Analyze Diet
Virology2010; 410(2); 327-335; doi: 10.1016/j.virol.2010.11.020

Properties of an equine herpesvirus 1 mutant devoid of the internal inverted repeat sequence of the genomic short region.

Abstract: The 150 kbp genome of equine herpesvirus-1 (EHV-1) is composed of a unique long (UL) region and a unique short (Us) segment, which is flanked by identical internal and terminal repeat (IR and TR) sequences of 12.7 kbp. We constructed an EHV-1 lacking the entire IR (vL11ΔIR) and showed that the IR is dispensable for EHV-1 replication but that the vL11ΔIR exhibits a smaller plaque size and delayed growth kinetics. Western blot analyses of cells infected with vL11ΔIR showed that the synthesis of viral proteins encoded by the immediate-early, early, and late genes was reduced at immediate-early and early times, but by late stages of replication reached wild type levels. Intranasal infection of CBA mice revealed that the vL11ΔIR was significantly attenuated as mice infected with the vL11ΔIR showed a reduced lung viral titer and greater ability to survive infection compared to mice infected with parental or revertant virus.
Publication Date: 2010-12-21 PubMed ID: 21176938PubMed Central: PMC3030640DOI: 10.1016/j.virol.2010.11.020Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
  • Journal Article
  • Research Support
  • N.I.H.
  • Extramural
  • Research Support
  • Non-U.S. Gov't

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research conducted experiments on a variant of Equine Herpesvirus-1 (EHV-1) that lacked a segment of the virus’s genetic makeup known as the internal inverted repeat (IR). The researchers found this deficient virus variant, named vL11ΔIR, showed slower growth and smaller size but could still replicate. Additionally, the vL11ΔIR was less damaging when infecting mice, resulting in lower virus levels in the lungs and higher survival rates compared to the original virus.

Study Design and Objective

  • The research team aimed to study the effects of removing the internal inverted repeat (IR), a 12.7 kbp sequence, from the genome of the equine herpesvirus-1 (EHV-1).
  • The primary objective was to investigate how this genetic modification affects the virus’s replication process, its protein synthesis, and severity of infection in a mammalian host.

Methods and Procedures

  • The researchers constructed a variant of EHV-1 that lacked the entire IR segment, referred to as vL11ΔIR.
  • The team then examined its growth kinetics and plaque size, which is a visible structure formed by virus-infected cells in cell cultures.
  • They analyzed protein synthesis using Western blot analyses at different stages of the replication process.
  • Finally, vL11ΔIR’s effects were observed in a live organism by infecting CBA mice intranasally (through the nose) and monitoring lung viral titers and survival after infection.

Key Findings

  • vL11ΔIR was capable of replication despite lacking the IR sequence, showing that IR is not essential for the virus’s replication process.
  • The mutant virus exhibited smaller plaque formation and delayed growth kinetics, suggesting that the virus’s growth and spread are hindered without the IR sequence.
  • Protein synthesis was initially reduced in vL11ΔIR-infected cells but later reached the levels of the wild type virus, indicating that the removal of IR sequence affects the early stages of viral replication and protein production.
  • When infecting mice, vL11ΔIR resulted in reduced lung viral titers, showing decreased viral load in internal organs. Also, mice infected with vL11ΔIR showed higher survival rates, suggesting that the IR-deficient virus is less virulent than its wild-type counterpart.

Implications of the Research

  • This study contributes to the understanding of the EHV-1 viral genome and machinations, particularly highlighting the role the IR sequence plays in the virus’s life cycle.
  • Such insights could aid in the development of viral attenuators or novel treatments against EHV-1 or similar virus types, which may subsequently improve health outcomes in horses and potentially other affected animals.

Cite This Article

APA
Ahn B, Zhang Y, Osterrieder N, O'Callaghan DJ. (2010). Properties of an equine herpesvirus 1 mutant devoid of the internal inverted repeat sequence of the genomic short region. Virology, 410(2), 327-335. https://doi.org/10.1016/j.virol.2010.11.020

Publication

ISSN: 1096-0341
NlmUniqueID: 0110674
Country: United States
Language: English
Volume: 410
Issue: 2
Pages: 327-335

Researcher Affiliations

Ahn, ByungChul
  • Center for Molecular and Tumor Virology and Department of Microbiology and Immunology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130-3932, USA.
Zhang, Yunfei
    Osterrieder, Nikolaus
      O'Callaghan, Dennis J

        MeSH Terms

        • Animals
        • Blotting, Western
        • DNA, Viral / genetics
        • Disease Models, Animal
        • Female
        • Herpesviridae Infections / pathology
        • Herpesviridae Infections / veterinary
        • Herpesvirus 1, Equid / genetics
        • Herpesvirus 1, Equid / growth & development
        • Herpesvirus 1, Equid / pathogenicity
        • Herpesvirus 1, Equid / physiology
        • Inverted Repeat Sequences
        • Lung / virology
        • Mice
        • Mice, Inbred CBA
        • Sequence Deletion
        • Survival Analysis
        • Viral Plaque Assay
        • Viral Proteins / biosynthesis
        • Virulence
        • Virus Replication

        Grant Funding

        • P20 RR018724-07 / NCRR NIH HHS
        • R01 AI022001 / NIAID NIH HHS
        • P20 RR018724-08 / NCRR NIH HHS
        • P20 RR018724 / NCRR NIH HHS
        • R01 AI022001-22 / NIAID NIH HHS
        • AI-22001 / NIAID NIH HHS
        • P20-RR018724 / NCRR NIH HHS

        References

        This article includes 56 references
        1. Ahn BC, Breitenbach JE, Kim SK, O'Callaghan DJ. The equine herpesvirus-1 IR3 gene that lies antisense to the sole immediate-early (IE) gene is trans-activated by the IE protein, and is poorly expressed to a protein.. Virology 2007 Jun 20;363(1):15-25.
          pmc: PMC1939811pubmed: 17306852doi: 10.1016/j.virol.2007.01.024google scholar: lookup
        2. Ahn BC, Zhang Y, O'Callaghan DJ. The equine herpesvirus-1 (EHV-1) IR3 transcript downregulates expression of the IE gene and the absence of IR3 gene expression alters EHV-1 biological properties and virulence.. Virology 2010 Jul 5;402(2):327-37.
          pmc: PMC3020145pubmed: 20417949doi: 10.1016/j.virol.2010.03.051google scholar: lookup
        3. Boldogköi Z, Braun A, Medveczky I, Glávits R, Gyúró B, Fodor I. Analysis of the equalization of inverted repeats and neurovirulence using a pseudorabies virus mutant strain altered at the Ul/Ir junction.. Virus Genes 1998;17(1):89-98.
          pubmed: 9778792doi: 10.1023/a:1008061220442google scholar: lookup
        4. Bowles DE, Holden VR, Zhao Y, O'Callaghan DJ. The ICP0 protein of equine herpesvirus 1 is an early protein that independently transactivates expression of all classes of viral promoters.. J Virol 1997 Jul;71(7):4904-14.
        5. Breeden CA, Yalamanchili RR, Colle CF, O'Callaghan DJ. Identification and transcriptional mapping of genes encoded at the IR/Us junction of equine herpesvirus type 1.. Virology 1992 Dec;191(2):649-60.
          pubmed: 1333117doi: 10.1016/0042-6822(92)90240-pgoogle scholar: lookup
        6. Breitenbach JE, Ebner PD, O'Callaghan DJ. The IR4 auxiliary regulatory protein expands the in vitro host range of equine herpesvirus 1 and is essential for pathogenesis in the murine model.. Virology 2009 Jan 20;383(2):188-94.
          pmc: PMC2655125pubmed: 19012943doi: 10.1016/j.virol.2008.10.017google scholar: lookup
        7. Caughman GB, Lewis JB, Smith RH, Harty RN, O'Callaghan DJ. Detection and intracellular localization of equine herpesvirus 1 IR1 and IR2 gene products by using monoclonal antibodies.. J Virol 1995 May;69(5):3024-32.
        8. Caughman GB, Staczek J, O'Callaghan DJ. Equine herpesvirus type 1 infected cell polypeptides: evidence for immediate early/early/late regulation of viral gene expression.. Virology 1985 Aug;145(1):49-61.
          pubmed: 2990102doi: 10.1016/0042-6822(85)90200-4google scholar: lookup
        9. Chen M, Garko-Buczynski KA, Zhang Y, O'Callaghan DJ. The defective interfering particles of equine herpesvirus 1 encode an ICP22/ICP27 hybrid protein that alters viral gene regulation.. Virus Res 1999 Feb;59(2):149-64.
          pubmed: 10082387doi: 10.1016/s0168-1702(98)00128-2google scholar: lookup
        10. Chen M, Harty RN, Zhao Y, Holden VR, O'Callaghan DJ. Expression of an equine herpesvirus 1 ICP22/ICP27 hybrid protein encoded by defective interfering particles associated with persistent infection.. J Virol 1996 Jan;70(1):313-20.
          pmc: PMC189819pubmed: 8523542doi: 10.1128/jvi.70.1.313-320.1996google scholar: lookup
        11. Ebner PD, Kim SK, O'Callaghan DJ. Biological and genotypic properties of defective interfering particles of equine herpesvirus 1 that mediate persistent infection.. Virology 2008 Nov 10;381(1):98-105.
          pmc: PMC2636567pubmed: 18805562doi: 10.1016/j.virol.2008.08.024google scholar: lookup
        12. Ebner PD, O'Callaghan DJ. Genetic complexity of EHV-1 defective interfering particles and identification of novel IR4/UL5 hybrid proteins produced during persistent infection.. Virus Genes 2006 Jun;32(3):313-20.
          pubmed: 16732484doi: 10.1007/s11262-005-6916-ygoogle scholar: lookup
        13. Flowers CC, O'Callaghan DJ. Equine herpesvirus 1 glycoprotein D: mapping of the transcript and a neutralization epitope.. J Virol 1992 Nov;66(11):6451-60.
        14. Frampton AR Jr, Smith PM, Zhang Y, Matsumura T, Osterrieder N, O'Callaghan DJ. Contribution of gene products encoded within the unique short segment of equine herpesvirus 1 to virulence in a murine model.. Virus Res 2002 Dec;90(1-2):287-301.
          pubmed: 12457983doi: 10.1016/s0168-1702(02)00245-9google scholar: lookup
        15. Garko-Buczynski KA, Smith RH, Kim SK, O'Callaghan DJ. Complementation of a replication-defective mutant of equine herpesvirus type 1 by a cell line expressing the immediate-early protein.. Virology 1998 Aug 15;248(1):83-94.
          pubmed: 9705258doi: 10.1006/viro.1998.9247google scholar: lookup
        16. Grundy FJ, Baumann RP, O'Callaghan DJ. DNA sequence and comparative analyses of the equine herpesvirus type 1 immediate early gene.. Virology 1989 Sep;172(1):223-36.
          pubmed: 2549711doi: 10.1016/0042-6822(89)90124-4google scholar: lookup
        17. Guggemoos S, Just FT, Neubauer A. The equine herpesvirus 1 UL20 product interacts with glycoprotein K and promotes egress of mature particles.. J Virol 2006 Jan;80(1):95-107.
        18. Harty RN, Colle CF, O'Callaghan DJ. Equine herpesvirus type 1 gene regulation: Characterization of transcription from the immediate early gene in productive infection.. Herpesvirus Transcriptional and Its Regulation 1990 pp. 319–338.
        19. Henry BE, Robinson RA, Dauenhauer SA, Atherton SS, Hayward GS, O'Callaghan DJ. Structure of the genome of equine herpesvirus type 1.. Virology 1981 Nov;115(1):97-114.
          pubmed: 6270904doi: 10.1016/0042-6822(81)90092-1google scholar: lookup
        20. Holden VR, Caughman GB, Zhao Y, Harty RN, O'Callaghan DJ. Identification and characterization of the ICP22 protein of equine herpesvirus 1.. J Virol 1994 Jul;68(7):4329-40.
        21. Holden VR, Harty RN, Yalamanchili RR, O'Callaghan DJ. The IR3 gene of equine herpesvirus type 1: a unique gene regulated by sequences within the intron of the immediate-early gene.. DNA Seq 1992;3(3):143-52.
          pubmed: 1335300doi: 10.3109/10425179209034010google scholar: lookup
        22. Holden VR, Yalamanchili RR, Harty RN, O'Callaghan DJ. Identification and characterization of an equine herpesvirus 1 late gene encoding a potential zinc finger.. Virology 1992 Jun;188(2):704-13.
          pubmed: 1316680doi: 10.1016/0042-6822(92)90525-tgoogle scholar: lookup
        23. Holden VR, Zhao Y, Thompson Y, Caughman GB, Smith RH, O'Callaghan DJ. Characterization of the regulatory function of the ICP22 protein of equine herpesvirus type 1.. Virology 1995 Jul 10;210(2):273-82.
          pubmed: 7618267doi: 10.1006/viro.1995.1344google scholar: lookup
        24. Jenkins FJ, Donoghue AM, Martin JR. Deletion of the Herpes simplex 1 internal repeat sequences affects pathogenicity in the mouse.. Front Biosci 1996 Oct 4;1:a59-68.
          pubmed: 9159195doi: 10.2741/a106google scholar: lookup
        25. Jenkins FJ, Martin JR. Role of the herpes simplex virus 1 internal repeat sequences in pathogenicity.. Intervirology 1990;31(2-4):129-38.
          pubmed: 2165040doi: 10.1159/000150147google scholar: lookup
        26. Jenkins FJ, Roizman B. Herpes simplex virus 1 recombinants with noninverting genomes frozen in different isomeric arrangements are capable of independent replication.. J Virol 1986 Aug;59(2):494-9.
          pmc: PMC253102pubmed: 3016310doi: 10.1128/jvi.59.2.494-499.1986google scholar: lookup
        27. Kim SK, Ahn BC, Albrecht RA, O'Callaghan DJ. The unique IR2 protein of equine herpesvirus 1 negatively regulates viral gene expression.. J Virol 2006 May;80(10):5041-9.
        28. Neubauer A, Osterrieder N. Equine herpesvirus type 1 (EHV-1) glycoprotein K is required for efficient cell-to-cell spread and virus egress.. Virology 2004 Nov 10;329(1):18-32.
          pubmed: 15476871doi: 10.1016/j.virol.2004.07.034google scholar: lookup
        29. O'Callaghan DJ, Colle CF 3rd, Flowers CC, Smith RH, Benoit JN, Bigger CA. Identification and initial characterization of the IR6 protein of equine herpesvirus 1.. J Virol 1994 Sep;68(9):5351-64.
        30. O'Callaghan DJ, Osterrieder N. Herpesviruses of Horses. Encyclopedia of Virology 2008 pp. 411–420.
        31. Osterrieder N, Neubauer A, Brandmuller C, Braun B, Kaaden OR, Baines JD. The equine herpesvirus 1 glycoprotein gp21/22a, the herpes simplex virus type 1 gM homolog, is involved in virus penetration and cell-to-cell spread of virions.. J Virol 1996 Jun;70(6):4110-5.
        32. Osterrieder N, Neubauer A, Brandmüller C, Kaaden OR, O'Callaghan DJ. The equine herpesvirus 1 IR6 protein influences virus growth at elevated temperature and is a major determinant of virulence.. Virology 1996 Dec 15;226(2):243-51.
          pubmed: 8955044doi: 10.1006/viro.1996.0652google scholar: lookup
        33. Osterrieder N, Neubauer A, Brandmüller C, Kaaden OR, O'Callaghan DJ. The equine herpesvirus 1 IR6 protein that colocalizes with nuclear lamins is involved in nucleocapsid egress and migrates from cell to cell independently of virus infection.. J Virol 1998 Dec;72(12):9806-17.
        34. Perdue ML, Kemp MC, Randall CC, O'Callaghan DJ. Studies of the molecular anatomy of the L-M cell strain of equine herpes virus type 1: proteins of the nucleocapsid and intact virion.. Virology 1974 May;59(1):201-16.
          pubmed: 4826204doi: 10.1016/0042-6822(74)90216-5google scholar: lookup
        35. Poffenberger KL, Roizman B. A noninverting genome of a viable herpes simplex virus 1: presence of head-to-tail linkages in packaged genomes and requirements for circularization after infection.. J Virol 1985 Feb;53(2):587-95.
          pmc: PMC254674pubmed: 2982037doi: 10.1128/jvi.53.2.587-595.1985google scholar: lookup
        36. Poffenberger KL, Tabares E, Roizman B. Characterization of a viable, noninverting herpes simplex virus 1 genome derived by insertion and deletion of sequences at the junction of components L and S.. Proc Natl Acad Sci U S A 1983 May;80(9):2690-4.
          pmc: PMC393893pubmed: 6302700doi: 10.1073/pnas.80.9.2690google scholar: lookup
        37. Roizman B. Herpesviridae. Field Virology 1996 pp. 2221–2230.
        38. Roizman B, Pellet PE. The Family of Herpesviridae: a brief introduction. Field Virology 2001 pp. 2381–2397.
        39. Rosas C, Van de Walle GR, Metzger SM, Hoelzer K, Dubovi EJ, Kim SG, Parrish CR, Osterrieder N. Evaluation of a vectored equine herpesvirus type 1 (EHV-1) vaccine expressing H3 haemagglutinin in the protection of dogs against canine influenza.. Vaccine 2008 May 2;26(19):2335-43.
        40. Rudolph J, O'Callaghan DJ, Osterrieder N. Cloning of the genomes of equine herpesvirus type 1 (EHV-1) strains KyA and racL11 as bacterial artificial chromosomes (BAC).. J Vet Med B Infect Dis Vet Public Health 2002 Feb;49(1):31-6.
        41. Ruyechan WT, Dauenhauer SA, O'Callaghan DJ. Electron microscopic study of equine herpesvirus type 1 DNA.. J Virol 1982 Apr;42(1):297-300.
          pmc: PMC256071pubmed: 6283147doi: 10.1128/jvi.42.1.297-300.1982google scholar: lookup
        42. Sauer A, Wang JB, Hahn G, McVoy MA. A human cytomegalovirus deleted of internal repeats replicates with near wild type efficiency but fails to undergo genome isomerization.. Virology 2010 May 25;401(1):90-5.
          pmc: PMC2849842pubmed: 20211481doi: 10.1016/j.virol.2010.02.016google scholar: lookup
        43. Smith PM, Kahan SM, Rorex CB, von Einem J, Osterrieder N, O'Callaghan DJ. Expression of the full-length form of gp2 of equine herpesvirus 1 (EHV-1) completely restores respiratory virulence to the attenuated EHV-1 strain KyA in CBA mice.. J Virol 2005 Apr;79(8):5105-15.
        44. Smith RH, Caughman GB, O'Callaghan DJ. Characterization of the regulatory functions of the equine herpesvirus 1 immediate-early gene product.. J Virol 1992 Feb;66(2):936-45.
          pmc: PMC240795pubmed: 1309921doi: 10.1128/jvi.66.2.936-945.1992google scholar: lookup
        45. Smith RH, Zhao Y, O'Callaghan DJ. The equine herpesvirus 1 (EHV-1) UL3 gene, an ICP27 homolog, is necessary for full activation of gene expression directed by an EHV-1 late promoter.. J Virol 1993 Feb;67(2):1105-9.
        46. Srinivasan R, Fink DJ, Glorioso JC. HSV vectors for gene therapy of chronic pain.. Curr Opin Mol Ther 2008 Oct;10(5):449-55.
          pubmed: 18830920
        47. Telford EA, Watson MS, McBride K, Davison AJ. The DNA sequence of equine herpesvirus-1.. Virology 1992 Jul;189(1):304-16.
          pubmed: 1318606doi: 10.1016/0042-6822(92)90706-ugoogle scholar: lookup
        48. Tischer BK, von Einem J, Kaufer B, Osterrieder N. Two-step red-mediated recombination for versatile high-efficiency markerless DNA manipulation in Escherichia coli.. Biotechniques 2006 Feb;40(2):191-7.
          pubmed: 16526409doi: 10.2144/000112096google scholar: lookup
        49. Trapp S, von Einem J, Hofmann H, Köstler J, Wild J, Wagner R, Beer M, Osterrieder N. Potential of equine herpesvirus 1 as a vector for immunization.. J Virol 2005 May;79(9):5445-54.
        50. von Einem J, Wellington J, Whalley JM, Osterrieder K, O'Callaghan DJ, Osterrieder N. The truncated form of glycoprotein gp2 of equine herpesvirus 1 (EHV-1) vaccine strain KyA is not functionally equivalent to full-length gp2 encoded by EHV-1 wild-type strain RacL11.. J Virol 2004 Mar;78(6):3003-13.
        51. Warming S, Costantino N, Court DL, Jenkins NA, Copeland NG. Simple and highly efficient BAC recombineering using galK selection.. Nucleic Acids Res 2005 Feb 24;33(4):e36.
          pmc: PMC549575pubmed: 15731329doi: 10.1093/nar/gni035google scholar: lookup
        52. Whalley JM, Robertson GR, Davison AJ. Analysis of the genome of equine herpesvirus type 1: arrangement of cleavage sites for restriction endonucleases EcoRI, BglII and BamHI.. J Gen Virol 1981 Dec;57(Pt 2):307-23.
          pubmed: 6275028doi: 10.1099/0022-1317-57-2-307google scholar: lookup
        53. Whalley JM, Ruitenberg KM, Sullivan K, Seshadri L, Hansen K, Birch D, Gilkerson JR, Wellington JE. Host cell tropism of equine herpesviruses: glycoprotein D of EHV-1 enables EHV-4 to infect a non-permissive cell line.. Arch Virol 2007;152(4):717-25.
          pubmed: 17171298doi: 10.1007/s00705-006-0885-xgoogle scholar: lookup
        54. Yamada H, Daikoku T, Yamashita Y, Jiang YM, Tsurumi T, Nishiyama Y. The product of the US10 gene of herpes simplex virus type 1 is a capsid/tegument-associated phosphoprotein which copurifies with the nuclear matrix.. J Gen Virol 1997 Nov;78 ( Pt 11):2923-31.
          pubmed: 9367380doi: 10.1099/0022-1317-78-11-2923google scholar: lookup
        55. Yokoyama H, Sasaki K, Franks ME, Goins WF, Goss JR, de Groat WC, Glorioso JC, Chancellor MB, Yoshimura N. Gene therapy for bladder overactivity and nociception with herpes simplex virus vectors expressing preproenkephalin.. Hum Gene Ther 2009 Jan;20(1):63-71.
          pmc: PMC2855255pubmed: 20377371doi: 10.1089/hum.2008.094google scholar: lookup
        56. Zhao Y, Holden VR, Smith RH, O'Callaghan DJ. Regulatory function of the equine herpesvirus 1 ICP27 gene product.. J Virol 1995 May;69(5):2786-93.

        Citations

        This article has been cited 1 times.
        1. Ahn BC, Kim S, Zhang Y, Charvat RA, O'Callaghan DJ. The early UL3 gene of equine herpesvirus-1 encodes a tegument protein not essential for replication or virulence in the mouse.. Virology 2011 Nov 10;420(1):20-31.
          doi: 10.1016/j.virol.2011.08.016pubmed: 21917286google scholar: lookup