Xylulose 5-phosphate fosters sustained antitumor activity of progenitor-like exhausted SLC35E2+ CD8+ T effector cells

Abstract

Metabolic adaptations involved in tumor metastasis and immune evasion merit investigation. Here, using in vivo metabolic CRISPR/Cas9 knockout screening, we identified xylulokinase (XYLB) as a tumor suppressor that impairs lung colonialization by producing xylulose 5-phosphate (Xu5P), which promotes CD8⁺ T cell cytotoxicity. Mechanistically, CD8⁺ T cells express relatively high levels of solute carrier family 35 member E2 (SLC35E2), a homolog of the plant Xu5P transporter, to facilitate Xu5P uptake and subsequently intensify the pentose phosphate pathway and glycolysis for energy/redox balance. Furthermore, we revealed that Xu5P potentiates CD8⁺ T cell response by promoting Xu5P-responsive progenitor-like SLC35E2⁺ CD8⁺ exhausted T cells via tet methylcytosine dioxygenase 3 (TET3)-mediated DNA demethylation of the Tcf7 promoter. Clinically, elevated XYLB or blood Xu5P correlates with enhanced CD8⁺ T cell efficacy and reduced metastasis. In murine models, Xu5P supplementation or adopting Xu5P-rich diets synergizes with anti-PD-1 therapy to enhance antitumor immunity. These findings offer insights into the potentiality of dietary interventions for metastatic cancer.

Keywords: Xu5P; dietary metabolite; immunotherapy; progenitor-like CD8(+) T cells; tumor metastasis.