Augmenting Immunotherapy Impact by Lowering Tumor TNF Cytotoxicity Threshold

Cell. 2019 Jul 25;178(3):585-599.e15. doi: 10.1016/j.cell.2019.06.014. Epub 2019 Jul 11.


New opportunities are needed to increase immune checkpoint blockade (ICB) benefit. Whereas the interferon (IFN)γ pathway harbors both ICB resistance factors and therapeutic opportunities, this has not been systematically investigated for IFNγ-independent signaling routes. A genome-wide CRISPR/Cas9 screen to sensitize IFNγ receptor-deficient tumor cells to CD8 T cell elimination uncovered several hits mapping to the tumor necrosis factor (TNF) pathway. Clinically, we show that TNF antitumor activity is only limited in tumors at baseline and in ICB non-responders, correlating with its low abundance. Taking advantage of the genetic screen, we demonstrate that ablation of the top hit, TRAF2, lowers the TNF cytotoxicity threshold in tumors by redirecting TNF signaling to favor RIPK1-dependent apoptosis. TRAF2 loss greatly enhanced the therapeutic potential of pharmacologic inhibition of its interaction partner cIAP, another screen hit, thereby cooperating with ICB. Our results suggest that selective reduction of the TNF cytotoxicity threshold increases the susceptibility of tumors to immunotherapy.

Keywords: TNF; TRAF2; birinapant; immune checkpoint blockade; immunotherapy; lung cancer; melanoma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • CD8-Positive T-Lymphocytes / cytology
  • CD8-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / metabolism
  • Cell Line, Tumor
  • Humans
  • Immunotherapy*
  • Inhibitor of Apoptosis Proteins / metabolism
  • Interferon-gamma / metabolism
  • Kaplan-Meier Estimate
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Neoplasms / mortality
  • Neoplasms / therapy
  • RNA, Guide / metabolism
  • Receptor-Interacting Protein Serine-Threonine Kinases / metabolism
  • Receptors, Interferon / deficiency
  • Receptors, Interferon / genetics
  • Signal Transduction / drug effects
  • TNF Receptor-Associated Factor 2 / deficiency
  • TNF Receptor-Associated Factor 2 / genetics
  • Tumor Necrosis Factor-alpha / metabolism*
  • Tumor Necrosis Factor-alpha / pharmacology


  • Inhibitor of Apoptosis Proteins
  • RNA, Guide
  • Receptors, Interferon
  • TNF Receptor-Associated Factor 2
  • Tumor Necrosis Factor-alpha
  • interferon gamma receptor
  • Interferon-gamma
  • RIPK1 protein, human
  • Receptor-Interacting Protein Serine-Threonine Kinases