Overview of Mechanisms Underlying Neuroimmune Diseases

Neuroimmune diseases are caused by autoimmune demyelination, neurodegeneration, opportunistic and neurotrophic infections, neuropsychiatric disorders, and paraneoplastic conditions. These neuroimmune diseases are multifactorial, complex, and heterogeneous, with varied clinical and pathological features, and are often triggered via the interplay of genetics, environmental factors, and dysregulated immune activation. The molecular mimicry of neuronal antigens, generation of onconeural antigens, inflammation-induced neuronal antigen release, and cross-presentation are thought to activate the autoreactive T and B lymphocytes. The activation of several innate immune pathways, generation of effector T cells, production of autoantibodies, inflamed blood-brain barrier, and activated microglia, astrocytes, oligodendrocytes, and neurons are known to contribute to the development of neuronal diseases. Most current research is focused on genetic association, biomarker discovery, differential diagnosis, treatment choices, and immunological and neurological basis identification of neuroimmune diseases. In this chapter, we discuss the clinical and pathological features of neuroimmune diseases and present an overview of the current understanding of the immunological and neurological mechanisms. We also highlighted the cellular and molecular interactions in generating autoantibodies, inflammatory CD4+ and CD8+ T cells, reactive microglia and astrocytes, and the importance of the blood-brain barrier in neuroinflammation and autoimmunity.