CD8A and infection: Moreover, Tim-3 expression on CD3+CD8+ Tc cells decreased at day 9 post-infection, but remained higher than that on day 3 post-infection (Figure 3C, left, day 3 vs. day 9: 1.07 ± 0.32 vs. 2.13 ± 0.25, P < 0.05), and the proportion of splenic CD3+CD8+ Tc cells at day 9 post-infection remained lower than that on day 3 post-infection (Figure 3D, left, day 3 vs. day 9: 20.80 ± 1.31 vs. 10.80 ± 0.75, P < 0.05) in the ME49 group.