IFNγ induces an M1 neuroinflammatory phenotype. Relative gene expression for genes representative of the M1, M2a, M2b, and M2c phenotypes. Data are shown as fold-change relative to mice receiving GFP-AAV at the given time point and genotype. (A) Wild-type (WT) mice receiving IFNγ-AAV for 4 months (4 m). (B) WT mice receiving IFNγ-AAV for 6 months (6 m). (C) APP/PS1 receiving IFNγ-AAV for 4 months. (D) APP/PS1 receiving IFNγ-AAV for 6 months. *P < 0.05, **P < 0.01, IFNγ-AAV compared to GFP-AAV of that time point and genotype. #P < 0.05, ##P < 0.01, 4-month IFNγ-AAV compared to 6-month IFNγ-AAV of that genotype. AAV, adeno-associated virus; AARG1, arginase 1; FCGR, Fc gamma receptor; GFP, green fluorescent protein; IFN, interferon; IL, interleukin; SPHK1, sphingosine kinase 1; TGFB, transforming growth factor beta.