Host-Protozoan Interactions Protect from Mucosal Infections through Activation of the Inflammasome Academic Article


  • Cell


  • While conventional pathogenic protists have been extensively studied, there is an underappreciated constitutive protist microbiota that is an integral part of the vertebrate microbiome. The impact of these species on the host and their potential contributions to mucosal immune homeostasis remain poorly studied. Here, we show that the protozoan Tritrichomonas musculis activates the host epithelial inflammasome to induce IL-18 release. Epithelial-derived IL-18 promotes dendritic cell-driven Th1 and Th17 immunity and confers dramatic protection from mucosal bacterial infections. Along with its role as a “protistic” antibiotic, colonization with T. musculis exacerbates the development of T-cell-driven colitis and sporadic colorectal tumors. Our findings demonstrate a novel mutualistic host-protozoan interaction that increases mucosal host defenses at the cost of an increased risk of inflammatory disease.

publication date

  • 2016-10-6


  • 167


  • Anti-Bacterial Agents
  • Bacterial Infections
  • Chemical activation
  • Colitis
  • Colorectal Neoplasms
  • Dendritic Cells
  • Homeostasis
  • Immunity
  • Infection
  • Inflammasomes
  • Interleukin-18
  • Microbiota
  • T-Lymphocytes
  • T-cells
  • Tritrichomonas
  • Tumors
  • Vertebrates

International Standard Serial Number (ISSN)

  • 0092-8674

start page

  • 444

end page

  • 456.e14