Anatomy

Pathology

Neuroscience

Central nervous system

Biology

Parenchyma

Neuroimmunology

Lymphatic system

Choroid plexus

Immunology

Meninges

Pia mater

Immunity

Cerebrospinal fluid

Dura mater

Medicine

Immune system

Annual Review of Immunology

Neuroimmunology, albeit a relatively established discipline, has recently sparked numerous exciting findings on microglia, the resident macrophages of the central nervous system (CNS). This review addresses meningeal immunity, a less-studied aspect of neuroimmune interactions. The meninges, a triple layer of membranes—the pia mater, arachnoid mater, and dura mater—surround the CNS, encompassing the cerebrospinal fluid produced by the choroid plexus epithelium. Unlike the adjacent brain parenchyma, the meninges contain a wide repertoire of immune cells. These constitute meningeal immunity, which is primarily concerned with immune surveillance of the CNS, and—according to recent evidence—also participates in postinjury CNS recovery, chronic neurodegenerative conditions, and even higher brain function. Meningeal immunity has recently come under the spotlight owing to the characterization of meningeal lymphatic vessels draining the CNS. Here, we review the current state of our understanding of meningeal immunity and its effects on healthy and diseased brains.

Meningeal Immunity and Its Function in Maintenance of the Central Nervous System in Health and Disease