Fig. 3

FFAR2 deletion reduces the accumulation of MDSCs. A Immunofluorescence analysis of infiltrating Gr-1⁺ cell in urethane-induced lung tumor nodules in mice (n = 5, biological replicates). B Ffar2^+/+ and Ffar2^−/− mice were injected subcutaneously with LLC cells (1 × 10⁶ cells/mouse). After 21 d of transplantation, single cell suspensions were prepared from tumors and subjected to flow cytometry analysis (n = 5, biological replicates). The percentage of tumor-infiltrating CD11b⁺Gr-1⁺-MDSC of total CD45⁺ tumor-infiltrating leukocytes (TILs) in LLC tumors were shown. C Ffar2^+/+ and Ffar2^−/− mice were injected subcutaneously with B16F10 cells (1 × 10⁶ cells/mouse). After 14 d of transplantation, single cell suspensions were prepared from tumors and subjected to flow cytometry analysis (n = 5, biological replicates). The percentage of tumor-infiltrating CD11b⁺Gr-1⁺-MDSC of total CD45⁺ tumor-infiltrating leukocytes (TILs) in B16F10 tumors in mice are shown. D Quantification of percentage of CD11C⁺MHCII⁺-DC and CD11b⁺Gr-1⁻-F4/80⁺-macrophage of total CD45⁺ tumor-infiltrating leukocytes (TILs) in LLC tumors (n = 4, biological replicates). E Mice were injected subcutaneously with LLC cells (1 × 10⁶ cells/mouse). After 21 d of transplantation, representative gating strategy and the percentage of CD11b⁺Gr-1^high-PMN-MDSCs of total CD45⁺ cells in LLC-tumor bearing mouse blood were determined by flow cytometry (n = 5, biological replicates). F The percentage of CD11b⁺Ly-6G⁺-PMN-MDSC (n = 5, biological replicates) and CD11b⁺Ly-6C^high-M-MDSC (n = 4, biological replicates) of total CD45⁺ cells in LLC-tumor bearing mouse spleen were determined by flow cytometry. G Representative images of immunofluorescence staining for CD15 and FFAR2 of human lung adenocarcinoma tissues with adjacent normal tissues, and the percentage of CD15⁺FFAR2⁺ cells in CD15⁺ total positive cells of human lung adenocarcinoma tissues and adjacent normal tissues (n = 73, biological replicates). B–G Data are shown as mean ± SEM, and the experiment was performed three times and a representative example is shown. Data were determined by unpaired Student's t-test (*P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001 and NS, not significant)