NLRP3 inflammasome activation by Paracoccidioides brasiliensis

PLoS Negl Trop Dis. 2013 Dec 5;7(12):e2595. doi: 10.1371/journal.pntd.0002595. eCollection 2013.

Abstract

Paracoccidioides brasiliensis is the etiologic agent of paracoccidioidomycosis (PCM), the most prevalent systemic mycosis that is geographically confined to Latin America. The pro-inflammatory cytokine IL-1β that is mainly derived from the activation of the cytoplasmic multiprotein complex inflammasome is an essential host factor against opportunistic fungal infections; however, its role in infection with a primary fungal pathogen, such as P. brasiliensis, is not well understood. In this study, we found that murine bone marrow-derived dendritic cells responded to P. brasiliensis yeast cells infection by releasing IL-1β in a spleen tyrosine kinase (Syk), caspase-1 and NOD-like receptor (NLR) family member NLRP3 dependent manner. In addition, P. brasiliensis-induced NLRP3 inflammasome activation was dependent on potassium (K+) efflux, reactive oxygen species production, phagolysosomal acidification and cathepsin B release. Finally, using mice lacking the IL-1 receptor, we demonstrated that IL-1β signaling has an important role in killing P. brasiliensis by murine macrophages. Altogether, our results demonstrate that the NLRP3 inflammasome senses and responds to P. brasiliensis yeast cells infection and plays an important role in host defense against this fungus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carrier Proteins / immunology*
  • Dendritic Cells / immunology*
  • Dendritic Cells / parasitology*
  • Host-Parasite Interactions*
  • Inflammasomes / immunology*
  • Interleukin-1beta / metabolism
  • Macrophages / immunology
  • Macrophages / parasitology
  • Mice
  • Mice, Inbred C57BL
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Paracoccidioides / immunology*

Substances

  • Carrier Proteins
  • Inflammasomes
  • Interleukin-1beta
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Nlrp3 protein, mouse

Grants and funding

The authors thank the Conselho Nacional de Desenvolvimento Cientifico e Tecnológico (CNPQ), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and Fundação de Amparo a Pesquisa do Distrito Federal (FAP-DF) for financial support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.