SOCS3 deletion in effector T cells confers an anti-tumorigenic role of IL-6 to the pro-tumorigenic cytokine

Abstract

Interleukin (IL)-6 is abundantly expressed in the tumor microenvironment and is associated with poor patient outcomes. Here, we demonstrate that the deletion of the suppressor of cytokine signaling 3 (SOCS3) in Tcells potentiates anti-tumor immune responses by conferring the anti-tumorigenic function of IL-6 in mouse and human models. In Socs3-deficient CD8+ Tcells, IL-6 upregulates the expression of type I interferon (IFN)-regulated genes and enhances the anti-tumor effector function of Tcells, while also modifying mitochondrial fitness to increase mitochondrial membrane potential and reactive oxygen species (ROS) levels and to promote metabolic glycolysis in the energy state. Furthermore, Socs3 deficiency reduces regulatory Tcells and increases T helper 1 (Th1) cells. SOCS3 knockdown in human chimeric antigen receptor T (CAR-T) cells exhibits a strong anti-tumor response in humanized mice. Thus, genetic disruption of SOCS3 offers an avenue to improve the therapeutic efficacy of adoptive Tcell therapy.