Zhao Liang, Luo Yingli, Huang Qiaoyi, Cao Ziyang, Yang Xianzhu
Guangzhou First People's Hospital, School of Biomedical Sciences and Engineering, South China University of Technology, Guangzhou, 510006, P. R. China.
Key Laboratory of Biomedical Engineering of Guangdong Province and National Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou, 510006, P. R. China.
Small. 2020 Dec 2:e2004879. doi: 10.1002/smll.202004879.
Blocking immune checkpoint pathways with an antibody or small interfering RNA (siRNA) has become a promising method to reactivate antitumor responses for cancer treatment. However, both blockade strategies achieve only temporary inhibition of these immune checkpoints. Herein, a photoswitched CRISPR/Cas9 system for genomic disruption of the PD-L1 gene is developed to achieve permanent blockade of the PD-1/PD-L1 pathway; this system is constructed by using a photoactivated self-degradable polyethyleneimine derivative and the plasmid pX330/sgPD-L1 (expression of the Cas9 protein and single-guide RNA targeting PD-L1). Under light irradiation, this photoswitched CRISPR/Cas9 system efficiently genetically disrupts the PD-L1 gene in not only bulk cancer cells but also cancer stem-like cells. As a result, the photoswitched CRISPR/Cas9 system significantly increases the infiltration of CD8 T cells into tumor tissue, leading to effective activation of a T cell-mediated antitumor response against cancer cells and cancer stem-like cells. This study provides an alternative strategy to block the PD-1/PD-L1 pathway for efficacious immune checkpoint therapy.
用抗体或小干扰RNA（siRNA）阻断免疫检查点通路已成为一种很有前景的重新激活抗肿瘤反应以用于癌症治疗的方法。然而，这两种阻断策略都只能暂时抑制这些免疫检查点。在此，开发了一种用于对PD-L1基因进行基因组破坏的光开关CRISPR/Cas9系统，以实现对PD-1/PD-L1通路的永久阻断；该系统通过使用光激活的可自降解聚乙烯亚胺衍生物和质粒pX330/sgPD-L1（表达Cas9蛋白和靶向PD-L1的单向导RNA）构建而成。在光照下，这种光开关CRISPR/Cas9系统不仅能在大量癌细胞中，还能在癌干细胞样细胞中有效地对PD-L1基因进行基因破坏。结果，光开关CRISPR/Cas9系统显著增加了CD8 T细胞向肿瘤组织的浸润，从而有效激活了针对癌细胞和癌干细胞样细胞的T细胞介导的抗肿瘤反应。这项研究为阻断PD-1/PD-L1通路以进行有效的免疫检查点治疗提供了一种替代策略。
