Highly enhanced transgene integration in human pluripotent stem cells by serine integrase BxbI

Abstract

Genome engineering and especially integration of large DNA payloads in human pluripotent stem cells (hPSC) remains challenging largely due to the sensitive nature of hPSCs. Site specific recombinases such as the serine integrase Bxb1 have been utilised successfully to target hPSC, however the targeting efficiencies remain low. Here we leveraged codon optimisation, inclusion of a nuclear localisation signal, mRNA modality and co-introduction of p53 dominant negative fragment to increase the transgene payload integration efficiency by up to 20-fold in defined genomic safe harbours in hPSCs.