Aging gene signature of memory CD8 + T cells is associated with neurocognitive functioning in Alzheimer's disease

Memory CD8 T cells expand with age. We previously demonstrated an age-associated expansion of effector memory (EM) CD8 T cells expressing low levels of IL-7 receptor alpha (IL-7Rα ) and the presence of its gene signature (i.e., IL-7Rα aging genes) in peripheral blood of older adults without Alzheimer's disease (AD). Considering age as the strongest risk factor for AD and the recent finding of EM CD8 T cell expansion, mostly IL-7Rα cells, in AD, we investigated whether subjects with AD have alterations in IL-7Rα aging gene signature, especially in relation to genes possibly associated with AD and disease severity. We identified a set of 29 candidate genes (i.e., putative AD genes) which could be differentially expressed in peripheral blood of patients with AD through the systematic search of publicly available datasets. Of the 29 putative AD genes, 9 genes (31%) were IL-7Rα aging genes (P