Carbon ion radiotherapy triggers immunogenic cell death and sensitizes melanoma to anti-PD-1 therapy in mice.
Carbon ion radiotherapy triggers immunogenic cell death and sensitizes melanoma to anti-PD-1 therapy in mice.
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碳离子放射疗法引发小鼠免疫原性细胞死亡并使黑色素瘤对抗 PD-1 疗法敏感
DOI：
10.1080/2162402x.2022.2057892
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发表时间：
2022
期刊：
影响因子：
7.2
通讯作者：
Wang J
中科院分区：
文献类型：
--
作者：
Zhou H;Tu C;Yang P;Li J;Kepp O;Li H;Zhang L;Zhang L;Zhao Y;Zhang T;Sheng C;Wang J
碳离子放射治疗（CIRT）是一种新兴的实体瘤放射治疗方法。近年来，越来越多的证据表明，CIRT 可以改善对免疫检查点阻断反应不佳的患者的治疗结果。在这里，我们的目的是确定 CIRT 诱导的肿瘤免疫原性和治疗效果的潜在机制。我们使用人 U2OS 骨肉瘤细胞进行免疫原性细胞死亡的体外评估，并建立了几种小鼠黑色素瘤的体内模型。我们采用常规放射、CIRT、PD-1 靶向免疫检查点阻断或放疗与检查点阻断的序贯组合治疗动物。我们利用流式细胞术、聚丙烯酰胺凝胶电泳 (PAGE) 和免疫印迹分析、免疫荧光、免疫组织化学以及酶联免疫吸附测定 (ELISA) 来评估体外免疫原性细胞死亡的生物标志物。通过肿瘤生长评估研究治疗效果，并通过流式细胞术和免疫组织化学分析肿瘤免疫浸润。与传统的放射免疫疗法相比，CIRT与抗PD-1的组合更有效地触发免疫原性细胞死亡的特征，包括钙网蛋白的暴露、三磷酸腺苷（ATP）的释放、高迁移率族蛋白1（HMGB1）的外流以及诱导1型干扰素反应。此外，CIRT联合抗PD-1导致CD4+和CD8+淋巴细胞向瘤床的浸润增加，显着降低肿瘤生长并延长荷黑素瘤小鼠的生存期。我们在此提供的证据表明 CIRT 触发免疫原性细胞死亡、增强肿瘤免疫原性并提高后续抗 PD-1 免疫疗法的疗效。
Carbon ion radiotherapy (CIRT) is an emerging type of radiotherapy for the treatment of solid tumors. In recent years, evidence accumulated that CIRT improves the therapeutic outcome in patients with otherwise poor response to immune checkpoint blockade. Here, we aimed at identifying the underlying mechanisms of CIRT-induced tumor immunogenicity and treatment efficacy. We used human U2OS osteosarcoma cells for the in vitro assessment of immunogenic cell death and established several in vivo models of melanoma in mice. We treated the animals with conventional radiation, CIRT, PD-1-targeting immune checkpoint blockade or a sequential combinations of radiotherapy with checkpoint blockade. We utilized flow cytometry, polyacrylamide gel electrophoresis (PAGE) and immunoblot analysis, immunofluorescence, immunohistochemistry, as well as enzyme-linked immunosorbent assays (ELISA) to assess biomarkers of immunogenic cell death in vitro. Treatment efficacy was studied by tumor growth assessment and the tumor immune infiltrate was analyzed by flow cytometry and immunohistochemistry. Compared with conventional radioimmunotherapy, the combination of CIRT with anti-PD-1 more efficiently triggered traits of immunogenic cell death including the exposure of calreticulin, the release of adenosine triphosphate (ATP), the exodus of high-mobility group box 1 (HMGB1) as well as the induction of type-1 interferon responses. In addition, CIRT plus anti-PD-1 led to an increased infiltration of CD4+, and CD8+ lymphocytes into the tumor bed, significantly decreased tumor growth and prolonged survival of melanoma bearing mice. We herein provide evidence that CIRT-triggered immunogenic cell death, enhanced tumor immunogenicity and improved the efficacy of subsequent anti-PD-1 immunotherapy.