[Advances in the role of meningeal immunity in viral infectious diseases].

The brain is protected by the blood-brain barrier and surrounded by the meninges, which are classically composed of dura, arachnoid and pia mater from superficial to deep layers. In recent years, a series of scientific breakthroughs has demonstrated the presence of the lymphatic system and immune cells in the meninges. Meningeal lymphatic vessels have recently been recognized as important participants in exchange of materials between cerebrospinal fluid and peripheral blood, as well as in immune surveillance. These studies suggest that the brain is no longer considered an "immune-privileged organ" isolated from peripheral immune systems. Given its unique location, structural composition and immunological characteristics, how meningeal immunity affects the central nervous system under homeostatic and pathological conditions is increasingly being investigated as a source of potential pathogenic mechanisms and new targets for interventions in central nervous system diseases. This article reviews the basic components and functions of meningeal immunity, and summarizes the role and advancement of meningeal immunity in different viral infectious diseases.