CatB deficiency increased while cystatin C deficiency decreased the survival of CVB3-induced VMC.

Mice were randomly assigned into 4 groups: WT group (n = 10); WT+CVB3 group (n = 14); Ctsb^-/-+CVB3 group (n = 12) and Cstc^-/-+CVB3 group (n = 11). Each mouse of the latter three groups received 1000 TCID₅₀ of CVB3 intraperitoneally, while the WT group received an equal amount of DMEM. (A) Western blot analysis of actived CatB expression to verify the deletion and overexpression of CatB in Ctsb^-/- mice and Cstc^-/- mice. (B) Survival was monitored daily until day 28 post-infection. The Kaplan-Meier curve showed a significant increase in survival in Ctsb^-/-+CVB3 group and a remarkable decrease in Cstc^-/-+CVB3 group, compared with WT+CVB3 group. (WT: wild-type; *P<0.05 vs. WT group; #P<0.05 vs. WT+CVB3 group; &&P<0.01 vs. Ctsb^-/-+CVB3 group).