• Korean Journal of Microbiology
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• v.38 no.3
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• pp.221-229
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• 2002

Japanese encephalitis virus (JEV) persistence was established and maintained in Vero cell culture for over 1 year. Eleven clones of plaque morphology mutant JEV, with large and small plaque sizes, were obtained from the cell culture supernatant. Genomic RNA replication efficiency of the mutants in naive Vero cell appeared to correspond to their different plaque sizes. No significant changes in envelop protein ORF or in non-coding regions at both ends of the RNA genome suggested that there could be an unidentified factor(s) playing role in JEV attenuation. Unlike to the replication of wild-type JEV, the mutants did not induce severe degree of cytopathic effect in Vero cells upon infection. While obvious decrease of Bcl-2 and its mRNA expression and sharp increase of p53 in naive Vero cells infected with either wild-type JEV or the large plaque-forming mutant, those changes were not observed with the small plaque-forming one. Together with these observation, internucleosomal DNA fragmentation and chromosomal DNA profile in the Vero cells infected with the mutants suggest that an overall changes in cytopathic effect in the plaque morphology mutants-infected cells should be primarily due to the reduced genomic RNA replication and the compromised degree of p53-independent apoptosis by the virus infection at least in part.

• The Journal of Korean Society of Virology
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• v.26 no.1
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• pp.131-137
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• 1996

The sequences of p10 gene its promoter of Hyphantria cunea NPV were determined. According to the sequence analysis, the putative p10 gene ORF has 285 bp. The 5'-non-coding leader sequence of the p10 gene promoter contained the TATA box and the putative transcription initiation site TAAG motif. Poly (A) tail signals, AATAAA sequence was at site 65 base upstream from the 3' terminus. The deduced amino acid sequence of p10 protein was 95 with a predicted molecular weight of 10.26 kDa. In the p10 protein sequence, a hydrophobic region was present at the N-terminus of the protein, whereas the C-terminus was highly hydrophilic. The p10 protein of H. cunea NPV did not contain cysteine, histidine, trytophan, tryptophane, tyrosine, glutamine and asparagine residues.

• Journal of Life Science
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• v.30 no.3
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• pp.285-290
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• 2020

Foot-and-mouth disease virus (FMDV), a member of the genus Aphthovirus in the Picornaviridae family, affects wild and domesticated ruminants and pigs. FMDV causes various clinical symptoms, including severe inflammation in infected tissue. Genome RNA of FMDV shows a positive single-strand chain approximately 8.3 kb long and encodes a single long open reading frame (ORF). The ORF is translated into structural and non-structural proteins by viral proteases. The FMDV 2C protein is one of the non-structural proteins encoded by FMDV and plays a critical role in FMD pathogenesis, including inflammation, apoptosis, and viral replication. In this study, we examined whether FMDV 2C induces intracellular expression of pro-inflammatory cytokine tumor necrosis factor alpha (TNFα). FMDV 2C expression in pig IBRS-2 cells increased mRNA and protein expression of TNFα at the transcriptional level via activation of TNFα promoter. Treatment with 4-phenylbutyric acid, an endoplasmic reticulum (ER) stress reducer, decreased TNFα expression induced by FMDV 2C. Activating transcription factor 4 (ATF4), a transcription factor mediating ER stress response, induced transactivation of TNFα promoter and expression of mRNA and protein of TNFα. However, the dominant negative mutant of ATF4 did not induce FMDV 2C-mediated TNFα expression. The results indicate that FMDV 2C protein increases clinical inflammation via ATF4-mediated TNFα expression and is associated with ER stress induction.

• Applied Biological Chemistry
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• v.48 no.4
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• pp.301-310
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• 2005

Foot-and-mouth disease (FMD) is a highly contagious disease of mammals and has a great potential for causing severe economic loss in susceptible cloven-hoofed animals, such as cattle, pigs, sheep, goats and buffalo. FMDV, a member of the Aphthovirus genus in the Picornaviridae family, is a non-enveloped icosahedral virus that contains a positive sense RNA of about 8.2 kb in size. The genome carries one open reading frame consisting of 3 regions: capsid protein coding region P1, replication related protein coding region P2, and RNA-dependent RNA polymerase coding region P3. FMDV infects pharynx epithelial cell in the respiratory tract and viral replication is active in lung epithelial cell. Morbidity is extremely high. A FMD outbreak in Korea in 2002 caused severe economic loss. Although intense research is undergoing to develop appropriate drugs to treat FMDV infection, there is no specific therapeutic for controlling FMDV infection. Moreover, there is an increasing demand for the development of vaccine strategies against FMDV infection in many countries. In this report, more effective prevention strategies against FMDV infection were reviewed.

• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.304-313
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• 1998

Sixteen Korean field transmissible gastroenteritis viruses (TGEVs) were isolated using swine testicular cell (STC) and the genomic diversity of them was analyzed. All TGEV isolates produced a typical cytopathic effect in STC and were confirmed as TGEV by immunofluorescence assay using monoclonal antibody against TGEV and PCR using TGEV specific primers. RNAs from TGEV field isolates and vaccine TGEV were extracted and amplified by RT and PCR. The RT-PCR products were digested with selected restriction enzymes and analyzed RFLP patterns. The N-terminal end region of S gene and ORF 3 and 3-1 genes of TGEV amplified by TGEV specific primer pairs seemed to be conserved. Most specific variations were detected in S gene amplified by TGEV 4/6 primer pairs which includes antigenic sites A and D. When the PCR products were treated with Sau3AI and Ssp I, Bvac(vaccine strain), field isolates 133 and 347 were differentiated from Miller and Purdue types. In the case of D5 field isolates, it was classified into Purdue type by Sau 3AI but classified into independent TGEV by Ssp I. Two different TGEV strains from D2 sample were confirmed by plaque purification and RT-PCR-RFLP analysis. To investigate the change occurring in TGEV genome after serial passage, the TGEV P44 strain was passaged through STC. There were specific changes in S gene and a large deletion was observed in ORF 3 and 3-1 genes. These studies showed that a distinct difference in genome exists among TGEV field isolates.

• Korean Journal of Veterinary Research
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• v.43 no.1
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• pp.129-137
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• 2003

Porcine reproductive and respiratory syndrome (PRRS) is characterized by reproductive failures in sows and respiratory problems in piglets. The nucleocapsid(N) protein, encoded by the open reading frame 7 (ORF7) gene, is known to be the most abundant and antigenic protein in PRRS virus. Therefore, it was suggested that the N protein could be a suitable candidate for the detection of PRRS virus-specific antibodies and diagnosis of PRRS. In the present study, the ORF7 gene encoding the N protein was cloned and expressed as a fusion protein with the glutathione S-transferase (GST) in Escherichia coli. The resulting GST-N recombinant protein was used as an antigen for an indirect sandwich enzyme-linked immunosorbent assay (i-ELISA). Expressed GST-N recombinant protein was migrated at 41 kDa and reacted with ORF7-specific monoclonal antibody by Western blotting. In order to increase the specificity of the ELISA for the detection of PRRS virus-specific antibodes, an i-ELISA was developed using an anti-GST antibody as a capture antibody. The sensitivity and specificity of developed i-ELISA were 92% and 96%, respectively. Based on these results, it was suggested that the i-ELISA is a simple and rapid test for screening a large number of swine sera for the anti-PRRS virus antibodies.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.588-591
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• 2018

Baculovirus was originally isolated from the alfalfa looper and contains a 134-kbp genome with 154 open reading frames (ORF). The major capsid protein VP39 together with some minor proteins forms the nucleocapsid ($21nm{\times}260nm$) that encloses the DNA with p6.9 protein. They are double-stranded, circular, supercoiled DNA molecules in a rod-shaped capsid. Wild-type baculoviruses exhibit both lytic and occluded life cycles that develop independently throughout the three phases of virus replication. Recombinant baculoviruses can transfer their vectors and express their recombinant proteins in a wide range of mammalian cell types. Especially, inclusion of a dominant selectable marker in these baculoviral vectors can express diverse recombinant genes in many cells. Baculoviral vectors were reconstructed with cytomegalovirus (CMV) promoter,uroplakin II promoter, polyhedron promoter, vesicular stomatitis virus G (VSVG), enhanced green fluorescent protein (EGFP), protein transduction domain (PTD) gene and so on. These reconstructed vectors were infected into various cell and cell lines. We performed transfection and expression of these recombinant vectors comparison with other control vectors. From this study, we knew that transfection and expression of these recombinant vectors have higher efficacy than any control vector. This work was supported by a grant from Mid-Career Researcher Program(NRF-2016R1A2B4016552) through the National Research Foundation of Korea(NRF) funded by the Ministry of Science, ICT & Future Planning(MSIP).

• Korean Journal of Veterinary Research
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• v.43 no.3
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• pp.439-448
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• 2003

The VP2 gene of infectious bursal disease virus (IBDV) Chinju which was previously detected in Chinju, Korea was cloned and sequenced to establish the information for the development of genetically engineered vaccines and diagnostic reagents against IBDV. The nucleotide sequence of the entire Chinju VP2 gene consisted of 1,356 bases long encoding 452 amino acids in a single open reading frame (ORF). It consisted of 368 adenine (27.1%), 363 cytosine (26.8%), 339 guanine (25.0%) and 286 thymine (21.1%) residues. The predicted $M_r$ of the Chinju VP2 protein was 48 kDa, and the protein contained 13 phosphorylation sites by protein kinase C, casein kinase II or tyrosine kinase, whereas 3 asparagine-linked glycosylation sites were recognized. The nucleotide sequence of Chinju VP2 ORF had a very close phylogenetic relationship with 98-99% homology to that of the very virulent IBDVs (vvIBDVs) HK46, OKYM, D6948, UK661, UPM97/61 and BD3/99. Also, the Chinju VP2 protein revealed a very close phylogenetic relationship with 99-100% homology to that of these vvIBDVs. The Chinju VP2 protein had 100% amino acid identity in the variable region of residues 206-360 with that of the D6948, HK46, OKYM and UK661, as well as 100% identity in two hypervariable regions of residues 212-224 and 314-324 with those of the D6948, HK46, OKYM, UK661, UPM97/61 and BD3/99. The amino acid sequence of the chinju VP2 protein contained a serine-rich heptapeptide of SWSASGS as in these vvIBDVs.

• Journal of Environmental Health Sciences
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• v.38 no.1
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• pp.57-65
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• 2012

Objectives: For our survey of the incidence of norovirus infections and the genogroup distribution of norovirus in Seoul, Republic of Korea, we evaluated through regular surveillance the prevalence of norovirus infections in patients with acute gastroenteritis occurring in Seoul from January 2007 to July 2011. Methods: For norovirus detection, we conducted epidemiological analyses on the basis of the junction of ORF1 and ORF2 (approximately 314 bp). 11,202 fecal specimens were collected from patients in Seoul with acute gastroenteritis between January 2007 and July 2011 and then tested for the presence of NoV via reverse transcription (RT) - polymerase chain reaction (PCR). Results: 16.6% (1,861/11,202) of the fecal specimens were determined to be positive for noroviruses. The incidences of norovirus infection in Seoul in the case of acute gastroenteritis with regular surveillance were 28.0% in 2007, 14.6% in 2008, 9.1% in 2009, 14.1% in 2010, and 12.9% in 2011, which shows that noroviruses constituted a major causative agent of acute gastroenteritis. Also, the incidence of noroviral infection in patients with acute gastroenteritis increased after the large-scale new influenza in 2009. Conclusions: The genetic characteristics of norovirus and the epidemiologic patterns of a viral pathogen in acute gastroenteritis patients may provide potentially effective data for epidemiological studies in Seoul, Korea.

• Journal of Life Science
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• v.21 no.6
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• pp.845-850
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• 2011

Norovirus (NoV) causes major acute non-bacterial gastroenteritis in humans. NoV genus is a member of the family Caliciviridae, which is transmitted by contaminated food and water or from human to human. Many genotypes of genogroups I and II have been reported because of their high genetic diversity. To obtain molecular epidemiological information on gastroenteritis sporadic cases in Busan, Korea, we analyzed the nucleotide sequences of NoV strains detected during 2008~2010. We performed one step RT-PCR amplifying the open reading frame (ORF) 2 (capsid region) followed by semi-nested PCR. Fecal samples were collected from 4,071 acute gastroenteritis, and genotypes of the 421 positive samples were determined by sequence analysis. Based on partial sequence of capsid region, 7 NoV were categorized into genogroup I and 13 into genogroup II. Prevalent genotypes among gastroenteritis patients within Busan were GII.4, GI.6, GII.5 in 2008~2010. The results of this study will contribute to the currently available epidemiological data and improve public health and hygiene via development of diagnostic methods and sustainable surveillance.