Tumor necrosis factor-alpha expression in white-tailed deer (Odocoileus virginianus) infected with Epizootic haemorrhagic disease virus.

Abstract

Epizootic haemorrhagic disease (EHD) is the most important infectious disease of white‑tailed deer (WTD), however little is known about the role of inflammatory mediators in the pathogenesis. We characterized the expression of tumor necrosis factor‑alpha (TNF-α) ex vivo in tissues of WTD experimentally or naturally infected with EHD virus serotype 2 and in WTD peripheral blood mononuclear cells (PBMC) infected with EHD virus serotype 2 in vitro. Circulating levels of TNF-α were evaluated in serum from experimentally infected deer via cytotoxicity assay. The expression of TNF-α in tissues was evaluated via immunohistochemistry (IHC) in both experimentally and naturally infected deer. Semi‑quantitative reverse transcriptase polymerase chain reaction (RT-PCR) was used to assess the level of TNF-α mRNA in tissues from experimentally infected deer and WTD's PBMC. Circulating levels of TNF-α were not increased in infected animals and TNF-α was not detected in tissues of infected deer. Increased transcription of TNF-α was detected neither in infected WTD nor in the PBMC. Tumor necrosis factor-alpha may not play a significant role in the pathogenesis of EHD virus infection in WTD.