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. 2007 Nov 2;3(11):e161. doi: 10.1371/journal.ppat.0030161

Figure 5. Macrophage Activation Antagonizes Caspase-3 Activity and Apoptosis during Infection with Wild-Type Yptb .

Figure 5

Untreated and LPS-activated BMDMs were infected with wild-type or YopJ− Yptb.

(A) Kinetics of caspase-3 activation in infected macrophages. Data shown are means and SDs calculated from three replicates and presented as relative light units (RLU) in cell lysates from infected samples minus uninfected controls. Representative of three experiments. At 150 min postinfection, caspase-3 activity in naïve macrophages undergoing YopJ-dependent apoptosis during infection with wild-type Yptb (289,340 ± 20,466 RLU) is greatly reduced in activated macrophages infected with wild-type Yptb (32,315 ± 2,881 RLU). Activated macrophages infected with YopJ− Yptb fail to activate caspase-3 (3,231 ± 1,531 RLU).

(B) Cleavage of the caspase-3 substrate ICAD was examined in uninfected macrophages (ui) and at 120 min postinfection with wild-type (wt) or YopJ− (J−) Yptb by Western blot and confirmed the absence of caspase-3 activity in activated macrophages. ERK1/2 was used as a loading control.