Neutrophilic NLRP3 inflammasome-dependent IL-1β secretion regulates the γδT17 cell response in respiratory bacterial infections

Mucosal Immunol. 2017 Jul;10(4):1056-1068. doi: 10.1038/mi.2016.113. Epub 2017 Jan 4.

Abstract

Traditionally regarded as simple foot soldiers of the innate immune response limited to the eradication of pathogens, neutrophils recently emerged as more complex cells endowed with a set of immunoregulatory functions. Using a model of invasive pneumococcal disease, we highlighted an unexpected key role for neutrophils as accessory cells in innate interleukin (IL)-17A production by lung resident Vγ6Vδ1+ T cells via nucleotide-binding oligomerization domain receptor, pyrin-containing 3 (NLRP3) inflammasome-dependent IL-1β secretion. In vivo activation of the NLRP3 inflammasome in neutrophils required both host-derived and bacterial-derived signals. Elaborately, it relies on (i) alveolar macrophage-secreted TNF-α for priming and (ii) subsequent exposure to bacterial pneumolysin for activation. Interestingly, this mechanism can be translated to human neutrophils. Our work revealed the cellular and molecular dynamic events leading to γδT17 cell activation, and highlighted for the first time the existence of a fully functional NLRP3 inflammasome in lung neutrophils. This immune axis thus regulates the development of a protective host response to respiratory bacterial infections.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Proteins / immunology
  • Cells, Cultured
  • Disease Models, Animal
  • Humans
  • Inflammasomes / metabolism
  • Interleukin-17 / genetics
  • Interleukin-17 / metabolism*
  • Interleukin-1beta / metabolism*
  • Macrophages, Alveolar / immunology*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • NLR Family, Pyrin Domain-Containing 3 Protein / genetics
  • NLR Family, Pyrin Domain-Containing 3 Protein / metabolism
  • Neutrophils / immunology*
  • Pneumococcal Infections / immunology*
  • Receptors, Antigen, T-Cell, gamma-delta / genetics
  • Receptors, Antigen, T-Cell, gamma-delta / metabolism
  • Respiratory Tract Infections / immunology*
  • Streptococcus pneumoniae / immunology*
  • Streptolysins / immunology
  • Th17 Cells / immunology*
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Bacterial Proteins
  • Inflammasomes
  • Interleukin-17
  • Interleukin-1beta
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Receptors, Antigen, T-Cell, gamma-delta
  • Streptolysins
  • Tumor Necrosis Factor-alpha
  • plY protein, Streptococcus pneumoniae