Altered CD8+ T cell associated aging gene signature in the peripheral blood of patients with Alzheimer's disease.

INTRODUCTIONEffector memory (EM) CD8+ T cells have been associated with poor cognition in Alzheimers disease (AD). Our lab recently discovered an age-associated gene expression signature of IL-7 receptor alpha (IL-7R)low EM CD8+ T cells. We hypothesized that individuals with AD have altered levels of this IL-7Rlow aging gene expression. METHODSForty genes associated with IL-7Rlow EM CD8+ T cells, AD, or memory, were analyzed in peripheral blood of participants with normal cognition, mild cognitive impairment, and dementia by qPCR. RESULTSOf the eight genes that were found to be differentially expressed based on clinical diagnosis, 5 genes (62.5%) were IL-7Rlow aging genes. Principal component analysis revealed 3 clusters of participants with dementia which had distinct expression levels of IL-7Rlow aging genes and cognitive function. DISCUSSIONOur findings support the possible relationship of the IL-7Rlow EM CD8+ T cell aging signature with cognition in individuals with dementia due to AD.