• ALGAE
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• v.30 no.2
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• pp.81-87
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• 2015

Recent studies have shown the importance of viruses as potential sources of plankton mortality, which affect primary production and biogeochemical functions of their hosts. Here, we report basic characteristics of a novel virus (Stephanopyxis palmeriana virus: SpalV) that causes lysis of a culture of the diatom S. palmeriana, which was isolated in Jaran Bay, Korea, in August 2008. SpalV is a round-shaped viral particle ~25-30 nm in diameter that propagates in its host's cytoplasm. In addition, it shows species-specific infectivity among the tested diatom species. The burst size and latent period are estimated to be roughly 92 infectious units $cell^{-1}$ and <80 h, respectively.

• The Plant Pathology Journal
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• v.34 no.2
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• pp.85-92
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• 2018

Enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR), widely used for the detection of plant viruses, are not easily performed, resulting in a demand for an innovative and more efficient diagnostic method. This paper summarizes the characteristics and research trends of biosensors focusing on the physicochemical properties of both interface elements and bioconjugates. In particular, the topological and photophysical properties of quantum dots (QDs) are discussed, along with QD-based biosensors and their practical applications. The QD-based Fluorescence Resonance Energy Transfer (FRET) genosensor, most widely used in the biomolecule detection fields, and QD-based nanosensor for Rev-RRE interaction assay are presented as examples. In recent years, QD-based biosensors have emerged as a new class of sensor and are expected to open opportunities in plant virus detection, but as yet there have been very few practical applications (Table 3). In this article, the details of those cases and their significance for the future of plant virus detection will be discussed.

• The Journal of Korean Society of Virology
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• v.30 no.1
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• pp.61-70
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• 2000

Standard plaque assay using agarose-overlay has long been used for titration of many infectious virus particle. Plaque assay for the titration of varicella-zoster virus and its live vaccine requires three intermittent agarose overlay to visualize plaques. Overall procedure of the assay takes at least nine days from virus inoculation and microbe contamination including fungi is frequently accompanied during incubation period. We studied whether an immunofocus assay in conjunction with peroxidase-mediated immunohistochemical reaction may replace the standard plaque assay for the virus titration by comparing the two methods. A linear relationship was observed between number of foci and virus dilution. The number of foci in a given dilution of virus appeared a little higher than counted plaques formed in standard plaque assay. Independent titration results obtained from two assay methods for a given dilution of virus demonstrated a strong correlation ($r^2=0.99$). Foci of virus infected cells as revealed by the enzyme reaction could be counted either 4 days post-infection (p.i.) under low magnification (40X) microscopy, or 6 days p.i. by naked eye observation. Larger size of cell cuture plate, virus adsorption at $35^{\circ}C$, and 10% FBS in diluent appeared to be better conditions for the assay. Immunofocus assay will be an effective and dependable titration method for varicella-zoster virus and its live vaccine in place of the standard plaque assay in respect to accuracy, costs, and experimental convenience.

• Korean Journal of Microbiology
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• v.29 no.2
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• pp.75-79
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• 1991

The yeast L-A virus (4.6 kb dsRNA genome) encodes the major coat protein and a "gag-pol" fusion minor coat protein that separately encapsidate itself and $M_{1}$, a 1.8 kb dsRNA satellite virus encoding a secreted protein toxin (the killer toxin). The teast chromosomal SKI genes prevent viral cytopathology by lowering the virus copy number. Thus, $ski^{-}$ mutants are ts and cs for growth. We transformed a ski2-2 virus-infested mutant with a yeast bank in a high copy cloning vector and selected the rare healthy transformants for analysis. One type of transformant segregated M-O L-A-O cells with high frequency. Elimination of the DNA clone from the ski2-2 strain eliminated this phinotype and introduction of the DNA clone recovered from such transformants into the parent ski2-2 strain, or into ski3 or ski6 mutants gave the same phenotype. This killer-curing phenotype was due to the curing of the helper L-A dsRNA virus. The 6.5 kb insert only had this activity when carried on a high copy vector and in $ski^{-}$ cells (not in $SKI^{+}$ cells). This 6.5 kb insert acts as a mutagen on L-A dsRNA producing a high rate of deletion mutations.mutations.

• Korean journal of applied entomology
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• v.30 no.3
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• pp.180-186
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• 1991

This study was carried out to acquire some basic biochemical informations on the granulosis virus(GV) of Pieris rapae and Pieris brassicae. The capsule protein was composed of a single polypeptide with a molecular weight of 30,000 dalton for P. rapae GV and 31,000 dalton for P. brassicae GV. The major amino acids of capsule protein were glutamic acid, aspartic acid and lysine. When the capsule protein was partially digested with trypsin, chymotrypsin, papain or Staphylococcus aureus V8 protease, the digested products of the two viruses showed no difference in electrophoretic mobility. The patterns of the polypeptides of the two virus particle on SOS-polyacrylamide gel showed a little difference in high molecular weight region(over MW 100 kd).

• Korean journal of applied entomology
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• v.34 no.3
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• pp.218-223
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• 1995

A nuclear polyhedrosis virus isolated from the oriental tobacco budworm larvae, Helicoverpa assulta (Guenee) was characterized by electron microscopy, SDS-PAGE, restriction endonuclease analysis and cross infectivity. The shape of a polyhedron was $1.0\mu\textrm{m}$ in average with icosahdral outline, and the virus particle was $65nm\times300nm$ in average with rod-shape. The nuclear polyhedrosis virus was contained a single nucleocapsid within a viral envelope embedded in a polyhedron. The polyhedral protein was composed of a single polypeptide with a M.W. of 31 Kd. The genome size of the virus by restriction endonuclease analysis was about 120 Kb. Among several nuclear polyhedrosis viruses, the nuclear polyhedrosis virus from Helicoverpa assulta (HaNPV) and Autographa california nuclear polyhedrosis virus (AcNPV) were infected the oriental tobacco budworm larvae.

• Korean Journal of Veterinary Research
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• v.35 no.3
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• pp.575-581
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• 1995

Both immunoelectron microscopy(IEM) and immunogold conjugate immunoelectron microscopy (IGC-IEM) techniques were developed for the detection of porcine epidemic diarrhea virus(PEDV) from the feces. Fecal samples were incubated sequentially with anti-PEDV monoclonal antibody(MoAb) and immunogold conjugated goat anti-mouse IgG+IgM. Then negatively stained, mounted on the formvar carbon-coated copper EM grids and observed by the transmission electron microscope. By the direct electron microscopy(DEM), coronavirus particles were observed from 17 cases of total 33 fecal samples of grower pigs and sows. The virons of coronavirus were moderately pleomorphic but mostly spherical, with a diameter ranged from 90 to 190nm. PED virus particles were identified from 15 cases of 17 DEM positive samples by the IEM and IGC-IEM techniques. Aggregates of PED virus coated with specific antibody were seen in fecal samples incubated with homologous anti-PED virus MoAb but not in control samples incubated with anti-TGE virus MoAb. Following incubation with immunogold-conjugated secondary antibody, the gold granules were usually distributed around and among the virus particles and soluble and viral particle-associated antigen. So, IEM and IGC-IEM techniques were proved a rapid and sensitive methods for detection and identification of PED virus from fecal and intestinal contents.

• Journal of Microbiology and Biotechnology
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• v.15 no.6
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• pp.1229-1239
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• 2005

Human immunodeficiency virus-like particles (HIVVLPs) with native conformations similar to that of the wild-type virion could be valid candidates for vaccine development. To this end, we used a Semliki Forest Virus (SFV) expression system to produce HIV- VLPs containing high quantities of native envelope proteins. Here, we described a single SFV replicon containing the HIV gagpol and env genes under the control of separate subgenomic promoters. Mature VLPs incorporating the Gag and Env proteins were detected in the supernatant of replicon-expressing cells by Western blot analysis. The HIV-VLPs showed the expected molecular density (1.14-1.18 g/ml) on a $20-60\%$ sucrose gradient; the particles were 100-120 nm in diameter and Env proteins were observed on their surfaces by immunogold electron microscopy. RT-PCR analysis of VLP-associated RNAs in mature HIV-VLPs revealed two SF V-derived RNA species (full-length and subgenomic). Immunization studies in Balb/c mice showed that these HIV-VLPs were capable of inducing both HIV-specific antibodies and cell-mediated immune responses. Taken together, our results indicate that the SFV replicon system is useful for the production of HIV-VLPs, which may be valuable candidates for an HIV vaccine.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.42 no.6
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• pp.327-336
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• 2016

Cervical cancer is the second most prevalent cancer among women, and it arises from cells that originate in the cervix uteri. Among several causes of cervical malignancies, infection with some types of human papilloma virus (HPV) is well known to be the greatest cervical cancer risk factor. Over 150 subtypes of HPV have been identified; more than 40 types of HPVs are typically transmitted through sexual contact and infect the anogenital region and oral cavity. The recently introduced vaccine for HPV infection is effective against certain subtypes of HPV that are associated with cervical cancer, genital warts, and some less common cancers, including oropharyngeal cancer. Two HPV vaccines, quadrivalent and bivalent types that use virus-like particles (VLPs), are currently used in the medical commercial market. While the value of HPV vaccination for oral cancer prevention is still controversial, some evidence supports the possibility that HPV vaccination may be effective in reducing the incidence of oral cancer. This paper reviews HPV-related pathogenesis in cancer, covering HPV structure and classification, trends in worldwide applications of HPV vaccines, effectiveness and complications of HPV vaccination, and the relationship of HPV with oral cancer prevalence.

• Korean Journal Plant Pathology
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• v.14 no.3
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• pp.229-239
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• 1998

Antibodies were raised against fusion proteins of the N-terminus and a region containing the GDNQ (Gly-Asp-Asn-Gln) polymerase motif of the L (polymerase) protein of sonchus yellow net virus (SYNV). Immunoblot analyses using these antibodies revealed the presence of the L protein in purified SYNV preparations and in nuclear extracts from infected tobacco. The serological analyses and detection in a polyacrylamide gels suggested that the L protein is present in at least a 20 fold lower abundance than the G, N, M1 and M2 proteins, and has size corresponding to a molecular weight of over 200 kDa as predicted from nucleotide sequence data. Electron microscopy with gold-labelled antibodies was used to localize the N, M2, and G proteins of SYNV in thin sections of infected tissue. When sections of SYNV-infected tissue were treated with antisera against total SYNV proteins and N protein, gold label could be detected in both the viroplasms and in virus particles. With the anti-M2 protein antiserum, the gold label was strongly localized in the viroplasms but only limited labelling of the virus particle sonly. Limited labelling of the L protein was observed in the viroplasms and the virus particles, presumably because of the low abundance of L protein in the tissues.