FIGURE 7 from The Cross-talk Between Intestinal Microbiota and MDSCs Fuels Colitis-associated Cancer Development

MDSC–bacteria interactions enhance the cells’ suppressive features and functions. A, FISH staining of bacterial 16S rRNA (red) combined with immunofluorescence staining of CD3ε+ T cells (green) and ly6C+ M-MDSCs (yellow) were performed on colon sections of CAC-bearing mice. Arrows indicate interactions between M-MDSCs and bacteria (n = 2–3 per group). Magnification: 20x, Scale bar, 50 µm. B, FISH staining of bacterial 16S rRNA (red) combined with immunofluorescence staining of Ly6G+ PMN-MDSCs (green) and ly6C+ M-MDSCs (yellow) was performed on colon sections of CAC-bearing mice. Arrows indicate interactions between MDSCs and bacteria (n = 2–3 per group). Magnification: 20x, Scale bar, 50 µm. Representative images of ImageStream analysis of PMN-MDSCs (C) and M-MDSCs (D) incubated with or without bacteria isolated from fecal samples of CAC mice at ratio of 1:50 (MDSC:bacteria; n = 4–6). E, Intracellular ROS production by isolated PMN-MDSCs following incubation with or without bacteria, measured by DCFDA MFI using flow cytometry (n = 4–6). F, Secretion of NO by isolated M-MDSCs following incubation with or without bacteria, measured by Griess reagent (n = 6). G, Arginase activity of isolated M-MDSCs following incubation with or without bacteria (n = 3–6). H, IL6, TNFα, IL10, MCP-1, IL27, IL23, IL1β, IFNβ, IL1α, IFNγ, IL17A, GMCSF, and IL12p70 levels in the supernatants of M-MDSCs following incubation with or without bacteria (n = 4–5). I, Proliferation of activated T cells cocultured with M-MDSCs that were preincubated with or without bacteria at ratio of 1:100, or T cells cocultured with bacteria at the same ratio. Representative histograms are shown (left), and proliferation index is summarized (right; n = 4–6). J, Expression levels of PDL-1 in M-MDSCs following incubation with or without bacteria (n = 6). Representative data of one out of two independent experiments. Results are represented as mean ± SEM; *, P < 0.05; **, P < 0.01; ****, P < 0.0001.