Immune Checkpoint Inhibition Followed by Tumor Infiltration of Dendritic Cells in Murine Neuro-2a Neuroblastoma
Immune Checkpoint Inhibition Followed by Tumor Infiltration of Dendritic Cells in Murine Neuro-2a Neuroblastoma
复制标题
小鼠 Neuro-2a 神经母细胞瘤中免疫检查点抑制继之以树突状细胞的肿瘤浸润
DOI：
10.1016/j.jss.2020.03.059
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Akio Odaka
中科院分区：
文献类型：
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作者：
Seiichiro Inoue;Yutaka Horiuchi;Yumiko Setoyama;Yuta Takeuchi;Yoshifumi Beck;Takashi Murakami;Akio Odaka
背景大多数对针对程序性细胞死亡蛋白 1 (PD1) 和程序性死亡配体 1 (PD-L1) 的单克隆抗体免疫疗法有反应的肿瘤显示 PD-L1 的表面表达。据报道，神经母细胞瘤表面存在低PD-L1表达。方法研究免疫检查点抑制剂对小鼠神经母细胞瘤的作用，并分析肿瘤微环境中的宿主免疫细胞。使用流式细胞仪分析 Neuro-2a 小鼠神经母细胞瘤细胞的共刺激分子的表达。将 Neuro-2a 细胞皮下接种到 A/J 小鼠体内，然后腹腔注射针对 PD-1 和 PD-L1 的抗体。接种肿瘤后第14天处死小鼠测量肿瘤重量，并使用流式细胞仪分析肿瘤浸润细胞。结果在培养的Neuro-2a细胞的细胞表面观察到PD-L1的微弱表达。抗体治疗显着抑制了皮下肿瘤的生长，并且表达 PD-L1 的肿瘤细胞被耗尽。我们证实，经抗 PD-L1 抗体调理的 Neuro-2a 细胞在体外被吞噬。在治疗的肿瘤微环境中，与对照组相比，CD8α+淋巴细胞和CD11c+MHC II+细胞显着积累。这些 CD11c+MHC II+ 细胞表达 CD80、CD86、CD14 和 CD40，但不表达 CD205、PD-L1 或 CTLA4。隐约检测到PD-1表达。在脾脏、区域淋巴结或肿瘤微环境中未观察到给予抗 PD-1 和 PD-L1 抗体对 CD11b+Gr-1+ 骨髓源性抑制细胞的免疫抑制作用。结论我们的研究结果提出了联合给予抗 PD-1 和抗 PD-L1 抗体对抑制肿瘤生长具有协同作用的可能性，并且可能是对抗 PD-L1 表达暗淡的神经母细胞瘤的有效疗法。
BackgroundMost tumors responding to immunotherapy with monoclonal antibodies targeting programmed cell death protein1 (PD1) and programmed death ligand-1 (PD-L1) show surface expression of PD-L1. Neuroblastoma has been reported to show low PD-L1 surface expression.MethodsThe effect of immune checkpoint inhibitor on mouse neuroblastoma was investigated, and host immune cells were analyzed in the tumor microenvironment. Expression of co-stimulatory molecules by Neuro-2a mouse neuroblastoma cells was analyzed using flow cytometer. Neuro-2a cells were inoculated subcutaneously into A/J mice, followed by intraperitoneal injection of antibodies targeting PD-1 and PD-L1. Mice were sacrificed for the measurement of tumor weights on day 14 following tumor inoculation, and tumor-infiltrating cells were analyzed using a flow cytometer.ResultsDim expression of PD-L1 was observed on the cell surface of cultured Neuro-2a cells. Growth of subcutaneous tumors was significantly suppressed, and PD-L1-expressing tumor cells were depleted by the antibody treatment. We confirmed that Neuro-2a cells opsonized by the anti-PD-L1 antibody were phagocytosed in thein vitrosetting. In the treated tumor microenvironments, CD8α+lymphocyte and CD11c+MHC II+cells were significantly accumulated in comparison with the control group. These CD11c+MHC II+cells expressed CD80, CD86, CD14, and CD40, but not CD205, PD-L1, or CTLA4. PD-1 expression was detected dimly. Immune suppressive effects of CD11b+Gr-1+myeloid-derived suppressor cells by the administration of anti-PD-1 and PD-L1 antibodies were not observed in spleen, regional lymph nodes, or tumor microenvironment.ConclusionsOur findings raise the possibility that co-administration of anti-PD-1 and anti-PD-L1 antibodies have a synergistic effect on inhibition of tumor growth and could be an effective therapy against neuroblastoma with dim expression of PD-L1.