Granzyme K Secreted by Aged T Cells Contributes to Cognitive Decline, an Effect that Can Be Reversed (opens in new tab)

The aging of the adaptive immune system, made up of B cells and T cells, is a complex process. Broadly, the pace at which new adaptive immune cells are created declines to a tiny fraction of youthful levels in most people by age 50, and this lack of replacements allows the adaptive immune system to become ever more populated by exhausted, senescent, and malfunctioning cells. This decline in the supply of new adaptive immune cells is in part a problem of hematopoietic cells in the bone marrow,...