Figure 6

Macrophages polarize toward a pro-inflammatory M1-like phenotype upon Salmonella infection at early stage but not at late stage. (A–F) Tg(mfap4:mCherry-F/tnfa:GFP-F) larvae were injected with PBS or Sal-E2Crimson in HBV. (A) Representative maximum projections of fluorescent confocal images extracted from a 4D sequence, showing recruitment of macrophages (mfap4+ cells, red) and M1-like activation (mfap4+-tnfa+ cells, yellow) to Salmonella (magenta) from 4 to 15 hpi. Asterisk: auto-fluorescence. Scale bar: 50 μm. (B) Quantification of the percentage of M1 macrophages at indicated time post-infection. Data of two replicates pooled (mean percentage/larva ± SEM, n = 12 per condition). (C) Zoom of fluorescent confocal images in A. Scale bar: 20 μm, arrow: infected tnfa+ macrophages and arrowhead tnfa+ bystander macrophages. (D) Representative maximum projections of fluorescent confocal images of PBS-injected and Sal-E2Crimson-infected larvae at 4 dpi (upper panels). Scale bar: 50 μm. Zooms of regions boxed by dotted lines (bottom panels). Scale bar zoom: 10 μm. (E) 3D reconstruction of macrophage clusters (red) containing persistent Salmonella (gray), surrounded by few tnfa+ macrophages (green) at 4 dpi. Scale bar: 10 μm. (F) Quantification of the percentage of M1 macrophages at 4 dpi. Data of four replicates pooled (mean percentage/larva ± SEM, 4 dpi, nSal = 23 larvae, nPBS = 20, one sample Wilcoxon test, ****p < 0.0001).

Expression Data

Expression Detail
Antibody Labeling
Phenotype Data

Phenotype Detail
Acknowledgments
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