Apoptosis-associated speck-like protein containing a caspase recruitment domain inflammasomes mediate IL-1β response and host resistance to Trypanosoma cruzi infection

J Immunol. 2013 Sep 15;191(6):3373-83. doi: 10.4049/jimmunol.1203293. Epub 2013 Aug 21.

Abstract

The innate immune response to Trypanosoma cruzi infection comprises several pattern recognition receptors (PRRs), including TLR-2, -4, -7, and -9, as well as the cytosolic receptor Nod1. However, there are additional PRRs that account for the host immune responses to T. cruzi. In this context, the nucleotide-binding oligomerization domain-like receptors (NLRs) that activate the inflammasomes are candidate receptors that deserve renewed investigation. Following pathogen infection, NLRs form large molecular platforms, termed inflammasomes, which activate caspase-1 and induce the production of active IL-1β and IL-18. In this study, we evaluated the involvement of inflammasomes in T. cruzi infection and demonstrated that apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) inflammasomes, including NLR family, pyrin domain-containing 3 (NLRP3), but not NLR family, caspase recruitment domain-containing 4 or NLR family, pyrin domain-containing 6, are required for triggering the activation of caspase-1 and the secretion of IL-1β. The mechanism by which T. cruzi mediates the activation of the ASC/NLRP3 pathway involves K⁺ efflux, lysosomal acidification, reactive oxygen species generation, and lysosomal damage. We also demonstrate that despite normal IFN-γ production in the heart, ASC⁻/⁻ and caspase-1⁻/⁻ infected mice exhibit a higher incidence of mortality, cardiac parasitism, and heart inflammation. These data suggest that ASC inflammasomes are critical determinants of host resistance to infection with T. cruzi.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis Regulatory Proteins
  • CARD Signaling Adaptor Proteins
  • Carrier Proteins / immunology
  • Caspase 1 / immunology
  • Chagas Disease / immunology*
  • Cytoskeletal Proteins / immunology*
  • Disease Resistance / immunology*
  • Flow Cytometry
  • Inflammasomes / immunology*
  • Interleukin-1beta / immunology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Oligonucleotide Array Sequence Analysis
  • Trypanosoma cruzi / immunology

Substances

  • Apoptosis Regulatory Proteins
  • CARD Signaling Adaptor Proteins
  • Carrier Proteins
  • Cytoskeletal Proteins
  • Inflammasomes
  • Interleukin-1beta
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Nlrp3 protein, mouse
  • Pycard protein, mouse
  • Caspase 1

Associated data

  • GEO/GSE41089