Aged CD8+ T cells drive cognitive decline
The role of non-infiltrating aged CD8+ T cells in brain function remains unclear.
Immune aging is characterized by Changes in peripheral CD8+ T cells but the role of aged non-infiltrating CD8+ T cells in brain aging is not well understood.
The researchers in this study showed that aged circulating CD8+ T cells and their secreted factors drove age-related cognitive decline.
The authors demonstrate that young mice exposed to aged CD8+ T cells elicited synaptic-related hippocampal changes and impaired cognition, and inhibiting activation, but not infiltration, mitigated their pro-aging effects. Conversely, targeting aged circulating CD8+ T cells restored youthful signatures and rescued cognition.
The researchers identified granzyme K (GZMK) as a secreted pro-aging CD8+ T cell-derived factor in plasma, and GZMK inhibition rescued cognition in aged animals.
https://www.cell.com/immunity/fulltext/S1074-7613%2826%2900176-7
