• Asian-Australasian Journal of Animal Sciences
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• v.23 no.7
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• pp.855-862
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• 2010

Among the known interferon-induced antiviral mechanisms, the Mx pathway is one of the most powerful pathways. The Mx protein has direct antiviral activity and inhibits a wide range of viruses by blocking an early stage of the viral replication cycle. Cloning, characterization, and expression of Mx in vivo and in vitro have been conducted. The chicken Mx gene spans 21 kb and is made up of 14 exons and 13 introns, of which the promoter region was analyzed. The real-time PCR results showed that Mx expression was increased in chicken embryo fibroblasts (CEF) after 12- and 24-h induction with polyI: C. Induction of Mx expression by poly I: C in vivo revealed tissue-specific patterns among the chicken tissues tested. A trace expression of Mx was detected in healthy chicken liver tissues from adult chickens without inducement; the expression levels in the liver, heart, and gizzard were higher than in the muscle and kidney. This is the first report to demonstrate the expression of a glutathione-S-transferase-tagged-Mx fusion protein of 75 KDa, as well as the biological activity tested by SDS-PAGE and western blotting.

• BMB Reports
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• v.38 no.1
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• pp.41-48
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• 2005

In this study we developed the transposon-mediated shuttle vector 'Hanpvid', which composed of HaNPV (Heliothis armigera nuclear polyhedrosis virus) genomic DNA and a transposon cassette from Bacmid of Bac-to-Bac system. Hanpvid replicates in E. coli in the same way as Bacmid and retains infective function in cotton bollworm cells (Hz-AM1). Using Hanpvid we constructed a recombinant virus, which could infect Hz-AM1 cells and generate recombinant HaNPV (rHa-Bar) containing the barnase gene, a ribonuclease gene from Bacillus amyloliquefaciens. Since the expression vector carrying barnase gene cannot replicate in the absence of barstar, a specific inhibitor of barnase, we constructed a new cotton bollworm cell line (AM1-NB) using the marker rescue method. In AM1-NB barstar was integrated into the cellular chromosome to sustain the replication of rHa-Bar. To screen out recombinant HaNPV for potential use as biopesticide, Hz-AM1 and AM1-NB cell lines were infected with rHa-Bar, respectively. The results obtained indicate that Viral progenies in AM1-NB were 23 and 160 times greater than those in Hz-AM1 48 h and 72 h after infection, respectively. With additional insertion of the polyhedron gene from AcNPV (Autographa californica nuclear polyhedrosis virus) into the Hanpvid genome, rHa-Bar regained the polyhedron phenotype and its pest-killing rate greatly improved. Toxic analysis showed that the lethal dosages ($LD_{50}$) and the lethal time(s) ($LT_{50}$) of rHa-Bar were reduced by 20% and 30%, respectively, compared to wt-HaNPV in the third instar larvae of cotton bollworm. This study shows that in AM1-NB barnase can be effectively produced and used as pest-killing agent for the biological control of cotton pests.

• Journal of Microbiology and Biotechnology
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• v.30 no.1
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• pp.38-43
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• 2020

Hand, foot, and mouth disease (HFMD) is caused by enterovirus 71 (EV71) in infants and children under six years of age. HFMD is characterized by fever, mouth ulcers, and vesicular rashes on the palms and feet. EV71 also causes severe neurological manifestations, such as brainstem encephalitis and aseptic meningitis. Recently, frequent outbreaks of EV71 have occurred in the Asia-Pacific region, but currently, no effective antiviral drugs have been developed to treat the disease. In this study, we investigated the antiviral effect of salvianolic acid B (SalB) on EV71. SalB is a major component of the Salvia miltiorrhiza root and has been shown to be an effective treatment for subarachnoid hemorrhages and myocardial infarctions. HeLa cells were cultured in 12-well plates and treated with SalB (100 or 10 ㎍/ml) and 10⁶ PFU/ml of EV71. SalB treatment (100 ㎍/ml) significantly decreased the cleavage of the eukaryotic eIF4G1 protein and reduced the expression of the EV71 capsid protein VP1. In addition, SalB treatment showed a dramatic decrease in viral infection, measured by immunofluorescence staining. The Akt signaling pathway, a key component of cell survival and proliferation, was significantly increased in EV71-infected HeLa cells treated with 100 ㎍/ml SalB. RT-PCR results showed that the mRNA for anti-apoptotic protein Bcl-2 and the cell cycle regulator Cyclin-D1 were significantly increased by SalB treatment. These results indicate that SalB activates Akt/PKB signaling and inhibits apoptosis in infected HeLa cells. Taken together, these results suggest that SalB could be used to develop a new therapeutic drug for EV71-induced HFMD.

• Fisheries and Aquatic Sciences
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• v.13 no.2
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• pp.96-101
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• 2010

Norovirus, which causes gastroenteritis in humans, is an important food-borne pathogen worldwide. In an effort to discover an antiviral substance against norovirus, extracts from several seaweeds were evaluated for antiviral activity against feline calicivirus (FCV), which was used as a surrogate. The methanolic extract of Undaria pinnatifida exhibited the most significant antiviral activity and virucidal efficacy against FCV. The concentrations of the extract that reduced viral replication by 50% ($EC_{50}$) and resulted in the death of 50% of the host cells ($CC_{50}$) were 0.05 mg/mL and 1.02 mg/mL, respectively. The selectivity index, calculated from the ratio of the $CC_{50}$ and $EC_{50}$ was 20.4. No FCV infection of host cells occurred following a 1-h incubation in the presence of 12.50 mg/mL U. pinnatifida extract, indicating that the virus was completely inactivated by the extract treatment. The results obtained in this study will contribute to the development of a natural antiviral substance that will prevent food-borne disease caused by norovirus.

• Korean Journal of Veterinary Service
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• v.19 no.1
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• pp.1-29
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• 1996

This study was conducted to elucidate the pathogenesis of Aujeszky's disease virus(ADV) by histopathologic examination. The first Korean ADV Isolate, which was isolated from piglets with clinical signs of Aujeszky's disease in Yangsan(YS) county, Kyungnam province, was inoculated into 32 days old piglets with a dose of $10^{5.9}$$TCID_{50}/ml$ through intranasal or intramuscular route. These piglets were sacrificed at intervals of every 24hrs for 8 days. The virulence of YS strain was determined by the observation of clinical signs, gross findings, and histopathologic changes in tissues. The virus recovery test was performed from brain, spleen, lung and tonsil in cell culture. The pathogenesis of YS strain was determined by the observation of histopathologlc lesions in CNS and neuronal tracts. The major clinical signs were fever, anorexia, dyspnea, constipation, tremor, ataxia, circling movement, hindleg paralysis and salivation. The clinical signs were more severe in piglets of the group inoculated intranasally than those of the intramuscularly inoculated gorup. Lymphocytopenia was detected on day 5 to day 6 postinoculation (PI). The ADV was recovered from the tissue homogenates of tonsil, lung, spleen and cerebrum in cell culture. The highest virus titer was detected from tonsil between day 6 and day 7 PI. Reddish sublobar consolidation foci were scattered in the apical and cardiac lobes of lung. Although yellowish necrotic foci were detected in tonsil and liver, hemorrhagic lesions were mainly observed in heart, kidney and lymph nodes. Histopathologically, degeneration and necrosis of nerve cells, nonsuppurative meningoe-ncephalitis, nodular gliosis and perivascular cuffings were observed in CNS. Multifocal fibronecrotic foci were observed in lung, liver, lymph nodes and spleen. The major pathologic changes were detected in the midbrain, pons and medulla oblongata. Eosinophilic intranuclear inclusion bodies were mainly observed in epithelia and /or macrophages of tonsil, liver, lung, spleen and submandibular lymph nodes, and neurons of brain, respectively. Observation of viral particles at various stages of replication were possible from the endothelial cells of the alveolar capillaries and tonsillar crypt epithelia by transmission electron microscope.

• Molecules and Cells
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• v.28 no.1
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• pp.19-24
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• 2009

The goal of this study was to create a novel baculovirus expression system that does not require recombinant virus purification steps. Transfection of insect cells with transfer vectors containing barnase under control of the Cotesia plutellae bracovirus (CpBV) promoters ORF3004 or ORF3005 reduced cell growth. Co-transfection with bApGOZA DNA yielded no recombinant viruses and nonrecombinant backgrounds. To further investigate the detrimental effects of barnase on insect cells, two recombinant bacmids harboring the barnase gene under control of the CpBV promoters, namely bAcFast-3004ProBarnase and bAcFast-3005ProBarnase, were constructed. While no viral replication was observed when only the recombinant bacmids were transfected, recombinant viruses were generated when the bacmids were co-transfected with the transfer vector, pAcUWPolh, through substitution of the barnase gene with the native polyhedrin gene by homologous recombination. Moreover, no non-recombinant backgrounds were detected from unpurified recombinant stocks using PCR analysis. These results indicate that CpBV promoters can be used to improve baculovirus expression vectors by means of lethal gene expression under the control of these promoters.

• BMB Reports
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• v.50 no.5
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• pp.275-280
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• 2017

Herpes simplex virus type 1 ICP27 is a multifunctional protein responsible for viral replication, late gene expression, and reactivation from latency. ICP27 interacts with various cellular proteins, including Daxx. However, the role of interaction between ICP27 and Daxx is largely unknown. Since Daxx is known to repress $NF-{\kappa}B$ activity, there is a possibility that ICP27 may influence the inhibitory effect of Daxx on $NF-{\kappa}B$ activity. In this study, we tested whether ICP27 affects the $NF-{\kappa}B$ activity through its interaction with Daxx. Interestingly, ICP27 enhanced the Daxx-mediated repression of $NF-{\kappa}B$ activity. In addition, we found that sumoylation of Daxx regulates its interaction with p65. ICP27 binds to Daxx, inhibits Daxx sumoylation, and enhances p65 deacetylation induced by Daxx. Consequently, ICP27 represses the $NF-{\kappa}B$ activity, by elevating the inhibitory effect of Daxx on $NF-{\kappa}B$ activity through desumoylation of Daxx.

• Archives of Pharmacal Research
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• v.28 no.4
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• pp.451-457
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• 2005

Experimental studies have demonstrated that the triple combination of amantadine (A)/ ursodeoxycholic acid (UDCA, U)/ biphenyl dimethyl dicarboxylate (DDB, D) might have a preferential antiviral effect compared with that observed in interferon-induced antiviral signal pathways, such as those of $STAT1\alpha$ and the 6-16 genes. To confirm the results, this study examined whether th signal transduction for the antiviral activity in HepG2 2.2.15 was induced dependently or independently of interferon. To accomplish this, the correlation between the $STAT1\alpha$ and 6-16 genes, and nitric oxide, for the mediation of the antiviral activity was assessed. The increase in nitric oxide in the UDCA groups suggests that the inhibition of viral gene replication was enhanced by the amantadine combinations (AU and AUD), and might be more effective if incubated for longer periods. It was found that $STAT1\alpha$ was activated by the amantadine combination, although to a lesser extent than that of $interferon-\alpha$, and the primary endpoints examined for the inhibition of gene expression (HBsAg and HBcAg) were remarkably well regulated. This suggests that the amantadine triple, or at least the double, combination had better clinical benefits than those of $IFN-\alpha$ and the nucleoside analogue single treatment. This demonstrates that the amantadine combination might be a substitute for the existing HBV therapy if the results of in vivo and in vitro studies concur.

• Molecules and Cells
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• v.38 no.2
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• pp.122-129
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• 2015

DBM-2198, a six-membered azasugar nucleotide (6-AZN)-containing phosphorothioate (P = S) oligonucleotide (AZPSON), was described in our previous publication [Lee et al. (2005)] with regard to its antiviral activity against a broad spectrum of HIV-1 variants. This report describes the mechanisms underlying the anti-HIV-1 properties of DBM-2198. The LTR-mediated reporter assay indicated that the anti-HIV-1 activity of DBM-2198 is attributed to an extracellular mode of action rather than intracellular sequence-specific antisense activity. Nevertheless, the antiviral properties of DBM-2198 and other AZPSONs were highly restricted to HIV-1. Unlike other P = S oligonucleotides, DBM-2198 caused no host cell activation upon administration to cultures. HIV-1 that was pre-incubated with DBM-2198 did not show any infectivity towards host cells whereas host cells pre-incubated with DBM-2198 remained susceptible to HIV-1 infection, suggesting that DBM-2198 acts on the virus particle rather than cell surface molecules in the inhibition of HIV-1 infection. Competition assays for binding to HIV-1 envelope protein with anti-gp120 and anti-V3 antibodies revealed that DBM-2198 acts on the viral attachment site of HIV-1 gp120, but not on the V3 region. This report provides a better understanding of the antiviral mechanism of DBM-2198 and may contribute to the development of a potential therapeutic drug against a broad spectrum of HIV-1 variants.

• Korean Journal of Veterinary Research
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• v.44 no.4
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• pp.539-549
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• 2004

Mean death time of inoculated embryonated egg is one of the methods to determine the virulence of the Newcastle disease viruses (NDV). Evaluation of tissue tropism of NDV in the host has been proposed as an another way to determine the pathogenicity of NDV based on the principal site of viral replication. To evaluate the tissue tropism among NDV, an immunohistochemistry(IHC) technique using monoclonal antibody was applied in one-day-old SPF chickens inoculated with different ND vaccine strains such as Ulster 2C, VG/GA and B1 viruses by eye drop instillation. The tissues used for this comparison were trachea, intestine, Harderian gland and cecal tonsil, which were collected at 0.5, 1, 2, 3, 5, 8, 10, 14 days post inoculation. Among test groups, chickens inoculated with B1 viurs, which is known to replicate in the respiratory system, have IHC positive staining mainly in the trachea and those inoculated with Ulster 2C have IHC positive staining mainly in the intestine. However, chickens inoculated with VG/GA strain have IHC positive staining in both the trachea and intestine. Therefore, a differences in tissue tropism among ND vaccine strains has been proved by the IHC technique. Based on this results, the IHC staining technique could be used to classify the NDV or to study the pathogenesis of NDV in chickens.