• Proceedings of the Korean Society of Veterinary Clinics Conference
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• 2009.10a
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• pp.264-264
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• 2009

• Journal of Microbiology
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• v.40 no.1
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• pp.11-19
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• 2002

Mice immunized with equine herpesvirus type-1(EHV-1) L-particles skewed a significant increase (p<7.75) in serum antibody titers. Upon a booster dose four weeks lateral antibody titers increased significantly. Interestingly, immunization via intravenous or intramuscular route induced significantly higher (p<0.75) antibody titers. However, mice iummunized with UV-treated L-particles, visions or immunization via intranasal route induced lower antibody titers. Upon challenge inoculation with wildtype EHV-1, our data showed there was a poor correlation between antibody titers and protection against virus replication. Therefore, the role of cell-mediated immunity Inwards protection was investigated. As predicted, the strongest cell-mediated immunity, as measured by delayed-hypersensitivity test, was detected in mice immunized with live virus particles. The magnitude of cell-mediated immune response correlated with the efficacy of L-particles as immunizing agent. The highest efficacy, as indicated in mice immunized via intranasal routed was highly correlated with cell-mediated immunity. A similar phenomenon was also demonstrated in mice immunized intranasally with UV-treated L-particles. However, the degree of protection was reduced when mice immunized intravenously or intramuscularly with UV-treated L-particles. In conclusion, protection conferred in these animals was highly implicated by immune cells and the least by antibodies. The route of immunization and the nature of the antigen also contributed to the efficacy of L-particles as immunizing agent. In contrast to that of herpes simplex virus type 1, our data showed EHV-1 non-infectious L-particles are highly suitable for immunization of the host against EHV-1 disease.

• Korean Journal of Veterinary Service
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• v.27 no.4
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• pp.355-369
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• 2004

The equine herpesvirus type 1 (EHV-1) immediate-early (IE) protein is a potent transactivator responsible for the activation of both early and late genes during the course of infection and is comprised of discrete functional domains that mediate its many functions. Interaction between trans activators such as the IE protein and various components of the RNA polymerase II transcription initiation machinery has been demonstrated to be critical for transactivation. In the present report, it is addressed the hypothesis that the IE protein interacts with various components of transcription machinery to mediate transactivation of target viral genes. In these studies, it is demonstrated that in vitro transcribed and translated IE protein interacts with TFIIB-agarose conjugate but not with TFIID-agarose conjugate. Additional immunoprecipitation studies using nuclear extracts derived from EHV-1 infected RK-13 cells confirmed that the IE protein interacts strongly with TFIIB, but fails to interact with TFIID. IR2, a truncated form of the IE protein lacking the potent transactivation domain and involved in the down-regulation of the IE gene, also interacted with TFIIB but not with TFIID. Studies were also performed to ascertain if particular TBP-associated factors (TAFs) could mediate IE or IR2 binding to TFIID. In vitro transcribed and translated TAF250 added to nuclear extracts generated from EHV-1 infected cells also failed to mediate an interaction between the IE protein or the IR2 protein and TFIID. This study demonstrated that the IE protein mediates transactivation of target viral genes by a mechanism that involves TFIIB. This is in contrast to mechanisms that have been proposed for both the herpes simplex virus ICP4 and VP16 protein which have been proposed to transactivate viral genes through interactions involving both TFIIB and TFIID. This study also intimates that IR2 mediate its repressive effects during the course of EHV-1 infection by a mechanism that involves sequestration of various transcription factors.

• Journal of Veterinary Clinics
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• v.28 no.4
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• pp.369-374
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• 2011

Coital exanthema of Thoroughbred horses had occurred firstly in Republic of Korea. This study was performed to evaluate clinical features of coital exanthema, and provide veterinary knowledge to equine practitioner as well as horse farms. The method was clinical, clinical pathology and sexual hormone, electron microscope and libido examination. Five stallions of 27, 45 broodmares of 416 showed clinical symptoms but 124 foals and a teaser did not show any abnormal appearance. Five stallion had papule, pustule, crust around a glans, body of penis, prepuce and remain decolorized spot after treatment. One laceration of glans and 3 gait disorder had been observed but it did not affect libido. Forty-five broodmares localized had papule, pustule, crust, and ulceration around perineal region, vulva, mucocutaneous junction remain decolorized spot after treatment.

• Journal of Practical Agriculture & Fisheries Research
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• v.16 no.1
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• pp.105-113
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• 2014

Equine herpesvirus type 1 (EHV-1) is an economically important pathogen of horses and exerts its major impact by inducing abortion storms and sporadic abortions in pregnant mares, early neonatal death in foals, and respiratory disease in young horses. Although equine herpesvirus type 4 (EHV-4) rarely causes clinical manifestations of disease in organs other than the respiratory track, isolated cases of myeloencephalopathy and sporadic abortions have been reported in EHV-4 infections. Here, we report an abortion storm in Thoroughbred breeding farms in Jeju island, South Korea. It occurred for 16 days from first abortion to last one. There were no clinical signs prior to abortion and stillbirth in broodmares. Two PCR-primers were made on glycoprotein B gene of EHV-1 and EHV-4 to amplify specific common regions of the viruses. We could detect the virus specific genes in aborted samples by PCR, and concluded that the cause of abortion storm was EHV infection. This report describes the first abortion storm case caused by EHV in Thoroughbred breeding farms in South Korea.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2005.11a
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• pp.49-51
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• 2005

• Journal of Microbiology
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• v.40 no.3
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• pp.183-192
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• 2002

Cells infected With equine herpesvirus type-1 (EHV-1) Produced both infectious and non-infectious Virus-related particles. Compared to the whole virion, non-infectious particles termed L-particles were deter-mined to lack 150 kDa protein, commonly known as nucleocapsid protein. The potential of L-particles to induce immune responses was studied in mice and foals. Intranasal immunization with L-particles or whole virions induced poor IgG antibody responses in mice. Interestingly, despite the poor antibody response, the conferred immunity protected the host from challenge infections. This was indicated by a significant reduction in virus titers in line with recovery towards normal body weight. Subsequently, the test on the usefulness of L-particles as immunizing agents was extended to foals. Immunization of specific-pathogen-free (SPF) foals resulted in similar results. As determined by a complement-fixing-antibody test (CFT), foals seroconverted when they were immunized either with inactivated L-particles or whole virions via intramuscular (i.m.) injections. The presence of the antibody correlated with the degree of protection. Beyond day 1 post challenge infection (p.i.), there was no virus shedding in the nasal mucus of foals immunized with whole EHV-1 virions. Virus shedding was observed in foals Immunized with L-particles but limited to days 6 to 8 p.i. only. In contrast, extended vim shedding was observed in non-immunized foals and it was well beyond day 14 p.i. Viremia was not detected for more than four days except in non-immunized foals. Immunization in mice via intranasal (i.n.) conferred good protection. However, compared to the i.n. route, a greater degree of protection was obtained in foals following immunization via i.m. route. Despite variation in the degree of protection due to different routes of immunization in the two animal species, our results have established significant evidence that immunization with L-particles confers protection in the natural host. It is suggested that non-infectious L-particles should be used as immunizing agents for vaccination of horses against EHV-1 infection.

• Korean Journal of Veterinary Service
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• v.34 no.2
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• pp.187-190
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• 2011

The Thoroughbred horse was an approximately 4-years-old castrated male with highly emaciation, nasal epistaxis and subsequently died. Gross necropsy revealed epistaxis and hyperemia on the lung, multiple hemorrhage in muscle, and liver was focally attached to the peritoneum with fibrin. According to polymerase chain reaction (PCR), Equine herpes virus type 1 and 4 (EHV type 1, 4) was detected in the lung and trachea. In bacterial culture from kidney, liver, spleen, muscle and blood, Streptococcus equi subsp. zooepidemicus was isolated. Based on the gross lesion and PCR, this horse was diagnosed as EHV type 1, 4 and S. zooepidemicus coinfection.

• Korean Journal of Veterinary Research
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• v.35 no.4
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• pp.743-752
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• 1995

The study was carried out to characterize the properties of Korean isolates of EHV from aborted fetuses and determine envelope protein profiles. The results obtained were summarized as follows; 1. Two strains of EHV was isolated from 2 liver samples among 10 aborted fetuses from which the virus isolation was attempted. 2. Morphological and some enzymatic properties of the Korean isolates of EHV which was designated as $LC_1$ and $LC_2$ was identical to those of a reference strain of Australia-N of EHV-1. The Korean isolates of EHV could be propagated on ED cell culture and they formed typical plaques 1 to 2 days after infection in the ED cells from which typical cuboidal particles of 150~170 nm diameter herpesvirus were observed. The virus could be detected specifically from neucleus and cytoplasm of infected cells by flourescent antibody technique using FITC labelled anti-Aust IV(EHV-1) antiserum. The Korean isolates, $LC_1$ and $LC_2$ were specifically neutralized by anti Aust IV antiserum and reacted positively to CELISA. 3. The structural polypeptides of purified enveloped virions of $LC_1$ and $LC_2$ isolates of EHV were determined by SDS-polyacrylamide gel electrophoresis to identify the envelope glycoproteins. $LC_1$ and $LC_2$ strains revealed 14 glycoproteins ranging in molecular weight from 190 kD to 31 kD while 17 structural proteins of Aust IV(EHV-1), of which 14 were identical to those of $LC_1$ and $LC_2$, were identified. Upon immunoblotting by rabbit antiserum against EHV isolates and EHV-1(Aust IV), 4 immunogenic proteins of $LC_1$ and $LC_2$ were 135 kD, 88 kD, 64 kD and 59 kD, of which 135 kD, 88 kD and 64 kD proteins were also found in Aust IV(EHV-1).

• Korean Journal of Veterinary Research
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• v.35 no.4
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• pp.753-758
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• 1995

The study was carried out to investigate the pathogenicity of EHV isolate to hamsters and mice and immunogenicity of experimentally produced. vaccine were evaluated in the horses. Hamsters infected. intranasally with $LC_1$ isolate showed symptoms of nasal discharge, conjunctivitis and body weight loss during the observation period of 12 days after infection, while only slight depression and body weight loss were noticed with mice infected with $LC_1$ indicating that hamsters are more susceptible to the virus. Antibody titer of mice and hamsters were gradually increased to highest level of 1:2560~10240, 1:640~1280, respectively, at 7~12 days post vaccination. Horses immunized against $LC_1$ killed vaccine reached to maximum antibody titer of 1:20480 around 4 weeks after 1st vaccination and declined after 12 weeks post vaccination. No significant antibody increase were detected after 2nd vaccination. Mean body temperature and mean total leukocyte counts remained within normal range and no adverse reaction were noticed after vaccination.