Fig. 3.

SINV replication and antibody responses in brain and spinal cord. WT, IRF3/5/7−/−, IRF3/7−/−, IRF3−/− and IRF7−/− mice were infected intracranially with 10³p.f.u. TE. The quantities of infectious virus in brain and spinal cord (a) homogenates were determined by plaque assay on BHK cells. The data were pooled from two independent experiments and are presented as the mean±SEM of 6–9 mice for each time point per strain. SINV E2 genome copies in brain and spinal cord (b) were determined by RT-qPCR. RNA levels are expressed as the mean SINV copy number (log₁₀)±SEM of 6–9 mice for each time point per strain. ****P<0.0001, WT vs IRF7−/−; ^^^^P<0.0001, IRF3−/− vs IRF7−/−, Tukey’s multiple comparison test. SINV-specific IgM (c) and IgG (d) in serum, brain and spinal cord were measured by EIA and are expressed as the mean optical density (OD) +/−SEM for three mice/time point. *P<0.05; **P<0.01; ***P<0.001 IRF3−/− vs WT.