Irradiation Mediates IFNα and CXCL9 Expression in Non-Small Cell Lung Cancer to Stimulate CD8+ T Cells Activity and Migration toward Tumors

Chun-Chia Cheng; Yi-Fang Chang; Ai-Sheng Ho; Zong-Lin Sie; Jung-Shan Chang; Cheng-Liang Peng; Chun-Chao Chang

doi:10.3390/biomedicines9101349

Irradiation Mediates IFNα and CXCL9 Expression in Non-Small Cell Lung Cancer to Stimulate CD8⁺ T Cells Activity and Migration toward Tumors

Biomedicines. 2021 Sep 29;9(10):1349. doi: 10.3390/biomedicines9101349.

Authors

Chun-Chia Cheng¹, Yi-Fang Chang^{2

3

4}, Ai-Sheng Ho⁵, Zong-Lin Sie⁵, Jung-Shan Chang⁶, Cheng-Liang Peng⁷, Chun-Chao Chang^{8

9}

Affiliations

¹ Radiation Biology Research Center, Institute for Radiological Research, Chang Gung University/Chang Gung Memorial Hospital, Taoyuan 333, Taiwan.
² Division of Hematology and Oncology, Department of Internal Medicine, Mackay Memorial Hospital, Taipei 104, Taiwan.
³ Laboratory of Good Clinical Research Center, Department of Medical Research, Mackay Memorial Hospital, New Taipei City 251, Taiwan.
⁴ Department of Medicine, Mackay Medical College, New Taipei City 252, Taiwan.
⁵ Division of Gastroenterology, Cheng Hsin General Hospital, Taipei 112, Taiwan.
⁶ Graduate Institute of Medical Sciences, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.
⁷ Institute of Nuclear Energy Research, Atomic Energy Council, Taoyuan 325, Taiwan.
⁸ Division of Gastroenterology and Hepatology, Department of Internal Medicine, Taipei Medical University Hospital, Taipei 110, Taiwan.
⁹ Division of Gastroenterology and Hepatology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.

Abstract

Irradiation-broken DNA fragments increase type I interferon and chemokines secretion in tumor cells. Since radiotherapy may augment tumor immunotherapy, we hypothesize that the chemokines increased by irradiation could recruit CD8⁺ T cells to suppress tumor proliferation. This study intended to unveil the secreted factors activating and recruiting CD8⁺ T cells in non-small-cell lung cancer (NSCLC). EGFR-positive A549 was selected and treated by X-irradiation (IR) to identify the overexpression of chemokines associated to CD8⁺ T cell cytotoxicity and recruitment. A transwell assay with Alexa 488-labeled CD8⁺ T cells was used to evaluate CD8⁺ T cell motility in vitro. A nuclear imaging platform by In¹¹¹-labeled nivolumab was used to track CD8⁺ T cells homing to tumors in vivo. The activation markers GZMB, PRF-1, and IFNγ, migration marker CD183 (CXCR3), and inhibitory marker CD274 (PD-1), were measured and compared in CD8⁺ T cells with A549 co-cultured, chemokines treated, and patients with late-stage lung cancer. We found that IR not only suppressed A549 proliferation but also induced IFNα and CXCL9 expression (p < 0.05). IFNα majorly increased IFNγ levels in CD8⁺ T cells (p < 0.05) and synergistically with CXCL9 enhanced CD8⁺ T cell migration in vitro (p < 0.05). We found that CXCR3 and PD-1 were down-regulated and up-regulated, respectively, in the peripheral blood CD8⁺ T cells in patients with lung cancer (n = 4 vs. healthy n = 3, both p < 0.05), which exhibited reduction of cell motility (p < 0.05). The in vivo nuclear imaging data indicated highly CD8⁺ T cells migrated to A549-induced tumors. In addition, we demonstrated that healthy PBMCs significantly suppressed the parallel tumor growth (p < 0.05) and the radioresistant tumor growth in the tumor xenograft mice (p < 0.05), but PBMCs from patients with lung cancer had lost the anti-tumor capacity. We demonstrated that IR induced IFNα and CXCL9 expression in A549 cells, leading to CD8⁺ T cell migration. This study unveiled a potential mechanism for radiotherapy to activate and recruit CD8⁺ T cells to suppress lung tumors.

Keywords: CD8+ T cells; CXCL9; CXCR3; IFNα; PD-1; irradiation; non-small-cell lung cancer; radiotherapy.

Abstract

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