5PDThe role of EGFR inhibitor (EGFRi) in immune cell infiltration and CD8+ T-cell activation in EGFR mutant lung cancer

Abstract Background Oncogenic MAP kinase pathway activating mutations have been shown to drive immune suppression in melanoma and colorectal cancers. In this study, we explored whether oncogenic EGFR mutations play an analogous role in non-small cell lung cancer (NSCLC), and whether EGFRi can relieve tumor-associated immune suppression. Methods Lung cancer cell lines expressing wild-type or mutated EGFR were treated with EGFRi, followed by collection of RNA and cell supernatants. In parallel, tumor biopsies from NSCLC patients receiving a personalized peptide vaccine with or without concurrent EGFRi treatment were obtained. RNAseq-based transcriptome profiles of tumor cell lines and patient tumor biopsies were compared to assess common gene signatures driven by EGFRi. Gene expression changes were confirmed at the protein level using Western blot, flow cytometry, and cytokine/chemokine Luminex. The impact of EGFRi on T-cell migration and tumor cell recognition by antigen-specific CD8+ T cells was also assessed. Results In addition to downregulating genes associated with cell proliferation, apoptosis and survival, EGFRi increased the transcription of genes associated with TNFa and TRAIL signaling, and antigen presentation. HLA class I protein upregulation was confirmed and correlated with increased recognition of tumor cells by cytotoxic T cells. Several chemokines and cytokines were up- or down-regulated following EGFRi treatment, and Luminex analysis confirmed changes to 10 of them. Migration assays demonstrated that chemotaxis of T cells towards EGFR-mutant cell supernatants increased in an EGFRi dose-dependent manner. Transcriptome profiling of tumor biopsies revealed similar gene expression changes in on-EGFRi treatment tumor samples. Furthermore, increased tumor immune cell infiltration observed in EGFRi-treated patient tumors was consistent with the upregulation of EGFRi signature chemokines at the tumor site. Conclusions These results provide evidence that EGFRi has the capacity to facilitate modulation of the tumor microenvironment to favor immune cell infiltration and promote T-cell mediated antitumor immunity. Legal entity responsible for the study The University of Texas MD Anderson Cancer Center. Funding Tianjin HengJia Biotechnology Development Co., Ltd. Disclosure F. Li: Shareholder/Stockholder/Stock options: Tianjin HengJia Biotechnology Development Co., Ltd.. G. Lizee: Advisory/Consultancy: HengJia Neoantigen Biotechnology (Tianjin) Co., Ltd.. P. Hwu: Advisory/Consultancy: Dragonfly Therapeutics; Advisory/Consultancy: GlaxoSmithKline; Advisory/Consultancy, Shareholder/Stockholder/Stock options: Immatics; Advisory / Consultancy: Sanofi; Research grant/Funding (institution): Genentech. L. Deng: Full/Part-time employment: Tianjin HengJia Biotechnology Development Co., Ltd.. Q. Zou: Full/Part-time employment: Tianjin HengJia Biotechnology Development Co., Ltd.. Y. Wang: Full/Part-time employment: Tianjin HengJia Biotechnology Development Co., Ltd.. R. Ataullakhanov: Full/Part-time employment: Bostongene. Llc. Bagaev: Full/Part-time employment: Bostongene. Llc. N. Kotlov: Full/Part-time employment: Bostongene. Llc. V. Svekolkin: Full/Part-time employment: Bostongene. Llc. N. Miheecheva: Full/Part-time employment: Bostongene. Llc. F. Frenkel: Full/Part-time employment: Bostongene. Llc. All other authors have declared no conflicts of interest.