Fig. 4From: A human macrophage – hepatocyte co-culture model for comparative studies of infection and replication of Francisella tularensis LVS strain and subspecies holarctica and mediasiatica Cytokine secretion by macrophage/hepatocyte co-cultures of a TNFα, b IL-1β, c IL-6 and d fractalkine (FKN) in response to infection with LVS (open bars), spp. holarctica (grey filled bars) or spp. mediasiatica (black filled bars) or untreated control (hatched bars) after 24, 48 and 72 h of cell culture. Statistical significance was calculated using student’s t-test: *** p < 0.001 compared to identical time point after infection with LVS; ### p < 0.001 compared to identical time point after infection with spp. holarctica Back to article page