Inflammasome activation is required for human rhinovirus-induced airway inflammation in naive and allergen-sensitized mice

Mucosal Immunol. 2019 Jul;12(4):958-968. doi: 10.1038/s41385-019-0172-2. Epub 2019 May 15.

Abstract

Activation of the inflammasome is a key function of the innate immune response that regulates inflammation in response to microbial substances. Inflammasome activation by human rhinovirus (RV), a major cause of asthma exacerbations, has not been well studied. We examined whether RV induces inflammasome activation in vivo, molecular mechanisms underlying RV-stimulated inflammasome priming and activation, and the contribution of inflammasome activation to RV-induced airway inflammation and exacerbation. RV infection triggered lung mRNA and protein expression of pro-IL-1β and NLRP3, indicative of inflammasome priming, as well as cleavage of caspase-1 and pro-IL-1β, completing inflammasome activation. Immunofluorescence staining showed IL-1β in lung macrophages. Depletion with clodronate liposomes and adoptive transfer experiments showed macrophages to be required and sufficient for RV-induced inflammasome activation. TLR2 was required for RV-induced inflammasome priming in vivo. UV irradiation blocked inflammasome activation and RV genome was sufficient for inflammasome activation in primed cells. Naive and house dust mite-treated NLRP3-/- and IL-1β-/- mice, as well as IL-1 receptor antagonist-treated mice, showed attenuated airway inflammation and responsiveness following RV infection. We conclude that RV-induced inflammasome activation is required for maximal airway inflammation and hyperresponsiveness in naive and allergic mice. The inflammasome represents a molecular target for RV-induced asthma exacerbations.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Allergens / immunology*
  • Animals
  • Disease Models, Animal
  • Humans
  • Immunization
  • Inflammasomes / metabolism*
  • Interleukin-1beta / genetics
  • Mice
  • NLR Family, Pyrin Domain-Containing 3 Protein / metabolism
  • Picornaviridae Infections / immunology*
  • Picornaviridae Infections / metabolism*
  • Picornaviridae Infections / virology
  • Pyroglyphidae / immunology
  • Respiratory Tract Infections / immunology*
  • Respiratory Tract Infections / metabolism*
  • Respiratory Tract Infections / virology
  • Rhinovirus / genetics
  • Rhinovirus / immunology*
  • Toll-Like Receptor 2 / metabolism

Substances

  • Allergens
  • Inflammasomes
  • Interleukin-1beta
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Toll-Like Receptor 2