2,3,7,8-Tetrachlorodibenzo-p-dioxin promotes BHV-1 infection in mammalian cells by interfering with iron homeostasis regulation

PLoS One. 2013;8(3):e58845. doi: 10.1371/journal.pone.0058845. Epub 2013 Mar 8.

Abstract

Mammalian cells require iron to satisfy metabolic needs or to accomplish specialized functions, and DNA viruses, like bovine herpesvirus 1 (BHV-1), require an iron-replete host to efficiently replicate, so that iron bioavailability is an important component of viral virulence. Cellular iron metabolism is coordinately controlled by the Iron Regulatory Proteins (IRP1 and IRP2), whose activity is affected by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a current and persistent environmental contaminant. Considering that TCDD enhances BHV-1 replication, herein we analyzed the effects of TCDD on iron metabolism during BHV-1 infection in MDBK cells, and presented evidences of a divergent modulation of IRP1 and IRP2 RNA-binding capacity. Moreover, an up-regulation of transferrin receptor 1 (TfR1) and a concomitant down-regulation of ferritin were observed. This scenario led to an expansion of the labile iron pool (LIP) and induces a significant enhance of viral titer, as confirmed by increased levels of BHV-1 infected cell protein 0 (bICP0), the major transcriptional regulatory protein of BHV-1. Taken together, our data suggest that TCDD increases the free intracellular iron availability thereby promoting the onset of BHV-1 infection and rendering bovine cells more vulnerable to the virus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cattle
  • Cell Line
  • Herpesviridae Infections / metabolism*
  • Herpesvirus 1, Bovine / metabolism*
  • Homeostasis / drug effects*
  • Iron / metabolism*
  • Iron Regulatory Protein 1 / metabolism
  • Iron Regulatory Protein 2 / metabolism
  • Polychlorinated Dibenzodioxins / pharmacology*
  • Teratogens / pharmacology*

Substances

  • Polychlorinated Dibenzodioxins
  • Teratogens
  • Iron
  • Iron Regulatory Protein 1
  • Iron Regulatory Protein 2

Grants and funding

Filomena Fiorito was supported by a fellowship from Polo delle Scienze e delle Tecnologie per la Vita dell′Universitá di Napoli “Federico II” (2012-4/STV-Progetto FORGIARE) co-funded by Compagnia San Paolo di Torino, Italy. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. No current external funding sources for this study.