BioProject

APOE4 is the strongest genetic risk factor for Alzheimer's disease (AD) with increased odds ratios in females. More...

APOE4 is the strongest genetic risk factor for Alzheimer's disease (AD) with increased odds ratios in females. Targeting amyloid plaques show modest improvement in male non-APOE4 carriers. Leveraging transcriptomics across APOE variants in both sexes, multiplex flow cytometry and validation in two independent cohorts of APOE4 female AD patients, we identify a new subset of neutrophils associated with cognitive impairment. This phenotype is defined by increased IL-17 and IL-1 co-expressed gene modules in blood neutrophils of cognitively impaired female APOE e4 carriers, showing increased infiltration to the AD brain. APOE4 female IL-17+ neutrophils upregulated the immunosuppressive cytokines IL-10 and TGFb, and immune checkpoints including LAG-3 and PD-1, associated with accelerated immune aging. Deletion of APOE4 in neutrophils reduced this immunosuppressive phenotype and restored microglial response to neurodegeneration (MGnD), limiting plaque pathology in AD mice. Mechanistically, IL-17Fupregulated in APOE4 neutrophils interacts with microglial IL-17RA to suppress the induction of MGnD phenotype, and blocking this axis supported cognitive improvement in AD mice. These findings provide a translational basis to target IL-17F in APOE e4 female carriers with cognitive impairment. Overall design: Transcriptomic investigation of splenic neutrophils from transgenic APP/PS1 mice carrying the human APOE3 or APOE4 gene and having neutrophil specific deletion of APOE4. Less...