Genome editing of PD-L1 mediated by nucleobase-modified polyamidoamine for cancer immunotherapy

• Published in: Journal of materials chemistry. B, Materials for biology and medicine Materials for biology and medicine, 2022-02, Vol.1 (8), p.1291-13
• Main Authors: Wei, Simeng, Shao, Xinxin, Liu, Yong, Xiong, Boyu, Cui, Pengfei, Liu, Ziling, Li, Quanshun
• Format: Article
• Language: English
• Subjects: Antibodies; Apoptosis; B7-H1 Antigen - genetics; B7-H1 Antigen - metabolism; Cancer; Cancer immunotherapy; CD8 antigen; CD8-Positive T-Lymphocytes - metabolism; Cell Line, Tumor; CRISPR; Cytokines; Gene Editing; Genetic modification; Genomes; Immune checkpoint; Immune system; Immunotherapy; Intravenous administration; L1 gene; Lymphocytes; Lymphocytes T; Melanoma; Nanoparticles; Neoplasms - genetics; Neoplasms - therapy; Nuclease; PD-1 protein; PD-L1 protein; Polyamines; Programmed Cell Death 1 Receptor; RNA, Small Interfering - pharmacology; siRNA; Tumor cells
• ISSN: 2050-750X; 2050-7518
• DOI: 10.1039/d1tb02688g

Immune checkpoint blockade therapy against programmed death protein-1 and its ligand (PD-1/PD-L1) has been accepted as a promising approach to activate the immune system's anti-tumor response. Although small interfering RNA (siRNA) or antibodies can block the PD-1/PD-L1 pathway, the effect of this blockade is temporary and reversible. Here, we developed a nano-delivery system to achieve permanent disruption of the PD-L1 gene based on Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated nuclease 9 (Cas9) gene editing technology. In this system, the CRISPR/Cas9 plasmid was delivered into melanoma B16F10 cells using a nucleobase-modified polyamidoamine (PAMAM) derivative namely AP-PAMAM, which was constructed through the modification with 2-amino-6-chloropurine. Meanwhile, the carrier could efficiently facilitate the endosomal escape of CRISPR/Cas9 plasmid and thereby inhibit PD-L1 expression in cancer cells. Moreover, the intravenous injection of AP-PAMAM/plasmid nanoparticles could recruit and activate CD8 + T cells at the tumor site, promoting the secretion of cytokines and the killing of tumor cells. Overall, this nano-delivery system for genome editing provided a promising strategy to block the PD-1/PD-L1 pathway and obtain effective tumor immunotherapy. Genome editing of PD-L1 mediated by nucleobase-modified polyamidoamine for cancer immunotherapy.