• Molecules and Cells
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• 제19권2호
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• pp.246-255
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• 2005

Retroviral integrases insert viral DNA into target DNA. In this process they recognize their own DNA specifically via functional domains. In order to analyze these functional domains, we constructed six chimeric integrases by swapping domains between HIV-1 and HFV integrases, and two point mutants of HFV integrase. Chimeric integrases with the central domain of HIV-1 integrase had strand transfer and disintegration activities, in agreement with the idea that the central domain determines viral DNA specificity and has catalytic activity. On the other hand, chimeric integrases with the central domain of HFV integrase did not have any enzymatic activity apart from FFH that had weak disintegration activity, suggesting that the central domain of HFV integrase was defective catalytically or structurally. However, these inactive chimeras were efficiently complemented by the point mutants (D164A and E200A) of HFV integrase, indicating that the central domain of HFV integrase possesses potential enzymatic activity but is not able to recognize viral or target DNA without the help of its homologous N-terminal and C-terminal domains.

• 공업화학
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• 제10권4호
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• pp.599-602
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• 1999

Chitosan을 아질산부해법을 이용하여 저분자화시킨 다음, 저분자량 chitosan의 유리 아민기와 trifluoroacetic anhydride를 반응시켜 새로운 함불소 chitosan 올리고머 유도체(FCO)를 합성하였다. 이들 반응의 진행은 FT-IR, $^{1}H\;NMR$, $^{19}F\{^{1}H\}NMR$ 등을 통해 확인하였다. FCO의 항바이러스 효과는 바이러스 감염용액에 다양한 농도의 FCO를 첨가하고 세포를 감염시킨 후, 36시간 후에 복제되고 있는 바이러스 DNA 양을 측정하여 조사하였다. 바이러스 복제는 FCO를 첨가하여 바이러스를 감염시킨 세포들에서, FCO를 첨가하지 않은 대조군에 비하여 첨가한 FCO의 농도에 비례하여 감소하여, FCO가 바이러스 감염을 효과적으로 억제함을 제시한다. 특히, 1% FCO의 감염용액으로 처리된 세포에서는 바이러스의 복제가 대조군에 비하여 40%로 감소하였다.

• Journal of Microbiology and Biotechnology
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• 제23권1호
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• pp.125-130
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• 2013

Influenza viruses cause significant morbidity and mortality in humans through epidemics or pandemics. Currently, two classes of anti-influenza virus drugs, M2 ion-channel inhibitors (amantadin and rimantadine) and neuraminidase inhibitors (oseltamivir and zanamivir), have been used for the treatment of the influenza virus infection. Since the resistance to these drugs has been reported, the development of a new antiviral agent is necessary. In this study, we examined the antiviral efficacy of the plant extracts against the influenza A/PR/8/34 infection. In vitro, the antiviral activities of the plant extracts were investigated using the cell-based screening. Three plant extracts, Thuja orientalis, Aster spathulifolius, and Pinus thunbergii, were shown to induce a high cell viability rate after the infection with the influenza A/PR/8/34 virus. The antiviral activity of the plant extracts also increased as a function of the concentration of the extracts and these extracts significantly reduced the visible cytopathic effect caused by virus infections. Furthermore, the treatment with T. orientalis was shown to have a stronger inhibitory effect than that with A. spathulifolius or P. thunbergii. These results may suggest that T. orientalis has anti-influenza A/PR/8/34 activity.

• Journal of Microbiology and Biotechnology
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• 제33권12호
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• pp.1576-1586
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• 2023

Vaccination is the most effective method for preventing the spread of the influenza virus. Cell-based influenza vaccines have been developed to overcome the disadvantages of egg-based vaccines and their production efficiency has been previously discussed. In this study, we investigated whether treatment with forskolin (FSK), an adenylyl cyclase activator, affected the output of a cell-based influenza vaccine. We found that FSK increased the propagation of three influenza virus subtypes (A/H1N1/California/4/09, A/H3N2/Mississippi/1/85, and B/Shandong/7/97) in Madin-Darby canine kidney (MDCK) cells. Interestingly, FSK suppressed the growth of MDCK cells. This effect could be a result of protein kinase A (PKA)-Src axis activation, which downregulates extracellular signal-regulated kinase (ERK)1/2 activity and delays cell cycle progression from G1 to S. This delay in cell growth might benefit the binding and entry of the influenza virus in the early stages of viral replication. In contrast, FSK dramatically upregulated ERK1/2 activity via the cAMP-PKA-Raf-1 axis at a late stage of viral replication. Thus, increased ERK1/2 activity might contribute to increased viral ribonucleoprotein export and influenza virus propagation. The increase in viral titer induced by FSK could be explained by the action of cAMP in assisting the entry and binding of the influenza virus. Therefore, FSK addition to cell culture systems could help increase the production efficiency of cell-based vaccines against the influenza virus.

• 생약학회지
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• 제42권1호
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• pp.9-14
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• 2011

The fruit body of Forsythiae Fructus (Oleaceae), a common Korean medical herb, is widely used in the treatment of cold and inflammation. In order to elucidate the action mechanism and the active principles from the plant against anti-influenza virus, the influenza virus hemagglutinin (HA) and neuraminidase (NA) gene RT-PCR and Viral Screening & Identification (VSI) assay were conducted, and the activity against viral replication was also investigated. Consequently, one active constituent, namely pinoresinol showed the in vitro antiviral principle using a cytopathic effect (CPE) reduction method, indicating pinoresinol possessed anti-influenza viral activity. Furthermore, combination of pinoresinol and Tamiflu exhibited higher activities than Tamiflu alone against influenza virus (H3N2) infection. The results suggested that combination of pinoresinol with Tamiflu could be a better candidate for an ant-H3N2 viral agent in the treatment of the influenza.

• Journal of Microbiology
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• 제45권3호
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• pp.187-192
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• 2007

REOviruses (Respiratory Enteric Orphan viruses) are ubiquitous, non-enveloped viruses containing 10 segments of double-stranded RNA (dsRNA) as their genome. They are common isolates of the respiratory and gastrointestinal tract of humans but are not associated with severe disease and are therefore considered relatively benign. An intriguing characteristic of reovirus is its innate oncolytic potential, which is linked to the transformed state of the cell. When immortalized cells are transfected in vitro with activated oncogenes such as Ras, Sos, v-erbB, or c-myc, they became susceptible to reovirus infection and subsequent cellular lysis, indicating that oncogene signaling pathways are exploited by reovirus. This observation has led to the use of the virus in clinical trials as an anti-cancer agent against oncogenic tumors. In addition to the exploitation of oncogene signaling, reovirus may further utilize host immune responses to enhance its antitumor activity in vivo due to its innate interferon induction ability. Reovirus is, however, not entirely benign to immunocompromised animal models. Reovirus causes so-called "black feet syndrome" in immunodeficient mice and can also harm neonatal animals. Because cancer patients often undergo immunosuppression due to heavy chemo/radiation-treatments or advanced tumor progression, this pathogenic response may be a hurdle in virus-based anticancer therapies. However, a genetically attenuated reovirus variant derived from persistent reovirus infection of cells in vitro is able to exert potent anti-tumor activity with significantly reduced viral pathogenesis in immunocompromised animals. Importantly, in this instance the attenuated, reovirus maintains its oncolytic potential while significantly reducing viral pathogenesis in vivo.

• 한국수산과학회지
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• 제54권5호
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• pp.644-651
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• 2021

Viral hemorrhagic septicemia virus (VHSV) is a fish pathogen responsible for causing enormous economic loss to the aquaculture industry not only in Korea but worldwide. Thus, it is necessary to identify natural compounds that can be used to control the spread of VHSV. In this study, the anti-VHSV activities of five catechol derivatives, i.e., catechol, pyrogallol, 3-methyl catechol, veratrole, and 3-methyl veratrole-extracted from green tea-were assessed. The antiviral activities of these derivatives were found to be dependent on their structure, i.e., the hydroxyl or methoxyl group and their substituent groups-on the benzene ring. Catechol, pyrogallol, and 3-methyl catechol exhibited relatively high 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities than veratrole, and 3-methyl veratrole. Moreover, 3-methyl catechol harboring a methyl substituent group increased the viability of the virus-infected cells and resulted in a 2.86 log reduction in the gene copies of VHSV N (per mL) in real-time PCR analysis. In conclusion, the catechol derivatives harboring hydroxyl groups in their benzene ring exhibited higher antioxidant activities than those harboring the methoxyl groups. However, catechol derivatives with a methyl group at the 3'-position of the benzene ring exhibited higher antiviral activity than those harboring a hydroxyl group. To our knowledge, this is the first study to evaluate the relationship between the structure and the anti-VHSV activity of catechol derivatives.

• BMB Reports
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• 제45권3호
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• pp.165-170
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• 2012

We report here that an ethanol extract of Tetracera scandens, a Vietnamese medicinal plant, has anti-HIV activity and possesses strong inhibitory activity against HIV-1 reverse transcriptase (RTase). Using a MT-4 cell-based assay, we found that the T. scandens extract inhibited effectively HIV virus replication with an $IC_{50}$ value in the range of 2.0-2.5 ${\mu}g$/ml while the cellular toxicity value (CC50) was more than 40-50 ${\mu}g$/ml concentration, thus yielding a minimum specificity index of 20-fold. Moreover, the anti-HIV efficacy of the T. scandens extract was determined to be due, in part, to its potent inhibitory activity against HIV-1 RTase activity in vitro. The inhibitory activity against the RTase was further confirmed by probing viral cDNA production, an intermediate of viral reverse transcription, in virus-infected cells using quantitative DNA-PCR analysis. Thus, these results suggest that T. scandens can be a useful source for the isolation and development of new anti-HIV-1 inhibitor(s).

• 대한약리학회지
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• 제28권2호
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• pp.213-222
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• 1992

Benzopyrene (BP), 7,12-dimehyl benzanthracene (DMBA), nitrosomethyl urea (NUMU) 및 nicotine과 같은 발암성 화학물질들이 바이러스 감염된 vero 세포의 단층 세포 배양에서 I형 단순성포진 바이러스 (HSV-1)의 복제, 세포융해, DNA합성 및 단백질 합성에 미치는 효과를 관찰하였다. 1. BP와 DMBA는 HSV-1의 복제와 세포융해작용을 유의성있게 억제하였으나 nicotine과 NMU는 별로 억제하지 않았다. 2. 모든 발암성 화학물질은 바이러스의 DNA합성을 억제하지 못하였지만 새로 합성되는 후손바이러스 DNA로 부터 표현되는 gamma 단백질의 표현은 BP와 DMBA에 의해서 현저하게 억제되었다. 그러나 모든 발암성 화학물질은 바이러스의 alpha 및 beta 단백질의 합성은 억제하지 못하였다. 이상의 결과로 보아 발암성화학물질이 존재하고 있는 배지내에서 새로 합성되는 바이러스의 DNA로 부터 표현되는 gamma 단백질의 결함이 있음을 알 수가 있었으며 이같은 개념은 발암화학물질의 존재하에서 바이러스의 DNA와 단백질이 거의 정상적으로 합성됨에도 불구하고 바이러스의 복제가 일어나지 않는다는 사실이 뒷받침해주고 있다.

• 대한수의학회지
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• 제61권2호
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• pp.13.1-13.8
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• 2021

Mammalian reovirus (MRV) causes respiratory and intestinal disease in mammals. Although MRV isolates have been reported to circulate in several animals, there are no reports on Korean MRV isolates from wildlife. We investigated the biological and molecular characteristics of Korean MRV isolates based on the nucleotide sequence of the segment 1 gene. In total, 144 swabs from wild animals were prepared for virus isolation. Based on virus isolation with specific cytopathic effects, indirect fluorescence assays, electron microscopy, and reverse transcription-polymerase chain reaction, only one isolate was confirmed to be MRV from a Korean roe deer (Capreolus pygargus). The isolate exhibited a hemagglutination activity level of 16 units with pig erythrocytes and had a maximum viral titer of 10^5.7 50% tissue culture infectious dose (TCID₅₀)/mL in Vero cells at 5 days after inoculation. The nucleotide and amino-acid sequences of the partial segment S1 of the MReo2045 isolate were determined and compared with those of other MRV strains. The MReo2045 isolate had nucleotide sequences similar to MRV-3 and was most similar (96.1%) to the T3/Bat/Germany/342/08 strain, which was isolated in Germany in 2008. The MReo2045 isolate will be useful as an antigen for sero-epidemiological studies and developing diagnostic tools.