Figure 2.

Immune cells that populate the meningeal spaces. A simplified schematic detailing the diverse repertoire of immune cells during homeostatic conditions at the dorsal meningeal spaces. The subarachnoid space is largely populated with T cells, specifically those with a CD4+ Tcm (Central memory) phenotype as well as some populations of myeloid cells including dendritic cells. Recent characterizations of skull bone marrow and dura have identified that immune cells can populate dural stroma without needing to first enter peripheral blood. Dorsal dural meningeal lymphatic vessels run alongside the superior sagittal sinus, and initial characterizations of the cellular composition of these meningeal lymphatic vessels have identified lymphocytes, DCs, and B-cells within the meningeal lymphatic lumen.