XIAP restricts TNF- and RIP3-dependent cell death and inflammasome activation

Cell Rep. 2014 Jun 26;7(6):1796-808. doi: 10.1016/j.celrep.2014.05.008. Epub 2014 May 29.

Abstract

X-linked inhibitor of apoptosis protein (XIAP) has been identified as a potent regulator of innate immune responses, and loss-of-function mutations in XIAP cause the development of the X-linked lymphoproliferative syndrome type 2 (XLP-2) in humans. Using gene-targeted mice, we show that loss of XIAP or deletion of its RING domain lead to excessive cell death and IL-1β secretion from dendritic cells triggered by diverse Toll-like receptor stimuli. Aberrant IL-1β secretion is TNF dependent and requires RIP3 but is independent of cIAP1/cIAP2. The observed cell death also requires TNF and RIP3 but proceeds independently of caspase-1/caspase-11 or caspase-8 function. Loss of XIAP results in aberrantly elevated ubiquitylation of RIP1 outside of TNFR complex I. Virally infected Xiap(-/-) mice present with symptoms reminiscent of XLP-2. Our data show that XIAP controls RIP3-dependent cell death and IL-1β secretion in response to TNF, which might contribute to hyperinflammation in patients with XLP-2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / physiology
  • Cell Death / physiology
  • Dendritic Cells / cytology
  • Dendritic Cells / drug effects
  • Dendritic Cells / physiology*
  • Female
  • Inflammasomes / drug effects
  • Inflammasomes / genetics
  • Inflammasomes / metabolism
  • Inflammasomes / physiology*
  • Interleukin-1beta / genetics
  • Interleukin-1beta / metabolism
  • Interleukin-1beta / physiology
  • Lipopolysaccharides / pharmacology
  • Male
  • Mice
  • Mice, Transgenic
  • Receptor-Interacting Protein Serine-Threonine Kinases / genetics
  • Receptor-Interacting Protein Serine-Threonine Kinases / metabolism
  • Receptor-Interacting Protein Serine-Threonine Kinases / physiology*
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / metabolism
  • Tumor Necrosis Factor-alpha / physiology*
  • X-Linked Inhibitor of Apoptosis Protein / genetics
  • X-Linked Inhibitor of Apoptosis Protein / metabolism
  • X-Linked Inhibitor of Apoptosis Protein / physiology*

Substances

  • Inflammasomes
  • Interleukin-1beta
  • Lipopolysaccharides
  • Tumor Necrosis Factor-alpha
  • X-Linked Inhibitor of Apoptosis Protein
  • Receptor-Interacting Protein Serine-Threonine Kinases
  • Ripk3 protein, mouse