Cholangiocarcinoma (CCA) is a poorly immunogenic malignancy associated with limited survival. Syngeneic immunocompetent mouse models of CCA are an essential tool to elucidate the tumor immune microenvironment (TIME), understand mechanisms of tumor immune evasion, and test novel immunotherapeutic strategies. The scope of this study was to develop and characterize immunocompetent CCA models with distinct genetic drivers, and correlate tumor genomics, immunobiology, and therapeutic response. A multifaceted approach including scRNA-seq, CITE-seq, whole exome and bulk RNA sequencing was employed. FDA-approved PD-1/PD-L1 antibodies were tested in humanized PD-1/PD-L1 mice (HuPD-H1). A genetic mouse model of intrahepatic CCA (iCCA) driven by intrabiliary transduction of ΔF/ that mimics human iCCA was generated. From the ΔF/ tumors, a murine cell line (FAC) and syngeneic model with genetic and phenotypic characteristics of human iCCA were developed. Established SB1 (/) and KPPC () models were compared to the FAC model. Although the models had transcriptomic similarities, they had substantial differences as well. Mutation patterns of FAC, SB1, and KPPC cells matched different mutational signatures in Western and Japanese CCA patient cohorts. KPPC tumors had a high tumor mutation burden. FAC tumors had a T cell-infiltrated TIME, while SB1 tumors had a preponderance of suppressive myeloid cells. FAC, SB1, and KPPC tumors matched different immune signatures in human iCCA cohorts. Moreover, FAC, SB1, and KPPC tumor-bearing HuPD-H1 mice displayed differential responses to nivolumab or durvalumab. Syngeneic iCCA models display a correlation between tumor genotype and TIME phenotype, with differential responses to FDA-approved immunotherapies. This study underscores the importance of leveraging multiple preclinical models to understand responses to immunotherapy in different genetic subsets of human CCA. Understanding the relationship between tumor genotype and the phenotype of the immune microenvironment is an unmet need in cholangiocarcinoma (CCA). Herein, we use syngeneic murine models of intrahepatic CCA with different genetic drivers to demonstrate a correlation between tumor genotype and immune microenvironment phenotype in murine models, which is associated with differential responses to FDA-approved immunotherapies. This information will help guide other preclinical studies. Additionally, it emphasizes that immune checkpoint inhibition in patients with CCA is not a “one-size-fits-all” approach. Our observations suggest that, as for targeted therapies, patients should be stratified and selected for treatment according to their tumor genetics.

中文翻译：

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具有不同免疫微环境的同基因小鼠模型代表了人类肝内胆管癌的子集

胆管癌（CCA）是一种免疫原性较差的恶性肿瘤，生存率有限。 CCA同基因免疫活性小鼠模型是阐明肿瘤免疫微环境（TIME）、了解肿瘤免疫逃避机制和测试新型免疫治疗策略的重要工具。本研究的范围是开发和表征具有不同遗传驱动因素的免疫活性 CCA 模型，并将肿瘤基因组学、免疫生物学和治疗反应关联起来。采用了多方面的方法，包括 scRNA-seq、CITE-seq、全外显子组和批量 RNA 测序。 FDA 批准的 PD-1/PD-L1 抗体在人源化 PD-1/PD-L1 小鼠 (HuPD-H1) 中进行了测试。生成了模拟人类 iCCA 的由胆内转导 ΔF/ 驱动的肝内 CCA (iCCA) 遗传小鼠模型。从 ΔF/ 肿瘤中，开发了具有人类 iCCA 遗传和表型特征的鼠细胞系 (FAC) 和同系模型。建立的SB1(/)和KPPC()模型与FAC模型进行了比较。尽管这些模型具有转录组相似性，但它们也存在显着差异。 FAC、SB1 和 KPPC 细胞的突变模式与西方和日本 CCA 患者队列中的不同突变特征相匹配。 KPPC 肿瘤具有较高的肿瘤突变负担。 FAC 肿瘤具有 T 细胞浸润的 TIME，而 SB1 肿瘤则具有大量抑制性骨髓细胞。 FAC、SB1 和 KPPC 肿瘤与人类 iCCA 队列中的不同免疫特征相匹配。此外，FAC、SB1 和 KPPC 荷瘤 HuPD-H1 小鼠对 nivolumab 或 durvalumab 表现出不同的反应。同基因 iCCA 模型显示肿瘤基因型和 TIME 表型之间存在相关性，并对 FDA 批准的免疫疗法具有不同的反应。这项研究强调了利用多种临床前模型来了解人类 CCA 不同遗传亚群对免疫治疗的反应的重要性。了解肿瘤基因型与免疫微环境表型之间的关系是胆管癌（CCA）中尚未满足的需求。在此，我们使用具有不同遗传驱动因素的肝内CCA同基因小鼠模型来证明小鼠模型中肿瘤基因型和免疫微环境表型之间的相关性，这与对FDA批准的免疫疗法的差异反应相关。这些信息将有助于指导其他临床前研究。此外，它强调 CCA 患者的免疫检查点抑制并不是一种“一刀切”的方法。我们的观察表明，对于靶向治疗，应根据肿瘤遗传学对患者进行分层和选择治疗。