Diet-derived galactose reprograms hepatocytes to prevent T cell exhaustion and elicit antitumour immunity

Abstract

Dietary nutrients are inextricably linked to antitumour immune responses. However, the effect of diet-derived galactose on antitumour immunity remains unclear. Here we show that dietary galactose augments CD8+ T cell immunity to suppress tumour progression. High-galactose feeding drives hepatocyte-derived insulin-like growth factor binding protein 1 (IGFBP-1) production, thus restraining IGF-1 signalling-dependent T cell exhaustion. IGF-1 receptor (IGF-1R) deficiency in T cells potentiates antitumour CD8+ T cell responses and phenocopies high-galactose feeding by preventing T cell exhaustion. Circulating galactose reprograms hepatocyte metabolism to inactivate mTORC1, thereby inducing the production of IGFBP-1 to boost CD8+ T cell function. Furthermore, patients with cancer who have high plasma IGFBP-1 levels exhibit blocked T cell exhaustion and enhanced T cell responses in tumour tissues. These findings reveal that dietary galactose specifically elicits potent antitumour CD8+ T cell responses by facilitating hepatocyte-derived IGFBP-1 production, providing insights into the development of more effective immunotherapies against cancers. X. Du, W. Li, G. Li, C. Guo et al. report that dietary galactose regulates the cellular crosstalk between hepatocytes and CD8+ T cells via IGFBP-1 production and IGF-1 signalling, thereby modulating T cell exhaustion and antitumour immunity.