Development of a compact bidirectional promoter-driven dual chimeric antigen receptor (CAR) construct targeting CD19 and CD20 in the Sleeping Beauty (SB) transposon system.

Background: A bidirectional promoter-driven chimeric antigen receptor (CAR) cassette provides the simultaneous expression of two CARs, which significantly enhances dual antigen-targeted CAR T-cell therapy.

Methods: We developed a second-generation CAR directing CD19 and CD20 antigens, incorporating them in a head-to-head orientation from a bidirectional promoter using a single Sleeping Beauty transposon system. The efficacy of bidirectional promoter-driven dual CD19 and CD20 CAR T cells was determined in vitro against cell lines expressing either, or both, CD19 and CD20 antigens.