Figure 8
EV71-specific antibody responses, neurological symptoms, pathological changes, and lethality in mice infected with EV71 of the C2 genotype. hSCARB2-Tg mice were intranasally immunised twice with PBS, EV71 (1 μg), or EV71 (1 μg) plus CpG (4 μg) on postnatal days 1 and 2 and were then s.c. challenged with 3 × 106 pfu of the 5746 EV71 strain. (a) Serum samples were collected from each mouse on postnatal day 8 before the mouse was s.c. challenged with 3 × 106 pfu of the 5746 EV71 strain, and the collected samples were assayed to determine the titres of EV71-specific IgG. (b) CNS disorder-like limb paralysis was scored according to the criteria described in the Methods section. Representative images showing symptoms of (c) the PBS-immunised group with limb paralysis and (d) protected mice in the EV71 or EV71 + CpG immunised group at day 7 postinfection with EV71 virus. (e) Histological examination of EV71-infected mice. The animals were sacrificed in the moribund state, and paraffin sections of the organs, including the muscle, intestine, brainstem, and spinal cord, were stained with H&E. Normal tissues were collected from mice without EV71 challenge as a mock control. (f) Daily survival rate, monitored after 8-day-old hSCARB2-Tg mice were s.c. infected with 3 × 106 pfu of the 5746 EV71 strain. Values shown are means ± SEMs of 8–10 mice in each experimental group; *p < 0.05, **p < 0.01, ***p < 0.001.
