Fig. 5.

Analysis of pathogenicity, neurovirulence, and immune cell markers of mice infected with 93/783, Torö, and Torö93E. Six- to 10-week-old C57/BL6 mice were infected intraperitoneally with 10⁴ FFU using the indicated strains (93/783 N = 4, Torö and Torö93E N = 5), and clinical score (a) and survival (b) were analyzed. Statistical significance between Torö and Torö93E (*P = 0.0311), between Torö and 93/783 (**P = 0.0039) and between Torö93E and 93/783 (**P = 0.0039) were calculated using log-rank (Mantel-Cox) test. Six- to 10-week-old mice were infected intracranially with 10² FFU of 93/783, Torö93E, or Torö and brain parts were isolated 5 d.p.i. Viral burdens in the olfactory bulb, cerebrum, cerebellum, and brainstem (c) were determined by qPCR; expression levels were normalized to the endogenous GAPDH expression and calculated using the ΔΔCT method. Caspase 3 (d), CD45 (e), Ly-9 (f), and CD3 (g) expression levels were detected with qPCR in the olfactory bulb, cerebrum, cerebellum, and brainstem; expression levels are shown as fold induction compared to mock-infected mice (N = 5). Asterisks indicate statistical significance calculated using Mann-Whitney test (*P < 0.05, **P < 0.01)