Exclusive dependence of IL-10Rα signalling on intestinal microbiota homeostasis and control of whipworm infection

PLoS Pathog. 2019 Jan 14;15(1):e1007265. doi: 10.1371/journal.ppat.1007265. eCollection 2019 Jan.

Abstract

The whipworm Trichuris trichiura is a soil-transmitted helminth that dwells in the epithelium of the caecum and proximal colon of their hosts causing the human disease, trichuriasis. Trichuriasis is characterized by colitis attributed to the inflammatory response elicited by the parasite while tunnelling through intestinal epithelial cells (IECs). The IL-10 family of receptors, comprising combinations of subunits IL-10Rα, IL-10Rβ, IL-22Rα and IL-28Rα, modulates intestinal inflammatory responses. Here we carefully dissected the role of these subunits in the resistance of mice to infection with T. muris, a mouse model of the human whipworm T. trichiura. Our findings demonstrate that whilst IL-22Rα and IL-28Rα are dispensable in the host response to whipworms, IL-10 signalling through IL-10Rα and IL-10Rβ is essential to control caecal pathology, worm expulsion and survival during T. muris infections. We show that deficiency of IL-10, IL-10Rα and IL-10Rβ results in dysbiosis of the caecal microbiota characterised by expanded populations of opportunistic bacteria of the families Enterococcaceae and Enterobacteriaceae. Moreover, breakdown of the epithelial barrier after whipworm infection in IL-10, IL-10Rα and IL-10Rβ-deficient mice, allows the translocation of these opportunistic pathogens or their excretory products to the liver causing organ failure and lethal disease. Importantly, bone marrow chimera experiments indicate that signalling through IL-10Rα and IL-10Rβ in haematopoietic cells, but not IECs, is crucial to control worm expulsion and immunopathology. These findings are supported by worm expulsion upon infection of conditional mutant mice for the IL-10Rα on IECs. Our findings emphasize the pivotal and complex role of systemic IL-10Rα signalling on immune cells in promoting microbiota homeostasis and maintaining the intestinal epithelial barrier, thus preventing immunopathology during whipworm infections.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cytokines / metabolism
  • Disease Models, Animal
  • Gastrointestinal Microbiome / immunology
  • Homeostasis
  • Interleukin-10 / metabolism*
  • Interleukins / metabolism
  • Intestines / microbiology
  • Intestines / pathology
  • Mice
  • Mice, Inbred C57BL
  • Receptors, Interleukin-10 / metabolism*
  • Signal Transduction
  • Trichuriasis / immunology
  • Trichuris / immunology*
  • Trichuris / parasitology

Substances

  • Cytokines
  • IL10 protein, human
  • Interleukins
  • Receptors, Interleukin-10
  • interferon-lambda protein, mouse
  • Interleukin-10
  • interleukin-22

Grant support

MADC has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 656347(www.ec.europa.eu/research/mariecurieactions/). The 3i consortium was supported by Wellcome Trust grant [100156] (www.immunophenotype.org). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.