Stage-specific roles of clonally expanded CD8+ T cells in Alzheimer’s disease pathology; early-stage Alzheimer's disease mouse models
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ABSTRACT: Clonally expanded CD8+ T cells may contribute to Alzheimer’s disease (AD) pathology through interactions with brain-resident cells. However, the functional impact of AD-specific T cell receptor (TCR) clonotypes remains unclear. Here, we demonstrate that CD8+ T cells undergo clonal expansion in early-stage AD mouse models and that their depletion reduces amyloid plaque accumulation. Expanded TCR-expressing CD8+ T cells preferentially infiltrate the brain, exacerbating plaque deposition. Moreover, brain-infiltrating CD8+ T cells impair microglial transition into disease-associated states, suppressing amyloid clearance via CCL5-CCR5 signaling. Pharmacological blockade of CCL5 attenuates amyloid deposition, whereas CCL5 administration aggravates pathology. Notably, T cell depletion at later disease stages exacerbates amyloid pathology, suggesting a temporal shift in their function. Early-stage CD8+ T cells exhibit cytotoxic and effector profiles, whereas late-stage cells acquire tissue-resident and exhausted phenotypes. This temporal switch—from pathogenic to protective roles—highlights the stage-specific contribution of CD8+ T cells to AD and their potential as therapeutic targets.
ORGANISM(S): Mus musculus
PROVIDER: GSE287555 | GEO | 2025/09/05
REPOSITORIES: GEO
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