TNFR1 delivers pro-survival signals that are required for limiting TNFR2-dependent activation-induced cell death (AICD) in CD8+ T cells

Eur J Immunol. 2011 Feb;41(2):335-44. doi: 10.1002/eji.201040639. Epub 2010 Dec 29.

Abstract

Members of the TNF and TNF receptor (TNFR) superfamily play important roles in the maintenance of homeostasis of the immune system. Furthermore, several members of the TNFR family participate in T-cell activation and sustaining T-cell responses. We have shown that TNFR2 regulates T-cell activation by lowering the activation threshold and providing costimulatory signaling. Furthermore, activated TNFR2(-/-) CD8(+) T cells are highly resistant to activation-induced cell death (AICD). Here, we showed that using anti-TNFR2 antibodies to block TNFR2 on activated WT CD8(+) T cells rendered them resistant to AICD. This resistance of activated TNFR2(-/-) CD8(+) T cells to AICD correlated with the accumulation of TNF receptor-associated factor 2 (TRAF2). Overexpression of TRAF2 by retroviral transfection and knockdown of TRAF2 by small interfering RNA also support this conclusion. Furthermore, neutralizing TNF-α reduced TRAF2 accumulation in activated TNFR2(-/-) CD8(+) T cells and increased their susceptibility to AICD. AICD-resistant TNFR2(-/-) CD8(+) T cells expressed elevated levels of phosphorylated IκBα and higher DNA-binding activity of the p65 NK-κB subunit and neutralization of TNF-α blocked this increase. Therefore, in activated TNFR2(-/-) CD8(+) T cells, TNFR1 functions as a survival receptor by utilizing high intracellular levels of TRAF2 to promote IκBα phosphorylation and NF-κB activation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies / immunology
  • Antibodies / pharmacology
  • Apoptosis / drug effects
  • Apoptosis / genetics
  • Apoptosis / immunology*
  • CD3 Complex / immunology
  • CD8-Positive T-Lymphocytes / cytology*
  • CD8-Positive T-Lymphocytes / drug effects
  • CD8-Positive T-Lymphocytes / metabolism*
  • Cell Death / drug effects
  • Cell Death / genetics
  • Cell Death / immunology
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Cell Survival / genetics
  • Cell Survival / immunology
  • Gene Expression / genetics
  • I-kappa B Proteins / metabolism
  • Interleukin-2 / pharmacology
  • Lymphocyte Activation / drug effects
  • Lymphocyte Activation / physiology*
  • Mice
  • Mice, Knockout
  • NF-KappaB Inhibitor alpha
  • NF-kappa B / metabolism
  • Phosphorylation / drug effects
  • RNA, Small Interfering / genetics
  • Receptors, Tumor Necrosis Factor, Type I / metabolism*
  • Receptors, Tumor Necrosis Factor, Type II / genetics
  • Receptors, Tumor Necrosis Factor, Type II / immunology
  • Receptors, Tumor Necrosis Factor, Type II / metabolism*
  • Signal Transduction / drug effects
  • Signal Transduction / genetics
  • Signal Transduction / immunology*
  • TNF Receptor-Associated Factor 2 / genetics
  • TNF Receptor-Associated Factor 2 / metabolism
  • Transcription Factor RelA / metabolism
  • Transduction, Genetic
  • Tumor Necrosis Factor-alpha / immunology
  • Tumor Necrosis Factor-alpha / metabolism
  • Tumor Necrosis Factor-alpha / pharmacology

Substances

  • Antibodies
  • CD3 Complex
  • I-kappa B Proteins
  • Interleukin-2
  • NF-kappa B
  • Nfkbia protein, mouse
  • RNA, Small Interfering
  • Receptors, Tumor Necrosis Factor, Type I
  • Receptors, Tumor Necrosis Factor, Type II
  • Rela protein, mouse
  • TNF Receptor-Associated Factor 2
  • Tnfrsf1a protein, mouse
  • Transcription Factor RelA
  • Tumor Necrosis Factor-alpha
  • NF-KappaB Inhibitor alpha