Figure 4 from CRISPR–Cas9 Screening Identifies KRAS-Induced COX2 as a Driver of Immunotherapy Resistance in Lung Cancer

COX2 inhibition enhances the efficacy of immunotherapy. A, Surface expression [mean fluorescence intensity (MFI)] of CD86 (left) and MHC II (right) on CD11b⁺ macrophages and CD11c⁺ macrophages in KPAR tumors treated for 7 days with 30 mg/kg celecoxib. B–D, Percentage of Arg1⁺ CD11b⁺ macrophages (B), quantification of M1/M2 macrophages (C), and frequency of CD69⁺ CD8⁺ T cells (D) in KPAR tumors treated as shown in A. E, Kaplan–Meier survival of mice treated intraperitoneally with 200 μg anti-PD1 and/or daily oral gavage of 30 mg/kg celecoxib after orthotopic transplantation of KPAR cells. Daily celecoxib treatment was initiated on day 7 and anti-PD1 began on day 10 and was administered twice weekly for a maximum of 3 weeks. Data from two independent experiments, n = 15–16 per group. Analysis of survival curves was carried out using the log-rank (Mantel–Cox) test. F, Quantification of CD8⁺ T cells by IHC in KPAR tumors treated for 7 days with celecoxib and/or anti-PD1. G, CD8⁺ T-cell phenotypes in KPAR tumors treated as shown in F. Tcm, central memory CD8⁺ T cells (CD44⁺CD62L⁺); Tem, effector memory CD8⁺ T cells (CD44⁺CD62L⁻). H, mRNA expression by qPCR of antitumor immunity genes in KPAR tumors treated as shown in F. Data are represented as mean ± SEM (A–D and F–H), n = 5–10 per group. Samples were analyzed using unpaired, two-tailed Student t test (A–D), one-way ANOVA, FDR 0.05 (F and H), or two-way ANOVA, FDR 0.05 (G). ns, not significant; *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001.