Blockade of CD73 delays glioblastoma growth by modulating the immune environment
Blockade of CD73 delays glioblastoma growth by modulating the immune environment
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DOI：
10.1007/s00262-020-02569-w
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发表时间：
2020-04-29
影响因子：
5.8
通讯作者：
Braganhol, E.
中科院分区：
文献类型：
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作者：
Azambuja, J. H.;Schuh, R. S.;Braganhol, E.
免疫治疗作为一种治疗癌症的方法，具有广阔的临床应用前景。CD73是一种产生细胞外腺苷的酶，它促进癌症的发展，并保护肿瘤免受免疫监视。虽然CD73最近被证明是治疗胶质瘤的潜在靶点，但它在调节炎性肿瘤微环境中的作用尚未被研究。因此，本研究探讨CD73受体阻断剂对胶质母细胞瘤的免疫治疗价值。在免疫活性的临床前胶质母细胞瘤模型中，体内评价了CD73阻断的免疫治疗价值。因此，携带胶质母细胞瘤的大鼠接受了15天的鼻腔治疗，用负载CD73的siRNA阳离子纳米乳剂(NE-siRNA CD73R)。Annexin-V染色流式细胞仪检测细胞凋亡率，免疫组织化学方法检测Ki67蛋白表达，分析细胞增殖情况。用流式细胞仪检测CD25(高)CD39(+)(Treg)T淋巴细胞；CD11b(+)CD45(高)巨噬细胞；CD11b(+)CD45(低)-小胶质细胞；CD206(+)-M2样细胞的频率以及CD39和CD73在肿瘤和肿瘤相关免疫细胞中的表达水平；用RT-qPCR检测与肿瘤进展相关的炎症标志物。NE-siRNA CD73阻断CD73可诱导肿瘤细胞凋亡。同时，肿瘤微环境中Tregs、小胶质细胞和巨噬细胞的数量显著减少，而IL-6、CCL17和CCL22的数量增加。该治疗选择性地降低了GB细胞以及肿瘤相关巨噬细胞/小胶质细胞中CD73的表达。这项研究表明，利用纳米技术将CD73基因敲除后，将siRNA-CD73经鼻递送到中枢神经系统，可能通过诱导细胞凋亡来调节胶质母细胞瘤的免疫微环境，延缓肿瘤的生长。
Immunotherapy as an approach for cancer treatment is clinically promising. CD73, which is the enzyme that produces extracellular adenosine, favors cancer progression and protects the tumor from immune surveillance. While CD73 has recently been demonstrated to be a potential target for glioma treatment, its role in regulating the inflammatory tumor microenvironment has not yet been investigated. Thus, this study explores the immunotherapeutic value of the CD73 blockade in glioblastoma. The immuno-therapeutic value of the CD73 blockade was evaluated in vivo in immunocompetent pre-clinical glioblastoma model. As such, glioblastoma-bearing rats were nasally treated for 15 days with a siRNA CD73-loaded cationic-nanoemulsion (NE-siRNA CD73R). Apoptosis was determined by flow cytometry using Annexin-V staining and cell proliferation was analyzed by Ki67 expression by immunohistochemistry. The frequencies of the CD4(+), CD8(+), and CD4(+)CD25(high)CD39(+) (Treg) T lymphocytes; CD11b(+)CD45(high) macrophages; CD11b(+)CD45(low)-microglia; and CD206(+)-M2-like phenotypes, along with expression levels of CD39 and CD73 in tumor and tumor-associated immune cells, were determined using flow cytometry, while inflammatory markers associated with tumor progression were evaluated using RT-qPCR. The CD73 blockade by NE-siRNA CD73 was found to induce tumor cell apoptosis. Meanwhile, the population of Tregs, microglia, and macrophages was significantly reduced in the tumor microenvironment, though IL-6, CCL17, and CCL22 increased. The treatment selectively decreased CD73 expression in the GB cells as well as in the tumor-associated-macrophages/microglia. This study indicates that CD73 knockdown using a nanotechnological approach to perform nasal delivery of siRNA-CD73 to CNS can potentially regulate the glioblastoma immune microenvironment and delay tumor growth by inducing apoptosis.