Transcriptional Signatures of First and Second Generation CAR T Cells

T cells engineered to express chimeric antigen receptors (CARs) targeting CD19 have produced impressive outcomes for the treatment of B cell malignancies. CARs have been developed by independent groups and have incorporated different costimulatory domains, such as CD28 or 4-1BB. Here we generated transcriptional profiles to provide a unique opportunity to characterize CAR T cells comprehensively. We hypothesized that the sum of comprehensive gene expression changes effected by different costimulatory domains of CARs drives the functional consequences of CAR T cell products. We performed bulk and single cell RNA sequencing of first-generation (Z) and second-generation human CAR T cells with 4-1BB (BBZ) or CD28 (28Z) costimulatory domains at rest and following stimulation through their CAR or endogenous TCR.