Inflammasomes and IL-1 biology in the pathogenesis of allograft dysfunction

J Clin Invest. 2017 Jun 1;127(6):2022-2029. doi: 10.1172/JCI93537. Epub 2017 Jun 1.

Abstract

Inflammasomes are high-molecular-weight cytosolic complexes that mediate the activation of caspases. There are many inflammasomes, and each is influenced by a unique pattern-recognition receptor response. Two signals are typically involved in the inflammasome pathways. Signal one involves recognition of pathogen-associated molecular patterns (PAMPs), such as LPS or other colonizing/invading microbes, that interact with TLRs, which induce the downstream production of pro-IL-1β. This is followed by signal two, which involves recognition of PAMPs or damage-associated molecular patterns (DAMPs), such as uric acid or ATP, via NLRP3, which leads to caspase-1-dependent cleavage of pro-IL-1β to active IL-1β and pyroptosis. Ultimately, these two signals cause the release of multiple proinflammatory cytokines. Both PAMPs and DAMPs can be liberated by early insults to the allograft, including ischemia/reperfusion injury, infections, and rejection. The consequence of inflammasome activation and IL-1 expression is the upregulation of adhesion molecules and chemokines, which leads to allograft neutrophil sequestration, mononuclear phagocyte recruitment, and T cell activation, all of which are key steps in the continuum from allograft insult to chronic allograft dysfunction.

Publication types

  • Review

MeSH terms

  • Allografts
  • Animals
  • Graft Rejection / immunology
  • Graft Rejection / metabolism
  • Humans
  • Immunity, Innate
  • Inflammasomes / physiology*
  • Interleukin-1 / physiology*
  • Primary Graft Dysfunction / immunology*
  • Primary Graft Dysfunction / metabolism

Substances

  • Inflammasomes
  • Interleukin-1