Deletion of the ORF2 gene of the neuropathogenic equine herpesvirus type 1 strain Ab4 reduces virulence while maintaining strong immunogenicity.
Abstract: Equine herpesvirus type 1 (EHV-1) induces respiratory infection, abortion, and neurologic disease with significant impact. Virulence factors contributing to infection and immune evasion are of particular interest. A potential virulence factor of the neuropathogenic EHV-1 strain Ab4 is ORF2. This study on 24 Icelandic horses, 2 to 4 years of age, describes the infection with EHV-1 Ab4, or its deletion mutant devoid of ORF2 (Ab4ΔORF2) compared to non-infected controls (each group n = 8). The horses' clinical presentation, virus shedding, viremia, antibody and cellular immune responses were monitored over 260 days after experimental infection. Results: Infection with Ab4ΔORF2 reduced fever and minimized nasal virus shedding after infection compared to the parent virus strain Ab4, while Ab4ΔORF2 established viremia similar to Ab4. Concurrently with virus shedding, intranasal cytokine and interferon α (IFN-α) production increased in the Ab4 group, while horses infected with Ab4ΔORF2 expressed less IFN-α. The antibody response to EHV-1 was evaluated by a bead-based multiplex assay and was similar in both infected groups, Ab4 and Ab4ΔORF2. EHV-1 specific immunoglobulin (Ig) G1 was induced 8 days after infection (d8 pi) with a peak on d10-12 pi. EHV-1 specific IgG4/7 increased starting on d10 pi, and remained elevated in serum until the end of the study. The intranasal antibody response to EHV-1 was dominated by the same IgG isotypes and remained elevated in both infected groups until d130 pi. In contrast to the distinct antibody response, no induction of EHV-1 specific T-cells was detectable by flow cytometry after ex vivo re-stimulation of peripheral blood mononuclear cells (PBMC) with EHV-1 in any group. The cellular immune response was characterized by increased secretion of IFN-γ and interleukin10 in response to ex vivo re-stimulation of PBMC with EHV-1. This response was present during the time of viremia (d5-10 pi) and was similar in both infected groups, Ab4 and Ab4ΔORF2. Conclusions: ORF2 is a virulence factor of EHV-1 Ab4 with impact on pyrexia and virus shedding from the nasal mucosa. In contrast, ORF2 does not influence viremia. The immunogenicity of the Ab4ΔORF2 and parent Ab4 viruses are identical. Graphical abstract - Deletion of ORF2 reduces virulence of EHV-1 Ab4. Graphical summary of the main findings of this study: ORF2 is a virulence factor of EHV-1 Ab4 with impact on pyrexia and virus shedding from the nasal mucosa.
Publication Date: 2018-08-22 PubMed ID: 30134896PubMed Central: PMC6106926DOI: 10.1186/s12917-018-1563-4Google Scholar: Lookup
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Summary
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The study investigates the impact of the ORF2 gene in EHV-1, a horse herpesvirus, showing that removing this gene in the neuropathogenic strain, Ab4, decreases the virus’s virulence but doesn’t affect its ability to provoke an immune response.
About EHV-1 and the ORF2 Gene
- Equine herpesvirus type 1 (EHV-1) is responsible for causing respiratory infections, abortions, and neurological conditions in horses. It is crucial to study the factors that lead to the infection and evasion of the immune system to better understand this virus. The study puts a particular focus on ORF2, a gene which is considered a potential virulence factor of the neuropathogenic EHV-1 strain called Ab4.
- Virulence factors are molecules produced by a virus that enable it to achieve its harmful effects on a host. They can increase the microbe’s ability to establish itself in the host’s body, evade the body’s defence mechanisms, and/or damage the host. In this case, the ORF2 gene is suspected to enhance the virulence of the EHV-1 strain Ab4.
Research Design and Methodology
- The researchers conducted a study involving 24 Icelandic horses aged between 2 and 4 years. They divided these horses into three groups: the control group which was not infected, one group infected with the full EHV-1 Ab4 virus, and another group infected with a version of the EHV-1 Ab4 virus that had the ORF2 gene removed (named Ab4ΔORF2).
- They monitored the clinical presentation of the horses, the virus shedding (virus replication and release), viremia (presence of the virus in the bloodstream), and the immune responses of the horses for a period of 260 days after infection.
Research Findings
- The infection with Ab4ΔORF2 caused less fever and led to less nasal virus shedding compared to the parent strain Ab4. However, both strains resulted in similar levels of viremia.
- The horses infected with Ab4 showed an increase in cytokine and interferon α (IFN-α) production with virus shedding. However, the Ab4ΔORF2 infected horses expressed less IFN-α.
- Despite these differences, the antibody response to the virus was similar in both infected groups (Ab4 and Ab4ΔORF2), as assessed by a bead-based multiplex assay. There was no induction of EHV-1 specific T-cells. However, secretion of IFN-γ and interleukin10 increased in response to ex vivo re-stimulation of peripheral blood mononuclear cells (PBMC) with the virus.
- The research concludes that the ORF2 gene affects the virulence of the virus and influences the occurrence of fever and nasal virus shedding. However, it does not have an impact on viremia. Overall, the immunogenicity of the altered Ab4ΔORF2 virus and the parent Ab4 viruses remained identical.
Implications and Relevance
- The study provides valuable knowledge about the role the ORF2 gene plays in the virulence of the EHV-1 virus strain Ab4. This understanding could have implications for developing treatments or vaccines for EHV-1 infections.
- Understanding that the ORF2 gene does not influence the virus’s immunogenicity could open up new ways of creating a weakened version of the virus (like Ab4ΔORF2) for use in a potential vaccine, given that it causes less severe symptoms but still triggers an immune response similar to the full-virulence virus.
Cite This Article
APA
Schnabel CL, Wimer CL, Perkins G, Babasyan S, Freer H, Watts C, Rollins A, Osterrieder N, Wagner B.
(2018).
Deletion of the ORF2 gene of the neuropathogenic equine herpesvirus type 1 strain Ab4 reduces virulence while maintaining strong immunogenicity.
BMC Vet Res, 14(1), 245.
https://doi.org/10.1186/s12917-018-1563-4 Publication
Researcher Affiliations
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.
- Institut für Virologie, Freie Universität Berlin, Philippstrasse 13, 10115, Berlin, Germany.
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA. bw73@cornell.edu.
MeSH Terms
- Animals
- Cytokines / metabolism
- Female
- Herpesviridae Infections / veterinary
- Herpesvirus 1, Equid / genetics
- Herpesvirus 1, Equid / immunology
- Herpesvirus 1, Equid / pathogenicity
- Horse Diseases / immunology
- Horse Diseases / virology
- Horses
- Leukocytes, Mononuclear / virology
- Male
- Nasal Mucosa / virology
- Sequence Deletion
- Viral Proteins / genetics
- Viremia / veterinary
- Virulence / genetics
- Virulence Factors / genetics
- Virus Shedding / genetics
Grant Funding
- 2015-67015-23091 / National Institute of Food and Agriculture
- 2005-01812 / National Institute of Food and Agriculture
- 2015-67015-23072 / National Institute of Food and Agriculture
Conflict of Interest Statement
ETHICS APPROVAL: The experimental EHV-1 infection and all sample collections for this study were carried out in accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institute of Health. The Institutional Animal Care and Use Committee at Cornell University approved the animal protocol (protocol #2011–0011). Since the study was performed in horses the work also followed the Guide for Care and Use of Animals in Agricultural Research and Teaching. All efforts were made to minimize suffering of the animals, for example by sedation of nervous or excited horses before sampling. At the end of this experimental study, all horses were kept at the facility at Cornell University as research horses. CONSENT FOR PUBLICATION: Not applicable. COMPETING INTERESTS: The authors declare that they have no competing interests with the content of this article. PUBLISHER’S NOTE: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
References
This article includes 76 references
- Borchers K, Thein R, Sterner-Kock A. Pathogenesis of equine herpesvirus-associated neurological disease: a revised explanation.. Equine Vet J 2006;38:283–287.
- Perkins GA, Goodman LB, Tsujimura K, Van de Walle GR, Kim SG, Dubovi EJ. Investigation of the prevalence of neurologic equine herpes virus type 1 (EHV-1) in a 23-year retrospective analysis (1984-2007). Vet Microbiol 2009;139:375–378.
- Pusterla N, David Wilson W, Madigan JE, Ferraro GL. Equine herpesvirus-1 myeloencephalopathy: a review of recent developments.. Vet J 2009;180:279–289.
- Lunn DP, Davis-Poynter N, Flaminio MJBF, Horohov DW, Osterrieder K, Pusterla N. Equine Herpesvirus-1 Consensus Statement.. J Vet Intern Med 2009;23:450–461.
- Patel JR, Edington N, Mumford JA. Variation in cellular tropism between isolates of equine herpesvirus-1 in foals.. Arch Virol 1982;74:41–51.
- Kydd JH, Smith KC, Hannant D, Livesay GJ, Mumford JA. Distribution of equid herpesvirus-1 (EHV-1) in the respiratory tract of ponies: implications for vaccination strategies.. Equine Vet J 1994;26:466–469.
- Kydd JH, Smith KC, Hannant D, Livesay GJ, Mumford JA. Distribution of equid herpesvirus-1 (EHV-1) in respiratory tract associated lymphoid tissue: implications for cellular immunity.. Equine Vet J 1994;26:470–473.
- Vandekerckhove AP, Glorieux S, Gryspeerdt AC, Steukers L, Van Doorsselaere J, Osterrieder N. Equine alphaherpesviruses (EHV-1 and EHV-4) differ in their efficiency to infect mononuclear cells during early steps of infection in nasal mucosal explants.. Vet Microbiol 2011;152:21–28.
- Edington N, Bridges CG, Patel JR. Endothelial cell infection and thrombosis in paralysis caused by equid herpesvirus-1: equine stroke.. Arch Virol 1986;90:111–124.
- Edington N, Smyth B, Griffiths L. The role of endothelial cell infection in the endometrium, placenta and foetus of equid herpesvirus 1 (EHV-1) abortions.. J Comp Pathol 1991;104:379–387.
- Smith KC, Mumford JA, Lakhani K. A comparison of equid herpesvirus-1 (EHV-1) vascular lesions in the early versus late pregnant equine uterus.. J Comp Pathol 1996;114:231–247.
- Slater JD, Borchers K, Thackray AM, Field HJ. The trigeminal ganglion is a location for equine herpesvirus 1 latency and reactivation in the horse.. J Gen Virol 1994;75:2007–2016.
- Allen GP. Risk factors for development of neurologic disease after experimental exposure to equine herpesvirus-1 in horses.. Am J Vet Res 2008;69:1595–1600.
- Allen GP. Antemortem detection of latent infection with neuropathogenic strains of equine herpesvirus-1 in horses.. Am J Vet Res 2006;67:1401–1405.
- Pusterla N, Mapes S, Wilson WD. Prevalence of equine herpesvirus type 1 in trigeminal ganglia and submandibular lymph nodes of equids examined postmortem.. Vet Rec 2010;167:376–379.
- Pusterla N, Mapes S, David WW. Prevalence of latent alpha-herpesviruses in thoroughbred racing horses.. Vet J 2012;193:579–582.
- Edington N, Bridges CG, Huckle A. Experimental reactivation of equid herpesvirus 1 (EHV 1) following the administration of corticosteroids.. Equine Vet J 1985;17:369–372.
- Edington N, Welch HM, Griffiths L. The prevalence of latent equid herpesviruses in the tissues of 40 abattoir horses.. Equine Vet J 1994;26:140–142.
- Taouji S, Collobert C, Gicquel B, Sailleau C, Brisseau N, Moussu C. Detection and isolation of equine herpesviruses 1 and 4 from horses in Normandy: an autopsy study of tissue distribution in relation to vaccination status.. J Vet Med B Infect Dis Vet Public Health 2002;49:394–399.
- USDA APHIS. Equine herpesvirus Myeloencephalopathy: a potentially emerging disease.. Vet. Serv. Info Sheet 2007.
- Patel JR, Heldens J. Equine herpesviruses 1 (EHV-1) and 4 (EHV-4) – epidemiology, disease and immunoprophylaxis: a brief review.. Vet J 2005;170:14–23.
- Goodman L, Wagner B, Flaminio M, Sussman K, Metzger S, Holland R. Comparison of the efficacy of inactivated combination and modified-live virus vaccines against challenge infection with neuropathogenic equine herpesvirus type 1 (EHV-1). Vaccine 2006;24:3636–3645.
- Goehring LS, Wagner B, Bigbie R, Hussey SB, Rao S, Morley PS. Control of EHV-1 viremia and nasal shedding by commercial vaccines.. Vaccine 2010;28:5203–5211.
- Kydd JH, Hannant D, Mumford JA. Residence and recruitment of leucocytes to the equine lung after EHV-1 infection.. Vet Immunol Immunopathol 1996;52:15–26.
- Heldens JG, Hannant D, Cullinane AA, Prendergast MJ, Mumford JA, Nelly M. Clinical and virological evaluation of the efficacy of an inactivated EHV1 and EHV4 whole virus vaccine (Duvaxyn EHV1,4). Vaccination/challenge experiments in foals and pregnant mares.. Vaccine 2001;19:4307–4317.
- Breathnach CC, Yeargan MR, Timoney JF, Allen GP. Detection of equine herpesvirus-specific effector and memory cytotoxic immunity in the equine upper respiratory tract.. Vet Immunol Immunopathol 2006;111:117–125.
- Kydd JH, Townsend HGG, Hannant D. The equine immune response to equine herpesvirus-1: the virus and its vaccines.. Vet Immunol Immunopathol 2006;111:15–30.
- Nugent J, Birch-Machin I, Smith KC, Mumford JA, Swann Z, Newton JR. Analysis of equid herpesvirus 1 strain variation reveals a point mutation of the DNA polymerase strongly associated with Neuropathogenic versus Nonneuropathogenic disease outbreaks.. J Virol 2006;80:4047–4060.
- Goodman LB, Loregian A, Perkins GA, Nugent J, Buckles EL, Mercorelli B. A point mutation in a herpesvirus polymerase determines Neuropathogenicity.. PLoS Pathog 2007;3:e160.
- Van de Walle G, Goupil R, Wishon C, Damiani A, Perkins G, Osterrieder N. A single nucleotide polymorphism in a herpesvirus DNA polymerase is sufficient to cause lethal neurological disease.. J Infect Dis 2009;200:20–25.
- Allen GP, Breathnach CC. Quantification by real-time PCR of the magnitude and duration of leucocyte-associated viraemia in horses infected with neuropathogenic vs. non-neuropathogenic strains of EHV- 1.. Equine Vet J 2006;38:252–257.
- Henninger RW, Reed SM, Saville WJ, Allen GP, Hass GF, Kohn CW. Outbreak of neurologic disease caused by equine herpesvirus-1 at a university equestrian center.. J Vet Intern Med 2007;21:157–165.
- Gryspeerdt A, Vandekerckhove A, Van Doorsselaere J, Van de Walle G, Nauwynck H. Description of an unusually large outbreak of nervous system disorders caused by equine herpesvirus 1 (EHV1) in 2009 in Belgium.. Vlaams Diergeneeskd Tijdschr 2011;80:147–153.
- Barbić L, Lojkić I, Stevanović V, Bedeković T, Starešina V, Lemo N. Two outbreaks of neuropathogenic equine herpesvirus type 1 with breed-dependent clinical signs.. Vet Rec 2012;170:227.
- Ma G, Feineis S, Osterrieder N, Van de Walle GR. Identification and characterization of equine herpesvirus type 1 pUL56 and its role in virus-induced downregulation of major histocompatibility complex class I.. J Virol 2012;86:3554–3563.
- Wagner B, Wimer C, Freer H, Osterrieder N, Erb HN. Infection of peripheral blood mononuclear cells with neuropathogenic equine herpesvirus type-1 strain Ab4 reveals intact interferon-α induction and induces suppression of anti-inflammatory interleukin-10 responses in comparison to other viral strains.. Vet Immunol Immunopathol 2011;143:116–124.
- Wimer CL, Damiani A, Osterrieder N, Wagner B. Equine herpesvirus type-1 modulates CCL2, CCL3, CCL5, CXCL9, and CXCL10 chemokine expression.. Vet Immunol Immunopathol 2011;140:266–274.
- Hübert PH, Birkenmaier S, Rziha HJ, Osterrieder N. Alterations in the equine herpesvirus type-1 (EHV-1) strain RacH during attenuation.. Zentralblatt vet. Reihe B J Vet Med Ser B 1996;43:1–14.
- Yalamanchili RR, Raengsakulrach B, O’Callaghan DJ. Equine herpesvirus 1 sequence near the left terminus codes for two open reading frames.. Virus Res 1991;18:109–116.
- Telford EA, Watson MS, McBride K, Davison AJ. The DNA sequence of equine herpesvirus-1.. Virology 1992;189:304–316.
- Soboll Hussey G, Ashton LV, Quintana AM, Van de Walle GR, Osterrieder N, Lunn DP. Equine herpesvirus type 1 pUL56 modulates innate responses of airway epithelial cells.. Virology 2014;464–465:76–86.
- Soboll Hussey G, Hussey SB, Wagner B, Horohov DW, Van de Walle GR, Osterrieder N. Evaluation of immune responses following infection of ponies with an EHV-1 ORF1/2 deletion mutant.. Vet Res 2011;42:23.
- Wagner B, Goodman LB, Babasyan S, Freer H, Torsteinsdóttir S, Svansson V. Antibody and cellular immune responses of naïve mares to repeated vaccination with an inactivated equine herpesvirus vaccine.. Vaccine 2015;33:5588–5597.
- Wagner B, Perkins G, Babasyan S, Freer H, Keggan A, Goodman LB. Neonatal Immunization with a Single IL-4/Antigen Dose Induces Increased Antibody Responses after Challenge Infection with Equine Herpesvirus Type 1 (EHV-1) at Weanling Age.. PLOS ONE 2017;12:e0169072.
- Crowhurst FA, Dickinson G, Burrows R. An outbreak of paresis in mares and geldings associated with equid herpesvirus 1.. Vet Rec 1981;109:527–528.
- Furr M, Reed S. Equine Neurology: Wiley; 2008.. .
- Elia G, Decaro N, Martella V, Campolo M, Desario C, Lorusso E. Detection of equine herpesvirus type 1 by real time PCR.. J Virol Methods 2006;133:70–75.
- Wagner B, Hillegas JM, Babasyan S. Monoclonal antibodies to equine CD23 identify the low-affinity receptor for IgE on subpopulations of IgM+ and IgG1+ B-cells in horses.. Vet Immunol Immunopathol 2012;146:125–134.
- Lunn DP, Holmes MA, Antczak DF, Agerwal N, Baker J, Bendali-Ahcene S. Report of the second equine leucocyte antigen workshop, squaw valley, California, July 1995.. Vet Immunol Immunopathol 1998;62:101–143.
- Keggan A, Freer H, Rollins A, Wagner B. Production of seven monoclonal equine immunoglobulins isotyped by multiplex analysis.. Vet Immunol Immunopathol 2013;153:187–193.
- Lunn DP, Holmes MA, Schram B, Duffus WP. Monoclonal antibodies specific for equine IgG sub-isotypes including an antibody which recognizes B lymphocytes.. Vet Immunol Immunopathol 1995;47:239–251.
- Goodman LB, Wimer C, Dubovi EJ, Gold C, Wagner B. Immunological correlates of vaccination and infection for equine herpesvirus 1.. Clin Vaccine Immunol 2012;19:235–241.
- Wagner B, Freer H. Development of a bead-based multiplex assay for simultaneous quantification of cytokines in horses.. Vet Immunol Immunopathol 2009;127:242–248.
- Wagner B, Ainsworth DM, Freer H. Analysis of soluble CD14 and its use as a biomarker in neonatal foals with septicemia and horses with recurrent airway obstruction.. Vet Immunol Immunopathol 2013;155:124–128.
- Brosnahan MM, Damiani A, van de Walle G, Erb H, Perkins GA, Osterrieder N. The effect of siRNA treatment on experimental equine herpesvirus type 1 (EHV-1) infection in horses.. Virus Res 2010;147:176–181.
- Edington N, Bridges CG, Griffiths L. Equine interferons following exposure to equid herpesvirus-1 or −4.. J Interf Res 1989;9:389–392.
- Wagner B, Hillegas JM, Flaminio MJ, Wattrang E. Monoclonal antibodies to equine interferon-alpha (IFN-alpha): new tools to neutralize IFN-activity and to detect secreted IFN-alpha.. Vet Immunol Immunopathol 2008;125(3–4):315–325.
- Randall RE, Goodbourn S. Interferons and viruses: an interplay between induction, signalling, antiviral responses and virus countermeasures.. J Gen Virol 2008;89:1–47.
- Bazil V, Horejsí V, Baudys M, Kristofová H, Strominger JL, Kostka W. Biochemical characterization of a soluble form of the 53-kDa monocyte surface antigen.. Eur J Immunol 1986;16:1583–1589.
- Landmann R, Fisscher AE, Obrecht JP. Interferon-gamma and interleukin-4 down-regulate soluble CD14 release in human monocytes and macrophages.. J Leukoc Biol 1992;52:323–330.
- Labeta MO, Durieux J-J, Fernandez N, Herrmann R, Ferrara P. Release from a human monocyte-like cell line of two different soluble forms of the lipopolysaccharide receptor, CD14.. Eur J Immunol 1993;23:2144–2151.
- Schütt C, Schilling T, Grunwald U, Schönfeld W, Krüger C. Endotoxin-neutralizing capacity of soluble CD14.. Res Immunol 1992;143:71–78.
- Haziot A, Rong GW, Lin XY, Silver J, Goyert SM. Recombinant soluble CD14 prevents mortality in mice treated with endotoxin (lipopolysaccharide). J Immunol 1995;154:6529.
- Wilsterman S, Soboll-Hussey G, Lunn DP, Ashton LV, Callan RJ, Hussey SB. Equine herpesvirus-1 infected peripheral blood mononuclear cell subpopulations during viremia.. Vet Microbiol 2011;149:40–47.
- Baghi HB, Nauwynck HJ. Impact of equine herpesvirus type 1 (EHV-1) infection on the migration of monocytic cells through equine nasal mucosa.. Comp Immunol Microbiol Infect Dis 2014;37:321–329.
- Osterrieder N, Van de Walle GR. Pathogenic potential of equine alphaherpesviruses: the importance of the mononuclear cell compartment in disease outcome.. Vet Microbiol 2010;143:21–28.
- Breathnach CC, Yeargan MR, Sheoran AS, Allen GP. The mucosal humoral immune response of the horse to infective challenge and vaccination with equine herpesvirus-1 antigens.. Equine Vet J 2001;33:651–657.
- Coombs DK, Patton T, Kohler AK, Soboll G, Breathnach C, Townsend HGG. Cytokine responses to EHV-1 infection in immune and non-immune ponies.. Vet Immunol Immunopathol 2006;111:109–116.
- Paillot R, Daly JM, Juillard V, Minke JM, Hannant D, Kydd JH. Equine interferon gamma synthesis in lymphocytes after in vivo infection and in vitro stimulation with EHV-1.. Vaccine 2005;23:4541–4551.
- Packiarajah P, Walker C, Gilkerson JR, Whalley JM, Love DN. Immune responses and protective efficacy of recombinant baculovirus expressed glycoproteins of equine herpesvirus 1 (EHV-1) gB gC and gD alone or in combinations in BALB/c mice.. Vet Microbiol 1998;61:261–278.
- Tewari D, Nair SV, De Ungria MC, Lawrence CL, Hayden M, Love DN, Field HJ, Whalley JM. Immunization with glycoprotein C of equine herpesvirus-1 is associated with accelerated virus clearance in a murine model.. Arch Virol 1995;140:789–797.
- Lewis MJ, Wagner B, Woof JM. The different effector function capabilities of the seven equine IgG subclasses have implications for vaccine strategies.. Mol Immunol 2008;45(3):818–827.
- Breathnach CC, Soboll G, Suresh M, Lunn DP. Equine herpesvirus-1 infection induces IFN-γ production by equine T lymphocyte subsets.. Vet Immunol Immunopathol 2005;103:207–215.
- Allen G, Yeargan M, Costa LR, Cross R. Major histocompatibility complex class I-restricted cytotoxic T-lymphocyte responses in horses infected with equine herpesvirus 1.. J Virol 1995;69:606–612.
- Kydd J, Wattrang E, Hannant D. Pre-infection frequencies of equine herpesvirus-1 specific, cytotoxic T lymphocytes correlate with protection against abortion following experimental infection of pregnant mares.. Vet Immunol Immunopathol 2003;96:207–217.
- O’Neill T, Kydd JH, Allen GP, Wattrang E, Mumford JA, Hannant D. Determination of equid herpesvirus 1-specific, CD8+, cytotoxic T lymphocyte precursor frequencies in ponies.. Vet Immunol Immunopathol 1999;70:43–54.
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