• IMMUNE NETWORK
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• v.13 no.2
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• pp.70-74
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• 2013

L-ascorbic acid (vitamin C) is one of the well-known antiviral agents, especially to influenza virus. Since the in vivo antiviral effect is still controversial, we investigated whether vitamin C could regulate influenza virus infection in vivo by using Gulo (-/-) mice, which cannot synthesize vitamin C like humans. First, we found that vitamin C-insufficient Gulo (-/-) mice expired within 1 week after intranasal inoculation of influenza virus (H3N2/Hongkong). Viral titers in the lung of vitamin C-insufficient Gulo (-/-) mice were definitely increased but production of anti-viral cytokine, interferon (IFN)-${\alpha}/{\beta}$, was decreased. On the contrary, the infiltration of inflammatory cells into the lung and production of pro-inflammatory cytokines, tumor necrosis factor (TNF)-${\alpha}$ and interleukin (IL)-${\alpha}/{\beta}$, were increased in the lung. Taken together, vitamin C shows in vivo antiviral immune responses at the early time of infection, especially against influenza virus, through increased production of IFN-${\alpha}/{\beta}$.

• The Plant Pathology Journal
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• v.24 no.4
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• pp.433-438
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• 2008

Potato virus X (PVX) resistance in potato is one of the best-characterized resistance models, however little is known in pepper. To evaluate the resistance to PVX in Capsicum annuum, a total of eleven pepper accessions were used for resistance screening against two PVX strains, USA and UK3. None of them were resistant against strain UK3, whereas four resistant genotypes were found against strain USA, three of which were further characterized. Two unlinked dominant genes were identified for both genotypes Bukang and Perennial; resistance in the genotype CV3 seemed to be conferred by two complementary dominant genes. These results demonstrated that the resistance to PVX in C. annuum is different from that in potato. This is the first report on genetic analysis of PVX resistance in C. annuum.

• Korean Journal of Veterinary Research
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• v.47 no.4
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• pp.425-428
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• 2007

From January to June 2006, 54 suckling pigs had been submitted in virology lab., College of Veterinary Medicine, Seoul National University. All pigs had suffered from various symptoms such as respiratory sign, enteric signs, neurologic signs, etc. Among 54 pigs, 24 pigs (44.4%) were positive for porcine hemagglutinating encephalomyelitis virus (HEV) through reverse transcription-nested polymerase chain reaction. According to this result, HEV infections seemed to be prevalent and widespread in Korean swine farms, and the infection is associated with respiratory signs and neurologic signs more than enteric signs. The HEV positive pigs showing respiratory signs were co-infected with viruses such as PRRSV, and PCV2, or bacteria such as Pasteurella spp. The single infection may subclinically have an influence on outbreak of other respiratory pathogens in suckling pigs.

• Pediatric Infection and Vaccine
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• v.9 no.2
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• pp.193-200
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• 2002

Purpose : This study was performed to investigate the epidemiology of viral acute lower respiratory tract infection(ALRI) in two different areas of Korea. Methods : A total of 796 patients hospitalized for ALRI aged 15 years or less from June 2000 to June 2001 in Samsung Seoul hospital(SSH) and Masan Fatima hospital(MFH) were enrolled. Viral etiologies were confirmed using nasopharyngeal aspirates. We compared etiologic agents, age distribution, clinical manifestations, and seasonal occurrence of viral ALRI between the two hospitals. Results : Virus was isolated in 208 patients(26.1%). The proportion of patients aged under 2 years in SSH was 60.2%, while those in MFH was 90.0%(P<0.05). Respiratory syncytial virus(RSV) was more prevalent in MFH, but adenovirus, influenza virus and parainfluenza virus were more prevalent in SSH(P<0.05). Croup and bronchiolitis occurred more frequently in MFH than in SSH(P<0.05). The most frequent viral pathogens causing bronchiolitis and croup were RSV and parainfluenza virus, respectively, in both hospitals. Adenovirus was the main cause of pneumonia in SSH, in contrast to RSV in MFH. In terms of tracheobronchitis, adenovirus was detected most frequently in SSH, whereas influenza virus-type A was mainly isolated in MFH. Similar pattern of seasonal occurrences of RSV, parainfluenza virus and influenza virus-type A was noted in both hospitals. Adenovirus was isolated sporadically throughout the study periods. Conclusion : Seasonal occurrence and clinical syndromes according to viral pathogens showed similar pattern in two areas. However, distribution of offending viruses was different, although this is mainly related to the different age distribution. An annual nationwide surveillance is necessary to understand the viral epidemiology associated with respiratory illnesses in Korea.

• Journal of the korean veterinary medical association
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• v.6 no.4
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• pp.24-28
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• 1962

Virus Pneumonia of Pigs was observed in Korea for the first time. The lung tissues observed were clinical cases of baby pigs and those of cases secured from Abattoir. They were examined Pathologically, both gross and microscopic. The results odserved were

• The Plant Pathology Journal
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• v.19 no.3
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• pp.162-165
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• 2003

Transformation of Fuji apple (Malus domestica 'Fuji') was performed using Agrobacterium tumefaciens harboring a coat protein (CP) gene of Cucumber mosaic virus (CMV). A plasmid DNA containing the virus CP and NPT II genes was introduced into the loaves of apple by th e Agrobacterium - mediated transformation procedure. Regenerated transformants of the apple were obtained by kanamycin resistance conferred by the introduced NPT II gene. PCR analysis showed that 3 out of 20 putatively selected R0 plant lines contain the CMV-CP gene. Nine putative transgenic lines out of 20 lines were investigated with the PCR analysis; 5 regenerants produced a 450 bp DNA band and 3 regenerants showed a 671 bp DNA band for the NPT II and CMV-CP genes, respectively. Southern hybyidization results demonstrate the successful integration of the CMV-CP gene into the genome of the apple. This is the first report on the generation of useful vius resistance source of transgenic apple for molecular breeding program.

• The Journal of Korean Society of Virology
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• v.28 no.3
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• pp.225-232
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• 1998

We have expressed GFP in Sf9 and Bm5 cells or Bombyx mori larvae by using Ac-Bm hybrid virus capable of replicating in both Bm5 and Sf9 cells. Genomic DNA of Ac-Bm hybrid virus expressing ${\beta}$-galactosidase was cotransfected with baculovirus transfer vector containing GFP gene, pBacPAK-GFP in Sf9 cells. The Ac-Bm hybrid virus harboring GFP was named as Ac-Bm hybrid virus-GFP. The Ac-Bm hybrid virus-GFP-infected insect cells were easily selected by detecting the emission of GFP from each well of cell culture dish on the UV illuminator. GFP produced by Ac-Bm hybrid virus-GFP in Sf9 and Bm5 cells or B. mori larvae was confirmed by SDS-PAGE and Western blot analysis using GFP antibody. In addition, B. mori larvae infected with Ac-Bm hybrid virus-GFP was apparently appeared fluorescence from the whole body at S days postinoculation. The fluorescence of GFP from the hemolymph and fat body of B. mori larvae infected with Ac-Bm hybrid virus-GFP was also observed by fluorescence microscope. In conclusion, our results demonstrated that in baculovirus expression vector system, use of Ac-Bm hybrid virus have an additional advantage of expanded host range for producing recombinant proteins.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.144.1-144
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• 2003

Attenuated viruses can protect their hosts against challenge to their related viruses. Increasing evidence shows that mutations of the tobamoviral 126/183 kDa protein play a major role in the viral attenuation and contribute to the cross protection mechanism. In this study, four mutants of Pepper mild mottle virus (PMMoV) have been constructed by mutagenesis; two mutants, pTPpoly348 and pTPpoly762, were substituted in the middle of replicase gene, and the others, pTPL3D:: $\Delta$6207 and pTPL3D:: $\Delta$6219, were deletion mutants made by deleting some parts of pseudoknot structures of the 3' noncoding region (NCR) of the virus. Progeny viruses generated from the four mutants were infectious on N. benthamiana plants with symptomless or mild mosaic symptom. Replication efficiency and viral product accumulations of four mutants were assessed by Northern and Western blot analyses on BY-2 protoplast cells. Accumulation of CP for the pTPL3D:: $\Delta$6207 and pTPL3D:: $\Delta$6219 were lower than that of other mutants and wild type virus. These data suggest that the 3'-NCR mutations contribute to the viral gene expression in host tissues, while mutants of replicase gene rather govern the symptom expression.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.113.1-113
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• 2003

A potexvirus, Hosta virus X (HVX-Kr), causing mosaic and mottle symptoms was isolated from hosta plants (Hosta spp.), and its entire genome RNA sequence was determined. in Korea using cDNA library and RACE methods. The genome of HVX encodes five open reading frames coding for viral replicase, triple gene block (TGB), and viral coat protein (CP) from the 5'to 3' ends, which is a typical genome structure of potexviruses. The 3-terminal region of the virus includes the TGBI (26 kDa), TGB2 (13 kDa), TGB3 (8 kDa), and 23 kDa coat protein (CP) and the 3-nontranslated region (NTR). The CP gene of the type isolate of HVX (HVX-U) was amplified by RT-PCR and its nucleotide sequence was determined. The CPs of HVX-Kr and HVX-U had 100％ and 98.9％ identical amino acids and nucleotides, respectively. Most of the regions of the genome HVX had over 50％ nucleotide identical to other sequenced potexviruses. This is the first report of complete genome sequence information of HVX and molecular evidence supporting the virus as a distinct species of the genus Potexvirus.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.115.2-116
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• 2003

Complete genomic nucleotide sequence of Daphe virus S (DVS), a member of the genus Carlavirus, causing leaf distortion and chlorotic spot disease symptoms in daphne plants, has been determined in this study. The genome of DVS contained six open reading fames coding for long viral replicase, triple gene block, 36 kDa viral coat protein (CP) and 12 kDa from the 5' to 3' ends, which is a typical genome structure of carlaviruses. Two Korean isolates of DVS isolates were 98.1％ and 93.6％ amino acid identical in the CP and 12kDa, respectively. The CP gene of DVS shares 25.2-55.2％ and 42.9-56.1％ similarities with that of 19 other carlaviruses at the amino acid and nucleotide levels, respectively. The 3'-proximal 12 kDa gene of DVS shares 20.2-57.8％ amino acid identities with that of 18 other members of the genus. The 3' noncoding region of DVS consists of 73 nucleotides with long excluding poly A tract, and shares 69.1-77.1％ identities to the known carlaviruses. In the phylogenetic analyses of the two proteins, DVS was closely related to Helenium virus S and Chrysanthemum virus B. This is the first complete sequence information for the DVS, and further confirms the classification of DVS as a distinct species of the genus Carlavirus.