Aged Circulating Cd8+ T Cells And Their Secreted Factors Drive Cognitive Decline
As we age, our bodies undergo many changes, and our immune system is no exception. Recent research sheds light on how certain aged immune cells, specifically a type of white blood cell known as CD8+ T cells, might play a surprising role in the cognitive decline often associated with getting older.
These studies suggest that as CD8+ T cells age, they release specific factors into the bloodstream that can negatively impact brain function, particularly in areas crucial for learning and memory. When these aged immune cells or their secreted factors were introduced into younger subjects, they led to impairments in memory and changes in brain regions like the hippocampus.
Crucially, the research identified a specific protein, granzyme K (GZMK), as one of the key culprits secreted by these aged CD8+ T cells. When the activity of these aged immune cells was reduced, or when GZMK was inhibited, it helped to restore cognitive function. This suggests that targeting these aged immune cells or the factors they release could be a promising avenue for developing new treatments to combat age-related cognitive decline. While the exact mechanisms of how these immune factors interact with brain cells are still being explored, this work highlights a fascinating connection between our immune system and brain health in aging.
Source: link to paper