Lactic acid promotes PD-1 expression in regulatory T cells in highly glycolytic tumor microenvironments
Menée in vitro et à l'aide de modèles murins, cette étude met en évidence un mécanisme par lequel l'acide lactique favorise l'expression de PD1 dans les lymphocytes T régulateurs des microenvironnements tumoraux à métabolisme fortement glycolytique
The balance of programmed death-1 (PD-1)-expressing CD8+ T cells and regulatory T (Treg) cells in the tumor microenvironment (TME) determines the clinical efficacy of PD-1 blockade therapy through the competition of their reactivation. However, factors that determine this balance remain unknown. Here, we show that Treg cells gain higher PD-1 expression than effector T cells in highly glycolytic tumors, including MYC-amplified tumors and liver tumors. Under low-glucose environments via glucose consumption by tumor cells, Treg cells actively absorbed lactic acid (LA) through monocarboxylate transporter 1 (MCT1), promoting NFAT1 translocation into the nucleus, thereby enhancing the expression of PD-1, whereas PD-1 expression by effector T cells was dampened. PD-1 blockade invigorated the PD-1-expressing Treg cells, resulting in treatment failure. We propose that LA in the highly glycolytic TME is an active checkpoint for the function of Treg cells in the TME via upregulation of PD-1 expression.
Cancer Cell , résumé, 2021