Fig. 4

Mast cells cause increased vascular leakage and worsened morbidity and mortality during JEV infection. a JEV induced increased EBD leakage into the brain in the WT mice but not in the Sash mice at 5 days after infection with JEV Nakayama by i.p. injection of 2 × 10⁷ PFU. * denotes P < 0.05, as analyzed by Student’s unpaired two-tailed t-test; n = 5, representative of three independent experiments. b Representative images of EBD leakage into the brain from a are presented. c WT mice showed increased virus burden in various parts of the brain, including cerebral cortex, subcortex, cerebellum, and brain stem, at 6 days post-Nakayama infection, quantified by real-time qPCR. * denotes P < 0.01, as analyzed by two-way ANOVA; n = 8, representative of three independent experiments. d Body mass and e grip strength of mice were measured daily and are presented as a percentage of their initial (day 0) values. WT mice showed increased weight loss and worsened neurologic deficits after Nakayama JEV infection compared to Sash mice. *** denotes P < 0.001, as analyzed by two-way ANOVA; n = 5, representative of three independent experiments. For d and e, lines connect points for individual mice and † denotes the last reading before death or humane endpoints were reached. The averages of n = 15 mice are included in Supplementary Figure 10. Error bars represent the SEM. f Increased mortality and shortened survival were observed in WT mice compared to Sash mice, after i.p. infection with Nakayama JEV. ** denotes P < 0.01, as analyzed by log-rank (Mantel–Cox) test, n = 15. Shadows represent the 95% confidence intervals. WT mice demonstrated worsened morbidity, neurologic deficits, and mortality compared to Sash mice after peripheral JEV infection