Fig. 4.

GPX3-induced IL-10 expression is required for tumor-polarized function of GPX3⁺ AT2 cells. (A) Heat map of differently expressed cytokine genes of purified AT2 cells in lungs from LLC-bearing (tumor) or healthy mice as determined by RNA-seq. (B) qPCR analysis of IL-10 and GPX3 messenger RNA expression in AT2 cells purified from tumor mice 14 d after LLC inoculation or from healthy ones. (C) Flow cytometry analysis of IL-10 expression in AT2 cells of GPX3^fl/fl and GPX3^cKO mice after LLC inoculation. (D) Flow cytometry analysis of CD4⁺ T cell proliferation cocultured with AT2 cells from healthy, GPX3^fl/fl, or GPX3^cKO mice after LLC inoculation with or without anti-IL-10 antibody treatment. (E) Immunofluorescent analysis of Sftpc, IL-10, and GPX3 expression and absolute numbers of Sftpc⁺ IL-10⁺ GPX3⁺ cells in the lungs of healthy or LLC-bearing mice. Scale bar, 100 μm. (F) Immunofluorescent analysis of Sftpc, IL-10, and GPX3 expression and absolute numbers of Sftpc⁺ IL-10⁺ GPX3⁺ cells in the lungs of GPX3^fl/fl or GPX3^cKO mice after LLC inoculation. Scale bar, 100 μm. (G) qPCR analysis of GPX3 expression in MLE-12 cells treated with or without tumor exosomes for 2 h. (H) qPCR analysis of IL-10 expression in control or GPX3-silenced MLE-12 cells treated with or without tumor exosomes for 2 h. siNC, silence of negative control; siGPX3, silence of GPX3. (I) Representative immunofluorescent analysis of Sftpc, IL-10, and GPX3 expression in lungs from healthy mice after LLC inoculation with or without exosome treatment. Scale bar, 100 μm. Data are mean ± SD of one representative experiment. Similar results were seen in three independent experiments. Unpaired Student’s t tests unless noted. **P < 0.01; ***P < 0.001.