Characterizing piggyBat—a transposase for genetic modification of T cells

• Published in: Molecular therapy. Methods & clinical development 2022-06, Vol.25, p.250-263
• Main Authors: Sutrave, Gaurav, Xu, Ning, Tang, Tiffany C.Y., Dolnikov, Alla, Gloss, Brian, Gottlieb, David J., Micklethwaite, Kenneth P., Gowrishankar, Kavitha
• Format: Article
• Language: English
• Subjects: CAR; CD19; chimeric antigen receptor; non-viral vector; Original; piggybat; T cell immunotherapy; transposons
• ISSN: 2329-0501; 2329-0501
• DOI: 10.1016/j.omtm.2022.03.012

Chimeric antigen receptor (CAR) T cells targeting CD19 have demonstrated remarkable efficacy in the treatment of B cell malignancies. Current CAR T cell manufacturing protocols are complex and costly due to their reliance on viral vectors. Non-viral systems of genetic modification, such as with transposase and transposon systems, offer a potential streamlined alternative for CAR T cell manufacture and are currently being evaluated in clinical trials. In this study, we utilized the previously described transposase from the little brown bat, designated piggyBat, for production of CD19-specific CAR T cells. PiggyBat demonstrates efficient CAR transgene delivery, with a relatively low variability in integration copy number across a range of manufacturing conditions as well as a similar integration site profile to super-piggyBac transposon and viral vectors. PiggyBat-generated CAR T cells demonstrate CD19-specific cytotoxic efficacy in vitro and in vivo. These data demonstrate that alternative, naturally occurring DNA transposons can be efficiently re-tooled to be exploited in real-world applications. [Display omitted] PiggyBat transposase can be utilized as a gene-modification tool for the efficient manufacture of chimeric antigen receptor T cells. It has a relatively low efficiency of transgene integration but demonstrates tighter control of vector copy number per cell, highlighting its potential for clinical applications.