Interferon-gamma promotes infection of astrocytes by Trypanosoma cruzi

PLoS One. 2015 Feb 19;10(2):e0118600. doi: 10.1371/journal.pone.0118600. eCollection 2015.

Abstract

The inflammatory cytokine interferon-gamma (IFNγ) is crucial for immunity against intracellular pathogens such as the protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease (CD). IFNγ is a pleiotropic cytokine which regulates activation of immune and non-immune cells; however, the effect of IFNγ in the central nervous system (CNS) and astrocytes during CD is unknown. Here we show that parasite persists in the CNS of C3H/He mice chronically infected with the Colombian T. cruzi strain despite the increased expression of IFNγ mRNA. Furthermore, most of the T. cruzi-bearing cells were astrocytes located near IFNγ+ cells. Surprisingly, in vitro experiments revealed that pretreatment with IFNγ promoted the infection of astrocytes by T. cruzi increasing uptake and proliferation of intracellular forms, despite inducing increased production of nitric oxide (NO). Importantly, the effect of IFNγ on T. cruzi uptake and growth is completely blocked by the anti-tumor necrosis factor (TNF) antibody Infliximab and partially blocked by the inhibitor of nitric oxide synthesis L-NAME. These data support that IFNγ fuels astrocyte infection by T. cruzi and critically implicate IFNγ-stimulated T. cruzi-infected astrocytes as sources of TNF and NO, which may contribute to parasite persistence and CNS pathology in CD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Astrocytes / drug effects*
  • Astrocytes / metabolism
  • Astrocytes / parasitology*
  • Cells, Cultured
  • Chagas Disease / immunology
  • Chagas Disease / parasitology
  • Chagas Disease / physiopathology*
  • Cytokines / metabolism
  • Female
  • Immunohistochemistry
  • Infliximab / pharmacology
  • Interferon-gamma / genetics
  • Interferon-gamma / metabolism
  • Interferon-gamma / pharmacology*
  • Mice
  • Mice, Inbred C3H
  • Mice, Inbred C57BL
  • NG-Nitroarginine Methyl Ester / pharmacology
  • Nitric Oxide / metabolism
  • Trypanosoma cruzi / growth & development

Substances

  • Cytokines
  • Nitric Oxide
  • Interferon-gamma
  • Infliximab
  • NG-Nitroarginine Methyl Ester

Grants and funding

This work was supported in part by grants from Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro/FAPERJ (Grants # APQ1- E-26/111.756/2008 and CNE/E-26/101.549/2010, E-26/110.153/2013, E-26/111.709/2013) and the Brazilian Research Council?CNPq (Grants #474234/2012-6-Universal and #302534/2008-3; National Institute for Science and Technology for Vaccines - INCTV?CNPq; #403979/2012-9-DECIT). J. Lannes-Vieira and R.T. Gazzinelli are research fellows of the CNPq. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.