Restoring immune tolerance in neuromyelitis optica: Part II

Abstract

Neuromyelitis optica spectrum disorder (NMO/SD) and its clinical variants have at their core the loss of immune tolerance to aquaporin-4 and perhaps other autoantigens. The characteristic phenotype is disruption of astrocyte function and demyelination of spinal cord, optic nerves, and particular brain regions. In this second of a 2-part article, we present further perspectives regarding the pathogenesis of NMO/SD and how this disease might be amenable to emerging technologies aimed at restoring immune tolerance to disease-implicated self-antigens. NMO/SD appears to be particularly well-suited for these strategies since aquaporin-4 has already been identified as the dominant autoantigen. The recent technical advances in reintroducing immune tolerance in experimental models of disease as well as in humans should encourage quantum leaps in this area that may prove productive for novel therapy. In this part of the article series, the potential for regulatory T and B cells is brought into focus, as are new approaches to oral tolerization. Finally, a roadmap is provided to help identify potential issues in clinical development and guide applications in tolerization therapy to solving NMO/SD through the use of emerging technologies. Each of these perspectives is intended to shine new light on potential cures for NMO/SD and other autoimmune diseases, while sparing normal host defense mechanisms.

Figure. Developmental pathway for tolerization therapies addressing neuromyelitis optica/spectrum disorder

In this illustration, key developmental milestones are sequenced from laboratory discovery (top) to clinical use (bottom). Approximate time (years) typically required to achieve each developmental milestone is shown in the chevron symbols to the left of respective milestones. Developmental goals (left column) and stages (right column) are also listed in relation to respective developmental milestones. CMC = chemistry/manufacturing/control; IND = investigational new drug application; MoA = mechanism of action; NDA = new drug application.