Caspase-1-Dependent and -Independent Cell Death Pathways in Burkholderia pseudomallei Infection of Macrophages
Figure 8
Deletion of B. pseudomallei BopE does not influence caspase-1 activation in macrophages.
(A) Processing of caspases-1, -9, -7 and PARP was detected by immunoblot in cell lysates of C57BL/6 BMM infected with B. pseudomallei E8 wild-type or mutants ΔBopE, ΔFliC and ΔFliCΔBopE at MOI of 50∶1 at 1.5 hours post infection. One experiment of at least three performed is shown. non-infected (n.i.). (B) Invasion and intracellular replication of respective B. pseudomallei strains was examined in BMM infected at MOI of 2∶1 at the indicated time points. (C) Induction of pyroptosis was measured as lactate dehydrogenase (LDH) release in cell culture supernatants of B. pseudomallei infected BMM (MOI 200∶1). (D) Secretion of mature IL-1β was measured in supernatants of B. pseudomallei infected BMM (MOI 50∶1) at 6 and 24 hours after infection. (B, C) Data are presented as mean with standard error of the mean (SEM) of triplicate determinations. One representative experiment out of three independent experiments is shown. (D) Data are presented as mean with SEM of four independent experiments (n = 4). Statistical analyses were performed using one-way ANOVA (*p<0.05; **p<0.01; ***p<0.001 compared to non-infected macrophages or as indicated). below detection (bd), non-infected (n.i.).