Miao Xiaofei, Zhang Ye, Li Zengyao, Huang Longchang, Xin Taojian, Shen Renhui, Wang Tong
Nanjing Medical University, Nanjing, 210000 Jiangsu, China.
Wuxi People's Hospital, Wuxi, 214023 Jiangsu, China.
Mol Ther Methods Clin Dev. 2021 Jan 5;20:442-450. doi: 10.1016/j.omtm.2020.12.013. eCollection 2021 Mar 12.
We investigated the immunogenic cell death provoked by oxaliplatin (OXA) and the involvement of OXA-induced immunosuppression in colorectal cancer. Immune-proficient or -deficient mice were employed to evaluate the therapeutic effects of OXA. Immunogenic cell death was characterized by cell-surface calreticulin, cytosol-translocated high migration rate group protein B1 (HMGB1), and secretory ATP content. Bone marrow-derived dendritic cell (BMDC) maturation and CD8 T cell expansion were measured by flow cytometry. Expression of immunosuppressive genes was quantified by both RT-PCR and western blots. The proliferative and apoptotic indexes of xenograft tumors were evaluated by immunohistochemistry and TUNEL assays, respectively. The secretory cytokines were measured with ELISA. OXA induced immunogenic cell death of murine colorectal cancer, which greatly depended on the host immune response. OXA-pretreated CT26 cells promoted BMDC maturation and CD8 T cell expansion. OXA significantly upregulated indoleamine 2,3-dioxygenase 1 (IDO1) in patient-derived colorectal cancer cells and in combination with the IDO1-specific inhibitor, NLG919, suppressed tumor progression. Simultaneous administration with both OXA and NLG919 greatly promoted CD8 T cell infiltration and decreased immunosuppressive cytokine transforming growth factor β (TGF-β) production, whereas increased immunostimulatory cytokines interleukin (IL)-12p70 and interferon (IFN)-γ. We demonstrated the upregulation of IDO1 by OXA, which combined with the IDO1 inhibitor, tremendously potentiated therapeutic effects of OXA against colorectal cancer.
我们研究了奥沙利铂（OXA）引发的免疫原性细胞死亡以及OXA诱导的免疫抑制在结直肠癌中的作用。采用免疫功能正常或缺陷的小鼠来评估OXA的治疗效果。免疫原性细胞死亡的特征为细胞表面钙网蛋白、胞质转位的高迁移率族蛋白B1（HMGB1）和分泌型ATP含量。通过流式细胞术检测骨髓来源的树突状细胞（BMDC）成熟情况和CD8 T细胞扩增情况。通过RT-PCR和蛋白质免疫印迹法对免疫抑制基因的表达进行定量分析。分别通过免疫组织化学和TUNEL检测评估异种移植肿瘤的增殖和凋亡指数。用ELISA检测分泌的细胞因子。OXA诱导小鼠结直肠癌发生免疫原性细胞死亡，这在很大程度上依赖于宿主的免疫反应。经OXA预处理的CT26细胞促进了BMDC成熟和CD8 T细胞扩增。OXA显著上调了患者来源的结直肠癌细胞中吲哚胺2,3-双加氧酶1（IDO1）的表达，并且与IDO1特异性抑制剂NLG919联合使用可抑制肿瘤进展。同时给予OXA和NLG919极大地促进了CD8 T细胞浸润，并减少了免疫抑制细胞因子转化生长因子β（TGF-β）的产生，而增加了免疫刺激细胞因子白细胞介素（IL）-12p70和干扰素（IFN）-γ。我们证明了OXA可上调IDO1的表达，其与IDO1抑制剂联合使用可极大地增强OXA对结直肠癌的治疗效果。
