Ex vivo bioluminescence detection of alcelaphine herpesvirus 1 infection during malignant catarrhal fever

J Virol. 2011 Jul;85(14):6941-54. doi: 10.1128/JVI.00286-11. Epub 2011 May 18.

Abstract

Alcelaphine herpesvirus 1 (AlHV-1), carried by wildebeest asymptomatically, causes malignant catarrhal fever (WD-MCF) when cross-species transmitted to a variety of susceptible species of the Artiodactyla order. Experimentally, WD-MCF can be reproduced in rabbits. WD-MCF is described as a combination of lymphoproliferation and degenerative lesions in virtually all organs and is caused by unknown mechanisms. Recently, we demonstrated that WD-MCF is associated with the proliferation of CD8(+) cells supporting a latent type of infection in lymphoid tissues. Here, we investigated the macroscopic distribution of AlHV-1 infection using ex vivo bioluminescence imaging in rabbit to determine whether it correlates with the distribution of lesions in lymphoid and nonlymphoid organs. To reach that goal, a recombinant AlHV-1 strain was produced by insertion of a luciferase expression cassette (luc) in an intergenic region. In vitro, the reconstituted AlHV-1 luc(+) strain replicated comparably to the parental strain, and luciferase activity was detected by bioluminescence imaging. In vivo, rabbits infected with the AlHV-1 luc(+) strain developed WD-MCF comparably to rabbits infected with the parental wild-type strain, with hyperthermia and increases of both CD8(+) T cell frequencies and viral genomic charge over time in peripheral blood mononuclear cells and in lymph nodes at time of euthanasia. Bioluminescent imaging revealed that AlHV-1 infection could be detected ex vivo in lymphoid organs but also in lung, liver, and kidney during WD-MCF, demonstrating that AlHV-1 infection is prevalent in tissue lesions. Finally, we show that the infiltrating mononuclear leukocytes in nonlymphoid organs are mainly CD8(+) T cells and that latency is predominant during WD-MCF.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Blotting, Southern
  • CD8-Positive T-Lymphocytes / immunology
  • Cattle
  • Cell Line
  • DNA Primers
  • Flow Cytometry
  • Fluorescent Antibody Technique, Indirect
  • Genes, Reporter
  • Herpesviridae Infections / diagnosis*
  • Luminescence
  • Malignant Catarrh / diagnosis*
  • Polymerase Chain Reaction
  • Rabbits

Substances

  • DNA Primers