ATRA metabolite curbs terminal CD8+ T-cell exhaustion in glioblastoma via WNT/β-catenin, enhancing anti-PD-1 in recurrent models

The team used in vitro hypoxia models to drive exhaustion in human CD8+ T cells, then added ATRA; treated cells retained higher IL-2, IFN-γ and TNF-α secretion and showed superior killing of glioma lines. In orthotopic mouse gliomas, oral ATRA alone increased tumor-infiltrating CD8+ numbers and function; combination with anti-PD-1 produced durable regressions and extended survival specifically in recurrent-tumor models where monotherapy failed. Analysis of public single-cell glioblastoma datasets revealed that anti-PD-1 responders expressed elevated retinoic-acid and WNT gene signatures, consistent with the mechanism. These data suggest ATRA may act as a metabolic rheostat that preserves progenitor-like T-cell states rather than reversing already terminal exhaustion, a distinction relevant for patients whose tumors recur after standard checkpoint blockade.