Development of a chimeric cytokine receptor that captures IL-6 and enhances the antitumor response of CAR-T cells

Abstract

The efficacy of chimeric antigen receptor (CAR)-engineered Tcell therapy is suboptimal in most cancers, necessitating further improvement in their therapeutic actions. However, enhancing antitumor Tcell response inevitably confers an increased risk of cytokine release syndrome associated with monocyte-derived interleukin-6 (IL-6). Thus, an approach to simultaneously enhance therapeutic efficacy and safety is warranted. Here, we develop 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 activates the JAK-STAT pathway (G6/7R or G6/7R-M452L). CAR-T cells with G6/7R efficiently absorb and degrade monocyte-derived IL-6 invitro. The G6/7R-expressing CAR-T cells show superior expansion and persistence invivo, resulting in durable antitumor response in both liquid and solid tumor mouse models. Our strategy can be widely applicable to CAR-T cell therapy to enhance its efficacy and safety, irrespective of the target antigen.