Gene expression profiles of chimeric cytokine receptor-engineered CAR-T cells

The efficacy of chimeric antigen receptor (CAR)-engineered T cell therapy is suboptimal in most of the cancer types , necessitating further improvement in their therapeutic actions. However, enhancing antitumor T cell response inevitably confers an increased risk of cytokine release syndrome associated with monocyte-derived IL-6 secretion. Thus, a novel approach to simultaneously enhance therapeutic efficacy and safety is warranted. In this study, we developed a chimeric cytokine receptor composed of the extracellular domains of GP130 and IL6RA linked to the transmembrane and cytoplasmic domain of IL-7R mutant that constitutively activate JAK-STAT pathway (G6/7R). CAR-T cells with G6/7R efficiently absorbed and degraded monocyte-derived IL-6 both in vitro and in vivo. The G6/7R-expressing CAR-T cells showed superior expansion and persistence in vivo, which resulted in durable antitumor response in multple tumor models. Our strategy can be widely applicable to CAR-T cell therapy to enhance its efficacy and safety, irrespective of the target antigen. Overall design: Human CD8+ T cells derived from three different healthy donors were retrovirally transduced with an anti-CD19 CAR gene (FMC63-28z) and stimulated with the CD19+ B-cell acute lymphoblastic leukemia cell line NALM-6 for three times. RNA was collected after the third stimulation, and gene expression profiles were analyzed by RNA sequencing.