Figure 2 from CRISPR–Cas9 Screening Identifies KRAS-Induced COX2 as a Driver of Immunotherapy Resistance in Lung Cancer

Tumor-intrinsic COX2 suppresses antitumor immunity. A, Kaplan–Meier survival of mice treated with 200 μg anti-NK1.1 and/or 200 μg anti-CD8 or corresponding isotype control (n = 5–7 per group) after orthotopic transplantation of Ptgs2−/− cells. Treatment was initiated 3 days before transplantation and was administered once weekly until endpoint. Analysis of survival curves was carried out using the log-rank (Mantel–Cox) test. B, Frequency of tumor-infiltrating T-cell populations and NK cells in KPAR and Ptgs2−/− orthotopic tumors. C, Quantification and representative IHC staining for NKp46⁺ NK cells. Scale bar, 100 μm. D, Stacked bar plots showing frequency of central memory (Tcm—CD44⁺CD62L⁺), effector memory (Tem—CD44⁺CD62L⁻), and naïve (CD44⁻CD62L⁺) CD8⁺ (left) and CD4⁺ (right) T cells. E, Surface expression (mean fluorescence intensity, MFI) of CD44 on CD8⁺ (left) and CD4⁺ (right) T cells. F, Surface expression (mean fluorescence intensity) of CD86 (left) and MHC II (right) on CD11b⁺ macrophages and CD11c⁺ macrophages. G, Percentage of Arg1⁺ CD11b⁺ macrophages. H, Quantification and representative IHC staining for the immunosuppressive macrophage marker Arg1. Scale bar, 100 μm. I, Representative flow cytometry plots of CD206 and MHC II surface expression on CD11b⁺ macrophages (left) and quantification of the M1/M2 ratio based on the gated populations (right). J, Heatmap showing hierarchical clustering of KPAR and Ptgs2−/− tumors based on mRNA expression of antitumor immunity genes assessed by qPCR. Data are represented as mean ± SEM for B–I, n = 6–9 per group. Symbols represent pooled tumors from individual mice. Statistics were calculated by paired, two-tailed Student t test (B, C, and E–I) or two-way ANOVA, FDR 0.05 (D). *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001.