Chimeric antigen receptor (CAR)-T cells directed to solid tumors have been less effective, due in part to the low or lost expression of specific tumor antigens. Herein, we developed a different strategy to enhance CAR-T cell persistence and efficacy by producing a multispecific CAR-T or vaccine based on immunogenic cell death (ICD). We demonstrated that ionizing radiation activates STAT1-IRF1-CD39 axis to upregulate CD39 expression to form an immunosuppressive tumor microenvironment (TME) to enhance radioresistance. CD39 blockade accumulates extracellular ATP, which activates NLRP3 inflammasome in dendritic cells via P2X7 receptor, thereby promoting radiation-induced ICD. Multispecific CAR-T cells in vitro prepared by elevated ICD suppress the growth of xenografts in nude mice. Radiation and CD39 inhibition-induced ICD of glioma stem cells as a vaccine enhance CAR-T expansion in peripheral blood, multifunctionality in the TME, and antitumor effect in a glioma model. The multispecificity of CAR-T cells, targeting CAR and tumor antigens, vastly enhances the function of conventional CAR-T cells, stimulates a native immune response, and overcomes obstacles of specific antigen loss or low expression of target cells in antitumor therapy.
© 2022. The Author(s).