Supplementary Figure 9: T cell-derived IFNγ targets microglia to mediate neurocognitive dysfunction during recovery from WNV and ZIKV infection.

(a) WNV infects neurons throughout the CNS. Anti-viral T cells that persist in the CNS after viral recovery produce IFNγ. IFNγ targeting of microglia leads to the elimination of presynaptic termini, most prominently in the CA3 region of the hippocampus, and the development of spatial learning and memory deficits. (b) ZIKV preferentially targets neurons in the hippocampus. Like WNV, IFNγ producing T cells persist in the CNS after ZIKV recovery. Targeting microglia, IFNγ induced apoptosis of neurons and the elimination of post-synaptic termini throughout the hippocampus. ZIKV inflicted mice subsequently develop spatial learning and memory deficits.