Biomarkers of Interferon Beta Therapy in Multiple Sclerosis

Acting centrally or peripherally: A renewed interest in the central nervous system penetration of disease-modifying drugs in multiple sclerosis

With the recent approval of cladribine tablets, siponimod and ozanimod, there has been a renewed interest into the extent to which these current generation disease-modifying therapies (DMTs) are able to cross into the central nervous system (CNS), and how this penetration of the blood-brain barrier (BBB) may influence their ability to treat multiple sclerosis (MS). The integrity of the CNS is maintained by the BBB, blood-cerebrospinal fluid barrier, and the arachnoid barrier, which all play an important role in preserving the immunological environment and homeostasis within the CNS. The integrity of the BBB decreases during the course of MS, with a putative temporal relationship to disease worsening. Furthermore, it is currently considered that progression of the disease is mediated mainly by resident cells of the CNS. The existing literature provides evidence to show that some of the current generation DMTs for MS are able to penetrate the CNS and potentially exert direct effects on CNS-resident cells, in particular the CNS-penetrating prodrugs cladribine and fingolimod, and other sphingosine-1 phosphate receptor modulators; siponimod and ozanimod. Other current generation DMTs appear to be restricted to the periphery due to their high molecular weight or physicochemical properties. As more effective brain penetrant therapies are developed for the treatment of MS, there is a need to understand whether the potential for direct effects within the CNS are of significance, and whether this brings additional benefits over and above treatment effects mediated in the periphery. In turn, this will require an improved understanding of the structure and function of the BBB, the role it plays in MS and subsequent treatments. This narrative review summarizes the data supporting the biological plausibility of a potential benefit from therapeutic molecules entering the CNS, and discusses the potential significance in the current and future treatment of MS.

Interferon-β corrects massive gene dysregulation in multiple sclerosis: Short-term and long-term effects on immune regulation and neuroprotection

Background

In multiple sclerosis (MS), immune up-regulation is coupled to subnormal immune response to interferon-β (IFN-β) and low serum IFN-β levels. The relationship between the defect in IFN signalling and acute and long-term effects of IFN-β on gene expression in MS is inadequately understood.

Methods

We profiled IFN-β-induced transcriptome shifts, using high-resolution microarrays on 227 mononuclear cell samples from IFN-β-treated MS Complete Responders (CR) stable for five years, and stable and active Partial Responders (PR), stable and active untreated MS, and healthy controls.

Findings

IFN-β injection induced short-term changes in 1,200 genes compared to baseline expression after 4-day IFN washout. Pre-injection after washout, and in response to IFN-β injections, PR more frequently had abnormal gene expression than CR. Surprisingly, short-term IFN-β induced little shift in Th1/Th17/Th2 gene expression, but up-regulated immune-inhibitory genes (ILT, IDO1, PD-L1). Expression of 8,800 genes was dysregulated in therapy-naïve compared to IFN-β-treated patients. These long-term changes in protein-coding and long non-coding RNAs affect immunity, synaptic transmission, and CNS cell survival, and correct the disordered therapy-naïve transcriptome to near-normal. In keeping with its impact on clinical course and brain repair in MS, long-term IFN-β treatment reversed the overexpression of proinflammatory and MMP genes, while enhancing genes involved in the oligodendroglia-protective integrated stress response, neuroprotection, and immunoregulation. In the rectified long-term signature, 277 transcripts differed between stable PR and CR patients.

Interpretation

IFN-β had minimal short-term effects on Th1 and Th2 pathways, but long-term it corrected gene dysregulation and induced immunoregulatory and neuroprotective genes. These data offer new biomarkers for IFN-β responsiveness.

Funding

Unrestricted grants from the US National MS Society, NMSS RG#4509A, and Bayer Pharmaceuticals

Shifting paradigms in multiple sclerosis: from disease-specific, through population-specific toward patient-specific

PURPOSE OF REVIEW

In recent years we notice paradigm shifts in the understanding of multiple sclerosis (MS), leading to important transition in the patients' management. This review discusses some of the recent findings and developments underlying the conceptual changes being translated from 'treating the disease' to 'treating the patient' with MS (PwMS).

RECENT FINDINGS

Applying advanced technologies combined with cross-disciplinary efforts in the fields of neuropathology, neuroimmunology, neurobiology, and neuroimaging, together with clinical neurology provided support for the notion that MS is not a single disease but rather a spectrum. Predictive markers of disease subtypes, disease activity and response to therapy are being developed; some already applied to practice, allowing informed management. In parallel, population-specific issues, some genetic-driven, others caused by environmental (sun-exposure, life-style, etc.), gender-related (hormones) and epigenetic factors, are being elucidated. Additionally, patient empowerment-based approaches, including integration of patient-reported outcome measures (PRO) as well as tools to enhance patients' adherence to medications, are being developed, some already provided as part of emerging mobile-health technologies.

SUMMARY

Developments in the MS field, elucidating disease subtypes and interpopulation diversities, together with integration of patient-centered approaches, allow transition toward precision medicine in MS clinical trials and patient care.

Interplay among cytokines and T cell subsets in the progression and control of immune-mediated diseases

Cytokines serve as key mediators of inflammation and tissue damage in a variety of immune-mediated disorders. The induction, progression, and resolution of inflammation in such disorders are characterized by a dynamic balance between both the pro-inflammatory and anti-inflammatory cytokines as well as the pathogenic and protective T cell subsets. Over the past two decades, the roles of the interleukin-17 (IL-17) /IL-23 axis and the T helper 17 (Th17)/ T regulatory (Treg) cell balance in the pathogenesis of autoimmunity and other inflammatory diseases have extensively been analyzed, and their significance validated. However, these studies, coupled with others devoted to well-established Th1/Th2 cytokines, have unraveled some challenging issues including the dual action of cytokines and the plasticity of T cell subsets. Nevertheless, major positive advances have also been made regarding cytokines and T cell subsets as therapeutic targets/agents. In this special issue, "Cytokines in Immune Pathology and Therapy," leading experts have shared their research work and perspectives on the roles of cytokines in the development and control of immune-mediated diseases. An outline of 14 articles in the first volume is presented here. The second volume will follow soon.