Fig. 3

ISG15 enhances the anti-tumor immunity of CD4⁺ T lymphocytes, which is related to PD-L1. A Growth of control or overexpressed with ISG15 (Lv-ISG15) or shRNA-ISG15 (Sh-ISG15) A549/ H1299 cells before and after co-culture with CD4⁺T cells. The bar chart below indicates the number of cells. B Western blot analysis the expression of apoptosis-related proteins in tumor cells after co-culture. C The IFN-γ secreted by CD4⁺ T cells co-cultured with A549 and H1299 under the three treatment conditions were evaluated by ELISA. D The expansion of CD4⁺ T cells co-cultured with irradiated A549/ H1299 cells or A549/ H1299 cells overexpressed/shRNA of ISG15 were assessed by CCK-8. E The secretion of ISG15 in the supernatant of tumor cells under three treatment conditions detected by ELISA. The data are shown as the mean ± SD. F Typical images of IHC staining for ISG15, granzyme B, perforin and PD-L1 in two patients with LUAD. Scale bars 100 μm. Magnification, ×400. G Number of cells positive for Granzyme B or Perforin in each high magnification (×400) field of view. H, correlation analysis of PD-L1 and ISG15 expression in 40 lung adenocarcinoma tissues. *P < 0.05, **P < 0.01, ***P < 0.001