(A) The coculture system. Human or mouse tumor cells were pretreated with IFN-β for 48 hours and cocultured with THP1-derived macrophages (THP1-MΦ) or RAW264.7 cells for another 48 hours. The macrophages were collected for analysis. (B) Heatmap showing the ISG15, IFI44, CXCL9, CXCL10, and SPP1 mRNA expression in cocultured THP1-MΦ. (C) Relative Cxcl9 and Cxcl10 expression in cocultured RAW264.7 cells. (D) CD86 and HLA-DR expression on cocultured THP1-MΦ. (E) CD40 expression on RAW264.7 cells cocultured with Usp5-deficient CT26 cells. (F) p-STAT2 and p-STAT1 in large extracellular vesicles (LEVs) from the culture medium of USP5-deficient SUNE1 and HK1 cells after IFN-β treatment. (G) p-STAT1 and p-STAT2 levels in THP1-MΦ after coculture with SUNE1 cells. (H–J) THP1-MΦ were treated with LEVs collected from the culture medium of STAT2-EGFP–transfected control and USP5-deficient SUNE1 cells after IFN-β treatment. The proportion of EGFP⁺ macrophages (H), CD86 and HLA-DR expression (I), and relative CXCL9 and CXCL1 expression (J) in EGFP⁺ and EGFP^– macrophages were measured. (K–M) Indicated B16 tumors were subjected to irradiation on day 10 after inoculation. The proportions of CXCL9⁺CD11b⁺ macrophages measured by multiplex immunofluorescent staining (K, n = 6 per group), the iNOS⁺CD11b⁺ macrophages and IFN-γ⁺TNF-α⁺CD8⁺ T cells measured by flow cytometry (L, n = 5 per group), and tumor growth (M, n = 6 per group) are reported. The results are representative of 3 independent experiments (B–J). Data are presented as mean ± SD. Comparisons were performed using 1-way ANOVA (H) or 2-way ANOVA with Bonferroni’s test (C–E and I–M) for multiple comparisons. **P < 0.01, ***P < 0.001, ****P < 0.0001.