IL-33 receptor ST2 regulates the cognitive impairments associated with experimental cerebral malaria

PLoS Pathog. 2017 Apr 27;13(4):e1006322. doi: 10.1371/journal.ppat.1006322. eCollection 2017 Apr.

Abstract

Cerebral malaria (CM) is associated with a high mortality rate and long-term neurocognitive impairment in survivors. The murine model of experimental cerebral malaria (ECM) induced by Plasmodium berghei ANKA (PbA)-infection reproduces several of these features. We reported recently increased levels of IL-33 protein in brain undergoing ECM and the involvement of IL-33/ST2 pathway in ECM development. Here we show that PbA-infection induced early short term and spatial memory defects, prior to blood brain barrier (BBB) disruption, in wild-type mice, while ST2-deficient mice did not develop cognitive defects. PbA-induced neuroinflammation was reduced in ST2-deficient mice with low Ifng, Tnfa, Il1b, Il6, CXCL9, CXCL10 and Cd8a expression, associated with an absence of neurogenesis defects in hippocampus. PbA-infection triggered a dramatic increase of IL-33 expression by oligodendrocytes, through ST2 pathway. In vitro, IL-33/ST2 pathway induced microglia expression of IL-1β which in turn stimulated IL-33 expression by oligodendrocytes. These results highlight the IL-33/ST2 pathway ability to orchestrate microglia and oligodendrocytes responses at an early stage of PbA-infection, with an amplification loop between IL-1β and IL-33, responsible for an exacerbated neuroinflammation context and associated neurological and cognitive defects.

MeSH terms

  • Animals
  • Brain / metabolism*
  • Brain / parasitology
  • Brain / physiopathology
  • Cognitive Dysfunction / etiology
  • Cognitive Dysfunction / genetics
  • Cognitive Dysfunction / metabolism*
  • Cognitive Dysfunction / parasitology
  • Female
  • Humans
  • Interleukin-1 Receptor-Like 1 Protein / genetics
  • Interleukin-1 Receptor-Like 1 Protein / metabolism*
  • Interleukin-1beta / genetics
  • Interleukin-1beta / metabolism
  • Interleukin-33 / genetics
  • Interleukin-33 / metabolism*
  • Malaria, Cerebral / complications*
  • Malaria, Cerebral / genetics
  • Malaria, Cerebral / metabolism
  • Malaria, Cerebral / parasitology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Plasmodium berghei / genetics
  • Plasmodium berghei / physiology*

Substances

  • Il1rl1 protein, mouse
  • Interleukin-1 Receptor-Like 1 Protein
  • Interleukin-1beta
  • Interleukin-33

Grants and funding

The project received support from University of Orleans and CNRS through International Associated Laboratory (N°236) between the Molecular and Experimental Immunology and Neurogenetics Laboratory (CNRS) and the Institute of Infectious Disease and Molecular Medicine of University of Cape Town. FR received a fellowship from Région Centre. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.