CAR-T cell therapy causes inflammation by IL-1 which activates inflammatory cytokine mast cells: anti-inflammatory role of IL-37.

Chimeric antigen receptor (CAR) T cells are genetically modified T cells that act against cancer. When CAR-T cells are administered they can trigger inflammatory cytokines and increase toxicity. Interleukin (IL)-1 is the classic cytokine that mediates inflammatory reactions including those that occur in CAR-T-cell therapy. IL-1 also induces IL-33 in mast cells (MCs), amplifying the allergic reaction. IL- 37 (ILF7) is an IL-1 family member which binds IL-18 receptor alpha (IL-18Rα) chain and suppresses innate and acquired immunity. IL-37 is an anti-inflammatory cytokine which inhibits pro-inflammatory cytokines including IL-1 and IL-33. Here, we hypothesize that inflammation and toxicity generated in tumor CAR-T therapy could be inhibited by IL-37, contributing to an improvement in the treatment of tumors with CAR-T therapy.