Immune Clearance of Attenuated Rabies Virus Results in Neuronal Survival with Altered Gene Expression

Rabies virus (RABV) is a highly neurotropic pathogen that typically leads to mortality of infected animals and humans. The precise etiology of rabies neuropathogenesis is unknown, though it is hypothesized to be due either to neuronal death or dysfunction. Our approach to study the survival and integrity of RABV-infected neurons was to infect Cre reporter mice with recombinant RABV expressing Cre-recombinase (RABV-Cre) to switch neurons constitutively expressing tdTomato (red) to expression of a Cre-inducible EGFP (green), permanently marking neurons that had been infected in vivo. We were able to isolate these previously infected neurons (“infected”) by flow cytometry and assayed their gene expression profiles compared to uninfected cells (“uninfected”) from the same mice. Two cre reporter mice were infected intranasally with RABV-Cre, allowed to resolve the acute infection, and then sacrificed at 3 months post-infection. EGFP+ cells from the brains of these mice were collected by FACS and represent those infected with RABV (“Infected-1” and “Infected-2”); tdTomato+ cells collected from these same mice represent uninfected cells (“Uninfected-1” and “Uninfected-2”). RNA was collected from these samples for microarray analysis.