Rapid generation of CD19 CAR-T Cells by minicircle DNA enables anti-tumor activity and prevents fatal CAR-B leukemia

Manufacturing CAR (chimeric antigen receptor)-T cell with viral vector is expensive and time-consuming. Besides, during viral transduction, the genes encoding CARs are randomly integrated into the genome, which could cause oncogenesis or produce devastating CAR-tumor cells. Here, using virus-free and non-transgenic minicircle DNA (mcDNA) vector, we enable rapid generation of CD19 CAR-T cells within two days. Further, we demonstrate in vitro and in xenograft models that the anti-tumor effects of CD19 CAR-T cells produced by mcDNA are as effective as those produced by viral vectors. Finally, we show that our manufacturing process can avoid the production of fatal CAR-tumor cells. Taken together, we provide a fast, effective, and therapeutically safe method to generate CD19 CAR-T cells for treating leukemia.