Construction of recombinant adenovirus-5 vector to prevent replication-competent adenovirus occurrence

Human adenovirus-5 (hAd5) is an important gene delivery vector, which has been widely used in various fields of biomedicine, such as gene therapy, cancer therapy, and vaccine development. However, replication-competent adenovirus (RCA) generated when adenoviral vectors are prepared in HEK293 cells has remained a concern. In this study, the human adenovirus-5 was modified to shorten the length of homologous sequence between the adenovirus and HEK293 genomic DNA, thereby reducing the production of RCA. The recombinant hAd5 was amplified and serially passaged 12 times in HEK293 cells. The amounts of RCA at passage 2, 4, 6, 8, 10, and 12 were detected by quantitative real-time PCR. The results demonstrated that the modification of adenoviral vector could effectively reduce the production of RCA during serial passages in HEK293 cells.