PD-1 blockade augments CD8+ T cell dependent antitumor immunity triggered by Ad-SGE-REIC in Egfr-mutant lung cancer

Takamasa Nakasuka, Kadoaki Oohashi, Kazuya Nishii, Atsuko Hirabae, Sachi Okawa, Nahoko Tomonobu, Kenji Takada, Chihiro Ando, Hiromi Watanabe, Go Makimoto, Kiichiro Ninomiya, Masanori Fujii, Toshio Kubo, Eiki Ichihara, Katsuyuki Hotta, Masahiro Tabata, Hiromi Kumon, Yoshinobu Maeda, Katsuyuki Kiura



Objectives: No immunotherapeutic protocol has yet been established in never-smoking patients with lung cancer harboring driver oncogenic mutations, such as epidermal growth factor receptor (EGFR) mutations. The immunostimulatory effect of Ad-REIC, a genetically engineered adenovirus vector expressing a tumor suppressor gene, reduced expression in immortalized cells (REIC), has been investigated in clinical trials for various solid tumors. However, the immunostimulatory effect of the Ad-REIC in EGFR-mutant lung cancer with a non-inflamed tumor microenvironment (TME) has not been explored. Materials and methods: We used a syngeneic mouse model developed by transplanting Egfr-mutant lung cancer cells into single or double flanks of C57BL/6J mice. Ad-SGE-REIC, a 2nd-generation vector with an enhancer sequence, was injected only into the tumors from one flank, and its antitumor effects were assessed. Tumor-infiltrating cells were evaluated using immunohistochemistry or flow cytometry. The synergistic effects of Ad-SGE-REIC and PD-1 blockade were also examined. Results: Injection of Ad-SGE-REIC into one side of the tumor induced not only a local antitumor effect but also a bystander abscopal effect in the non-injected tumor, located on the other flank. The number of PD-1+CD8+ T cells increased in both injected and non-injected tumors. PD-1 blockade augmented the local and abscopal antitumor effects of Ad-SGE-REIC by increasing the number of CD8+ T cells in the TME of Egfr-mutant tumors. Depletion of CD8+ cells reverted the antitumor effect, suggesting they contribute to antitumor immunity. Conclusion: Ad-SGE-REIC induced systemic antitumor immunity by modifying the TME status from non-inflamed to inflamed, with infiltration of CD8+ T cells. Additionally, in Egfr-mutant lung cancer, this effect was enhanced by PD-1 blockade. These findings pave the way to establish a novel combined immunotherapy strategy with Ad-SGE-REIC and anti-PD-1 antibody for lung cancer with a non-inflamed TME.

ジャーナルLung Cancer
出版ステータスPublished - 4月 2023

ASJC Scopus subject areas

  • 腫瘍学
  • 呼吸器内科
  • 癌研究


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