Polyethylenimine-Mediated CCR5 Gene Knockout Using Transcription Activator-Like Effector Nucleases

CCR5 acts as one of the key coreceptors for human immunodeficiency virus infection, which leads to acquired immune deficiency syndrome. CCR5 gene knockout comes up as an alternative method for treatment of the disease. Transcription activator-like effector nuclease is a powerful gene editing tool characterized by the ease of design, high rates of cleavage activity, and the accessibility of all ranges of transcription activator-like effector nucleases. In this study, transcription activator-like effector nuclease plasmids specifically targeting to knock out CCR5 gene were designed, constructed and then transfected to Hela and HEK293T cell lines with the assistance of the well-established gene delivery carrier polyethylenimine. The transfection efficiency of polyethylenimine reached 50-60% at the optimized N/P ratio of 6/1. The genomic CCR5 sequencing results suggested an estimated knockout efficiency of around 50% under the optimized condition. Thus, CCR5 gene knockout was achieved in cell lines by the polyethylenimine-mediated transfection of transcription activator-like effector nuclease plasmids of interest. More efforts such as the improvement of transfection efficiency of gene delivery carrier could be made to achieve higher gene knockout efficiency of transcription activator-like effector nucleases.