Figure 4.

Rebalancing Smad3/Smad7 Signaling with AA and NG Enhances the Production of IFN-γ and Granzyme B by NK Cells

(A and B) Two-color immunofluorescence detects NK1.1⁺ granzyme B⁺ (A) and NK1.1⁺ IFN-γ⁺ (B) NK cells infiltrating the LLC tumor microenvironment. NK1.1, green; IFN-γ or granzyme B, red; DAPI, blue. Each bar represents the mean ± SEM for groups of three to four mice. Scale bar, 100 μm. (C and D) ELISA shows IFN-γ (C) and granzyme B (D) levels in homogenized LLC tissue. *p < 0.05, **p < 0.01, and ***p < 0.001 compared to control; #p < 0.05, ##p < 0.01, and ###p < 0.001 as indicated. (E and F) Effect of AA (10 μM), NG (100 μM), and their combination on the productions of IFN-γ (E) and granzyme B (F) in splenic NK cells (sp-NK) with TGF-β1 (5 ng/mL) stimulation detected by ELISA. (G) NK cell cytotoxicity assay with AA or/and NG pre-treated bone marrow-derived NK cells as effector cells and LLC as target cells at E:T ratios of 5:1, 10:1, and 20:1 in the TGF-β1 (5 ng/mL) condition. Each bar represents the mean ± SEM for groups of three independent experiments; *p < 0.05 and ***p < 0.001 compared to TGF-β1; ##p < 0.01 and ###p < 0.001 as indicated.