Biotherapy in Inflammatory Diseases of the CNS: Current Knowledge and Applications

Phosphorylation of ERK-Dependent NF-κB Triggers NLRP3 Inflammasome Mediated by Vimentin in EV71-Infected Glioblastoma Cells

Enterovirus 71 (EV71) is a dominant pathogenic agent that may cause severe central nervous system (CNS) diseases among infants and young children in the Asia-pacific. The inflammasome is closely implicated in EV71-induced CNS injuries through a series of signaling pathways. However, the activation pathway of NLRP3 inflammasome involved in EV71-mediated CNS injuries remains poorly defined. In the studies, EV71 infection, ERK1/2 phosphorylation, and activation of NLRP3 are abolished in glioblastoma cells with low vimentin expression by CRISPR/Cas9-mediated knockdown. PD098059, an inhibitor of p-ERK, remarkably blocks the vimentin-mediated ERK1/2 phosphorylation in EV71-infected cells. Nuclear translocation of NF-κB p65 is dependent on p-ERK in a time-dependent manner. Moreover, NLRP3 activation and caspase-1 production are limited in EV71-infected cells upon the caffeic acid phenethyl ester (CAPE) administration, an inhibitor of NF-κB, which contributes to the inflammasome regulation. In conclusion, these results suggest that EV71-mediated NLRP3 inflammasome could be activated via the VIM-ERK-NF-κB pathway, and the treatment of the dephosphorylation of ERK and NF-κB inhibitors is beneficial to host defense in EV71-infected CNS.

The development of biological therapies for neurological diseases: moving on from previous failures

INTRODUCTION

Although years of research have expanded the use of biologics for several clinical conditions, such development has not yet occurred in the treatment of neurological diseases. With the advancement of biologic technologies, there is promise for these therapeutics as novel therapeutic approaches for neurological diseases. Areas covered: In this article, the authors review the therapeutic potential of different types of biologics for the treatment of neurological diseases. Preclinical and clinical studies that investigate the efficacy and safety of biologics in the treatment of neurological diseases, namely Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson disease, multiple sclerosis, and stroke, were reviewed. Moreover, the authors describe the key challenges in the development of therapeutically safe and effective biologics for the treatment of neurological diseases. Expert opinion: Several biologics have shown promise in the treatment of neurological diseases. However, the complexity of the CNS, as well as a limited understanding of disease progression, and restricted access of biologics to the CNS has limited successful development. Therefore, more research needs to be conducted to overcome these hurdles before developing effective and safe biologics for neurological diseases. The emergence of new technologies for the design, production and delivery of biologics will accelerate translating biologics to the clinic.

Prediction of natalizumab anti-drug antibodies persistency

Background:

Anti-drug antibodies (ADA) against natalizumab develop early during treatment. ADA persistency is defined by two consecutive positive results as performed by the current qualitative ELISA assay (positive/negative). Very little is known about the magnitude of the natalizumab ADA response and persistency.

Design/methods:

We developed a highly sensitive natalizumab ADA titration assay on the Meso Scale Discovery (MSD) platform and a pharmacokinetic (PK) assay. We included 43 patients with a positive ELISA-ADA result within 6 months of treatment initiation (baseline) of whom a follow-up serum sample was available 12–30 months after treatment start. MSD-ADA titres and drug levels were measured.

Results:

Median MSD-ADA titre at baseline was 4881 and 303 at follow-up. A titre of >400 at baseline had a 94% sensitivity and 89% specificity to predict ADA persistency. Reversion to ADA negativity occurred in 10 patients with mean drug levels of 10.8 μg/mL. The median trough drug level in ADA-positive samples was 0 µg/mL. PK levels and ADA titres correlated strongly negatively ( r = −0.67).

Conclusion:

High baseline natalizumab ADA titres accurately predict persistency. Despite continuous treatment, the majority of patients with persistent ADA had no detectable drug levels indicating loss of efficacy in line with phase 3 study results.

Immunotherapeutics in Pediatric Autoimmune Central Nervous System Disease: Agents and Mechanisms

Beyond the major advances produced by careful clinical-radiological phenotyping and biomarker development in autoimmune central nervous system disorders, a comprehensive knowledge of the range of available immune therapies and a deeper understanding of their action should benefit therapeutic decision-making. This review discusses the agents used in neuroimmunology and their mechanisms of action. First-line treatments typically include corticosteroids, intravenous immunoglobulin, and plasmapheresis, while for severe disease second-line "induction" agents such as rituximab or cyclophosphamide are used. Steroid-sparing agents such as mycophenolate, azathioprine, or methotrexate are often used in potentially relapsing or corticosteroid-dependent diseases. Lessons from adult neuroimmunology and rheumatology could be translated into pediatric autoimmune central nervous system disease in the future, including the potential utility of monoclonal antibodies targeting lymphocytes, adhesion molecules for lymphocytic migration, cytokines or their receptors, or complement. Finally, many agents used in other fields have multiple mechanisms of action, including immunomodulation, with potential usefulness in neuroimmunology, such as antibiotics, psychotropic drugs, probiotics, gut health, and ketogenic diet. All currently accepted and future potential agents have adverse effects, which can be severe; therefore, a "risk-versus-benefit" determination should guide therapeutic decision-making.