Calreticulin (CALR) exposure is required for most immunogenic cell death (ICD) in the anti-tumor immunity induced by chemotherapeutic agents. The present study aimed to explore the anti-tumor efficacy of the combined administration of oxaliplatin (OXA) and R848 (an agent for macrophage polarization) in lung cancer cells. Flow cytometry and immunostaining assays were performed to evaluate CALR exposure induced by OXA in the murine Lewis lung carcinoma (LLC) cells. The phagocytosis of macrophages was determined using flow cytometry and western blotting assays. The anti-tumor efficacy of the OXA and R848 combination was evaluated using flow cytometry and western blotting in vitro and in vivo. OXA induced CALR exposure on the surface of LLC cells after low dose and short duration of treatment (20 μM OXA for 24 h). LLC cells pretreated with OXA were more prone to be phagocytized by M1 than M2 macrophages. M2 macrophages repolarized to M1 by R848 in vitro showed enhanced phagocytic ability to OXA-treated LLC cells. Finally, combined administration of OXA and R848 exhibited a synergistic anti-tumor effect than single agent applied in vitro and in vivo. Macrophage polarization from pro-tumor M2 to anti-tumor M1 synergizes with OXA in lung cancer immunotherapy via enhanced tumor cell phagocytosis.

在化疗药物诱导的抗肿瘤免疫中，大多数免疫原性细胞死亡 (ICD) 都需要钙网蛋白 (CALR) 暴露。本研究旨在探讨奥沙利铂 (OXA) 和 R848（一种巨噬细胞极化剂）联合给药对肺癌细胞的抗肿瘤功效。进行流式细胞术和免疫染色测定以评估小鼠路易斯肺癌 (LLC) 细胞中 OXA 诱导的 CALR 暴露。巨噬细胞的吞噬作用通过流式细胞术和蛋白质印迹分析来确定。OXA 和 R848 组合的抗肿瘤功效在体外和体内使用流式细胞术和蛋白质印迹法进行评估。在低剂量和短时间处理（20 μM OXA 24 小时）后，OXA 在 LLC 细胞表面诱导 CALR 暴露。用 OXA 预处理的 LLC 细胞比 M2 巨噬细胞更容易被 M1 吞噬。M2 巨噬细胞在体外被 R848 重新极化为 M1，显示出对 OXA 处理的 LLC 细胞的吞噬能力增强。最后，OXA 和 R848 的联合给药比体外和体内应用的单一药物表现出协同抗肿瘤作用。从促肿瘤 M2 到抗肿瘤 M1 的巨噬细胞极化通过增强的肿瘤细胞吞噬作用与 OXA 在肺癌免疫治疗中协同作用。