A new T‐antigen negative HEK293 cell line with improved AAV productivity

Abstract

AbstractViral vectors for gene therapy, such as recombinant adeno‐associated viruses, are produced in human embryonic kidney (HEK) 293 cells. However, the presence of the SV40 T‐antigen‐encoding CDS SV40GP6 and SV40GP7 in the HEK293T genome raises safety issues when these cells are used in manufacturing for clinical purposes. We developed a new T‐antigen‐negative HEK cell line from ExcellGene's proprietary HEKExpress,® using the CRISPR‐Cas9 strategy. We obtained a high number of clonally‐derived cell populations and all of them were demonstrated T‐antigen negative. Stability study and AAV production evaluation showed that the deletion of the T‐antigen‐encoding locus did not impact neither cell growth nor viability nor productivity. The resulting CMC‐compliant cell line, named HEKzeroT,® is able to produce high AAV titers, from small to large scale.