IL-36? Armored CAR T Cells Reprogram Neutrophils to Induce Endogenous Antitumor Immunity

Chimeric antigen receptor (CAR) T cells are ineffective against solid tumors due to obstacles of antigen heterogeneity and the immunosuppressive tumor microenvironment (TME). Previous efforts focused on enhancing cytotoxicity and persistence of CAR T cells, while the feasibility of improving their therapeutic efficacy by leveraging the modulatory effects of CAR T cells on host anti-tumor immunity remains unclear. Here, we report that IL-36? armored CAR T cells eradicated primary solid tumors and enabled rejection of rechallenged antigen-negative tumors. IL-36? armored CAR T cells favorably modulated the TME and reprogrammed unique neutrophil subsets with tumoricidal ability and antigen-(cross)presenting functions, resulting in the induction of endogenous T cells recognizing tumor antigens beyond CAR-targeted antigens. Our study demonstrates that neutrophil engagement by CAR T cells is a critical step in the establishment of the cancer-immunity cycle and introduces a broadly applicable method to overcome key barriers to adoptive cell therapies for solid tumors. Overall design: Mouse SCLC tumors were collected four days after CAR T cell treatment. CD45? live cells were then isolated using a BD FACSAria cell sorter for single-cell sequencing analysis.