Yellow Fever 17DD Vaccine Virus Infection Causes Detectable Changes in Chicken Embryos

PLoS Negl Trop Dis. 2015 Sep 15;9(9):e0004064. doi: 10.1371/journal.pntd.0004064. eCollection 2015.

Abstract

The yellow fever (YF) 17D vaccine is one of the most effective human vaccines ever created. The YF vaccine has been produced since 1937 in embryonated chicken eggs inoculated with the YF 17D virus. Yet, little information is available about the infection mechanism of YF 17DD virus in this biological model. To better understand this mechanism, we infected embryos of Gallus gallus domesticus and analyzed their histopathology after 72 hours of YF infection. Some embryos showed few apoptotic bodies in infected tissues, suggesting mild focal infection processes. Confocal and super-resolution microscopic analysis allowed us to identify as targets of viral infection: skeletal muscle cells, cardiomyocytes, nervous system cells, renal tubular epithelium, lung parenchyma, and fibroblasts associated with connective tissue in the perichondrium and dermis. The virus replication was heaviest in muscle tissues. In all of these specimens, RT-PCR methods confirmed the presence of replicative intermediate and genomic YF RNA. This clearer characterization of cell targets in chicken embryos paves the way for future development of a new YF vaccine based on a new cell culture system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animal Structures / virology
  • Animals
  • Chick Embryo
  • Histocytochemistry
  • Vaccines, Attenuated
  • Virus Replication
  • Yellow Fever Vaccine*
  • Yellow fever virus / growth & development*

Substances

  • Vaccines, Attenuated
  • Yellow Fever Vaccine

Grants and funding

This work was supported by Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (www.faperj.br) (E-26/010.001530/2014), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (www.capes.gov.br), and Fundação Oswaldo Cruz (WWW.fiocruz.br). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.