CAR T cells engineered to secrete IFN-κ induce tumor ferroptosis via an IFNAR/STAT1/ACSL4 axis

Ferroptosis is an iron-dependent form of cell death that influences cancer immunity. Therapeutic modulation of ferroptosis is considered a potential strategy to enhance the efficacy of other cancer therapies, including immunotherapies such as chimeric antigen receptor (CAR) T cell therapy. In this study, we demonstrated that IFN-κ influenced the induction of ferroptosis. IFN-κ could enhance the sensitivity of tumor cells to ferroptosis induced by the small molecule compound erastin and the polyunsaturated fatty acid arachidonic acid. Mechanistically, IFN-κ in combination with arachidonic acid induced immunogenic tumor ferroptosis via an IFNAR/STAT1/ACSL4 axis. Moreover, CAR T cells engineered to express IFN-κ showed increased antitumor efficiency against H460 cells (antigen positive) and H322 cells (antigen negative) both in vitro and in vivo. We conclude that IFN-κ is a potential cytokine that could be harnessed to enhance the antitumor function of CAR T cells by inducing tumor ferroptosis.