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Di Genova C, Sutton G, Paillot R, Temperton N, Pronost S, Scott SD. Studying longitudinal neutralising antibody levels against Equid herpesvirus 1 in experimentally infected horses using a novel pseudotype based assay. Virus Res 2024; 339:199262. [PMID: 37931881 PMCID: PMC10694342 DOI: 10.1016/j.virusres.2023.199262] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 11/02/2023] [Accepted: 11/03/2023] [Indexed: 11/08/2023]
Abstract
Infection with equid herpesvirus 1 (EHV-1), a DNA virus of the Herpesviridae family represents a significant welfare issue in horses and a great impact on the equine industry. During EHV-1 infection, entry of the virus into different cell types is complex due to the presence of twelve glycoproteins (GPs) on the viral envelope. To investigate virus entry mechanisms, specific combinations of GPs were pseudotyped onto lentiviral vectors. Pseudotyped virus (PV) particles bearing gB, gD, gH and gL were able to transduce several target cell lines (HEK293T/17, RK13, CHO-K1, FHK-Tcl3, MDCK I & II), demonstrating that these four EHV-1 glycoproteins are both essential and sufficient for cell entry. The successful generation of an EHV-1 PV permitted development of a PV neutralisation assay (PVNA). The efficacy of the PVNA was tested by measuring the level of neutralising serum antibodies from EHV-1 experimentally infected horses (n = 52) sampled in a longitudinal manner. The same sera were assessed using a conventional EHV-1 virus neutralisation (VN) assay, exhibiting a strong correlation (r = 0.82) between the two assays. Furthermore, PVs routinely require -80 °C for long term storage and a dry ice cold-chain during transport, which can impede dissemination and utilisation in other stakeholder laboratories. Consequently, lyophilisation of EHV-1 PVs was conducted to address this issue. PVs were lyophilised and pellets either reconstituted immediately or stored under various temperature conditions for different time periods. The recovery and functionality of these lyophilised PVs was compared with standard frozen aliquots in titration and neutralisation tests. Results indicated that lyophilisation could be used to stably preserve such complex herpesvirus pseudotypes, even after weeks of storage at room temperature, and that reconstituted EHV-1 PVs could be successfully employed in antibody neutralisation tests.
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Affiliation(s)
- Cecilia Di Genova
- Viral Pseudotype Unit, Medway School of Pharmacy, Universities of Kent and Greenwich, Chatham Maritime, Kent ME4 4 TB, United Kingdom; Animal and Plant Health Agency (APHA), Weybridge, Surrey KT15 3NB, United Kingdom
| | - Gabrielle Sutton
- LABÉO Frank Duncombe, 14280 Saint-Contest, France; BIOTARGEN, Normandie Univ, UNICAEN, 14000 Caen, France; Université de Montréal, H3C 3J7 Montreal, Quebec, Canada
| | - Romain Paillot
- LABÉO Frank Duncombe, 14280 Saint-Contest, France; BIOTARGEN, Normandie Univ, UNICAEN, 14000 Caen, France; School of Equine and Veterinary Physiotherapy, Writtle University College, Writtle, Chelmsford, Essex CM1 3RR, United Kingdom
| | - Nigel Temperton
- Viral Pseudotype Unit, Medway School of Pharmacy, Universities of Kent and Greenwich, Chatham Maritime, Kent ME4 4 TB, United Kingdom
| | - Stéphane Pronost
- LABÉO Frank Duncombe, 14280 Saint-Contest, France; BIOTARGEN, Normandie Univ, UNICAEN, 14000 Caen, France
| | - Simon D Scott
- Viral Pseudotype Unit, Medway School of Pharmacy, Universities of Kent and Greenwich, Chatham Maritime, Kent ME4 4 TB, United Kingdom.
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2
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The Neuropathic Itch Caused by Pseudorabies Virus. Pathogens 2020; 9:pathogens9040254. [PMID: 32244386 PMCID: PMC7238046 DOI: 10.3390/pathogens9040254] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 03/24/2020] [Accepted: 03/25/2020] [Indexed: 12/13/2022] Open
Abstract
Pseudorabies virus (PRV) is an alphaherpesvirus related to varicella-zoster virus (VZV) and herpes simplex virus type 1 (HSV1). PRV is the causative agent of Aujeskzy’s disease in swine. PRV infects mucosal epithelium and the peripheral nervous system (PNS) of its host where it can establish a quiescent, latent infection. While the natural host of PRV is the swine, a broad spectrum of mammals, including rodents, cats, dogs, and cattle can be infected. Since the nineteenth century, PRV infection is known to cause a severe acute neuropathy, the so called “mad itch” in non-natural hosts, but surprisingly not in swine. In the past, most scientific efforts have been directed to eradicating PRV from pig farms by the use of effective marker vaccines, but little attention has been given to the processes leading to the mad itch. The main objective of this review is to provide state-of-the-art information on the mechanisms governing PRV-induced neuropathic itch in non-natural hosts. We highlight similarities and key differences in the pathogenesis of PRV infections between non-natural hosts and pigs that might explain their distinctive clinical outcomes. Current knowledge on the neurobiology and possible explanations for the unstoppable itch experienced by PRV-infected animals is also reviewed. We summarize recent findings concerning PRV-induced neuroinflammatory responses in mice and address the relevance of this animal model to study other alphaherpesvirus-induced neuropathies, such as those observed for VZV infection.
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3
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Oladunni FS, Horohov DW, Chambers TM. EHV-1: A Constant Threat to the Horse Industry. Front Microbiol 2019; 10:2668. [PMID: 31849857 PMCID: PMC6901505 DOI: 10.3389/fmicb.2019.02668] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 11/01/2019] [Indexed: 12/17/2022] Open
Abstract
Equine herpesvirus-1 (EHV-1) is one of the most important and prevalent viral pathogens of horses and a major threat to the equine industry throughout most of the world. EHV-1 primarily causes respiratory disease but viral spread to distant organs enables the development of more severe sequelae; abortion and neurologic disease. The virus can also undergo latency during which viral genes are minimally expressed, and reactivate to produce lytic infection at any time. Recently, there has been a trend of increasing numbers of outbreaks of a devastating form of EHV-1, equine herpesviral myeloencephalopathy. This review presents detailed information on EHV-1, from the discovery of the virus to latest developments on treatment and control of the diseases it causes. We also provide updates on recent EHV-1 research with particular emphasis on viral biology which enables pathogenesis in the natural host. The information presented herein will be useful in understanding EHV-1 and formulating policies that would help limit the spread of EHV-1 within horse populations.
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Affiliation(s)
- Fatai S. Oladunni
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, United States
- Department of Veterinary Microbiology, University of Ilorin, Ilorin, Nigeria
| | - David W. Horohov
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, United States
| | - Thomas M. Chambers
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, United States
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4
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Ma G, Azab W, Osterrieder N. Equine herpesviruses type 1 (EHV-1) and 4 (EHV-4)—Masters of co-evolution and a constant threat to equids and beyond. Vet Microbiol 2013; 167:123-34. [DOI: 10.1016/j.vetmic.2013.06.018] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Revised: 05/08/2013] [Accepted: 06/28/2013] [Indexed: 12/28/2022]
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5
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Azab W, El-Sheikh A, Abdel-Gawad A. In vitro characterization of EHV-4 gG-deleted mutant. Virus Genes 2011; 44:109-11. [PMID: 21960433 DOI: 10.1007/s11262-011-0677-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2011] [Accepted: 09/16/2011] [Indexed: 11/25/2022]
Abstract
Equine herpesvirus 4 (EHV-4) is an important pathogen that causes respiratory tract disease in horse populations worldwide. Glycoprotein G (gG) homologs have been identified in several alphaherpesviruses as minor non-essential membrane-anchored glycoproteins. In this study, EHV-4 gG deletion mutant has been generated by using bacterial artificial chromosome technology to investigate the role of gG in viral pathogenesis. Our findings reported here revealed no significant difference between parental EHV-4 and gG-negative strain in their replication cycle in cell culture. Furthermore, virus titers and plaque formation were comparable in both viruses. It is noteworthy that these findings disagree with the previously published study describing gG deletion in another EHV-4 strain.
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Affiliation(s)
- Walid Azab
- Department of Virology, Zagazig University, Zagazig, Egypt.
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6
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Azab W, Kato K, Abdel-Gawad A, Tohya Y, Akashi H. Equine herpesvirus 4: recent advances using BAC technology. Vet Microbiol 2011; 150:1-14. [PMID: 21292410 DOI: 10.1016/j.vetmic.2011.01.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Revised: 12/17/2010] [Accepted: 01/03/2011] [Indexed: 10/18/2022]
Abstract
The equine herpesviruses are major infectious pathogens that threaten equine health. Equine herpesvirus 4 (EHV-4) is an important equine pathogen that causes respiratory tract disease, known as rhinopneumonitis, among horses worldwide. EHV-4 genome manipulation with subsequent understanding of the viral gene functions has always been difficult due to the limited number of susceptible cell lines and the absence of small-animal models of the infection. Efficient generation of mutants of EHV-4 would significantly contribute to the rapid and accurate characterization of the viral genes. This problem has been solved recently by the cloning of the genome of EHV-4 as a stable and infectious bacterial artificial chromosome (BAC) without any deletions of the viral genes. Very low copy BAC vectors are the mainstay of present genomic research because of the high stability of inserted clones and the possibility of mutating any gene target in a relatively short time. Manipulation of EHV-4 genome is now feasible using the power of BAC technology, and should aid greatly in assessing the role of viral genes in the virus-host interaction.
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Affiliation(s)
- Walid Azab
- Department of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
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7
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Pathogenic potential of equine alphaherpesviruses: The importance of the mononuclear cell compartment in disease outcome. Vet Microbiol 2010; 143:21-8. [DOI: 10.1016/j.vetmic.2010.02.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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8
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Zhao Y, Wang JW, Ma B, Liu F. Molecular analysis of duck enteritis virus US3, US4, and US5 gene. Virus Genes 2009; 38:289-94. [PMID: 19153825 DOI: 10.1007/s11262-008-0326-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2008] [Accepted: 12/30/2008] [Indexed: 10/21/2022]
Abstract
Here, we first present unique short (US)3, US4, and US5 gene sequences, with analysis, of duck enteritis virus (DEV) vaccine strain C-KCE. The assembled sequence comprises 5,742 nucleotides, which are amplified from the DEV genome by single oligonucleotide-nested polymerase chain reaction with primers designed according to our previous acquired sequence deposited in GenBank (accession no. EF619046). The predicted gene arrangement is colinear with the alphaherpesvirus herpes simplex virus within the US region. The N-glycosylated sites, signal peptide, transmembrane helices, RNA polymerase II transcriptional control elements, and polyadenylation signal, were predicted with network prediction programs. Phylogenetic analysis of the three putative proteins revealed that they had a close evolutionary relationship with the subfamily of Alphaherpesvirinae.
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Affiliation(s)
- Yan Zhao
- Northeast Agricultural University, Harbin, 150030, China
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9
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Black WD, Hartley CA, Ficorilli NP, Studdert MJ. Virion associated proteins of equine rhinitis B virus 1 (ERBV1): the non-structural protein 3C(pro) co-purifies with virions. Virus Res 2008; 140:205-8. [PMID: 19041914 DOI: 10.1016/j.virusres.2008.11.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2008] [Revised: 10/28/2008] [Accepted: 11/03/2008] [Indexed: 11/17/2022]
Abstract
Equine rhinitis B virus (ERBV), genus Erbovirus, is most closely related to the Cardiovirus genus in the family Picornaviridae. The structural proteins (VP1-4) of erboviruses are not well described, but are predicted by sequence to be 35, 29, 26 and 7 kDa. Methods for the purification of cardioviruses (polyethylene glycol, trypsin treatment) were used to characterise the structural proteins of ERBV1. Only one of the virus proteins detected was an expected molecular mass, and this 26 kDa protein was identified as VP3 by N-terminal amino acid sequencing. N-terminal sequencing of the 56 and a 29 kDa protein identified sequences consistent with VP2 and VP1 respectively, despite these being 27 kDa larger and 6 kDa smaller than predicted. Virus purified without trypsin showed proteins more consistent with masses predicted for VP1, VP2 and VP3 at 35, 29 and 26 kDa respectively. These proteins were further identified with antibodies affinity purified to recombinant VP1, VP2, VP3 produced in E. coli. Interestingly, antibodies affinity purified to the non-structural protein 3C(pro), produced in insect cells, strongly detected a 27 kDa protein in western blots of virus purified with and without trypsin treatment, suggesting the non-structural 27 kDa 3C(pro) co-purifies with ERBV1 virions.
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Affiliation(s)
- Wesley D Black
- Centre for Equine Virology, School of Veterinary Science, The University of Melbourne, Victoria 3010, Australia
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10
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Helferich D, Veits J, Teifke JP, Mettenleiter TC, Fuchs W. The UL47 gene of avian infectious laryngotracheitis virus is not essential for in vitro replication but is relevant for virulence in chickens. J Gen Virol 2007; 88:732-742. [PMID: 17325345 DOI: 10.1099/vir.0.82533-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The genome of infectious laryngotracheitis virus (ILTV) exhibits several differences from those of other avian and mammalian alphaherpesviruses. One of them is the translocation of the conserved UL47 gene from the unique long (UL) to the unique short (US) genome region, where UL47 is inserted upstream of the US4 gene homologue. As in other alphaherpesviruses, UL47 encodes a major tegument protein of ILTV particles, whereas the US4 gene product is a non-structural glycoprotein, gG, which is secreted from infected cells. For functional characterization, an ILTV recombinant was isolated in which US4 together with the 3′-terminal part of UL47 was replaced by a reporter gene cassette encoding green fluorescent protein. From this virus, UL47 and US4 single-gene deletion mutants without foreign sequences were derived and virus revertants were also generated. In vitro studies revealed that both genes were non-essential for ILTV replication in cultured cells. Whereas US4-negative ILTV exhibited no detectable growth defects, maximum virus titres of the double deletion mutant and of UL47-negative ILTV were reduced about 10-fold compared with those of wild-type virus and rescued virus. Experimental infection of chickens demonstrated that UL47-negative ILTV was significantly attenuated in vivo and was shed in reduced amounts, whereas wild-type and rescued viruses caused severe disease and high mortality rates. As all immunized animals were protected against subsequent challenge infection with virulent ILTV, the UL47 deletion mutant might be suitable as a live-virus vaccine.
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Affiliation(s)
- Dorothee Helferich
- Institute of Molecular Biology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Jutta Veits
- Institute of Molecular Biology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Jens P Teifke
- Institute of Infectology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Thomas C Mettenleiter
- Institute of Molecular Biology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Walter Fuchs
- Institute of Molecular Biology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
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11
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Ibrahim ESM, Kinoh M, Matsumura T, Kennedy M, Allen GP, Yamaguchi T, Fukushi H. Genetic relatedness and pathogenicity of equine herpesvirus 1 isolated from onager, zebra and gazelle. Arch Virol 2006; 152:245-55. [PMID: 17051419 DOI: 10.1007/s00705-006-0855-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2006] [Accepted: 08/16/2006] [Indexed: 12/01/2022]
Abstract
Equine herpesvirus 1 was isolated from an onager in 1985, a zebra in 1986 and a Thomson's gazelle in 1996 in USA. The genetic relatedness and pathogenicity of these three viruses were investigated based on the nucleotide sequences of the glycoprotein G (gG) gene, experimental infection in hamsters, and comparison with horse isolates. The gG gene sequences of EHV-1 from onager and zebra were identical. The gG gene sequences of the gazelle isolate showed 99.5% identity to those of onager and zebra isolates. The gG gene sequences of EHV-1 isolated from horses were 99.9-100% identical and 98, 98 and 97.8% similar to gG from onager, zebra and gazelle isolates, respectively. Hamsters inoculated with onager, zebra and gazelle isolates had severe weight loss, compared with hamsters inoculated with horse isolates. The histopathological findings were related to the virulence of each isolate. The results indicated that EHV-1 isolates from onager, zebra and gazelle differ from horse EHV-1 and are much more virulent in hamsters.
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Affiliation(s)
- E S M Ibrahim
- Department of Applied Veterinary Sciences, United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
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12
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Hartley CA, Wilks CR, Studdert MJ, Gilkerson JR. Comparison of antibody detection assays for the diagnosis of equine herpesvirus 1 and 4 infections in horses. Am J Vet Res 2005; 66:921-8. [PMID: 15934623 DOI: 10.2460/ajvr.2005.66.921] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To compare methods of detecting equine herpesvirus type 1 (EHV1)- and EHV4-specific antibodies in horse sera. SAMPLE POPULATION 33 acute and convalescent serum samples from experimentally or naturally infected horses after confirmed EHV1 or EHV4 infection. PROCEDURE For each sample, serum antibody titers against EHV1 and EHV4 were determined by use of virus neutralization (VN) and complement fixation (CF) assays. The ELISA absorbance values for each serum sample were determined against the EHV1 and EHV4 recombinant ELISA antigens. Values obtained for acute and convalescent sera in each assay were compared. RESULTS Following experimental infection of foals, EHV1 or EHV4 antibodies that were specific for the inoculating virus were detected only by use of the ELISA. Results of VN and CF assays indicated that the foals seroconverted to EHV1 and EHV4 following infection with EHV4 only. After EHV1-induced abortion, myeloencephalitis, or respiratory tract disease, the VN and CF assay results revealed seroconversion to EHV1 and EHV4, whereas results of the ELISA revealed seroconversion to EHV1 only. Similarly, after confirmed EHV4-induced respiratory tract disease, increases in EHV4-specific antibodies were detected only by use of the ELISA with no indication of an increase in EHV1 antibodies. The CF and, to a lesser degree, VN assays revealed that seroconversion to EHV1 and EHV4 occurred between the time of obtaining acute and convalescent serum samples. CONCLUSIONS AND CLINICAL RELEVANCE The EHV1/EHV4 type-specific antibody ELISA clearly identifies horses that have been infected with EHV1 or EHV4 by use of acute and convalescent sera. Results of VN and CF assays indicate that cross-reactive antibodies greatly limit their use.
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Affiliation(s)
- Carol A Hartley
- School of Veterinary Science, The University of Melbourne, Victoria 3010, Australia
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Stevenson RA, Huang JA, Studdert MJ, Hartley CA. Identification of a neutralizing epitope in the βE–βF loop of VP1 of equine rhinitis A virus, defined by a neutralization-resistant variant. J Gen Virol 2004; 85:2545-2553. [PMID: 15302948 DOI: 10.1099/vir.0.80175-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Equine rhinitis A virus strain 393/76 (ERAV.393/76) was passaged in the presence of post-infection ERAV.393/76 equine polyclonal antiserum (EPA). Viruses with increased resistance to neutralization by EPA were obtained after 15 passages. Compared with the parent virus, five plaque-purified, neutralization-resistant mutant viruses, in addition to the non-plaque-purified viruses that were examined, had a Glu→Lys change at position 658, which is located in the predicted βE–βF (EF) loop of VP1. Rabbit antiserum was prepared against the isolated EF loop of ERAV.393/76 VP1 expressed as a fusion protein with glutathione S-transferase. This antiserum bound to purified ERAV.393/76 in Western blots, but not to the neutralization-resistant mutant virus or to ERAV.PERV/62, a naturally occurring ERAV strain that has a Lys residue at position 658. These results suggest that the EF loop of VP1 is involved in a neutralization epitope of ERAV.
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Affiliation(s)
- Rachel A Stevenson
- Centre for Equine Virology, School of Veterinary Science, University of Melbourne, Parkville, VIC 3010, Australia
| | - Jin-An Huang
- Centre for Equine Virology, School of Veterinary Science, University of Melbourne, Parkville, VIC 3010, Australia
| | - Michael J Studdert
- Centre for Equine Virology, School of Veterinary Science, University of Melbourne, Parkville, VIC 3010, Australia
| | - Carol A Hartley
- Centre for Equine Virology, School of Veterinary Science, University of Melbourne, Parkville, VIC 3010, Australia
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Studdert MJ, Hartley CA, Dynon K, Sandy JR, Slocombe RF, Charles JA, Milne ME, Clarke AF, El-Hage C. Outbreak of equine herpesvirus type 1 myeloencephalitis: new insights from virus identification by PCR and the application of an EHV-1 -specific antibody detection ELISA. Vet Rec 2003; 153:417-23. [PMID: 14582730 DOI: 10.1136/vr.153.14.417] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Five of 10 pregnant, lactating mares, each with a foal at foot, developed neurological disease. Three of them became recumbent, developed complications and were euthanased; of the two that survived, one aborted an equine herpesvirus type 1 (EHV-1)-positive fetus 68 days after the first signs were observed in the index case and the other gave birth to a healthy foal on day 283 but remained ataxic and incontinent. The diagnosis of EHV-1 myeloencephalitis was supported by postmortem findings, PCR identification of the virus and by serological tests with an EHV-1-specific ELISA. At the time of the index case, the 10 foals all had a heavy mucopurulent nasal discharge, and PCR and the ELISA were used to detect and monitor EHV-1 infection in them. The status of EHV-1 infection in the five in-contact mares was similarly monitored. Sera from three of the affected mares, taken seven days after the index case were negative or had borderline EHV-1-specific antibody titres. In later serum samples there was an increase in the titres of EHV-1-specific antibody in two of the affected mares. In contrast, sera from the five unaffected in-contact mares were all EHV-1-antibody positive when they were first tested seven or 13 days after the index case.
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Affiliation(s)
- M J Studdert
- Centre for Equine Virology, School of Veterinary Science, University of Melbourne, Parkville 3010, Australia
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15
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Stevenson RA, Hartley CA, Huang JA, Studdert MJ, Crabb BS, Warner S. Mapping epitopes in equine rhinitis A virus VP1 recognized by antibodies elicited in response to infection of the natural host. J Gen Virol 2003; 84:1607-1612. [PMID: 12771431 DOI: 10.1099/vir.0.18848-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Equine rhinitis A virus (ERAV) is an important respiratory pathogen of horses and is of additional interest because of its close relationship and common classification with foot-and-mouth disease virus (FMDV). As is the case with FMDV, the VP1 capsid protein of ERAV has been shown to be a target of neutralizing antibodies. In FMDV VP1, such antibodies commonly recognize linear epitopes present in the betaG-betaH loop region. To map linear B cell epitopes in ERAV VP1, overlapping fragments spanning its length were expressed in Escherichia coli as glutathione S-transferase (GST) fusion proteins. These fusion proteins were tested for reactivity with sera from ERAV-infected horses and with polyclonal sera from ERAV-immunized rabbits and mice. Regions at the N- and C-termini as well as the betaE-betaF and the betaG-betaH loop regions contained B cell epitopes that elicited antibodies in the natural host. GST fusion proteins of these regions also elicited antibodies following immunization of rabbits and mice, which, in general, strongly recognized native ERAV VP1 but which were non-neutralizing. It is concluded that the N-terminal region of ERAV VP1, in particular, contains strong B cell epitopes.
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Affiliation(s)
- Rachel A Stevenson
- Centre for Equine Virology, School of Veterinary Science, The University of Melbourne, Victoria 3010, Australia
| | - Carol A Hartley
- Centre for Equine Virology, School of Veterinary Science, The University of Melbourne, Victoria 3010, Australia
| | - Jin-An Huang
- Centre for Equine Virology, School of Veterinary Science, The University of Melbourne, Victoria 3010, Australia
| | - Michael J Studdert
- Centre for Equine Virology, School of Veterinary Science, The University of Melbourne, Victoria 3010, Australia
| | - Brendan S Crabb
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3050, Australia
| | - Simone Warner
- Department of Microbiology and Immunology and the Co-operative Research Centre for Vaccine Technology, The University of Melbourne, Victoria 3010, Australia
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Bryant NA, Davis-Poynter N, Vanderplasschen A, Alcami A. Glycoprotein G isoforms from some alphaherpesviruses function as broad-spectrum chemokine binding proteins. EMBO J 2003; 22:833-46. [PMID: 12574120 PMCID: PMC145452 DOI: 10.1093/emboj/cdg092] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Mimicry of host chemokines and chemokine receptors to modulate chemokine activity is a strategy encoded by beta- and gammaherpesviruses, but very limited information is available on the anti-chemokine strategies encoded by alphaherpesviruses. The secretion of chemokine binding proteins (vCKBPs) has hitherto been considered a unique strategy encoded by poxviruses and gammaherpesviruses. We describe a family of novel vCKBPs in equine herpesvirus 1, bovine herpesvirus 1 and 5, and related alphaherpesviruses with no sequence similarity to chemokine receptors or other vCKBPs. We show that glycoprotein G (gG) is secreted from infected cells, binds a broad range of chemokines with high affinity and blocks chemokine activity by preventing their interaction with specific receptors. Moreover, gG also blocks chemokine binding to glycosaminoglycans, an interaction required for the correct presentation and function of chemokines in vivo. In contrast to other vCKBPs, gG may also be membrane anchored and, consistently, we show chemokine binding activity at the surface of cells expressing full-length protein. These alphaherpesvirus vCKBPs represent a novel family of proteins that bind chemokines both at the membrane and in solution.
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Affiliation(s)
| | - Nick Davis-Poynter
- Department of Medicine and Division of Virology, Department of Pathology, University of Cambridge, Addenbrooke’s Hospital, Hills Road, Cambridge CB2 2QQ,
Animal Health Trust, Lanwades Park, Kentford, Newmarket CB8 7UU, UK and Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, B43b, University of Liège, B-4000 Liège, Belgium Corresponding author e-mail:
| | - Alain Vanderplasschen
- Department of Medicine and Division of Virology, Department of Pathology, University of Cambridge, Addenbrooke’s Hospital, Hills Road, Cambridge CB2 2QQ,
Animal Health Trust, Lanwades Park, Kentford, Newmarket CB8 7UU, UK and Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, B43b, University of Liège, B-4000 Liège, Belgium Corresponding author e-mail:
| | - Antonio Alcami
- Department of Medicine and Division of Virology, Department of Pathology, University of Cambridge, Addenbrooke’s Hospital, Hills Road, Cambridge CB2 2QQ,
Animal Health Trust, Lanwades Park, Kentford, Newmarket CB8 7UU, UK and Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, B43b, University of Liège, B-4000 Liège, Belgium Corresponding author e-mail:
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17
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Nakamichi K, Matsumoto Y, Otsuka H. Bovine herpesvirus 1 glycoprotein G is necessary for maintaining cell-to-cell junctional adherence among infected cells. Virology 2002; 294:22-30. [PMID: 11886262 DOI: 10.1006/viro.2001.1264] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glycoproteins gE and gG of bovine herpesvirus 1 (BHV-1) are involved in viral cell-to-cell transmission. We have compared the subcellular localizations of gE and gG and examined the cell-to-cell adherence of bovine kidney (MDBK) cells infected with BHV-1 mutants lacking gE or gG. In BHV-1-infected MDBK cells, gE was observed at cell junctions but did not localize at apical or basal plasma membranes. BHV-1 gG was primarily found in the cytoplasm and was also observed at boundaries among infected cells. During the infection with wild-type or gE-negative BHV-1, the filamentous actin and the adherent junctional proteins accumulated at the cell junctions. In contrast, cell junctions of MDBK cells infected with gG-negative BHV-1 were loosened, and the junctional proteins and BHV-1 gE were distributed in the cytoplasm. These data indicate that BHV-1 gG facilitates viral cell-to-cell spread by maintaining the cell-to-cell junctions among the infected cells.
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Affiliation(s)
- Kazuo Nakamichi
- Department of Global Agricultural Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
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18
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Liljeqvist JÅ, Trybala E, Hoebeke J, Svennerholm B, Bergström T. Monoclonal antibodies and human sera directed to the secreted glycoprotein G of herpes simplex virus type 2 recognize type-specific antigenic determinants. J Gen Virol 2002; 83:157-165. [PMID: 11752712 DOI: 10.1099/0022-1317-83-1-157] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Glycoprotein G-2 (gG-2) of herpes simplex virus type 2 (HSV-2) is cleaved to a secreted amino-terminal portion (sgG-2) and to a cell-associated carboxy-terminal portion which is further O-glycosylated to constitute the mature gG-2 (mgG-2). In contrast to mgG-2, which is known to elicit a type-specific antibody response in the human host, information on the immunogenic properties of sgG-2 is lacking. Here the sgG-2 protein was purified on a heparin column and used for production of monoclonal antibodies (mAbs). Four anti-sgG-2 mAbs were mapped using a Pepscan technique and identified linear epitopes which localized to the carboxy-terminal part of the protein. One additional anti-sgG-2 mAb, recognizing a non-linear epitope, was reactive to three discrete peptide stretches where the most carboxy-terminally located stretch was constituted by the amino acids (320)RRAL(323). Although sgG-2 is rapidly secreted into the cell-culture medium after infection, the anti-sgG-2 mAbs identified substantial amounts of sgG-2 in the cytoplasm of HSV-2-infected cells. All of the anti-sgG-2 mAbs were HSV-2 specific showing no cross-reactivity to HSV-1 antigen or to HSV-1-infected cells. Similarly, sera from 50 HSV-2 isolation positive patients were all reactive to sgG-2 in an enzyme immunoassay whilst no reactivity was seen in 25 sera from HSV-1 isolation positive patients or in 25 serum samples from HSV-negative patients suggesting that sgG-2 is a novel antigen potentially suitable for type-discriminating serodiagnosis.
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Affiliation(s)
- Jan-Åke Liljeqvist
- Department of Virology, Göteborg University, Guldhedsgatan 10 B, S-413 46 Göteborg, Sweden1
| | - Edward Trybala
- Department of Virology, Göteborg University, Guldhedsgatan 10 B, S-413 46 Göteborg, Sweden1
| | - Johan Hoebeke
- UPR9021 du CNRS, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France2
| | - Bo Svennerholm
- Department of Virology, Göteborg University, Guldhedsgatan 10 B, S-413 46 Göteborg, Sweden1
| | - Tomas Bergström
- Department of Virology, Göteborg University, Guldhedsgatan 10 B, S-413 46 Göteborg, Sweden1
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19
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Nakamichi K, Kuroki D, Matsumoto Y, Otsuka H. Bovine herpesvirus 1 glycoprotein G is required for prevention of apoptosis and efficient viral growth in rabbit kidney cells. Virology 2001; 279:488-98. [PMID: 11162805 DOI: 10.1006/viro.2000.0740] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
In rabbit kidney (RK13) cells, gG-negative BHV-1 exhibited significant defects in plaque formation and growth compared to that of gG-positive BHV-1. RK13 cells infected with gG-negative BHV-1 exhibited a distinctive CPE and contained a larger number of cells stained with trypan blue dye compared to those infected with gG-positive strains, suggesting that gG-negative BHV-1 inflicted more damage to the infected cells than gG-positive BHV-1. Apoptotic cell death was induced in RK13 cells infected with gG-negative BHV-1 within 8 h. In contrast, the onset of apoptosis in gG-positive BHV-1-infected RK13 cells was around 12-16 h postinfection. In the presence of caspase inhibitor Z-Asp-CH2-DCB, multiplication of gG-negative minus BHV-1 was significantly increased. These results demonstrate that BHV-1 gG is involved in stabilizing the cell structure, postponing apoptotic process, and efficient BHV-1 replication in infected RK13 cells.
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Affiliation(s)
- K Nakamichi
- Department of Global Agricultural Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Tokyo, Bunkyo-ku, 113-8657, Japan
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20
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Seyboldt C, Granzow H, Osterrieder N. Equine herpesvirus 1 (EHV-1) glycoprotein M: effect of deletions of transmembrane domains. Virology 2000; 278:477-89. [PMID: 11118370 DOI: 10.1006/viro.2000.0664] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Equine herpesvirus 1 (EHV-1) recombinants that carry either a deletion of glycoprotein M (gM) or express mutant forms of gM were constructed. The recombinants were derived from strain Kentucky A (KyA), which also lacks genes encoding gE and gI. Plaques on RK13 cells induced by the gM-negative KyA were reduced in size by 80%, but plaque sizes were restored to wild-type levels on gM-expressing cells. Electron microscopic studies revealed a massive defect in virus release after the deletion of gM in the gE- and gI-negative KyA, which was caused by a block in secondary envelopment of virions at Golgi vesicles. Recombinant KyA expressing mutant gM with deletions of predicted transmembrane domains was generated and characterized. It was shown that mutant gM was expressed and formed dimeric and oligomeric structures. However, subcellular localization of mutant gM proteins differed from that of wild-type gM. Mutant glycoproteins were not transported to the Golgi network and consequently were not incorporated into the envelope of extracellular virions. Also, a small plaque phenotype of mutant viruses that was indistinguishable from that of the gM-negative KyA was observed. Plaque sizes of mutant viruses were restored to wild-type levels by plating onto RK13 cells constitutively expressing full-length EHV-1 gM, indicating that mutant proteins did not exert a transdominant negative effect on wild-type gM.
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Affiliation(s)
- C Seyboldt
- Institutes of Molecular Biology, Insel Riems, D-17498, Germany
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21
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Nakamichi K, Ohara K, Kuroki D, Otsuka H. Bovine herpesvirus 1 glycoprotein G is required for viral growth by cell-to-cell infection. Virus Res 2000; 68:175-81. [PMID: 10958989 DOI: 10.1016/s0168-1702(00)00171-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The bovine herpesvirus 1 (BHV-1) US4 gene encodes glycoprotein G (gG), which is conserved in the majority of alphaherpesviruses. In order to identify the role of BHV-1 gG in the viral infection cycle, a gG minus BHV-1 mutant and its gG-positive revertant were constructed and their growth characteristics in Madin-Darby bovine kidney (MDBK) cells were compared. The gG minus mutant formed smaller plaques than the gG-positive BHV-1 in MDBK cells. When a monolayer culture of MDBK cells was infected with BHV-1 at a low multiplicity of infection and overlaid with semi-solid growth medium, under which adsorption of the mature virion released in the medium was inhibited, gG-positive BHV-1 multiplied, while the growth of the gG negative BHV-1 was severely inhibited. These data suggest that BHV-1 gG functions in direct cell-to-cell transmission mechanism of BHV-1 in tissue culture.
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Affiliation(s)
- K Nakamichi
- Department of Global Agricultural Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, 113-8657, Tokyo, Japan
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22
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Abstract
Canine herpesvirus (CHV) is an alpha-herpesvirus of limited pathogenicity in healthy adult dogs and infectivity of the virus appears to be largely limited to cells of canine origin. CHV's low virulence and species specificity make it an attractive candidate for a recombinant vaccine vector to protect dogs against a variety of pathogens. As part of the analysis of the CHV genome, the authors determined the complete nucleotide sequence of the CHV US region as well as portions of the flanking inverted repeats. Seven full open reading frames (ORFs) encoding proteins larger than 100 amino acids were identified within, or partially within the CHV US: cUS2, cUS3, cUS4, cUS6, cUS7, cUS8 and cUS9; which are homologs of the herpes simplex virus type-1 US2; protein kinase; gG, gD, gI, gE; and US9 genes, respectively. An eighth ORF was identified in the inverted repeat region, cIR6, a homolog of the equine herpesvirus type-1 IR6 gene. The authors identified and mapped most of the major transcripts for the predicted CHV US ORFs by Northern analysis.
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Affiliation(s)
- E J Haanes
- Heska Corporation, Fort Collins, CO 80525, USA.
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23
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Damiani AM, Matsumura T, Yokoyama N, Maeda K, Miyazawa T, Kai C, Mikami T. Nucleotide sequences of glycoprotein I and E genes of equine herpesvirus type 4. J Vet Med Sci 1998; 60:219-25. [PMID: 9524947 DOI: 10.1292/jvms.60.219] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The nucleotide sequences of the glycoprotein I (gI) and E (gE) genes of equine herpesvirus type 4 (EHV-4) strain TH20 were determined. The predicted region encoding the EHV-4 gI gene is 1,263 nucleotides, corresponding to a polypeptide of 420 amino acids in length. The predicted region encoding the EHV-4 gE gene is 1,647 nucleotides, corresponding to a polypeptide of 548 amino acids in length. The EHV-4 gI and gE genes show 74% and 85% identity at the amino acid level with those of equine herpesvirus type 1 (EHV-1), respectively. Furthermore, we have found an open reading frame homologous to the EHV-1 gene 75, which overlaps in part with the 3' end of EHV-4 gE gene. These sequence data will be useful for development of a modified live vaccine against equine herpesvirus type 1 and 4 infections.
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Affiliation(s)
- A M Damiani
- Department of Veterinary Microbiology, Faculty of Agriculture, University of Tokyo, Japan
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24
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Schneider PA, Hatalski CG, Lewis AJ, Lipkin WI. Biochemical and functional analysis of the Borna disease virus G protein. J Virol 1997; 71:331-6. [PMID: 8985354 PMCID: PMC191055 DOI: 10.1128/jvi.71.1.331-336.1997] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The Borna disease virus (BDV) antigenome is comprised of five major open reading frames (ORFs). Products have been reported only for ORFs I, II, and III, encoding N (p40), P (p24/p23), and M (gp18), respectively. ORF IV predicts a 57-kDa protein with several potential glycosylation sites. Analysis of radiolabeled extracts from BDV-infected C6 cells and BHK-21 cells transfected with a Semliki Forest virus vector that contains ORF IV demonstrated the presence of a 94-kDa protein (G protein) which was sensitive to tunicamycin, endoglycosidase F/N-glycosidase, and endoglycosidase H but not to O-glycosidase. Sera from BDV-infected rats detected the G protein and had neutralization activity that was reduced following immunoadsorption with the G protein. Preincubation of cells with the G protein interfered with BDV infectivity. This effect was enhanced by treatment of the G protein with the exoglycosidase alpha-mannosidase and reduced after subsequent treatment with N-acetyl-beta-D-glucosaminidase. In concert these findings indicate that ORF IV encodes a 94-kDa N-linked glycoprotein with extensive high mannose- and/or hybrid-type oligosaccharide modifications. The presence of neutralization epitopes on the G protein and its capacity to interfere with infectivity suggest that the G protein is important for viral entry.
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Affiliation(s)
- P A Schneider
- Department of Microbiology and Molecular Genetics, University of California-Irvine, 92697-4290, USA
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25
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Kliche S, Stitz L, Mangalam H, Shi L, Binz T, Niemann H, Briese T, Lipkin WI. Characterization of the Borna disease virus phosphoprotein, p23. J Virol 1996; 70:8133-7. [PMID: 8892940 PMCID: PMC190889 DOI: 10.1128/jvi.70.11.8133-8137.1996] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Borna disease virus infection is diagnosed by the presence of serum antibodies reactive with the major viral proteins, p40 and p23. Although p40 and p23 are unrelated in amino acid sequence structure, cross-reactive antibodies are described. Protein fragments and synthetic peptides were analyzed to characterize the specificities of antibodies to p23. Epitope mapping revealed eight continuous epitopes accessible on the surface of a predicted structural model for the monomeric and the disulfide-linked dimeric forms of p23. None of these epitopes was reactive with antibodies to p40. Cross-reactivity with monospecific sera and monoclonal antibodies to p40 was found for one discontinuous epitope located at the amino terminus of p23.
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Affiliation(s)
- S Kliche
- Laboratory for Neurovirology, Department of Neurology, University of California, Irvine, 92697, USA
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26
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Keil GM, Engelhardt T, Karger A, Enz M. Bovine herpesvirus 1 U(s) open reading frame 4 encodes a glycoproteoglycan. J Virol 1996; 70:3032-8. [PMID: 8627780 PMCID: PMC190163 DOI: 10.1128/jvi.70.5.3032-3038.1996] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Sequence analysis of the short unique (Us) segment of the bovine herpesvirus 1 (BHV-1) genome predicted that the Us open reading frame (ORF) 4 encodes a protein with homology to glycoprotein G (gG) of other alpha-herpesviruses (P. Leung-Tack, J.-C. Audonnet, and M. Riviere, Virology 199:409-421, 1994). RNA analysis showed that the Us ORF4 is contained within two transcripts of 3.5 and 1.8 kb. The 3.5 kb RNA represents a structurally bicistronic RNA which encompasses the Us ORF3 and Us ORF4, whereas the 1.8-kb RNA constitutes the monocistronic Us ORF4 mRNA. To identify the predicted BHV-I gG, recombinant vaccinia virus expressing the Us ORF4 was used to raise specific antibodies in rabbits. The antiserum recognized a 65-kDa polypeptide and a very diffusely migrating species of proteins with an apparent molecular mass of between 90 and greater than 240 kDa in supernatants of BHV-1-infected cells which was also precipitated together with 61- and 70-kDa polypeptides from cell-associated proteins. The specificity of the reaction was demonstrated by the absence of these proteins from the supernatant of cells infected with the Us ORF4 deletion mutant BHV-l/gp1-8. Treatment of the immunoprecipitated proteins with glycosidases and chondroitinase AC showed that the 65-kDa protein constitutes gG, which contains both N- and O-linked carbohydrates, and that the high-molecular-mass proteins contain glycosaminoglycans linked to a 65-kDa glycoprotein that is antigenically related to gG. These molecules were therefore named glycoproteoglycan C (gpgG). Pulse chase experiments indicated that gG and gpgG were processed from a common precursor molecule with an apparent molecular mass of 61 kDa via a 70-kDa intermediate. Both gG and gpgG could not be found associated with purified virions. In summary, our results identify the BHV-I gG protein and demonstrate the presence of a form of posttranslational modification, glycosamino-glycosylation, that has not yet been described for a herpesvirus-encoded protein.
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Affiliation(s)
- G M Keil
- Institute for Molecular and Cellular Virology, Insel Riems, Germany
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27
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Crabb BS, Studdert MJ. Expression of small regions of equine herpesvirus 1 glycoprotein C in Escherichia coli. Vet Microbiol 1995; 46:181-91. [PMID: 8545955 DOI: 10.1016/0378-1135(95)00082-l] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A series of truncated equine herpesvirus 1 (EHV1) glycoprotein C (gC) molecules was examined for use as serodiagnostic antigens for EHV1 and EHV4. 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. Sera obtained from horses, including sera from specific-pathogen-free (SPF) foals, following exposure to either EHV1, EHV4 or both viruses were used. Several of the fusion proteins were shown to encompass EHV1 specific epitopes while others encompassed strong, cross-reactive epitopes. One clone, termed pEC-3, produced a soluble and stable fusion protein which encompassed amino acids 107-275 of EHV1 gC. Strong cross-reactive epitopes on pEC-3 were localised to a region encompassed by amino acids 137 to approximately 152 while EHV1 specific epitope(s) were identified downstream of this region, i.e., approximately amino acids 152 to 275. E. coli expressed EHV1 gC polypeptides showed clear potential for use as diagnostic reagents for the detection of cross-reactive and type-specific EHV1 and EHV4 antibodies present in convalescent equine sera.
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Affiliation(s)
- B S Crabb
- Centre for Equine Virology, School of Veterinary Science, University of Melbourne, Parkville, Vic, Australia
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28
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Ficorilli N, Studdert MJ, Crabb BS. The nucleotide sequence of asinine herpesvirus 3 glycoprotein G indicates that the donkey virus is closely related to equine herpesvirus 1. Arch Virol 1995; 140:1653-62. [PMID: 7487497 DOI: 10.1007/bf01322539] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The nucleotide sequence of the glycoprotein G (gG) homologue of asinine herpesvirus 3 (AHV3), a respiratory alphaherpesvirus of donkeys, was determined. The AHV3 gG gene consists of 1233 base pairs (bp) and codes for a predicted protein of 411 amino acids. This is identical in size to the equine herpesvirus 1 (EHV1) gG gene and 6 amino acids longer than the equine herpesvirus 4 (EHV4) gG gene. The predicted amino acid sequence of AHV3 gG has characteristics of a class 1 membrane protein. The amino acid sequence of AHV3 gG shows 92% and 60% identity to EHV1 gG and EHV4 gG respectively. Two regions within the gG amino acid sequences of EHV1 and EHV4 were previously defined, an N-terminal constant region and an immunodominant highly variable region located toward the C-terminus. In the corresponding constant region of AHV3 gG there was 96% and 75% amino acid identity with EHV1 and EHV4 gGs respectively. In the variable region, there was 73% and 24% identity respectively. Phylogenetic analyses using the gG nucleotide sequences indicated that AHV3 is much closer in evolutionary distance to EHV1 than either virus is to EHV4. These findings provide additional support for the view that AHV3, or another closely related virus, may be the progenitor of EHV1 and has adapted to horses in relatively recent times.
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Affiliation(s)
- N Ficorilli
- Centre for Equine Virology, School of Veterinary Science, University of Melbourne, Parkville, Victoria, Australia
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29
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Crabb BS, MacPherson CM, Reubel GH, Browning GF, Studdert MJ, Drummer HE. A type-specific serological test to distinguish antibodies to equine herpesviruses 4 and 1. Arch Virol 1995; 140:245-58. [PMID: 7710353 DOI: 10.1007/bf01309860] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We describe a type-specific ELISA, which distinguishes antibody to equine herpesvirus 4 (EHV4; equine rhinopneumonitis) and EHV1 (equine abortion virus) thereby identifying horses that have been infected with either or both of these antigenically related viruses. The antigens used are parts of the EHV4 and EHV1 glycoprotein G (gG) homologues expressed in E. coli as fusion proteins [Crabb and Studdert, 1993: J Virol 67: 6332-6338). The expressed proteins comprise corresponding regions of the gG molecules that are highly divergent and encompass strong, typespecific epitopes. Plasma samples from 97 Thoroughbred and 174 Standardbred horses were tested, all of which were unvaccinated. All horses were strongly EHV4 ELISA positive while 30% were EHV1 ELISA positive. The type-specificity of the EHV1 gG antigen was tested in cross-absorption experiments and it was found that 96% (66 of 69) of EHV1 ELISA positive horses were true EHV1 antibody positives. It was also shown that 100% (26 of 26) horses known to have been exposed to EHV1, either by infection or immunisation with EHV1, had significant levels of antibody against the EHV1 gG antigen (i.e., all horses recognised the EHV1 epitope(s) contained within this molecule). Maintenance of EHV1 gG antibody was examined by testing sera obtained from mares four years after confirmed EHV1 abortion. Seven out of 10 of these mares remained EHV1 ELISA positive. In summary, the ELISA is highly specific and is sufficiently sensitive to detect all horses previously infected with EHV4 and most previously infected with EHV1.
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Affiliation(s)
- B S Crabb
- Centre for Equine Virology, School of Veterinary Science, University of Melbourne, Parkville, Victoria, Australia
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30
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Hatalski CG, Kliche S, Stitz L, Lipkin WI. Neutralizing antibodies in Borna disease virus-infected rats. J Virol 1995; 69:741-7. [PMID: 7815538 PMCID: PMC188637 DOI: 10.1128/jvi.69.2.741-747.1995] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Borna disease is a neurologic syndrome caused by infection with a nonsegmented, negative-strand RNA virus, Borna disease virus. Infected animals have antibodies to two soluble viral proteins, p40 and p23, and a membrane-associated viral glycoprotein, gp18. We examined the time course for the development of neutralization activity and the expression of antibodies to individual viral proteins in sera of infected rats. The appearance of neutralizing activity correlated with the development of immunoreactivity to gp18, but not p40 or p23. Monospecific and monoclonal antibodies to native gp18 and recombinant nonglycosylated gp18 were also found to have neutralizing activity and to immunoprecipitate viral particles or subparticles. These findings suggest that gp18 is likely to be present on the surface of the viral particles and is likely to contain epitopes important for virus neutralization.
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Affiliation(s)
- C G Hatalski
- Department of Neurology, University of California, Irvine 92717
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31
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Crabb BS, Studdert MJ. Equine herpesviruses 4 (equine rhinopneumonitis virus) and 1 (equine abortion virus). Adv Virus Res 1995; 45:153-90. [PMID: 7793324 DOI: 10.1016/s0065-3527(08)60060-3] [Citation(s) in RCA: 125] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- B S Crabb
- Centre for Equine Virology, School of Veterinary Science, University of Melbourne, Parkville, Victoria, Australia
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32
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Wilson L, Neilan J, Brady I, Coyle D, Cullinane AA. Use of lambda gt11 to identify antigenic components of equine herpesvirus 4. Virus Genes 1994; 8:159-63. [PMID: 7521096 DOI: 10.1007/bf01703073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A library of the equine herpesvirus 4 (EHV-4) genome was constructed in the lambda gt11 expression vector. Recombinant bacteriophage expressing EHV-4 antigens as beta-galactosidase fusion proteins were detected with rabbit antiserum raised against EHV-4 virions and convalescent horse serum. EHV-4 DNA sequences contained in the immunopositive recombinants were used as hybridization probes for mapping the genes encoding the antigens on the viral genome. The DNA sequence of the probes was determined. Screening the library with rabbit antiserum led to the identification of 40 recombinants, 26 of which were further characterized. Determination of the DNA sequence of the EHV-4 inserts revealed that 23 of the recombinants encode an identical portion of glycoprotein gB. Two of the recombinants encode a portion of the previously unidentified EHV-4 homologue of the EHV-1 immediate early protein. The EHV-4 insert of the remaining recombinant encodes a portion of the previously unidentified EHV-4 homologue of herpes simplex virus 1 (HSV-1) UL36, a tegument protein. Screening the library with horse serum led to the identification of three recombinants, one of which encodes the same gB sequence as the gB recombinant recognized with the rabbit serum. The other two contain overlapping sequences that encode a portion of EHV-4 gX.
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Affiliation(s)
- L Wilson
- AFRC Institute for Animal Health, Compton, Newbury, Berkshire, UK
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33
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Crabb BS, Studdert MJ. Epitopes of glycoprotein G of equine herpesviruses 4 and 1 located near the C termini elicit type-specific antibody responses in the natural host. J Virol 1993; 67:6332-8. [PMID: 7690425 PMCID: PMC238063 DOI: 10.1128/jvi.67.10.6332-6338.1993] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
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. Recently, we identified EHV4 glycoprotein G (gG) and characterized it as a type-specific, secreted glycoprotein (B. S. Crabb, H. S. Nagesha, and M. J. Studdert, Virology 190:143-154, 1992). This paper shows that EHV1 gG also possesses type-specific epitopes and describes the localization of strong, type-specific epitopes to the apparently corresponding and highly variable regions comprising amino acids 287 to 382 of EHV4 gG and 288 to 350 of EHV1 gG. Fusion proteins expressing these variable regions reacted strongly and type specifically with sera from four foals, three of which were colostrum-deprived, specific-pathogen-free foals, whose history with respect to exposure to EHV4 or EHV1 was well-defined. These antigens provided the basis for the development of a single-well diagnostic enzyme-linked immunosorbent assay to distinguish horses infected with EHV4, EHV1, or both. Such a type-specific test provides for the first time the opportunity to differentiate antibodies to these viruses, and it has, therefore, important implications for understanding the epidemiology of these equine pathogens. Evidence for the existence of EHV1 in Australia 10 years prior to the first confirmed case of EHV1 abortion is presented.
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Affiliation(s)
- B S Crabb
- School of Veterinary Science, University of Melbourne, Parkville, Victoria, Australia
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Kongsuwan K, Johnson MA, Prideaux CT, Sheppard M. Identification of an infectious laryngotracheitis virus gene encoding an immunogenic protein with a predicted M(r) of 32 kilodaltons. Virus Res 1993; 29:125-40. [PMID: 8212855 DOI: 10.1016/0168-1702(93)90054-q] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The nucleotide sequence of an infectious laryngotracheitis virus (ILTV) gene which maps immediately upstream from the glycoprotein 60 (gp60) gene was determined. The gene, designated p32, encodes a predicted polypeptide of 298 amino acids with an estimated M(r) of 32,000 daltons. The predicted protein sequence has four potential N-glycosylation sites and a signal sequence at the N-terminal region. Amino acid residues in the NH2-terminal region of the p32 protein exhibit similarity to glycoprotein X (gX) of pseudorabies virus (PRV) and its homolog in equine herpesvirus type 1 (EHV-1). Within the conserved (N-terminus) region, one putative N-linked glycosylation site and four cysteine residues are aligned in these proteins. These common structural features of the gX-like proteins were also found in glycoprotein G (gG) of human herpes simplex virus type 2 (HSV-2) and equine herpesvirus type 4 (EHV-4). High level bacterial production of the p32 protein was achieved by cloning the p32 open reading frame into a pGEX-2T expression vector. Western blot analysis of the fusion protein produced in E. coli using immune chicken sera confirms that p32 protein is of viral origin and is an immunogen in birds with infectious laryngotracheitis (ILT). An antiserum from chicken immunized with the fusion protein detected a substantial amount of p32 protein in the medium of ILTV-infected cells in Western blotting. Moreover tunicamycin treatment of cells infected with the virus indicated that p32 was glycosylated. This allows us to conclude that p32 is a glycoprotein and like gX of PRV accumulates in the medium of infected cells.
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Affiliation(s)
- K Kongsuwan
- CSIRO Division of Animal Health, Animal Health Research Laboratory, Parkville, Australia
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Su HK, Fetherston JD, Smith ME, Courtney RJ. Orientation of the cleavage site of the herpes simplex virus glycoprotein G-2. J Virol 1993; 67:2954-9. [PMID: 8386284 PMCID: PMC237626 DOI: 10.1128/jvi.67.5.2954-2959.1993] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
During the synthesis of glycoprotein G-2 (gG-2) of herpes simplex virus type 2, the 104,000-Da gG-2 precursor (104K precursor) is cleaved to generate the 72K and the 31K intermediates. The 72K product is processed to generate the mature gG-2 (molecular mass, 108,000 Da), while the 31K product is additionally processed and secreted into the extracellular medium as the 34K component (H. K. Su, R. Eberle, and R. J. Courtney, J. Virol. 61:1735-1737, 1987). In this study, the orientations of the 31K and 72K products on the 104K precursor were determined by using two antipeptide sera produced in rabbits and a monoclonal antibody, 13 alpha C6, directed against gG-2. The sera prepared against synthetic peptides corresponding to the terminal amino acid residues 67 to 78 and an internal peptide at amino acids 247 to 260 of gG-2 recognized the 104K precursor and the 31K cleavage product but not the 72K intermediate. In contrast, 13 alpha C6 detected the 72K cleavage product and the uncleaved precursor but not the 31K cleavage component. The epitope recognized by 13 alpha C6 was mapped within amino acids 486 to 566. These results suggest that the 31K cleavage product is derived from the amino-terminal portion of the 104K precursor molecule and that the 72K intermediate is derived from the carboxyl terminus. In support of our model described above for the synthesis of gG-2, antibodies recognizing either of the cleavage products reacted with the uncleaved precursor but not with the other cleavage product. By using partial endo-beta-N-acetylglucosaminidase H analysis, two N-linked glycosylation sites were found on each of the cleavage products. The distribution of the N-linked glycosylation sites and the reactivities of the antipeptide sera allowed the cleavage region on the precursor to be mapped to within amino acids 260 to 437.
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Affiliation(s)
- H K Su
- Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, Hershey 17033
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Riggio MP, Onions DE. DNA sequence of a gene cluster in the equine herpesvirus-4 genome which contains a newly identified herpesvirus gene encoding a membrane protein. Arch Virol 1993; 133:171-8. [PMID: 8240007 DOI: 10.1007/bf01309752] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Complete DNA sequences for the equine herpesvirus-4 (EHV-4) genes analogous to equine herpesvirus-1 (EHV-1) genes 8, 9, 10, and 11, varicella zoster virus (VZV) genes 7, 8, 9 A, and 9, and herpes simplex virus type 1 (HSV-1) genes UL51, UL50, UL49A, and UL49 are presented. The EHV-4 gene corresponding to EHV-1 gene 10/VZV gene 9A/HSV-1 UL49A is of particular interest in that it is a newly identified herpesvirus gene whose product demonstrates features characteristic of membrane-inserted proteins. Furthermore, this gene has counterparts in all herpesvirus genomes sequenced to date.
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Affiliation(s)
- M P Riggio
- Department of Veterinary Pathology, University of Glasgow Veterinary School, U.K
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Nagesha HS, Crabb BS, Studdert MJ. Analysis of the nucleotide sequence of five genes at the left end of the unique short region of the equine herpesvirus 4 genome. Arch Virol 1993; 128:143-54. [PMID: 8380320 DOI: 10.1007/bf01309795] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Eco RI fragment G of equine herpesvirus 4 strain 405/76 (EHV 4.405/76) is located at the left end of the unique short region close to or extending into the internal repeat region of the prototypic arrangement of the genome. The nucleotide sequence of two subclones designated HS and G 19, contiguous within Eco RI fragment G, was determined for each strand by obtaining a nested set of deletion clones of these double-stranded DNA plasmids. Analysis of the nucleotide sequence revealed that the two subclones contain 5449 base pairs with four complete open reading frames (ORFs) and part of a fifth ORF. Comparison of the predicted amino acid sequences of these reading frames showed that they correspond to ORFs 67, 68, 69, 70, and 71 of equine herpesvirus type 1 (EHV 1) [41], of which ORFs 68, 69, and 70 are homologous to human herpes simplex virus (HSV) genes in the unique short (US) region, i.e., US 2, US 3, and US 4. ORF 67' of EHV 4 and ORF 67 of EHV 1 are homologous (65.7%) but these genes have no homologue in HSV 1.
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Affiliation(s)
- H S Nagesha
- School of Veterinary Science, University of Melbourne, Parkville, Victoria, Australia
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