• Particle and aerosol research
• /
• v.15 no.4
• /
• pp.173-182
• /
• 2019

Since airborne viruses have been known to aggravate indoor air quality, studies on the development of anti-viral air filter increase recently. In this study, the pressure drop and anti-viral efficiency of TiO₂ coated ceramic ball filter were evaluated. After the filter being inserted into a commercial room air cleaner, chamber test with aerosolized bacteriophage MS2 was performed. The porosity of TiO₂ coated ceramic ball filter was 0.85, and pressure drop was about 13 Pa for 1 m/s of air velocity. The anti-viral efficiency was about 93% when the reaction time was 25 minutes in a 1 ㎥ chamber.

• Korean journal of applied entomology
• /
• v.30 no.3
• /
• pp.187-195
• /
• 1991

This study was carried out to acquire some basic biological informations on the granulosis virus (GV) of Pieris rapae and Pieris brassicae. Purified fractions of GV capsules in an sucrose density gradient centrifugation yielded on homogenous and sharp peak without a shoulder. Electron microscopy revealed that GV capsules were mostly ovalglove in shape. P. rapae and P. rapae GV isolated from P. rapae comprised granules($396\pm38\times238\pm25nm$ for P. rapae GV. $375\pm40\times255\pm28nm$ for P. brassicae GV) which contained single virus particle. The virus particles were 250- $275{\times}63$ -73nm for P. rapae GV and 243-250 $\times$ 63-75nm for P. brassicae GV containing a nucleocapsid 225 $\times$ 31nm for P. rapae, 225 $\times$ 29nm for P. brassicae within an envelope. The virulent difference between the two viruses was very small in their virulence for P. rapae larvae showing the $LC_{50}$( -log) with 5.5673 for P. rapae GV and 5.8104 for P. brassicae GV. Also the $LT_{50}$ of the 3rd instar P. rapae larvae against $10^{-6}$ inoculum was 8.17 days for P. rapae GV and 7.16 days for P. brassicae GV.

• Journal of the Korean Magnetic Resonance Society
• /
• v.5 no.1
• /
• pp.29-36
• /
• 2001

The structures of two VBS (viral binding site) RNAs, SL1 and SL2, of Yeast Saccharomyces cerevisiae vims have been studied by 2D and 3D NMR experiments. VBSs play a crucial role in viral particle binding to the plus strand and packaging of the RNA. The secondary structures of the two VBS RNAs share a common feature of the stem-internal loop-stem-hairpin loop structure although the size of the internal loops of SL1 and SL2 differs. 2D experiments were sufficient for fill assignments of SL1. However, isotope labeling of the sample and multidimensional experiments were required for 28-nucleotide-long SL2 due to the spectral overlap. Several 3D HCCH experiments have accomplished full assignment of SL2 RNA.

• Journal of Plant Biotechnology
• /
• v.36 no.3
• /
• pp.224-229
• /
• 2009

Human lactoferrin is an iron-binding glycoprotein with many biological activities, including the protection against microbial and virus infection and stimulation of the immune system. We introduced a human lactoferrin (hLf) cDNA under the control of 35S promoter into sweet potato by particle bombardment. Transgenic plants were regenerated via somatic embryogenesis. Transgenic plants were produced typical tuberous roots in soil. PCR, Southern and northern analyses confirmed that the hLf cDNA was incorporated into the plant genome and was properly expressed in plants. Western blot analysis showed that the 80 kDa full length hLf protein was produced in transgenic tuberous roots. Overall results indicated that sweet potato would be an excellent host to produce human therapeutic proteins.

• Research in Plant Disease
• /
• v.17 no.2
• /
• pp.191-195
• /
• 2011

This experiment was attempted to investigate a cause of the scion death in green pepper grafting system. A tobamovirus particle examined in the rootstock of the sample but not in the scion showing necrosis. The virus isolated from the rootstock was identified as Pepper mild mottle virus (PMMoV), pepper tobamovirus pathotype P1.2. (PMMoV-2), by nucleotide sequence analysis and host plant reaction. The virus isolate infected systematically in 6 commercial rootstock varieties using for green pepper grafting seedling production. Green pepper varieties 'Long green mart' and 'Daechan' represented resistance to the virus showing local lesions only on the inoculated leaves and 'Manitda' was systematically infected. In the experiment with grafting 'Long green mart' or 'Daechan' onto the those rootstocks, the upper leaves of the scions first showed vein necrosis and wilt symptoms 7 days after inoculation with PMMoV-2 on the cotyledon of the rootstock, following to the scion stem necrosis and then only the scion death. The virus was detected in the rootstock but not in the scion. However, 'Manitda' of susceptible variety in the grafting system showed mottle symptom on the leaves of the scion but not necrosis on the plant. PMMoV-3 isolate, pepper tobamovirus pathotype P1.2.3, did not cause the scion death in the grafting system. All of the varieties were susceptible to PMMoV-3. These results suggest that the scion death is caused by infecting with pepper tobamovirus pathotype P1.2. in the green pepper grafting system combined with the susceptible rootstock and the resistance scion to the virus pathotype.

• Journal of Life Science
• /
• v.13 no.4
• /
• pp.541-550
• /
• 2003

E2 glycoprotein of hepatitis C virus (HCV) comprises a surface of viral particle together with E1 glycoprotein, and is thought to be involved in the attachment of HCV viral particle to receptor (s) on the permissible cells including hepatocytes, B cells, T cells, and monocytes. We constructed a phage library expressing cellular proteins of hepatocytes on the phage surface, which turned out to be 8.8${\times}$$10^5$ cfu of diversity and carried inserts in 95% of library. We screened both cDNA phage library and 12-mer peptide library to identify the cellular proteins binding to E2 protein. Some intracellular proteins including tensin and membrane band 4.1 which are involved in signal transduction of survival and cytoskeleton organization, were selected from cDNA phage library through several rounds of panning and screening. On the contrary, membrane proteins such as CCR7, CKR-L2, and insulin-like growth factor-1 receptor were identified through screening of peptide library. Phages expressing peptides corresponding to those membrane proteins were bound to E2 protein specifically as determined by neutralization of binding assay. Since it is well known that HCV can infect T cells as well as hepatocytes, we examined to see if E2 protein can bind to CCR7, a member of C-protein coupled receptor family expressed on T cells, using CCR7 transfected tells. Human CCR7 cDNA was cloned into pcDNA3.1(-) vector and transfected into human embryonic kidney cell, 293T, and expressed on the surface of the cell as shown by flow cytometer. Binding assay of E2 protein using CCR7 transfected cells indicated that E2 protein bound to CCR7 by dose-dependent mode, giving rise to the possibility that CCR7 might be a putative cellular receptor for HCV.

• Particle and aerosol research
• /
• v.18 no.1
• /
• pp.9-21
• /
• 2022

In this study, a novel antiviral coating method for the air filtration system of subway station was investigated. Using dry aerosol coating process, we developed a high-performance antiviral air filter with spark discharger and carbon brush type ionizer. Silver nanoparticles were produced by a spark discharge generation system with ion injection system and were used as antiviral agents coated onto a medium grade air filter. The pressure drop, filtration efficiency, and antiviral ability of the filter against aerosolized MS2 virus particles as a surrogate of SARS-CoV-2 virus were tested with dust contamination. Dust contamination caused the increase of the filtration efficiency and pressure drop, while the antiviral agents (in this study, silver nanoparticles) coating did not have any significant effect on the filtration efficiency and pressure drop. Using these properties, we suggested a novel method to maximize the antiviral performance of the antiviral air filter that was contaminated by dust particles. Moreover theoretical analysis of antiviral ability with dust contamination and re-coated antiviral agents was carried out using a mathematical model to calculate the time-dependent antiviral effect of the filter under actual conditions of subway station. Our model can be used to apply on antiviral air filtration system of subway station for prevention of pandemic diffusion, and predict the life cycle of an antiviral filter.

• Molecules and Cells
• /
• v.38 no.2
• /
• pp.122-129
• /
• 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 Service
• /
• v.43 no.2
• /
• pp.107-112
• /
• 2020

Foot-and-mouth disease (FMD) and avian influenza (AI) are highly pathogenic viral disease which affects the livestock industry worldwide. Outbreak of these viruses causes great impact in the livestock industry; thus, disease infected animals were immediately disposed. Burial is the commonly used disposal method for deceased animals. However, there is potential for secondary environmental contamination, as well as the risk that infectious agents persisting in the environment due to the limited environmental controls in livestock burial sites during the decomposition of the carcasses. Therefore, this study aimed to investigate the detection of FMD and AI viruses from animal carcass disposal sites using real-time reverse transcription PCR. Soil samples of more than three years post-burial from livestock carcass disposal sites were collected and processed RNA isolation using a commercial extraction kit. The isolated RNA of the samples was used for the detection of FMDV and AIV using qRT-PCR. Based on the qPCR assay result, no viral particle was detected in the soil samples collected from the animal disposal sites. This indicates that 3 years of burial and their carcass disposal method is efficient for the control or at least reduction of spread infections in the surrounding environment.

• Journal of the Korean Society of Visualization
• /
• v.20 no.3
• /
• pp.136-145
• /
• 2022

Later flow immunoassay (LFIA) is a protein analytical method based on immunoreaction. On the LFIA based protein analytical method, bioreceptor molecule plays a key role, and so a system that evaluates and manages the binding affinity of bioreceptor is needed to secure detection reliability. In this study, Lateral Flow Immunoassay based rapid Bioreceptor Screening Method (rBSM) is presented that provide a simple and quick evaluating method for the binding affinity to the target protein of the antibody as model bioreceptor. To verify this evaluation method, Virus-like particles (VLP) and anti-VLP antibodies are selected as a model norovirus, which is target protein, and the candidate bioreceptors respectively. Among the 5 different candidate antibodies, appropriate antibody could be sorted out within 30 minutes through rBSM. In addition, selected antibodies were applied to two representative LFIA based techniques, sandwich assay and competitive assay. Among these methods, sandwich assay showed more effective VLP detection method. Through applying selected antibodies and techniques to the commercialized mass production lines, an VLP detecting LFIA kit was developed with a detection limit of 10¹² copies/g of VLPs in real samples. Since this proposed method in this study could be easily transformable into other combinations with bioreceptors, it is expected that this technique would be applied to LFIA kit development system and bioreceptor quality management.