Meningeal Immunity, Drainage, and Tertiary Lymphoid Structure Formation.

For decades, the brain has been considered an immune-privileged organ, meaning that the brain was mainly ignored by the immune system and that the presence of immune cells, notably of the adaptive arm, was a hallmark of pathological conditions. Over the past few decades, the definition of the immune privilege continues to be refined. There has been evidence accumulating that shows that the immune system plays a role in proper brain function. This evidence may represent an effective source of therapeutic targets for neurological disorders. In this chapter, we discuss the recent advances in understanding the immunity of the brain and describe how tertiary lymphoid structures can be generated in the central nervous system, which might represent a new avenue to treat neurological disorders.