The CSF1R-Microglia Axis Has Protective Host-Specific Roles During Neurotropic Picornavirus Infection

Goal: Determine the role of microglia in the antiviral response during neurotropic picornavirus infection of C57BL/6J and SJL/J mice and whether absence of microglia would affect CD4 and CD8 T cell functions. Methods: Brains from C57BL/6J and SJL/J mice treated with PLX5622 (to deplete microlgia) or control diet were harvested at 6 days post TMEV-infection. CD4+ T cells and CD8+ T cells were obtained using Easy Sep Mouse CD4+ T cell isolation Kit and Easy Sep Mouse CD8+ T cell isolation Kit (Stemcell). RNA was obtained using RNeasy (QIAGEN) and Illumina TruSeq stranded RNA Kit with Ribo-Zero Gold was then utilized to prepare cDNA library for RNA-seq. Results: Our results demonstrate strain-specific effects of the CSF1R-microglia axis in the context of neurotropic viral infection as well as inherent differences in microglial antigen presentation and subsequent T cell crosstalk that contribute to susceptibility to neurotropic picornavirus infection. RNA was isolated from CD4 and CD8 T cells obtained from the brains of C57BL/6J (n=20) and SJL/J (n=20) treated with PLX5622 (n=10/mouse strain) or control diet (n=10/mouse strain), at 6 days post TMEV-infection of the CNS.