Fig. 4
From: FFAR2 expressing myeloid-derived suppressor cells drive cancer immunoevasion
FFAR2 expressing MDSCs contribute to cancer progression. A Lethally irradiated Ffar2+/+ mice received BMs transplants from Ffar2+/+ or Ffar2−/− mice and lethally irradiated Ffar2−/− mice received BMs transplants from Ffar2+/+ or Ffar2−/− mice. Ten weeks after transplantation, chimeric mice were injected subcutaneously with LLC (1 × 106 cells/mice, n = 6, biological replicates). Tumors were photographed. Tumor growth and tumor weight were recorded. B Mice bearing LLC tumors (n = 6, biological replicates) were injected intraperitoneally with isotype or anti-Gr-1 antibodies (200 μg/mouse, every 4 days). Tumor growth and tumor weight were recorded. C Tumor growth and tumor weight in WT mice injected with LLC cells (5 × 105 cells/mouse, n = 6, biological replicates) or co-injected with LLC cells and Ffar2+/+ MDSCs (5 × 105:5 × 105, n = 6, biological replicates) or co-injected with LLC cells and Ffar2−/− MDSCs (5 × 105:5 × 105, n = 6, biological replicates). MDSCs were isolated from the spleen of LLC tumor-bearing mice and tumor growth was recorded. D Mice received weekly intraperitoneal (i.p.) injections of urethane (1 g/kg body weight) for 10 weeks, and lung tumor nodules in mice were photographed and quantified (n = 8, biological replicates). E Representative histopathology of tumor-bearing lungs was analyzed by H&E staining (n = 5, biological replicates). F LLC tumor growth was recorded (n = 6, biological replicates). G Immunofluorescence analysis of infiltrating Gr-1+-MDSC in LLC tumors. H The percentage of tumor-infiltrating CD11b+Gr-1+-MDSC of total CD45+ tumor-infiltrating leukocytes (TILs) in tumors of Ffar2fl/fl and Ffar2fl/flLyz2-cre mice were analyzed by flow cytometry (n = 6, biological replicates). I-K, Representative images of multicolored immunofluorescence staining for CD4+ and CD8+ in LLC tumors (I). CD4+ T cells (J) (n = 7, biological replicates), and CD8+ T cells (K) (n = 7, biological replicates) were quantified. All data are shown as mean ± SEM, and the experiment was performed three times and a representative example is shown. A–C were analyzed by two-way ANOVA. D, F, H, J and K were analyzed by unpaired Student's t-test (*P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001 and NS, not significant)