Acidity suppresses CD8+ T-cell function by perturbing IL-2, mTORC1, and c-Myc signaling
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ABSTRACT: CD8+ T cells have critical roles in tumor control, but a range of factors in their microenvironment such as low pH can suppress their function. Here, we demonstrate that acidity restricts T-cell expansion mainly through impairing IL-2 responsiveness, lowers cytokine secretion upon re-activation, and reduces the cytolytic capacity of CD8+ T cells expressing low-affinity TCR. We further find decreased mTORC1 signaling activity and c-Myc levels at low pH. Mechanistically, nuclear/cytoplasmic acidification is linked to mTORC1 suppression in a Rheb-, Akt/TSC2/PRAS40-, GATOR1- and Lkb1/AMPK-independent manner, while c-Myc levels drop due to both decreased transcription and higher levels of proteasome-mediated degradation. In addition, lower intracellular levels of glutamine, glutamate, and aspartate, as well as elevated proline levels are observed with no apparent impact on mTORC1 signaling or c-Myc levels. Overall, we suggest that, due to the broad impact of acidity on CD8+ T cells, multiple interventions will be required to restore T-cell function unless intracellular pH is effectively controlled.
SUBMITTER: Dr. Romain Vuillefroy de Silly
PROVIDER: S-SCDT-10_1038-S44318-024-00235-W | biostudies-other |
REPOSITORIES: biostudies-other
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