Platinum TALEN-mediated nonviral gene editing facilitates clinical-scale production of cancer antigen-reactive T cells.

BACKGROUND AIMSRecently, target-genome editing has emerged as a next-generation tool for the clinical development of designed cellular products. Although Clustered Regularly Interspaced Short Palindromic Repeats-Cas9 (CRISPR-Cas9) is the most frequently adopted nuclease for therapeutic genome editing, its widespread use is still hampered by potential off-target effects and high patent royalties. Platinum transcription activator-like effector nuclease (TALEN) is a modified TALEN that harbors non-repeat-variable di-residue (non-RVD) variations and confers higher efficiency than conventional TALENs lacking non-RVD variations.

METHODSIn this study, using Platinum TALEN targeting T-cell receptor (TCR) gene loci and a single-stranded DNA homology-directed repair (HDR) template, we aimed to produce TCR-replaced human T cells reprogrammed to recognize a cancer antigen and kill cancer cells.

RESULTSThis system can reproducibly produce TCR-engineered T cells from ∼50 mL of peripheral blood on a clinical scale. The resulting genome-edited T cells retain naïve/naïve-like and memory phenotype cells in both CD4+ and CD8+ fractions and exhibit efficient cytolytic activity against cancer cell lines in vitro.

CONCLUSIONIn conclusion, Platinum TALEN-mediated nonviral genome editing facilitates the replacement of the endogenous TCR with a desired TCR and can be applied to the clinical manufacturing of therapeutic T-cell products.