Transforming growth factor-β-regulated mTOR activity preserves cellular metabolism to maintain long-term T cell responses in chronic infection

Sarah S. Gabriel, Carlson Tsui, David Chisanga, Flora Weber, Manuela Llano-León, Patrick M. Gubser, Laurent Bartholin, Fernando Souza-Fonseca-Guimaraes, Nicholas D. Huntington, Wei Shi, Daniel T. Utzschneider, Axel Kallies

Research output: Contribution to journalArticleResearchpeer-review

108 Citations (Scopus)

Abstract

Antigen-specific CD8+ T cells in chronic viral infections and tumors functionally deteriorate, a process known as exhaustion. Exhausted T cells are sustained by precursors of exhausted (Tpex) cells that self-renew while continuously generating exhausted effector (Tex) cells. However, it remains unknown how Tpex cells maintain their functionality. Here, we demonstrate that Tpex cells sustained mitochondrial fitness, including high spare respiratory capacity, while Tex cells deteriorated metabolically over time. Tpex cells showed early suppression of mTOR kinase signaling but retained the ability to activate this pathway in response to antigen receptor signals. Early transient mTOR inhibition improved long-term T cell responses and checkpoint inhibition. Transforming growth factor-β repressed mTOR signaling in exhausted T cells and was a critical determinant of Tpex cell metabolism and function. Overall, we demonstrate that the preservation of cellular metabolism allows Tpex cells to retain long-term functionality to sustain T cell responses during chronic infection.

Original languageEnglish
Pages (from-to)1698-1714.e5
Number of pages23
JournalImmunity
Volume54
Issue number8
DOIs
Publication statusPublished - 10 Aug 2021

Keywords

  • checkpoint inhibition
  • mitochondria
  • OXPHOS
  • precursors of exhausted T cells
  • progenitor T cells
  • rapamycin
  • stem-like T cells
  • T cell exhaustion
  • T cell function
  • TCF1

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