Sequence and recombination analyses of archived field isolates of equine herpesviruses 1 and 4

High-throughput sequencing of complete viral genomes has recently allowed natural (field) recombination to be studied in a number of different alphaherpesviruses, however, such studies have not been applied to equine herpesvirus 1 (EHV-1) or equine herpesvirus 4 (EHV-4). The neurological form of disease is called equine herpesvirus myeloencephalopathy (EHM). Recently, we identified EHV4 glycoprotein G (gG) and characterized it as a type-specific, secreted glycoprotein (B. S. EHV-1 gH gene products in recombinant baculovirus infected insect cells were identified as 105 kDa and 110 kDa species compared with a 115 kDa product detected in EHV-1 infected mammalian cells. Since 2007, several case reports from America, Europe and the United Kingdom have further characterised the clinical presentation and laboratory findings of this disease. The equine herpesvirus 1 (EHV-1) strain HVS25A regulatory genes IE and UL5, encoding homologues of herpes simplex virus 1 (HSV-1) ICP4 and ICP27 respectively, were cloned into a eukaryotic expression vector and the DNA injected intramuscularly into mice.

Your library or institution may give you access to the complete full text for this document in ProQuest. Seventeen New Zealand isolates of equine herpesvirus 5 (EHV-5) were compared to the Australian prototype strain. The unusual mucin-like high molecular mass (Mr) glycoprotein 2 (gp2) has only been described in the equid alphaherpesviruses, among which there is considerable antigenic cross-reactivity. It is hoped that the vaccine new vaccine will help break that cycle. Specific serological diagnosis of equine herpesvirus 4 (EHV4; equine rhinopneumonitis virus) and EHV1 (equine abortion virus) hitherto has not been possible because of extensive antigenic cross-reactivity between these two closely related but distinct viruses. A 1 mL annual revaccination in previously vaccinated horses is recommended. The New South Wales, Australia, Department of Primary Industries is encouraging horse owners to vaccinate their horses against hendra virus as the winter months approach in the Southern Hemisphere.

All samples were negative for EHV-1; however, 3 were positive for EHV-4. Signal cleavage of EHV-1 gD occurred between Arg35 and Ala36 in a region of basic amino acids resembling the endoproteolytic cleavage sites of viral glycoproteins, nine amino acids downstream of the predicted site, while EHV-1 gB was cleaved as predicted between Ala85 and Val86. Whilst there are differences between the model and natural infection in the horse, literature suggests that EHV-1 infection of pregnant mice can be used to assess the potential ability of vaccine candidates to protect against abortion. Antibodies produced in this way detected the IE or UL5 gene products as diffuse material in nuclei of RK13 cells transfected with the individual genes but as discrete punctate or large aggregates in RK13 cells infected with EHV-1. DESIGN: A longitudinal population study in groups of Thoroughbred weanling foals. The 3.4 kb transcript encoded EHV-1 gB and the 5′ RNA terminus was located approximately 30 bases downstream from a probable TATA element. Here, we provide an unequivocal demonstration that gp2 is encoded by gene 71.

EHV-1 gD was detected as multiple forms (56, 52, and 48 kDa) from 18 to 96 h postinfection. A 4.3 kbp EHV-1 PstI-ClaI sequence (0.40 to 0.43 map units) contained an open reading frame flanked by appropriate control elements and was capable of encoding a polypeptide of 980 amino acids. Recombinant gD was N-terminally cleaved at the same site as gD in EHV-1 infected cells and expression was associated with enhanced levels of cell-cell fusion, indicating a role for EHV-1 gD in cell-to-cell transmission of virus. The recombinant lacZ62/63-EHV-1 had similar growth kinetics in cell culture to those of the parental wild type (wt) virus, with indistinguishable cytopathic effects and plaque morphology. Primary infection caused a leucocytosis due to a neutrophilia during days 1 and 2 post-infection (pi) and a B lymphocytosis at day 1 pi. Small regions of EHV1 glycoprotein C, an immunodominant EHV1 glycoprotein, were expressed in Escherichia coli as glutathione S-transferase (GST) fusion proteins using the bacterial expression vector pGEX-2T. An equine herpesvirus 1 glycoprotein D deletion mutant constructed using red recombination in E.

The restriction endonuclease DNA fingerprints of 57 isolates of equine herpesvirus 1 from abortion, perinatal foal mortalities and encephalitis from 15 epidemics that occurred in Australasia over the 14 years are reported and their epidemiological implications examined. High molecular mass products (>200 kDa) in the Bac-EgB infected insect cells were consistent with oligomerisation of the recombinant EHV-1 gB products, and analysis with tunicamycin and endoglycosidases indicated that the baculovirus-expressed gB contained N-linked sugars with high mannose and hybrid chains. Terminal fragments were identified by exonuclease treatments, and linkage of fragments was deduced by a combination of single- and double-digest experiments and cross-blot hybridizations. In order to investigate the potential of gp2 as a vaccine antigen, expression vectors were constructed to encode full-length gp2, a truncated version lacking the membrane anchor, and the C-terminal region. School of Veterinary Science, The University of Melbourne, Victoria 3010, Australia.