CD8+ T cells and fatty acids orchestrate tumor ferroptosis and immunity via ACSL4

Cancer Cell. 2022 Apr 11;40(4):365-378.e6. doi: 10.1016/j.ccell.2022.02.003. Epub 2022 Feb 24.

Abstract

Tumor cell intrinsic ferroptosis-initiating mechanisms are unknown. Here, we discover that T cell-derived interferon (IFN)γ in combination with arachidonic acid (AA) induces immunogenic tumor ferroptosis, serving as a mode of action for CD8+ T cell (CTL)-mediated tumor killing. Mechanistically, IFNγ stimulates ACSL4 and alters tumor cell lipid pattern, thereby increasing incorporations of AA into C16 and C18 acyl chain-containing phospholipids. Palmitoleic acid and oleic acid, two common C16 and C18 fatty acids in blood, promote ACSL4-dependent tumor ferroptosis induced by IFNγ plus AA. Moreover, tumor ACSL4 deficiency accelerates tumor progression. Low-dose AA enhances tumor ferroptosis and elevates spontaneous and immune checkpoint blockade (ICB)-induced anti-tumor immunity. Clinically, tumor ACSL4 correlates with T cell signatures and improved survival in ICB-treated cancer patients. Thus, IFNγ signaling paired with selective fatty acids is a natural tumor ferroptosis-promoting mechanism and a mode of action of CTLs. Targeting the ACSL4 pathway is a potential anti-cancer approach.

Keywords: ACSL4; PD-L1; T cell; arachidonic acid; cancer; ferroptosis; immunotherapy; interferon; oleic acid; palmitoleic acid.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • CD8-Positive T-Lymphocytes / metabolism
  • Coenzyme A Ligases / metabolism
  • Fatty Acids
  • Ferroptosis*
  • Humans
  • Neoplasms*

Substances

  • Fatty Acids
  • Coenzyme A Ligases