Ilheus and Saint Louis encephalitis viruses elicit cross-protection against a lethal Rocio virus challenge in mice

PLoS One. 2018 Jun 13;13(6):e0199071. doi: 10.1371/journal.pone.0199071. eCollection 2018.

Abstract

Rocio virus (ROCV) was the causative agent of an unprecedented outbreak of encephalitis during the 1970s in the Vale do Ribeira, Sao Paulo State, in the Southeast region of Brazil. Surprisingly, no further cases of ROCV infection were identified after this outbreak; however, serological surveys have suggested the circulation of ROCV among humans and animals in different regions of Brazil. Cross-protective immunity among flaviviruses is well documented; consequently, immunity induced by infections with other flaviviruses endemic to Brazil could potentially be responsible for the lack of ROCV infections. Herein, we evaluated the cross-protection mediated by other flaviviruses against ROCV infection using an experimental C57BL/6 mouse model. Cross-protection against ROCV infection was observed when animals had prior exposure to Ilheus virus or Saint Louis encephalitis virus, suggesting that cross-reactive anti-flavivirus antibodies may limit ROCV disease outbreaks.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Neutralizing / blood
  • Antibodies, Neutralizing / immunology
  • Antibodies, Viral / blood
  • Antibodies, Viral / immunology
  • Disease Susceptibility
  • Encephalitis Virus, St. Louis / immunology*
  • Encephalitis Virus, St. Louis / pathogenicity
  • Evolution, Molecular
  • Female
  • Flavivirus / pathogenicity*
  • Flavivirus Infections / immunology
  • Flavivirus Infections / mortality
  • Flavivirus Infections / prevention & control*
  • Flavivirus Infections / veterinary
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Survival Rate

Substances

  • Antibodies, Neutralizing
  • Antibodies, Viral

Grants and funding

This work was supported by the Sao Paulo Research Foundation (FAPESP), Brazil, Grant Nº. 2014/15548-4 and 2014/02438-6. AAO was supported by an FAPESP Scholarships Nº. 2012/08778-8 and Fundação de Apoio ao Ensino, Pesquisa e Assistência (FAEPA) from the Hospital of the Medical School of Ribeirão Preto, University of Sao Paulo (Scholarships Nº 97/16). VHA holds a CNPq-PQ scholarship (Grant no. 310735/2013-0). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.