Cancer suppresses mitochondrial chaperone activity in macrophages to drive immune evasion
摘要
Contrary to tumor-infiltrating T cells with dysfunctional mitochondria, tumor-associated macrophages (TAMs) preserve their mitochondrial activity in the nutrient-limited tumor microenvironment (TME) to sustain immunosuppression. Here we identify TNF receptor-associated protein-1 (TRAP1), a mitochondrial HSP90 chaperone, as a metabolic checkpoint that restrains oxidative respiration and limits macrophage suppressive function. In the TME, TRAP1 is downregulated through TIM4–AMPK signaling, and its loss enhances immunoinhibitory activity, limits proinflammatory capacity and promotes tumor immune escape. Mechanistically, TRAP1 suppression augments electron transport chain activity and elevates the α-ketoglutarate/succinate ratio, remodeling mitochondrial homeostasis. The resulting accumulation of α-ketoglutarate further potentiates JMJD3-mediated histone demethylation, establishing transcriptional programs that reinforce an immunosuppressive state. Restoring TRAP1 by targeting TIM4 and JMJD3 reprograms TAMs, disrupts the immune-evasive TME and bolsters antitumor immunity. These findings establish TRAP1 as a critical regulator integrating metabolic and epigenetic control of suppressive TAM function and position the TRAP1 pathway as a promising target for cancer immunotherapy.