Chen Jiang, Amoozgar Zohreh, Liu Xin, Aoki Shuichi, Liu Zelong, Shin Sarah, Matsui Aya, Pu Zhangya, Lei Pin-Ji, Datta Meenal, Zhu Lingling, Ruan Zhiping, Shi Lei, Staiculescu Daniel, Inoue Koetsu, Munn Lance L, Fukumura Dai, Huang Peigen, Bardeesy Nabeel, Ho Won Jin, Jain Rakesh K, Duda Dan G
Edwin. L. Steele Laboratories for Tumor Biology, Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School; 100 Blossom Street, Cox-734, MA 02114, USA.
Department of Medicine, Massachusetts General Hospital and Harvard Medical School; 185 Cambridge Street, Simches Building, CPZN-4216, Boston, MA 02114, USA.
bioRxiv. 2023 Jan 27:2023.01.26.525680. doi: 10.1101/2023.01.26.525680.
Intrahepatic cholangiocarcinoma (ICC) has limited therapeutic options and a dismal prognosis. Anti-PD-L1 immunotherapy combined with gemcitabine/cisplatin chemotherapy has recently shown efficacy in biliary tract cancers, but responses are seen only in a minority of patients. Here, we studied the roles of anti-PD1 and anti-CTLA-4 immune checkpoint blockade (ICB) therapies when combined with gemcitabine/cisplatin and the mechanisms of treatment benefit in orthotopic murine ICC models. We evaluated the effects of the combined treatments on ICC vasculature and immune microenvironment using flow cytometry analysis, immunofluorescence, imaging mass cytometry, RNA-sequencing, qPCR, and T-cell depletion and CD8 T-cell transfer using orthotopic ICC models and transgenic mice. Combining gemcitabine/cisplatin with anti-PD1 and anti-CTLA-4 antibodies led to substantial survival benefits and reduction of morbidity in two aggressive ICC models, which were ICB-resistant. Gemcitabine/cisplatin treatment increased the frequency of tumor-infiltrating lymphocytes and normalized the ICC vessels, and when combined with dual CTLA-4/PD1 blockade, increased the number of activated CD8Cxcr3IFN-γ T-cells. Depletion of CD8 but not CD4 T-cells compromised efficacy. Conversely, CD8 T-cell transfer from versus mice into immunodeficient mice restored the anti-tumor effect of gemcitabine/cisplatin/ICB combination therapy. Finally, rational scheduling of the ICBs (anti-CTLA-4 "priming") with chemotherapy and anti-PD1 therapy achieved equivalent efficacy with continuous dosing while reducing overall drug exposure. In summary, gemcitabine/cisplatin chemotherapy normalizes vessel structure, increases activated T-cell infiltration, and enhances anti-PD1/CTLA-4 immunotherapy efficacy in aggressive murine ICC. This combination approach should be clinically tested to overcome resistance to current therapies in ICC patients.
肝内胆管癌（ICC）的治疗选择有限，预后不佳。抗程序性死亡受体1（PD-L1）免疫疗法联合吉西他滨/顺铂化疗最近在胆道癌中显示出疗效，但仅在少数患者中观察到反应。在此，我们研究了抗程序性死亡蛋白1（PD-1）和抗细胞毒性T淋巴细胞相关抗原4（CTLA-4）免疫检查点阻断（ICB）疗法与吉西他滨/顺铂联合使用时的作用，以及在原位小鼠ICC模型中的治疗获益机制。我们使用流式细胞术分析、免疫荧光、成像质谱流式细胞术、RNA测序、定量聚合酶链反应（qPCR），以及原位ICC模型和转基因小鼠的T细胞耗竭和CD8 T细胞转移，评估联合治疗对ICC血管系统和免疫微环境的影响。在两种具有ICB抗性的侵袭性ICC模型中，吉西他滨/顺铂与抗PD-1和抗CTLA-4抗体联合使用可带来显著的生存获益并降低发病率。吉西他滨/顺铂治疗增加了肿瘤浸润淋巴细胞的频率并使ICC血管正常化，与双重CTLA-4/PD-1阻断联合使用时，增加了活化的CD8Cxcr3IFN-γ T细胞的数量。耗竭CD8而非CD4 T细胞会损害疗效。相反，将野生型（WT）小鼠而非基因敲除小鼠的CD8 T细胞转移到免疫缺陷小鼠中，可恢复吉西他滨/顺铂/ICB联合治疗的抗肿瘤作用。最后，将ICB（抗CTLA-4“启动”）与化疗和抗PD-1治疗进行合理的给药安排，在持续给药的情况下可达到同等疗效，同时减少总体药物暴露。总之，吉西他滨/顺铂化疗可使血管结构正常化，增加活化T细胞浸润，并增强侵袭性小鼠ICC中抗PD-1/CTLA-4免疫疗法的疗效。这种联合方法应进行临床试验，以克服ICC患者对当前疗法的耐药性。
