DNA of bovine herpesvirus type 1 in the trigeminal ganglia of latently infected calves.
ABSTRACT Twelve calves infected with bovine herpesvirus type 1 (BHV-1) were killed when in a latent state of infection. Latency was verified 30 days after virus inoculation of the calves by seroconversion, absence of virus shedding, and in 2 calves, by recrudescence of the infection after they were treated with dexamethasone. By in situ hybridization techniques and autoradiography, DNA of BHV-1 was detected in 13 of 23 trigeminal ganglia of latently infected calves. Viral DNA was restricted to the nucleus of nerve cells. Single neurons harboring BHV-1 DNA were observed in 4.9% of the sections (n = 325) of the trigeminal ganglia. The results obtained correspond to those known from herpes simplex virus infections in mice. The implications for the virus-host relationship are discussed.
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ABSTRACT: The latency-related (LR) RNA encoded by bovine herpesvirus 1 is abundantly expressed in the trigeminal ganglia of latently infected calves. Expression of LR proteins is necessary for reactivation from latency and the protection of infected neurons from apoptosis. In this study, we demonstrated that an LR-encoded protein, open reading frame 2 (ORF-2), or ORF-2 fusion proteins encoded by alternatively spliced LR transcripts inhibit cold shock or Fas ligand-induced apoptosis in mouse neuroblastoma (neuro-2A) cells. Frameshift mutants of ORF-2 do not inhibit apoptosis, which suggests that protein expression, not LR RNA expression, mediates the antiapoptotic activity of the LR gene in transfected neuro-2A cells.Journal of Virology 09/2008; 82(21):10940-5. · 5.08 Impact Factor
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ABSTRACT: Members of the viral subfamily Alphaherpesvirinae establish latency from which they can be reactivated. Bovine herpesvirus 1 causes infectious bovine rhinotracheitis and infectious pustular vulvovaginitis in cattle, as well as abortion and weak calves. Serological evidence of alphaherpesvirus infection has been reported for wild and semidomesticated reindeer (Rangifer tarandus tarandus) in Norway. To address the possibility that reindeer alphaherpesvirus (cervid herpesvirus 2 [CvHV-2]) infection might affect the respiratory system and in part explain the relatively high mortality of reindeer calves during their first year, tissue samples were obtained from reindeer and reindeer fetuses at slaughterhouses in Finnmark County, Norway. A nested pan-alphaherpesvirus PCR amplification targeting the highly conserved UL27 gene (encoding glycoprotein B) was used. Sequencing of amplicons revealed the presence of CvHV-2 DNA. The detection of CvHV-2 DNA in trigeminal ganglia (27 of 143 samples), nasal swabs (5 of 75 samples), and fetal tissues (12 of 48 samples) indicates that CvHV-2 infection is endemic in this reindeer population. Moreover, the virus is transmitted horizontally by the respiratory route, establishing latency in the trigeminal ganglion, and vertically to the fetus through the placenta. Further studies should focus on the reproductive impact of CvHV-2 infection in reindeer.Journal of clinical microbiology 04/2009; 47(5):1309-13. · 4.16 Impact Factor
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ABSTRACT: Bovine herpesvirus 1 (BHV-1), an alphaherpesvirinae subfamily member, establishes latency in sensory neurons. Elevated corticosteroid levels, due to stress, reproducibly triggers reactivation from latency in the field. A single intravenous injection of the synthetic corticosteroid dexamethasone (DEX) to latently infected calves consistently induces reactivation from latency. Lytic cycle viral gene expression is detected in sensory neurons within 6 h after DEX treatment of latently infected calves. These observations suggested that DEX stimulated expression of cellular genes leads to lytic cycle viral gene expression and productive infection. In this study, a commercially available assay-Bovine Gene Chip-was used to compare cellular gene expression in the trigeminal ganglia (TG) of calves latently infected with BHV-1 versus DEX-treated animals. Relative to TG prepared from latently infected calves, 11 cellular genes were induced more than 10-fold 3 h after DEX treatment. Pentraxin three, a regulator of innate immunity and neurodegeneration, was stimulated 35- to 63-fold after 3 or 6 h of DEX treatment. Two transcription factors, promyelocytic leukemia zinc finger (PLZF) and Slug were induced more than 15-fold 3 h after DEX treatment. PLZF or Slug stimulated productive infection 20- or 5-fold, respectively, and Slug stimulated the late glycoprotein C promoter more than 10-fold. Additional DEX-induced transcription factors also stimulated productive infection and certain viral promoters. These studies suggest that DEX-inducible cellular transcription factors and/or signaling pathways stimulate lytic cycle viral gene expression, which subsequently leads to successful reactivation from latency in a small subset of latently infected neurons.Journal of Virology 12/2011; 86(5):2459-73. · 5.08 Impact Factor