Fig. 2

Detection of intracellular LPS and cell death in macrophage (6 %) / hepatocyte (94 %) co-cultures infected with LVS (open bars), spp. holarctica (grey filled bars) or spp. mediasiatica (black filled bars) and untreated control (hatched bars). a-b Flow cytometric (FACS) detection of intracellular Francisella tularensis by detection of LPS in a macrophages and b hepatocytes in the mono-cell culture (left side of dashed line) and co-culture (right side of dashed line) (MFI mean fluorescence intensity); c fold change of increase in cell death in macrophages (left side of dashed line) and hepatocytes (right side of dashed line) compared to untreated control in the co-culture; d percentage of detectable macrophages in the co-culture 72 h after infection without (w/o) and with incubation of LVS strain (LVS), F. tularensis holarctica (F. t. hol.) or F. tularensis mediasiatica (F. t. med.). Statistical significance was calculated using student’s t-test (a-d: * p < 0.05 compared to corresponding condition 24 h after infection with the respective strain; # p < 0.05, statistical significance between indicated conditions calculated with student’s t-test)