Figure 5.

Gadd45α triggers Shigella-mediated apoptotic cell death in infected HeLa cells. Activity of caspase-8 (A), caspase-9 (B) and caspase-3 (C), and TUNEL assay (E and F) on HeLa cells transiently transfected with a Gadd45α or a scramble siRNA. Cells were infected with M90T at MOI of 100 for the reported time points. HeLa cells treated with STP or with CHX plus TNF-α, as detailed in Figure 2, were used as a control (D). HeLa NI, non-infected HeLa cells. Report assay data correspond to the mean±S.D. (triplicate determinations) and are representative of three independent luminometric assays. ^*P<0.05, ^**P<0.01, ^***P<0.001 after Student's t-test. (F) A representative cytofluorimetric output of TUNEL analysis performed at 1 h (upper panel, a and b), 3 h (middle panel, c and d) and 5 h of incubation p.i. (lower panel, e and f)