF-R on activated T cells is functional, whether it is co-regulated with Th17-associated molecules, and whether it is implicated in Th17 function. 3). To determine PAF-R expression in MS. We show that PAF-R is expressed on activated T cells, and is inducible by IL-23 and IL-17, which in turn are induced by PAF binding to PAF-R. PAF-R is co-expressed with IL-17 and regulated similarly with Th17 markers IL-17A, IL-17F, IL-22 and RORC. PAF-R is upregulated on PBMC and T cells of MS patients, and levels correlate with IL-17 and with MS disability scores. Our results show that PAF-R on T cells is associated with the Th17 phenotype and function. Clinical Implications Targeting PAF-R may interfere with Th17 function and offer therapeutic intervention in Th17-associated conditions, including MS.

Aberrant STAT phosphorylation signaling in peripheral blood mononuclear cells from multiple sclerosis patients

Background

Multiple sclerosis (MS) is characterized by increased activation of peripheral blood mononuclear cells (PBMCs), linked to perturbations in the phosphorylation of signaling proteins.

Methods

We developed a phosphoflow cytometry protocol to assess the levels of 11 phosphorylated nuclear proteins at baseline conditions and after cell activation in distinct PBMC populations from 41 treatment-naïve relapsing-remitting (RR) MS subjects and 37 healthy controls, and in a second cohort of 9 untreated RRMS patients and 10 secondary progressive (SP) MS patients. Levels of HLA-ABC, HLA-E, and HLA-DR were also assessed. Phosphorylation levels of selected proteins were also assessed in mouse splenocytes isolated from myelin oligodendrocyte glycoprotein (MOG)_35–55-induced experimental autoimmune encephalomyelitis (EAE).

Results

Modest differences were observed at baseline between patients and controls, with general lower phosphorylation levels in cells from affected individuals. Conversely, a dramatic increase in phosphorylated p38MAPK and STAT proteins was observed across all cell types in MS patients compared to controls after in vitro activation. A similar phosphorylation profile was observed in mouse lymphocytes primed in vivo with MOG. Furthermore, levels of all p-STAT proteins were found directly correlated with HLA expression in monocytes. Levels of phosphorylated proteins did not differ between relapsing-remitting and secondary progressive MS patients either in baseline conditions or after stimulation. Lastly, phosphorylation levels appear to be independent of the genotype.

Conclusion

The response to IFN-α through STAT proteins signaling is strongly dysregulated in MS patients irrespective of disease stage. These findings suggest that the aberrant activation of this pathway could lead to changes in the expression of HLA molecules in antigen presenting cells, which are known to play important roles in the regulation of the immune response in health and disease.

Electronic supplementary material

The online version of this article (10.1186/s12974-018-1105-9) contains supplementary material, which is available to authorized users.