• 한국어병학회지
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• 제37권1호
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• pp.1-8
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• 2024

The advantages of replicon vectors of RNA viruses include a high ability to stimulate innate immunity and exponential amplification of target mRNA leading to high expression of foreign antigens. The present study aimed to construct a DNA-layered nervous necrosis virus (NNV) replicon vector system in which the capsid protein gene was replaced with a foreign antigen gene and to compare the efficiency of foreign antigen expression between the conventional DNA vaccine vector and the present replicon vector. We presented the first report of a nodavirus DNA replicon-based foreign antigen expression system. Instead of a two-vector system, we devised a one-vector system containing both an NNV RNA-dependent RNA polymerase cassette and a foreign antigen-expressing cassette. This single-vector approach circumvents the issue of low foreign protein expression associated with the low co-transfection efficiency of a two-vector system. Cells transfected with a vector harboring hammerhead ribozyme-fused RNA1 and RNA2 (with the capsid gene ORF replaced with VHSV glycoprotein ORF) exhibited significantly higher transcription of the VHSV glycoprotein gene compared to cells transfected with either a vector without hammerhead ribozyme or a conventional DNA vaccine vector expressing the VHSV glycoprotein. Furthermore, the transcription level of the VHSV glycoprotein in cells transfected with a vector harboring hammerhead ribozyme-fused RNA1 and RNA2 showed a significant increase over time. These results suggest that NNV genome-based DNA replicon vectors have the potential to induce stronger and longer expression of target antigens compared to conventional DNA vaccine vectors.

• 대한수의학회지
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• 제43권2호
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• pp.271-281
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• 2003

Virulent and avirulent H5N1 viruses were inoculated intranasally to BALB/c and immunodeficient mice, and compared the pathogenesis by histology and immunohistochemistry. All of mice infected with virulent virus died by systemic infection at 6 to 7 days postinfection (PI). BALB/c mice infected with avirulent virus survived from the infection, whereas immunodeficient mice showed nervous symptoms in addition to respiratory disease and died at 13 days PI. Viral positive antigens was detected from multiple organs including central nervous system in immunodeficient mice infected with avirulent virus. These results suggest that avirulent H5N1 influenza virus can aquire the multiple tissue tropism under immunosuppresed condition and host immune system is a important factor to protect the development of disease.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.315-319
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• 2003

A novel method is developed to yield virus titers in 10 h, is easy to .perform using 96-well plates, and applicable to both any Autographa californica nucleopolyhyderovirus (AcNPV) and Bombyx mori nucleopolyhedrovirus (BmNPV)-based recombinant baculovirus. This assay uses an antibody to a DNA-binding protein to detect the infected cells via immune-staining. The titer is determined by counting foci produced due to infection of virus under a fluorescent microscopy. The required incubation period was shortened considerably because infected cells expressed viral antigens at the post infection time of 4 h. Therefore, 10 hours were enough to estimate the virus titer including virus infection time, insect cell culture, and estimation of virus titer.

• 한국임상수의학회지
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• 제15권1호
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• pp.46-55
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• 1998

This study was performed to verify the effect of modified live virus vaccine against canine parvovirus (CPV) infection. Serum hemagglutination inhibition (Hl) test, histopathological and immunohistochemical techniques and polymerase chain reaction were used. The results were as follows: 1. During the experimental terms after vaccination, serum Hl titer was stable. Geometric mean titer (GMT) after the 1st vaccination was 280. After virulent CPV was challenged, GMT was 1,306. 2. After challenge by virulent CPV, the vaccinated group was not shown clinical signs and gross and histopathological findings. 3. After challenge by virulent CPV, the vaccinated group was not detected viral antigens in the small intestine immunohistochemically. 4. After challenge by violent CPV, the vaccinated group was not shown virus shedding in feces. In conclusions the overall results confirmed that modified live virus vaccine was effective on prevention of canine parvovirus infection.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제7권2호
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• pp.143-152
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• 2004

목적: 급성 설사로 입원한 소아의 대변 검체에서 rotavirus, adenovirus, astrovirus, calicivirus 및 enterovirus의 바이러스 항원을 검출하고 임상 증상과의 연관성을 알기 위해 본 연구를 시도하였다. 방법: 이화여자대학교 의과대학 목동병원 소아과에 1996년 3월부터 1999년 12월 사이에 입원하였던 소아 74명의 대변을 채취하였는데, 53개는 급성 설사 환자에서 채취하여 이를 설사군으로, 21개는 동일시기에 설사가 없는 타질환으로 입원한 소아에서 무작위로 채취하여 이는 대조군으로 분류하였다. 대변 검체는 영하 $20^{\circ}C$에서 냉동 보관 후 단클론 항체를 이용한 간접 효소 면역측정법으로 바이러스 항원 검출을 하였고 각 바이러스 검출과 임상 증상을 비교하였다. 결과: 바이러스 항원은 설사군에서 46례와 대조군에서 14례 검출되었다. 이 중 enterovirus 47례, rotavirus 26례, adenovirus 16례, astrovirus 11례, 그리고 calicivirus가 11례 검출되었다. 시기적으로 바이러스 항원은 봄(3>5월)에 많이 검출되었다(63%). 하나의 바이러스 항원이 검출된 경우는 설사군 22례, 대조군 6례로 모두 28례이었다. 바이러스 항원이 동시 검출된 경우는 30례이며, Salmonella group B와 enterovirus의 동시 감염 2례 있었다. 여러 항원이 검출된 30례를 세분하면, 두 종류의 바이러스가 검출된 경우가 15례, 세 종류의 바이러스가 검출된 경우가 11례, 네 종류의 바이러스가 검출된 경우가 2례, 다섯 종류의 바이러스가 모두 검출된 경우도 2례 있었다. 대변에서 바이러스 항원이 동시 검출된 다중성이나 종류에 따른 임상 증상의 차이는 없었다. 결론: 본 연구에서는 대변 내 바이러스 항원에 대한 단클론 항체를 이용한 간접 효소 면역측정법으로 검사하였으며, 각 바이러스 항원과 임상 증상과의 연관성은 없었다. 앞으로 더 많은 소아를 대상으로 역전사 중합효소 연쇄반응, 바이러스 배양 검사 등으로 다양하게 검사하여 소아 설사의 바이러스성 원인과 역학이 연구되어야 할 것이다.

• 대한바이러스학회지
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• 제28권4호
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• pp.317-325
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• 1998

The primary culture of human nasal epithelial cells was performed using the inferior nasal turbinate tissues, and infected with Hantaan virus to examine the hypothesis of airborne transmission of Hantaan virus in humans. The primary culture cells were identified as epithelial cells by morphologic and immunologic analyses. The viral antigens were detected in the primary human nasal epithelial cells infected with Hantaan virus by immunofluorescence staining. The ICAM-1 induction by Hantaan virus or $IFN-{\gamma}$ was examined in the primary human nasal epithelial cells and human lung fibroblasts (WI-38). Hantaan virus induced the surface ICAM-1 in WI-38 cells in a time-dependent manner, and $IFN-{\gamma}$ induced the surface ICAM-1 in a dose-dependent manner in HNEC and WI-38 cells. These results revealed that the human nasal epithelial cells are susceptible to Hantaan viral infection supporting the hypothesis of airborne transmission of Hantaan virus in humans. The human lung fibroblasts also might have an important role in the pathogenesis of Hantaan virus through the induction of ICAM-1.

• 한국어병학회지
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• 제33권2호
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• pp.103-109
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• 2020

In order to use nervous necrosis virus (NNV) virus-like particles (VLPs) as a delivery tool for heterologous antigens or plasmids, we attempted to produce red-spotted grouper nervous necrosis virus (RGNNV) VLPs displaying a partial region of viral hemorrhagic septicemia virus (VHSV) glycoprotein at the surface and VLPs that are harboring DNA vaccine plasmids within the VLP. A peptide encoding 105 amino acids of VHSV glycoprotein was genetically inserted in the loop region of NNV capsid gene, and VLPs expressing the partial part of VHSV glycoprotein were successfully produced. However, in the transmission electron microscope analysis, the shape and size of the partial VHSV glycoprotein-expressing NNV VLPs were irregular and variable, respectively, indicating that the normal assembly of capsid proteins was inhibited by the relatively long foreign peptide (105 aa) on the loop region. To encapsulate by simultaneous transformation with both NNV capsid gene expressing plasmids and DNA vaccine plasmids (having an eGFP expressing cassette under the CMV promoter), NNV VLPs containing plasmids were produced. The encapsulation of plasmids in the NNV VLPs was demonstrated by PCR and cells exposed to the VLPs encapsulating DNA vaccine plasmids showed fluorescence. These results suggest that the encapsulation of plasmids in NNV VLPs can be done with a simple one-step process, excluding the process of disassembly-reassembly of VLPs, and NNV VLPs can be used as a delivery tool for DNA vaccine vectors.

• 대한수의학회지
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• 제63권2호
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• pp.12.1-12.7
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• 2023

Bovine viral diarrhea virus (BVDV) is an RNA virus belonging to Pestivirus in the family Flaviviridae. BVDV has economic significance for the livestock industry because of its association with acute disease, fetal loss, and birth of persistently infected (PI) animals. This study aimed to investigate the BVDV infection rates in Korean native cattle farms in Jeju for further planning of a BVDV control program in the Jeju Province. BVDV antibodies and antigens were tested in 15,842 sera collected from 302 Korean native cattle herds between January 2014 and June 2017 using enzyme-linked immunosorbent assay (ELISA). Viral antigen was detected by reverse transcription-polymerase chain reaction from 60 sera that were antigen ELISA-positive. BVDV antibodies were found in 90.7% (274/302) herds and 61.1% (9,678/15,842) cows. BVDV antigens were found in 13.2% (40/302) herds and 0.4% (61/15,842) cows. The oldest animal group (> 8 years) exhibited the highest sero-positive rates (91%), while the youngest animal group (< 1 years) had the highest antigen positivity rates (0.52%). Of the 60 antigen-positive sera, BVDV types 1 and 2 were found in 36 and 12 sera, respectively. Additionally, six animals were considered to be PI as BVDV was continually detected in annual examination.

• 한국동물위생학회지
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• 제14권1호
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• pp.27-40
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• 1991

In order to investigate the biological properties, pathogenicity and immune responses in artficially infected SPF chickens with Avian infectious bronchitis virus that was isolated from chickens showing IB like signs in southern region of Chung buk. Results obtained throuth the experiments are summarized as follows. 1. From 15 IB suspected cases, two strains of IB virus were isolated, one each from the tracheas and lungs. 2. Infectious bronchitis specific embryo lesions were observed after four serial passages of the isolates in chicken embryos. 3. The field isolates and M-41 strain of IB virus interfered with the replication of Newcastle disease virus in chicken embryos. 4. When specific pathogen free chickens, two week old, were inoculated with the IB virus isolates, clinical respiratory signs as dyspnea, coughing were observed. Airsacculitis was observed by necropsy. 5. AGP antibody positive rates of inoculated SPF chickens were highest on day 14 and lowest on day 36, while HI antibody responses were detected on day 14 in all Groups, the reinoculated Group was shown highest titers. 6. By Indirect immunofluorescence antibody assay of artificially infected SPF chickens, the viral antigens were detected in tissues of larynx, trachea and lung on the 4 th to 7 th days post inoculation.

• 한국동물위생학회지
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• 제20권4호
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• pp.331-338
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• 1997

The purpose of this study was to establish early diagnosis for bovine virus diarrhea-mucosal disease(BVD-MD) Two Holstein among 22 breeding cows were shown ulcer in the mouth and watery diarrhea. Diarrheal feces and ulcerous lesion of the mouth from 2 cows were sampled for detection of viral antigen. BVD virus was isolated by inoculation of the samples to MDBK cells, and the cytopathic effects were observed in cultured MDBK cells which inoculated with virus isolates from the feces. Viral antigens were detected in the feces and ulceruous lesion by immunogold staining. The serum neutralization titers were shown 1 : 64 or greater in 8 blood samples by using BVD virus (NADL strain). By the RT-PCR, using reverse primer 5'-ACTCCATGTGCCATGTACAG-3', forward primer 5'-ACTCCATGTGCCATGTACAG-3', 285 base pair band specific to BVD virus was detected. In conclusions, the results of above tests which executed using the diarrheal feces and ulcerous lesion of the mouth and the isolates were conformed as BVD virus.