• 한국동물위생학회지
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• 제32권1호
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• pp.19-25
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• 2009

Porcine reproductive and respiratory syndrome (PRRS) virus is the etiological agent of diseases characterized by reproductive losses in sows and respiratory disorders in piglets. The PRRS virus is a small enveloped virus containing a positive-sense, single-stranded RNA genome. In the present study, ORF6 gene of Korean PRRS virus isolate, CNV, was cloned and expressed in baculovirus expression system. The ORF6 gene and expressed protein in the recombinant virus were confirmed by PCR/indirect fluorescence antibody (IFA) test and Western blotting, respectively. The recombinant protein with a molecular weight of approximately 24KDa was confirmed by Western blotting using His6 and PRRS virus-specific antiserum. Expressed ORF6 protein was applied for IFA to detect antibody against PRRS virus using field porcine sera. However, the sensitivity and specificity of developed IFA using expressed ORF6 protein were considerably low compared to those of commercial ELISA kit. This results suggest that IFA using expressed ORF6 protein could not be used as a diagnostic test for PRRS virus infection without further improvements.

• International Journal of Industrial Entomology and Biomaterials
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• 제7권2호
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• pp.127-131
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• 2003

Protein disulfide isomerase (PDI) found in the endoplasmic reticulum (ER) catalyzes disulfide bond exchange and assists in protein folding of newly synthesized proteins. PDI also functions as a molecular chaperone and has been found to be associated with proteins in the ER. In addition, PDI functions as a subunit of two more complex enzyme systems: the prolyl-4-hydroxylase and the triacylglycerol transfer proteins. A cDNA that encodes protein disulfide isomerase was previously isolated from Bombyx mori (bPDI), in which open reading frame of 494 amino acids contained two PDI-typical thioredoxin active site of WCGHCK and an ER retention signal of the KDEL motif at its C-terminal, and we report its functional characterization here. This putative bPDI cDNA is expressed in insect Sf9 cells as a recombinant proteins using baculovirus expression vector system. The bPDI recombinant proteins are successfully recognized by antirat PDI antibody, and shown to be biologically active in vitro by mediating the oxidative refolding of reduced and scrambled RNase. This suggests that bPDI may play an important role in protein folding mechanism of insects.

• Journal of Microbiology and Biotechnology
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• 제31권4호
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• pp.529-539
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• 2021

The beet armyworm, Spodoptera exigua, is a serious insect pest infesting various vegetable crops. Two infectious insect viruses, baculovirus and iflavirus, are known to induce epizootics in S. exigua populations. Indeed, some laboratory colonies have appeared to be covertly infected by these viruses. Diagnostic PCR tests detected two different viruses: Spodoptera exigua multiple nucleopolyhedrosis virus (SeMNPV) and iflaviruses (SeIfV1 and SeIfV2). Viral extract from dead larvae of S. exigua could infect Sf9 cells and produce occlusion bodies (OBs). Feeding OBs to asymptomatic larvae of S. exigua caused significant viral disease. Interestingly, both SeIfV1 and SeIfV2 increased their titers at late larval stages. Sterilization of laid eggs with 1% sodium hypochloride significantly reduced SeMNPV titers and increased larval survival rate. Double-stranded RNA (dsRNA) specific to SeIfV1 or SeIfV2 significantly reduced viral titers and increased larval survival rate. To continuously feed dsRNA, a recombinant Escherichia coli HT115 expressing SeIfV1-dsRNA was constructed with an L4440 expression vector. Adding this recombinant E. coli to the artificial diet significantly reduced the SeIfV1 titer and increased larval survival. These results indicate that laboratory colony collapse of S. exigua is induced by multiple viral infections. In addition, either suppression of SeMNPV or SeIfV infection significantly increased larval survival, suggesting a cooperative pathogenicity between baculovirus and iflavirus against S. exigua.

• Journal of Microbiology and Biotechnology
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• 제8권6호
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• pp.685-691
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• 1998

Baculovirus Hyphantrin. cunea nuclear polyhedrosis virus (HcNPV) insecticide containing the insecticidal protein (ICP) gene from Bacillus thuringiensis subsp. kurstaki HD1 was constructed using a lacZ-HcNPV system. The ICP ($\delta$-endotoxin) gene was placed under the control of the polyhedrin gene promoter of the HcNPV. A polyhedrin-negative virus was derived and named ICP-HcNPV insecticide. Then, the insertion of the ICP gene in the ICP-HcNPV genome was confirmed by Southern hybridization analysis. Polyacrylamide gel electrophoresis (PAGE) analysis of the Spodoptera frugiperda cell extracts infected with the ICP-HcNPV showed that the ICP was expressed in the insect cells as 130 kDa at 5 days post-infection. The ICP produced in the cells was present in aggregates. When extracts from the cells infected with the ICP-HcNPV were fed to 20 Bombyx mori larvae, the following mortality rate was seen; 8 larvae at 1 h, 10 larvae at 3 h, and 20 larvae at 12 h. These data indicate that the B. thuringiensis ICP gene was expressed by the baculovirus insecticide in insect cells and there was a high insecticidal activity. The biological activities of the recombinant virus ICP-HcNPV were assessed in conventional bioassay tests by feeding virus particles and ICP to the insect larvae. The initial baculovirus insecticide ICP-HcNPV was developed in our laboratory and the significance of the genetically engineered virus insecticides is discussed.

• 한국잠사곤충학회지
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• 제38권1호
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• pp.42-47
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• 1996

AcNPV와 BmNPV를 배양세포주에서 동시감염시켜 선발한 숙주범위가 넓어진 재조합 바이러스인 RecB-727과 RecS-A6의 분자생물학적인 특성들을 조사하였다. 재조합 바이러스의 LT50 값을 조사한 결과, RecS-A6는 모바이러스인 BmNPV 보다 비교적 낮은 병원성을 보았으나 RecB-727은 거의 비슷한 수준의 높은 병원성을 나타내었다. 재조합 바이러스 DNA를 분리하여 모바이러스 DNA와 함께 제한효소 패턴을 비교한 결과 DNA 수준에서 재조합이 일어났음을 확인할 수 있었으며, 일부 유전자의 재조합을 예측할 수 있었다. 또한 p10 유전자에 대한 Southern blot 분석 결과 RecB-727의 p10 유전자는 AcNPV에서 유래되었으며, RecS-A6는 BmNPV의 p10 유전자를 갖고 있는 것으로 추정된다. 재조합 바이러스의 숙주범위 확장에 중요한 역할을 하는 것으로 알려진 DNA helicase 유전자 내의 HindIII-SacI 0.6kb 부위에 대하여 약 250 bp의 염기서열을 조사한 결과, 이 부위의 염기서열은 BmNPV helicase의 염기서열과 동일하였다.

• International Journal of Industrial Entomology and Biomaterials
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• 제15권2호
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• pp.131-135
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• 2007

Open reading frame 4 of Bombyx mori nucleopolyhedrovirus (BmNPV), designated as Bm4, is a gene whose function is completely unknown. With the recently developed BmNPV bacmid and a modified pFastBac1 whose polyhedrin promoter was replaced with ie1 promoter, a recombinant bacmid expressing Bm4-EGFP fusion protein under the control of ie1 promoter in BmN cells was successfully constructed. The result not only showed that the polyhedrin promoter can be replaced efficiently with other promoters to direct the expression of foreign gene in BmN cells by using Bac-to-Bac/BmNPV baculovirus expression system but also laid the foundation for rescue experiment of Bm4 deletion mutant due to the ability of ie1 promoter to direct gene expression throughout the infection cycle.

• 한국미생물·생명공학회지
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• 제24권1호
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• pp.72-76
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• 1996

To investigate the expression efficiency of new transfer vector of Bombyx mori nuclear polyhedrosis virus (BmNPV), Escherichia coli lacZ gene was inserted into new transfer vector pBmKSK1, under the control of polyhedrin promoter and expressed in BmN-4 cells and larvae of silkworm, Bombyx mori. The recombinant virus containing lacZ gene was isolated from BmN-4 cells coinfected with transfer vectro pBmKSK1-LacZ and wild type BmNPV genome, and analysed by Southern blotting. The expression of ${\beta}$-galactosidase was characterized by SDS-PAGE, Western blotting and ${\beta}$-galactosidase activity assay. The results showed that the level of expression in silkworm larvae was higher than that of BmN-4 cells.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 춘계학술대회
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• pp.711-714
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• 2016

재조합 베큘로바이러스는 cytomegalovirus (CMV) promoter, polyhedron promoter, vesicular stomatitis virus G (VSVG), enhanced green fluorescent protein (EGFP), protein transduction domain (PTD) 유전자로 구성된다. 본 재조합 베큘로바이러스 벡터는 세포주와 조직에 감염시켰고 그 결과 다른 벡터 시스템에 비교하여 재조합된 유전자의 전이와 유전자 발현에 있어서 새로운 가능성이 발견되었다. 본 재조합 베큘로바이러스 시스템의 유전자의 전이와 발현의 효율은 타 벡터시스템 보다 우수하였다.

• Journal of Microbiology and Biotechnology
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• 제10권1호
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• pp.115-118
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• 2000

Recombinant plasmids harboring a heterologous gene coding for the enhanced green fluorescent protein (EGFP) were transfected and expressed in Drosophila melanogaster S2 cells. A stable transformation of polyclonal cell populations expressing EGFP were isolated after 4 weeks of selection with hygromycin B. The recombinant EFGP expressed in transformed S2 cells consisted of a molecular weight of 27 kDa. EGFP expression was also confirmed by fluorometric measurement. The maximum EGFP concentration was about 9.3 mg/I. The present findings demonstrate not only the successful stable expression of EGFP in Drosophuila was about 9.3 mgI. The present findings demonstrate not only the successful stable expression of EGFP in Drosophila S2 cells, but also the use of EGFP as a reporter to analyze gene expression, with its potential of a Drosophila cell expression system for recombinant protein production being an alternative to a baculovirus-insect cell expression system.

• Parasites, Hosts and Diseases
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• 제55권2호
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• pp.143-148
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• 2017

Toxoplasma gondii infections occur throughout the world, and efforts are needed to develop various vaccine candidates expressing recombinant protein antigens. In this study, influenza matrix protein (M1) virus-like particles (VLPs) consisting of T. gondii rhoptry antigen 4 (ROP4 protein) were generated using baculovirus (rBV) expression system. Recombinant ROP4 protein with influenza M1 were cloned and expressed in rBV. SF9 insect cells were coinfected with recombinant rBVs expressing T. gondii ROP4 and influenza M1. As the results, influenza M1 VLPs showed spherical shapes, and T. gondii ROP4 protein exhibited as spikes on VLP surface under transmission electron microscopy (TEM). The M1 VLPs resemble virions in morphology and size. We found that M1 VLPs reacted with antibody from T. gondii-infected mice by western blot and ELISA. This study demonstrated that T. gondii ROP4 protein can be expressed on the surface of influenza M1 VLPs and the M1 VLPs containing T. gondii ROP4 reacted with T. gondii-infected sera, indicating the possibility that M1 VLPs could be used as a coating antigen for diagnostic and/or vaccine candidate against T. gondii infection.