FIG 1.

Activation of caspase-3 in RAW264.7 macrophages by SipA is dependent on activation state and MOI. (A) SipA induces increased caspase-3 activation in infected activated macrophages over the first 4 h of infection at an MOI of 10. This increase in caspase-3 activation is dependent on the activation state of RAW264.7 cells, with resting cells not exhibiting a SipA-dependent increase in activity. (B) An MOI of 100 also removes the SipA dependence of increased caspase-3 activity in activated macrophages. The data presented are representative of three independent infections, and statistically significant differences are denoted. P values: *, <0.05; **, <0.01; ***, <0.001; ****, <0.0001.