Defective interfering genes (DIGs) are short viral genomes and interfere with wild-type viral replication. Here, we demonstrate that the new designed SARS-CoV-2 DIG (CD3600) can significantly inhibit the replication of SARS-CoV-2 including Alpha, Delta, Kappa and Omicron variants in human HK-2 cells and influenza DIG (PAD4) can significantly inhibit influenza virus replication in human A549 cells. One dose of influenza DIGs prophylactically protects 90% mice from lethal challenge of A(H1N1)pdm09 virus and CD3600 inhibits SARS-CoV-2 replication in hamster lungs when DIGs are administrated to lungs one day before viral challenge. To further investigate the gene delivery vector in the respiratory tract, a peptidic TAT2-P1&LAH4, which can package genes to form small spherical nanoparticles with high endosomal escape ability, is demonstrated to dramatically increase gene expression in the lung airway. TAT2-P1&LAH4, with the dual-functional TAT2-P1 (gene-delivery and antiviral), can deliver CD3600 to significantly inhibit the replication of Delta and Omicron SARS-CoV-2 in hamster lungs. This peptide-based nanoparticle system can effectively transfect genes in lungs and deliver DIGs to inhibit SARS-CoV-2 variants and influenza virus in vivo, which provides the new insight into the drug delivery system for gene therapy against respiratory viruses.

缺陷干扰基因（DIG）是短病毒基因组，会干扰野生型病毒复制。在此，我们证明新设计的 SARS-CoV-2 DIG (CD3600) 可以显着抑制 SARS-CoV-2（包括 Alpha、Delta、Kappa 和 Omicron 变体）在人 HK-2 细胞中的复制，而流感 DIG (PAD4) 可以显着抑制 SARS-CoV-2 的复制。显着抑制流感病毒在人A549细胞中的复制。一剂流感 DIG 可以预防性地保护 90% 的小鼠免受 A(H1N1)pdm09 病毒的致命攻击，并且在病毒攻击前一天将 DIG 注射到肺部时，CD3600 可以抑制仓鼠肺部的 SARS-CoV-2 复制。为了进一步研究呼吸道中的基因递送载体，肽TAT2-P1&LAH4可以包装基因形成具有高内体逃逸能力的小球形纳米粒子，被证明可以显着增加肺气道中的基因表达。 TAT2-P1&LAH4具有双功能TAT2-P1（基因递送和抗病毒），可以递送CD3600，显着抑制Delta和Omicron SARS-CoV-2在仓鼠肺部的复制。这种基于肽的纳米粒子系统可以有效转染肺部基因并递送DIG以抑制体内SARS-CoV-2变异体和流感病毒，这为针对呼吸道病毒的基因治疗的药物递送系统提供了新的见解。