The recent (re)discovery of the meningeal lymphatic system has opened new theories as to how immune cells traffic and interact with the central nervous system (CNS). While evidence is accumulating on the contribution of the meningeal lymphatic system in both homeostatic and disease conditions, a lot remains unknown about the mechanisms that allow for interaction between the meningeal lymphatic system and immune cells. In this review, we synthesize the knowledge about the lymphatic immune interaction in the CNS and highlight the important questions that remain to be answered.

No abstract

No abstract

The central nervous system has traditionally been viewed as an immune privilege site with increased tolerance towards antigens that would induce rejection and limited immune responses against CNS antigens. 1 Sir Peter Medawar established this concept when performing his transplantation experiments demonstrating delayed rejection of skin graft in the brain. 2 He postulated that the immune privilege function of the brain arose primarily from (i) lack of drainage of CNS antigens to mount immune responses; (ii) isolation of the brain from peripheral infiltration through the blood brain barrier; and (iii) the relative absence of antigen presenting cells within the CNS. However, further studies demonstrated that rather than isolation and ignorance of the CNS by the immune system, it is rather tightly regulated interactions between immune cells and the CNS that control the apparent immune privilege status of the brain. 3,4 Likely, these controlled interactions are in place to limit neuronal damages while ensuring protection of the brain from infections and facilitate tissue repair.The anatomical sites where most of these interactions appear to take place are particularly located at the borders of the CNS. While the brain parenchyma is virtually devoid of immune cells, with exception of microglia and mast cells, its borders are populated with numerous innate and adaptive immune cells that actively communicate with the periphery to ensure surveillance and protection of the CNS.Yet we still know very little about the establishment, maintenance, and function of these brain borders. New technical advances and a deeper understanding of neuroimmune interactions are driving the field toward the definition of compartmentalized interactions between the brain and the immune system to allow for synergic control and maintenance of brain function in health and disease.Here, we will discuss the establishment and maintenance of the three primary brain borders, the meninges, the choroid plexus, and the blood brain barrier. We then dive into the described roles of the

No abstract

No abstract

No abstract

No abstract