Antitumor responses of CD8 ⁺ T cells are tightly regulated by distinct metabolic fitness. High levels of glutathione (GSH) are observed in the majority of tumors, contributing to cancer progression and treatment resistance in part by preventing glutathione peroxidase 4–dependent (GPX4-dependent) ferroptosis. Here, we show the necessity of adenosine A2A receptor (A2AR) signaling and the GSH/GPX4 axis in orchestrating metabolic fitness and survival of functionally competent CD8 ⁺ T cells. Activated CD8 ⁺ T cells treated ex vivo with simultaneous inhibition of A2AR and lipid peroxidation acquire a superior capacity to proliferate and persist in vivo, demonstrating a translatable means to prevent ferroptosis in adoptive cell therapy. Additionally, we identify a particular cluster of intratumoral CD8 ⁺ T cells expressing a putative gene signature of GSH metabolism (GMGS) in association with clinical response and survival across several human cancers. Our study addresses a key role of GSH/GPX4 and adenosinergic pathways in fine-tuning the metabolic fitness of antitumor CD8 ⁺ T cells.

Activating the immune costimulatory receptor 4-1BB (CD137) with agonist antibody binding and crosslinking-inducing agents that elicit 4-1BB intracellular signaling potentiates the antitumor responses of CD8 ⁺ T cells. However, the underlying in-depth mechanisms remain to be defined. Here, we show that agonistic 4-1BB treatment of activated CD8 ⁺ T cells under continuous antigenic stimulation makes them more metabolically vulnerable to redox perturbation by ablation of intracellular glutathione (GSH) and glutathione peroxidase 4 (GPX4) inhibition. Further, genetic deletion of adenosine A2B receptor (A2BR) induces superior survival and expansion advantage of competent CD8 ⁺ T cells with agonistic 4-1BB costimulation, leading to more effective antitumor efficacy of adoptive cell therapy (ACT). Mechanistically, A2BR deletion helps sustain the increased energy and biosynthetic requirements through the GSH/GPX4 axis upon 4-1BB costimulation. A2BR deletion in combination with agonistic 4-1BB costimulation displays a greater ability to promote antitumor CD8 ⁺ effector T cell survival and expansion while mitigating T cell exhaustion. Thus, the A2BR pathway plays an important role in metabolic reprogramming with potentiation of the GSH/GPX4 cascade upon agonistic 4-1BB costimulation that allows the fine-tuning of the antitumor responses of CD8 ⁺ T cells.