Fig 6.

IL-23p19 induction by LVS, but not SchuS4, is caspase-1 dependent in vitro. Peritoneal macrophages (6 wells/group) from C57BL/6 mice were infected with F. tularensis LVS or SchuS4 at a multiplicity of infection of ∼30. Macrophages were also treated with the caspase-1 inhibitor YVAD-cmk or DMSO (vehicle control). Twenty h after infection, intracellular bacterial CFU were quantified (A), and mRNA expression of immune-related genes was determined via qRT-PCR (plotted as log₂ induction relative to mock-infected macrophages) (B). Error bars depict SEM. *, P < 0.05 compared to DMSO-treated macrophages infected with the same strain of Francisella. ^, P < 0.05 compared to macrophages treated with DMSO and infected with SchuS4. Data are representative of 2 to 3 independent experiments.