METHODS: Preclinical orthotopic HCC mouse models were used to elucidate the efficacy of 5-fluorouracil (5-FU) and ICB. The mice were intrahepatically injected with RIL-175 or Hepa1-6 cells, followed by treatment with 5-FU and anti-programmed cell death ligand 1 (PD-L1) antibody. Myeloid-derived suppressor cells (MDSCs) were depleted to validate their role in attenuating sensitivity to immunotherapy. Flow cytometry-based immune profiling and immunofluorescence staining were performed in mice and patient samples, respectively.
RESULTS: 5-FU could induce intratumoral MDSC accumulation to counteract the infiltration of T lymphocytes and natural killer cells, thus abrogating the anti-tumor efficacy of PD-L1 blockade. In clinical samples, MDSCs accumulated and CD8+ T cell numbers decreased following transarterial chemoembolization.
CONCLUSIONS: 5-FU can trigger the accumulation of immunosuppressive MDSCs, impairing the response to PD-L1 blockade in HCC. Our data suggest that the combination of specific chemotherapy and ICB may impair anti-tumor immune responses, warranting further study in preclinical models and consideration in clinical settings.
BACKGROUND: Our findings suggest that some chemotherapies may impair the anti-tumor efficacy of immunotherapy. Further studies are required to uncover the specific effects of different chemotherapies on the immunological profile of tumors. This data will be critical for the rational design of combination immunotherapy strategies for patients with hepatocellular carcinoma.
方法:使用临床前原位HCC小鼠模型来阐明5-氟尿嘧啶(5-FU)和ICB的功效。小鼠肝内注射RIL-175或Hepa1-6细胞,然后用5-FU和抗程序性细胞死亡配体1(PD-L1)抗体处理。骨髓来源的抑制细胞(MDSC)被耗尽以验证其在减弱对免疫疗法的敏感性中的作用。在小鼠和患者样本中进行基于流式细胞术的免疫谱分析和免疫荧光染色,分别。
结果:5-FU可以诱导肿瘤内MDSC的积累,以抵消T淋巴细胞和自然杀伤细胞的浸润,从而取消PD-L1阻断的抗肿瘤功效。在临床样本中,经动脉化疗栓塞后,MDSCs积累,CD8+T细胞数量减少。
结论:5-FU可以引发免疫抑制MDSCs的积累,在HCC中损害对PD-L1阻断的反应。我们的数据表明,特异性化疗和ICB的组合可能会损害抗肿瘤免疫反应,需要在临床前模型中进一步研究,并在临床环境中考虑。
背景:我们的研究结果表明,一些化疗可能会损害免疫治疗的抗肿瘤功效。需要进一步的研究来揭示不同化疗对肿瘤免疫谱的具体影响。这些数据对于合理设计肝细胞癌患者的联合免疫治疗策略至关重要。