Microglia activation orchestrates CXCL10-mediated CD8+ T cell recruitment to promote aging-related white matter degeneration (fixed scRNA-seq)

Aging is the major risk factor for neurodegeneration and associated with structural and functional alterations in white matter. Myelin is particularly vulnerable to aging resulting in white matter-associated microglia activation. In this study, we employed pharmacological and genetic approaches to investigate microglial functions related to aging-associated changes in myelinated axons of mice. Our results reveal that maladaptive microglia activation promotes the accumulation of CD8+ T cells, leading to degeneration of myelinated axons and subsequent impairment of brain function and behavior. We characterize glial heterogeneity and aging-related changes in white matter by single-cell and spatial transcriptomics and reveal elaborate glial-immune interactions. Mechanistically, we show that the CXCL10-CXCR3 axis is crucial for the recruitment and retention of CD8+ T cells in aged white matter, where they exert pathogenic effects. Our results indicate that myelin-related microglia dysfunction promotes adaptive immune reactions in aging and identify putative targets to mitigate their detrimental impact. Overall design: The optic nerve were collect from mouse (adult, aged and PLX5622 treated aged) and analyzed by 10X Chromium Fixed RNA Profiling Reagent Kits.