Compensatory electron transfer from the ubiquinol pool circumvents cytochrome c oxidase deficiency and restores effector and memory T cell function

The ultimate goal of immunometabolism is to modulate metabolic pathways to enhance immunity. Here, we investigate the potential of an alternative oxidase (AOX) to counteract cytochrome c oxidase (COX) deficiency in T cells. COX is vital for oxidative phosphorylation (OXPHOS), and its deficiency leads to redox imbalances, impaired metabolism, reactive oxygen species (ROS), and apoptosis, resulting in T cell immunodeficiency. We introduced an AOX into COX-deficient T cells, which revealed a normalization of genes involved in redox balance, apoptosis, and metabolic pathways. Mitochondrial function, glycolysis and TCA cycle function were also restored. AOX-enhanced T cells showed improved activation, proliferation, differentiation, and memory formation, resulting in better immune responses against viral challenges. These findings suggest that targeting the ubiquinol pool could be a promising therapeutic strategy for enhancing T cell function in conditions characterized by COX dysfunction and compromised immune responses.