A helminth-derived suppressor of ST2 blocks allergic responses

Elife. 2020 May 18:9:e54017. doi: 10.7554/eLife.54017.

Abstract

The IL-33-ST2 pathway is an important initiator of type 2 immune responses. We previously characterised the HpARI protein secreted by the model intestinal nematode Heligmosomoides polygyrus, which binds and blocks IL-33. Here, we identify H. polygyrus Binds Alarmin Receptor and Inhibits (HpBARI) and HpBARI_Hom2, both of which consist of complement control protein (CCP) domains, similarly to the immunomodulatory HpARI and Hp-TGM proteins. HpBARI binds murine ST2, inhibiting cell surface detection of ST2, preventing IL-33-ST2 interactions, and inhibiting IL-33 responses in vitro and in an in vivo mouse model of asthma. In H. polygyrus infection, ST2 detection is abrogated in the peritoneal cavity and lung, consistent with systemic effects of HpBARI. HpBARI_Hom2 also binds human ST2 with high affinity, and effectively blocks human PBMC responses to IL-33. Thus, we show that H. polygyrus blocks the IL-33 pathway via both HpARI which blocks the cytokine, and also HpBARI which blocks the receptor.

Keywords: Helminth; IL-33; ST2; allergy; asthma; human; immunology; infectious disease; inflammation; microbiology; mouse; parasite.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alternaria / immunology*
  • Animals
  • Antigens, Helminth / metabolism*
  • Asthma / pathology*
  • Cell Line
  • Humans
  • Immunologic Factors / metabolism
  • Interleukin-1 Receptor-Like 1 Protein / antagonists & inhibitors*
  • Interleukin-1 Receptor-Like 1 Protein / metabolism
  • Interleukin-33 / antagonists & inhibitors*
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Nematospiroides dubius / immunology
  • Nematospiroides dubius / metabolism*
  • Ovalbumin / immunology

Substances

  • Antigens, Helminth
  • IL1RL1 protein, human
  • IL33 protein, human
  • Il1rl1 protein, mouse
  • Immunologic Factors
  • Interleukin-1 Receptor-Like 1 Protein
  • Interleukin-33
  • Ovalbumin