Fig 4

Fig 4

A,B. Macrophages and neutrophils are recruited to S. sonnei in vivo. Larvae of the Tg(mpeg1:Gal4-FF)^gl25/Tg(UAS-E1b:nfsB.mCherry)^c264 strain (labelling macrophages, A) or of the Tg(lyz:dsRed)^nz50 strain (labelling neutrophils, B) were injected with PBS (blue) or S. sonnei (red) in the HBV. Recruitment was quantified from images at 6 hpi. Experiments are cumulative of 3 biological replicates. Statistics: two-tailed Mann-Whitney test; ****p<0.0001. C,D. Macrophage ablation does not increase susceptibility to S. sonnei. Survival curves (C) and Log₁₀-transformed CFU counts (D) of Tg(mpeg1:Gal4-FF)^gl25/Tg(UAS-E1b:nfsB.mCherry)^c264 larvae which were treated with either Metronidazole (Mtz, macrophage ablated group, blue) or control DMSO vehicle (DMSO, red) prior to infection in the HBV with S. sonnei. Experiments are cumulative of 3 biological replicates. In D, full symbols represent live larvae and empty symbols represent larvae that at the plating timepoint had died within the last 16 hours. Statistics: Log-rank (Mantel-Cox) test (C); unpaired t-test on Log₁₀-transformed data (D); ns, non-significant. E,F. pu.1 morpholino knockdown increases susceptibility to S. sonnei. Survival curves (E) and Log₁₀-transformed CFU counts (F) of pu.1 morphant (blue) or control (red) larvae infected in the HBV with S. sonnei. Experiments are cumulative of 3 biological replicates. In F, full symbols represent live larvae and empty symbols represent larvae that at the plating timepoint had died within the last 16 hours. Statistics: Log-rank (Mantel-Cox) test (E); unpaired t-test on Log₁₀-transformed data (F); ns, non-significant; ****p<0.0001. G,H. Virulence of ΔO-Ag S. sonnei can be observed in pu.1 morphants. Survival curves (G) and Log₁₀-transformed CFU counts (H) of pu.1 morphant (blue) or control (red) larvae infected in the HBV with ΔO-Ag S. sonnei. To allow full ablation of immune cells by morpholino knockdown, infections were performed at 30 hours post-fertilisation (hpf). Experiments are cumulative of 3 biological replicates. In H, full symbols represent live larvae and empty symbols represent larvae that at the plating timepoint had died within the last 16 hours. Statistics: Log-rank (Mantel-Cox) test; ****p<0.0001.