• Journal of Microbiology and Biotechnology
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• v.25 no.11
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• pp.1960-1965
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• 2015

Rabbit hemorrhagic disease virus (RHDV) is highly contagious and often causes fatal disease that affects both wild and domestic rabbits of the species Oryctolagus cuniculus. A highly pathogenic RHDV variant (RHDVa) has been circulation in the Korean rabbit population since 2007 and has a devastating effect on the rabbit industry in Korea. A highly pathogenic RHDVa was isolated from naturally infected rabbits, and the gene encoding the VP60 protein was cloned into a baculovirus transfer vector and expressed in insect cells. The hemagglutination titer of the Sf-9 cell lysate infected with recombinant VP60 baculovirus was 131,072 units/50 μl and of the supernatant 4,096 units/50 μl. Guinea pigs immunized twice intramuscularly with a trial inactivated RHDVa vaccine containing recombinant VP60 contained 2,152 hemagglutination inhibition (HI) geometric mean titers. The 8-week-old white rabbits inoculated with one vaccine dose were challenged with a lethal RHDVa 21 days later and showed 100% survival rates. The recombinant VP60 protein expressed in a baculovirus system induced high HI titers in guinea pigs and rendered complete protection, which led to the development of a novel inactivated RHDVa vaccine.

• Microbiology and Biotechnology Letters
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• v.46 no.3
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• pp.269-276
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• 2018

Rabies virus (RABV)-specific antibodies in animals and humans are measured using standard methods such as fluorescent antibody virus neutralization (FAVN) tests and rapid fluorescent focus inhibition tests, which are based on cell culture systems. An alternative assay that is safe and easy to perform is required for rapid sero-surveillance following mass vaccination of animals. Two purified monoclonal antibodies (4G36 and B2H17) against RABV were selected as capture and detection antibodies, respectively. A genetically modified RABV, the ERAGS strain, was propagated and concentrated by polyethylene glycol precipitation. Optimal conditions for the RABV antigen, antibodies, and serum dilution for a blocking enzymelinked immune sorbent assay (B-ELISA) were established. We evaluated the sensitivity, specificity, and accuracy of the B-ELISA using serum samples from 138 dogs, 71 raccoon dogs, and 25 cats. The B-ELISA showed a diagnostic sensitivity of 95.8-96.3%, specificity of 91.3-100%, and accuracy of 96.0-97.2% compared to the FAVN test. These results suggest that the B-ELISA is useful for sero-surveillance of RABV in dogs, raccoon dogs, and cats.

• BMB Reports
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• v.53 no.11
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• pp.565-575
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• 2020

Gene therapy is emerging as a treatment option for inherited genetic diseases. The success of this treatment approach greatly depends upon gene delivery vectors. Researchers have attempted to harness the potential of viral vectors for gene therapy applications over many decades. Among the viral vectors available, gutless adenovirus (GLAd) has been recognized as one of the most promising vectors for in vivo gene delivery. GLAd is constructed by deleting all the viral genes from an adenovirus. Owing to this structural feature, the production of GLAd requires a helper that supplies viral proteins in trans. Conventionally, the helper is an adenovirus. Although the helper adenovirus efficiently provides helper functions, it remains as an unavoidable contaminant and also generates replication-competent adenovirus (RCA) during the production of GLAd. These two undesirable contaminants have raised safety concerns and hindered the clinical applications of GLAd. Recently, we developed helper virus-free gutless adenovirus (HF-GLAd), a new version of GLAd, which is produced by a helper plasmid instead of a helper adenovirus. Utilization of this helper plasmid eliminated the helper adenovirus and RCA contamination in the production of GLAd. HF-GLAd, devoid of helper adenovirus and RCA contaminants, will facilitate its clinical applications. In this review, we discuss the characteristics of adenoviruses, the evolution and production of adenoviral vectors, and the unique features of HF-GLAd as a new platform for gene therapy. Furthermore, we highlight the potential applications of HF-GLAd as a gene delivery vector for the treatment of various inherited genetic diseases.

• BMB Reports
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• v.30 no.4
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• pp.269-273
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• 1997

Heptocvte-specific expression induced by Hepatitis B virus (HBV) enhancer 2-core gene promoter was examined in various hepatocyte and non-hepatocyte cell lines. using non-viral and retroviral vector systems in which chloramphenicol acetyltransferase (CAT) is used as a reporter. The non-viral plasmid containing the HBV enhancer 2-core promoter exhibited 22 and 66% of CAT activities in hepatoma cell lines. HepG2 and Hep3B, respectively when compared with CAT activity expressed by CMV promoter. The CAT activities, however. were found to be marginal in other tested hepatoma cell lines as well as mouse primary hepatocytes and non-hepatocytes. The HBV enhancer 2 located upstream the CMV promoter did not affect the CMV promoter activity nor provided hepatocyte-specific expression. Transfection of retroviral plasmid DNA containing the HBV enhancer 2-core promoter as an internal promoter exhibited high and specific CAT expression in HepG2 and Hep3B cell lines but the activity value was 5 to 10 fold lower than the non-viral plasmid with identical promoter. These results suggest that the usage of HBV enhancer 2-core promoter for liver specific expression is limited to certain vectors and hepatocyte cell lines.

• Journal of fish pathology
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• v.30 no.2
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• pp.149-154
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• 2017

Mouse monoclonal antibodies (MAbs) were produced by using viral hemorrhagic septicemia virus (VHSV, genotype IVa) as an immunogen, isolated from diseased olive flounder (Paralichthys olivaceus). Four hybridoma clones secreting MAbs against VHSV were established. The MAbs were recognized the nucleoprotein (MAb 4), phosphoprotein (MAb 1) and matrix protein (MAbs 2 and 3) of VHSV by western blot analysis. Among them, the MAbs 1 and 4 strongly reacted with the VHSV-infected FHM cells, but not normal FHM cells. In enzyme linked immunosorbent assay, the four MAbs reacted with the VHSV, but not different six fish viruses (infectious hematopoietic necrosis virus, hirame rhabdovirus, spring viraemia of carp virus, infectious pancreatic necrosis virus, marine birnavirus and nervous necrosis virus). These results indicate that the MAbs are useful for diagnosis of VHSV infection.

• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.241-259
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• 2006

Polydnavirus is a mutualistic DNA virus found in some braconid and ichneumonid wasps. Its genome is integrated into host chromosome as a provirus. Its replication occurs at ovarian calyx epithelium during host pupal stage to form episomal viral particles. The viral particles are delivered into hemocoel of the parasitized insect along with eggs during wasp oviposition. Several polydnaviral genomes, which are isolated from the episomal virus particles, have been sequenced and exhibit some gene families with speculative physiological functions. This review presents the viral characteristics in terms of Its parasitic physiology. For developing new insect pest control tactics, it also discusses several application strategies exploiting the viral genome to manipulate insect physiology.

• Korean Journal of Pharmacognosy
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• v.42 no.1
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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.

• The Plant Pathology Journal
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• v.17 no.3
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• pp.115-122
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• 2001

Potato virus X (PVX) is a flexuous rod-shaped virus containing a single plus-strand RNA. Viral RNA synthesis is precisely regulated by regulatory viral sequences and by viral and/or host proteins. RNA sequence element as well as stable RNA stem-loop structure in the 5' end of the genome affect accumulation of genomic RNA and subgenomic RNA (sgRNA). The putative sgRNA promoter regions upstream of the PVX triple gene block (TB) and coat protein (CP) gene were critical for both TB and CP sgRNA accumulation. Mutations that disrupted complementarity between a region at the 5' end of the genomic RNA and the sequences located upstream of each sgRNA initiation site is important for PVX RNA accumulation. Compensatory mutations that restore complementarity restored sgRNA accumulation levels. However, the extent of reductions in RNA levels did not directly correlate with the degree of complementarity, suggesting that the sequences of these elements are also important. Gel-retardation assays showed that the 5' end of the positive-strand RNA formed an RNA-protein complex with cellular proteins, suggesting possible involvement of cellular proteins for PVX replication. Future studies on cellular protein binding to the PVX RNA and their role in virus replication will bring a fresh understanding of PVX RNA replication.

• Korean Journal of Veterinary Research
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• v.47 no.2
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• pp.163-167
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• 2007

Bovine viral diarrhea (BVD) is very important disease in cattle industry with a worldwide distribution. Detection and elimination of persistently infected calves with bovine viral diarrhea virus (BVDV) was valuable strategy for BVD eradication because those calves were main source for transmission. We surveyed persistent infection with BVDV by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) using whole blood and skin. Five hundred thirty nine Korean native calves were tested. Four calves (0.7%) were positive for BVDV antigen for both tests. Those calves remained positive for follow-up by RT-PCR and IHC. Therefore they were identified as persistently infected with BVDV. We confirmed that immunohistochemistry using skin biopsy samples was very useful tool to detect persistently infected calves with BVDV. As far as we know, this would be first report on persistent infection with BVDV in Korea.

• Journal of Microbiology
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• v.44 no.2
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• pp.217-225
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• 2006

Kaposi's sarcoma-associated herpesvirus (KSHV) RTA transcription factor is recruited to its responsive elements through interaction with RBP-Jk that is a downstream transcription factor of the Notch signaling pathway that is important in development and cell fate determination. This suggests that KSHV RTA mimics cellular Notch signal transduction to activate viral lytic gene expression. Here, I demonstrated that unlike other B lymphoma cells, KSHV -infected primary effusion lymphoma BCBL1 cells displayed the constitutive activation of ligand-mediated Notch signal transduction, evidenced by the Jagged ligand expression and the complete proteolytic process of Notch receptor I. In order to investigate the effect of Notch signal transduction on KSHV gene expression, human Notch intracellular (hNIC) domain that constitutively activates RBP-Jk transcription factor activity was expressed in BCBL1 cells, TRExBCBL1-hNIC, in a tetracycline inducible manner. Gene expression profiling showed that like RTA, hNIC robustly induced expression of a number of viral genes including KS immune modulatory gene resulting in downregulation of MHC I and CD54 surface expression. Finally, the genetic analysis of KSHV genome demonstrated that the hNIC-mediated expression of KS during viral latency consequently conferred the downregulation of MHC I and CD54 surface expression. These results indicate that cellular. Notch signal transduction provides a novel expression profiling of KSHV immune deregulatory gene that consequently confers the escape of host immune surveillance during viral latency.