FIGURE LEGENDS
Figure 1. Schematic view of the role and location of T cell subsets in homeostasis and inflammaging in the different compartments of the brain. In homeostatic conditions (left), the vascular BBB, the blood-CSF barrier and the meningeal barrier limits the access of the T cell population to the CNS. In the context of aging (right), these barriers are compromised by the increased pro-inflammatory cytokine release, allowing the entry of mostly CD8+ T cells, T regulatory cells and other effector T cells into the parenchyma. If the contribution of the different cytokine signatures results in a pro-inflammatory microenvironment, the consequences on the resident immune cells, glia and neurons would induce cognitive impairment.