PT - JOURNAL ARTICLE AU - Maud Plaschka AU - Valentin Benboubker AU - Maxime Grimont AU - Justine Berthet AU - Laurie Tonon AU - Jonathan Lopez AU - Myrtille Le-Bouar AU - Brigitte Balme AU - Garance Tondeur AU - Arnaud de la Fouchardière AU - Lionel Larue AU - Alain Puisieux AU - Yenkel Grinberg-Bleyer AU - Nathalie Bendriss-Vermare AU - Bertrand Dubois AU - Christophe Caux AU - Stéphane Dalle AU - Julie Caramel TI - ZEB1 transcription factor promotes immune escape in melanoma AID - 10.1136/jitc-2021-003484 DP - 2022 Mar 01 TA - Journal for ImmunoTherapy of Cancer PG - e003484 VI - 10 IP - 3 4099 - http://jitc.bmj.com/content/10/3/e003484.short 4100 - http://jitc.bmj.com/content/10/3/e003484.full SO - J Immunother Cancer2022 Mar 01; 10 AB - Background The efficacy of immunotherapies in metastatic melanoma depends on a robust T cell infiltration. Oncogenic alterations of tumor cells have been associated to T cell exclusion. Identifying novel cancer cell-intrinsic non-genetic mechanisms of immune escape, the targeting of which would reinstate T cell recruitment, would allow to restore the response to anti-programmed cell death protein 1 (PD-1) antibody therapy. The epithelial-to-mesenchymal transition (EMT)-inducing transcription factor ZEB1 is a major regulator of melanoma cell plasticity, driving resistance to mitogen-activated protein kinase (MAPK) targeted therapies. We thus wondered whether ZEB1 signaling in melanoma cells may promote immune evasion and resistance to immunotherapy.Methods We evaluated the putative correlation between ZEB1 expression in melanoma cells and the composition of the immune infiltrate in a cohort of 60 human melanoma samples by combining transcriptomic (RNA-sequencing) and seven-color spatial multi-immunofluorescence analyses. Algorithm-based spatial reconstitution of tumors allowed the quantification of CD8+, CD4+ T cells number and their activation state (PD-1, Ki67). ZEB1 gain-of-function or loss-of-function approaches were then implemented in syngeneic melanoma mouse models, followed by monitoring of tumor growth, quantification of immune cell populations frequency and function by flow cytometry, cytokines secretion by multiplex analyses. Chromatin-immunoprecipitation was used to demonstrate the direct binding of this transcription factor on the promoters of cytokine-encoding genes. Finally, the sensitivity to anti-PD-1 antibody therapy upon ZEB1 gain-of-function or loss-of-function was evaluated.Results Combined spatial and transcriptomic analyses of the immune infiltrates in human melanoma samples demonstrated that ZEB1 expression in melanoma cells is associated with decreased CD8+ T cell infiltration, independently of β-catenin pathway activation. ZEB1 ectopic expression in melanoma cells impairs CD8+ T cell recruitment in syngeneic mouse models, resulting in tumor immune evasion and resistance to immune checkpoint blockade. Mechanistically, we demonstrate that ZEB1 directly represses the secretion of T cell-attracting chemokines, including CXCL10. Finally, Zeb1 knock-out, by promoting CD8+ T cell infiltration, synergizes with anti-PD-1 antibody therapy in promoting tumor regression.Conclusions We identify the ZEB1 transcription factor as a key determinant of melanoma immune escape, highlighting a previously unknown therapeutic target to increase efficacy of immunotherapy in melanoma.Trial registration number NCT02828202.Data are available in a public, open access repository. All data relevant to the study are included in the article or uploaded as supplementary information. RNA-Seq data have been deposited in the GEO repository under accession number GSE169203. Other data relevant to the study are included in the article or uploaded as supplementary information.