Achieving CD8+ T cell-dependent lethality by targeting cancer USP14 in hepatocellular carcinoma

Abstract Background & aims: The application of immunotherapy in hepatocellular carcinoma has been hindered by resistance to therapeutics. Cancer cell-induced CD8+ T cell malfunction may account for the failure of tumor immunotherapies. The crucial regulators in HCC that mediate resistance to CD8+ T cell-based cancer immunotherapy are still obscure. Methods: Three independent CRISPR genome-wide screening was constructed. HCC cell-CD8+T cell co-culture model and mouse HCC models were performed to explore the effect of cancer USP14 in vitro and in vivo . Metabolomics, glucose up-take analysis and immune co-precipitation were performed for mechanismstudy. scRNA-seq, HCC PDO and PDX models were used to validate the therapeutic potential of targeting cancer USP14. Results: USP14 was identified as an essential driver of HCC cells tolerating to CD8+ T cells. Cancer USP14 was upregulated and positively correlated with resistance to anti-PD1 therapy and poor prognoses in HCC patients. Inhibition of cancer USP14 reduced the growth of HCC cell with CD8+ T cell co-culturing and enhanced the function of co-cultured CD8+ T cells. Targeting cancer USP14 inhibited HCC tumor growth and boosted anti-PD1-induced tumor immunity in vivo. USP14 highly-expressed HCC cells were avidly consumed and outcompeted CD8+ T cells for glucose by stabilizing GLUT1, resulting in CD8+ T cells starving and malfunction. These HCC cells also lead to acidification in the TME, causing CD8+ T cell dysfunction. The PDO and PDX models confirmed the above results. Conclusions: Our data defined a pro-immunoevasiverole for cancer USP14 in CD8+ T cell-based tumor immunity. Combining USP14 inhibition and PD1 blockade constitutes a potential therapy for HCC. Lay summary: Cancer USP14 sever as a potential therapeutic target for HCC.