Figure 6.
ac4C mutant virus exhibited reduced pathogenicity in mice. (A) Survival of mice challenged with EV71 WT or ac4C mutant (i.p., 105 PFU). Control mice received DMEM. Seven mice were used per group. *P ≤ 0.05, **P ≤ 0.01, Log-rank (Mantel-Cox) tests. (B) Daily weights of mice from (A). **P ≤ 0.01, two-way ANOVA. (C) Symptoms of mice challenged with EV71 WT or ac4C mutant on day 3 postinfection (i.p., 105 PFU). Symptoms included reduced motility and hind limb paralysis. (D–F) Viral RNA in the limb muscles (D), intestines (E), and brain (F) of AG6 mice infected with EV71, as quantified by qRT-PCR. Data are means ± SEMs (n = 6). *P ≤ 0.05, **P ≤ 0.01, ns: not significant, unpaired Student's t-tests. (G, H) Hematoxylin and eosin staining of the limb muscles (48 and 72 hpi) (G), brain, and intestines (72 hpi) (H). Scale bars, 100 μm. (I) Detection of EV71 particles in the limb muscles, intestines, and brain (72 hpi) using immunohistochemistry. Scale bars, 100 μm.