• Journal of Life Science
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• v.20 no.8
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• pp.1181-1185
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• 2010

This study was carried out to evaluate the vaccination effects of recombinant fusion protein rVP19+28 against WSSV in shrimp, Litopenaeus vannamei. The VP19+28 gene fused with VP19 and VP28 genes was inserted into pET-28a(+) expression vector and cloned in E. coli BL21 (DE3) to produce fused gene product recombinant VP19+VP28 as a single protein. For the vaccination, the shrimps were fed with pellets coated with purified recombinant protein, rVP19+28, for 2 weeks. Then, constant amounts of WSSV at $1{\times}10^2$ diluted stocks were injected to the muscle of the shrimp for the in vivo challenge tests. Non-vaccinated shrimps showed a cumulative mortality of 100% at 11 days post-challenge. The shrimps vaccinated with the inactivated E. coli BL21 as a host cell control showed cumulative mortality of 100% at 17 days post-challenge. The shrimps vaccinated with rVP19, rVP28 and rVP19+28 showed mortalities of 66.7%, 41.7% and 41.7% at 21 days post-challenge, respectively. These results indicated that the rVP28 and rVP19+28 had relatively high vaccination effects against WSSV infection. However, this study suggests that the fusion protein rVP19+28 was more effective for the protection of shrimp against WSSV than rVP28, even though the cumulative mortalities were the same 21 days post-challenge.

• BMB Reports
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• v.37 no.6
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• pp.726-734
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• 2004

White spot disease (WSD) is caused by the white spot syndrome virus (WSSV), which results in devastating losses to the shrimp farming industry around the world. However, the mechanism of virus entry and spread into the shrimp cells is unknown. A binding assay in vitro demonstrated VP28-EGFP (envelope protein VP28 fused with enhanced green fluorescence protein) binding to shrimp cells. This provides direct evidence that VP28-EGFP can bind to shrimp cells at pH 6.0 within 0.5 h. However, the protein was observed to enter the cytoplasm 3 h post-adsorption. Meanwhile, the plaque inhibition test showed that the polyclonal antibody against VP28 (a major envelope protein of WSSV) could neutralize the WSSV and block an infection with the virus. The result of competition ELISA further confirmed that the envelope protein VP28 could compete with WSSV to bind to shrimp cells. Overall, VP28 of the WSSV can bind to shrimp cells as an attachment protein, and can help the virus enter the cytoplasm.

• Journal of fish pathology
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• v.27 no.1
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• pp.11-16
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• 2014

The resistance against white spot syndrome virus (WSSV) infection in wild marine crab Gaetice depressus by the immunization of a recombinant glutathione-S-transferase (GST) fused VP28 protein (GST-VP28) was evaluated. The cumulative mortalities of GST-VP28 injected groups were lower than those of the control groups at 10 days of post-challenge, and the time to death of 50% crab ($TD_{50}$) was delayed by the immunization using GST-VP28. The group boosted with GST-VP28 after 2 weeks of primary immunization clearly showed longer $TD_{50}$ than non-boosted group against challenge with WSSV. This result suggests that boosting with the antigen protein elicit stronger immune responses similar to adaptive immune responses of vertebrates. However, the short $TD_{50}$ was observed in the group challenged at 3 weeks post boosting comparing to the group challenged at 1 week post boosting. This suggests that the protective strength of immunization decreased by the time.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2003.10a
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• pp.41-41
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• 2003

White spot syndrome virus (WSSV) is the causative agent of a disease that has led to severe mortalities of cultured shrimps in Korea and many other countries. Since 1993, massive mortalities due to the viral infection have also occurred in the penaeid shrimps cultured in Korea. WSSV is a large, circular, double stranded (ds) DNA virus and an enveloped, ellipsoid virus with a rod-shaped nucleocapsid with flat ends. In order to identify the characteristics of this Korean isolate of WSSV, the genes for four virion proteins, VP15, VP19, VP28 and VP35 were cloned and their sequences were compared with the available pool of WSSV gene sequences in the GenBank/EMBL databases. From these comparisons, we confirm the occurrence of WSSV in Korea and deduce that, VP15, VP28 and VP35 genes are identically conserved among the Korean isolate and geographically different foreign isolates, but VP19 amino acid sequences of the Korean WSSV isolates changed valine of the foreign isolates into aspartate. (omitted)

• Journal of fish pathology
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• v.32 no.1
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• pp.45-48
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• 2019

We developed and subsequently characterized mouse monoclonal antibodies (MAbs) against recombinant VP28 structural protein (rVP28) of white spot syndrome virus (WSSV). We established six hybridoma clones secreting MAbs against rVP28: 15A11, 20G6, 31H2, 34H6, 38D1 and 43A1. All six MAbs recognized the 25 kDa of protein in gill homogenates of WSSV-infected shrimp by western blot analysis, while no reactivity was observed in gill homogenates of normal shrimp. Moreover, high enzyme-linked immunosorbent assay (ELISA) optical density (OD) values (0.8-2.68) were observed in the hemolymphs from WSSV-infected shrimp, while low OD values (less than 0.24) were recorded in the hemolymphs from normal shrimp, by using these six MAbs produced in this study. These results suggest that these six MAbs are useful for the detection of WSSV.

• Journal of fish pathology
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• v.28 no.2
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• pp.93-98
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• 2015

Full-length recombinant VP2 and VP3 proteins of aquabirnavirus isolated from olive flounder were expressed successfully in E. coli expression system. After rats were immunized with these proteins, antisera were used for in vitro and in vivo neutralization test. In in vitro test, VP2 antibody titers were higher than that of VP3. In in vivo assays, fish challenged with aquabirnavirus neutralized with VP2 antibody survived longer than other fish.

• Journal of Life Science
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• v.28 no.4
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• pp.478-482
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• 2018

Human rotavirus is a causative agent of acute diarrhea among children. The artificial gene encoding the truncated $VP8^*$ protein of human rotavirus A (serotype 1 strain WA) was synthesized according to the Escherichia coli codon preference. The synthetic $VP8^*$ gene also possessed the NdeI and HindIII restriction sites for the convenient in-frame cloning for translation and a 6-histidine tag at C-terminus for Ni+ affinity purification. Molecular weight of the truncated $VP8^*$ protein deduced from the nucleotide sequences of the artificial gene was a 19.7-kDa. This synthetic $VP8^*$ DNA fragment was inserted into the pT7-7 expression vector and transformed into E. coli BL21 (DE3). Transformants harboring the synthetic gene encoding the $VP8^*$ protein was induced by supplement of a final concentration of 0.05 mM ITPG at $20^{\circ}C$. Protein crude extract from the E. coli transformants was subjected to Western blotting with the mouse anti-rotavirus capsid antibody, showing ~20-kDa $VP8^*$ protein band. The truncated $VP8^*$ protein band was also observed by Western blotting using the rabbit polyclonal antibody serum made against the truncated $VP8^*$ protein. This study suggested that the synthetic gene could be used as an easy way to produce the antigenic vaccine candidate for control of virus-associated diseases or to develop antibodies for diagnostic purpose.

• The Journal of Korean Society of Virology
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• v.28 no.2
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• pp.165-174
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• 1998

Characterizations of the VP4 (P type) and VP7 (G type) genes of Korean isolates of bovine rotavirus were performed using RT-PCR/RFLP and nucleotide sequencing analysis. After RT-PCR amplification of partial length (1094bp) of the VP4 and full length (1062bp) of the VP7 genes, amplified PCR products were digested with restriction endonucleases and digestion patterns were compared with those of reference rotaviruses. With the VP4 genes, four RFLP (A-D) profiles were observed; three (A, Band C) were the same as those of bovine rotavirus NCDV (P[1]), IND (P[5]) and B223 (P[11]), respectively. Profile D was the same as that of porcine rotavirus OSU (P[7]). With the VP7 genes, five RFLP profiles (I-V) were observed; three of them (I, II and III) were the same as those of bovine rotavirus NCDV (G6), Cody 1-801 (G8), and B223 (G10), respectively. Profile IV and V were atypical to those of reference bovine rotaviruses used in this study. These two profiles were identified as G6 and G5, respectively, after analyzing and comparing the nucleotide sequences. The G typing analysis revealed that 61.9% (26/42) were G6, which included G6 subtype; 28.6% (12/42) were G5; 7.1% (3/42) were G10; 2.4% (1/42) were G8. The P typing analysis revealed that 54.8% (23/42) were P[5]; 28.6% (12/42) were P[7]; 11.8% (5/42) were [11]; 4.8% (2/42) were P[1]. Our results showed that G6/P[5] were the most prevalent rotaviruses in diarrheic calves in Korea. Also, this is the first report that G5/P[7] rotaviruses were identified from cattle with diarrhea.

• Journal of Microbiology and Biotechnology
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• v.21 no.2
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• pp.170-175
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• 2011

This study was carried out for the molecular level identification of recombinant protein vaccine efficacy, by oral feeding against white spot syndrome virus infection, with the comparison of viral mRNA transcriptional levels in shrimp cells. For the determination of WSSV dilution ratio for the vaccination experiment by oral feeding, in vivo virus titration was carried out using different virus dilutions of virus stock ($1{\times}10^2$, $2{\times}10^2$, and $1{\times}10^3$). Among the dilution ratios, $2{\times}10^2$ diluted WSSV stock was chosen as the optimal condition because this dilution showed 90% mortality at 10 days after virus injection. Recombinant viral proteins, rVP19 and rVP28, produced as protein vaccines were delivered in shrimps by oral feeding. The cumulative mortalities of the shrimps vaccinated with rVP19 and rVP28 at 21 days after the challenge with WSSV were 66.7% and 41.7%, respectively. This indicates that rVP28 showed a better protective effect against WSSV in shrimp than rVP19. Through the comparison of mRNA transcriptional levels of viral genes from collected shrimp organ samples, it was confirmed that viral gene transcriptions of vaccinated shrimps were delayed for 4~10 days compared with those of unvaccinated shrimps. Protection from WSSV infection in shrimp by the vaccination with recombinant viral proteins could be accomplished by the prevention of entry of WSSV due to the shrimp immune system activated by recombinant protein vaccines.

• Journal of IKEEE
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• v.3 no.1 s.4
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• pp.22-28
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• 1999

The existing CREG-VP, a technique to compensate the successive cell losses caused by traffic congestion using the FEC method on the Vp, has the merits of the short average encoding decoding time and the compatibility with the ATM standard cell format, but it has the restriction in the number of regenerable cells. In this thesis, we propose a scheme to efficiently regenerate the cell losses even in the burst traffic property by the expansion of the CREG-VP. The proposed scheme improves the detection capability of the lost cells by changing the CRP and the regeneration performance of the successive cells by using the interleaved parity cell. The simulation result shows that the proposed method produces much improvements compared with the existing ones in the cell loss rate reduction factor.