• Title/Summary/Keyword: Baculovirus expression system

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Expression of Bombyx mori Nucleopolyhedrovirus ORF4 under the Control of BaculoviruS Ie1 Promoter by a Novel Bac-to-Bac/BmNPV Baculovirus Expression System

  • Su, Wujie;Wu, Yan;Wu, Huiling;Wang, Wenbing
    • International Journal of Industrial Entomology
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    • v.15 no.2
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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.

Expression of Immunologically Active Porcine Recombinant TGF-${\beta}1$ Precursor Protein in Baculovirus System

  • Lim, Hyun;Kim, Pyeung-Hyeun;Chun, Gie-Taek;Choi, Eui-Yul;Yie, Se-Won
    • Journal of Microbiology
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    • v.35 no.4
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    • pp.341-346
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    • 1997
  • In order to express recombinant porcine TGF-${\beta}1$ protein in a baculovirus expression system the entire TGF-${\beta}1$gene containing extra amino acids at the N terminus was cloned into pFBa and pFBb of the Bac-To-$Bac^{TM}$ baculovirus expression system. One of the clones contained 106 extra amino acids and was designated pFBa-106 TGF-${\beta}1$, and the other had 28 extra amino acids and was designated pFBb-28 TGF-${\beta}1$. The orientation of the gene was identified with restriction enzyme mapping and PCR with internal TGF-${\beta}1$ primers. Sf-9 cells were infected at a m.o.i. of 10 by the recombinant viruses generated from the two expected sizes of 55 kD and 46.4kD. these precursor forms of TGF-${\beta}1$ with a polyclonal antibody against human TGF-${\beta}1$. No mature form of TGF-${\beta}1$ protein was detected on SDS gels and an immunoblot indicated that TGF-${\beta}1$ precursor is not properlu processed in insect cells.

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Expression and Characterization of Recombinant E2 Protein of Hepatitis C Virus by Insect Cell/Baculovirus Expression System

  • Han, Bong-Kwan;Lee, Bum-Yong;Min, Mi-Kyung;Jung, Kyung-Hwan
    • Journal of Microbiology and Biotechnology
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    • v.8 no.4
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    • pp.361-368
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    • 1998
  • The E2 protein of HCV (hepatitis C virus) is thought to have a potential role in the development of subunit vaccines and diagnostics. To express it by the insect cell/baculovirus expression (Bacu) system, we constructed a recombinant Autographa californica nuclear polyhedrosis virus (AcIL3E2), determined the most appropriate expression conditions in terms of host cell line and culture medium, and characterized the expressed HCV E2 protein. A culture system using Trichoplusia ni BTI-TN5Bl-4 cells and SF 900IISFM medium expressed a relatively high level of HCV E2 protein. It was revealed that its glycosylation properties and subcellular localization were almost the same as the ones in the mammalian cell expression system previously reported, suggesting the recombinant HCV E2 protein derived from our Bacu system can be utilized for development of a subunit vaccine and diagnostics. Interestingly, HCV E2 protein was not degraded at all even at 43 h post-heat shock in the heat shock-induced necrotic cells, probably due to its integration into the microsomal membrane, indicating that heat shock can be employed to purify HCV E2 protein.

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Secretory Production of Biologically Active Human Thrombopoietin by Baculovirus Expression System

  • Koh, Yeo-Wook;Lim, Seung-Wook;Park, Seung-Kook;Park, Myung-Hwan;Na, Doe-Sun;Yang, Jai-Myung
    • BMB Reports
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    • v.31 no.5
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    • pp.453-458
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    • 1998
  • Human thrombopoietin (hTPO) was expressed to high levels in insect cells using the baculovirus expression system. Full-length hTPO cDNA containing a native signal peptide sequence was amplified by PCR from a human fetal liver cDNA library and cloned into the Autographa californica nuclear polyhedrosis virus (AcNPV) expression vector. Immunoblot analysis with antiserum against hTPO indicated that an approximately 55 kDa protein was produced in recombinant AcNPV infected insect cells. Recombinant hTPO was produced 4-fold higher in Trichoplusia ni (Tn5) cells than in Spodoptera frugiperda (Sf9) cells. with most of the hTPO produced in Tn5 cells secreted into the culture medium. Addition of tunicamycin in the culture medium resulted in the reduction of the size of hTPO to 35-38 kDa, and most of the protein remained within the cell. These results suggest that N-glycosylation of hTPO is required for the secretion of the protein into the culture medium in insect cells. hTPO produced in insect cells induced proliferation and maturation of megakaryocyte progenitors, indicating that it is in a biologically active form.

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Construction of Modified Bacillus thuringiensis cry1Ac Genes for Transgenic Crop Through Multi Site-directed Mutagenesis

  • Xu, Hong Guang;Roh, Jong-Yul;Wang, Yong;Choi, Jae-Young;Shim, Hee-Jin;Liu, Qin;Tao, Xueying;Woo, Soo-Dong;Jin, Byung-Rae;Je, Yeon-Ho
    • International Journal of Industrial Entomology
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    • v.19 no.1
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    • pp.199-204
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    • 2009
  • The newly cloned Bacillus thuringiensis cry1-5 gene showed high activity to both Plutella xylostella and Spodoptera exigua, while cry1Ac only showed high activity against P. xylostella but low to S. exigua. Through the alignment of amino acid sequences between Cry1Ac and Cry1-5, we found 12 different residues in domain I (6 residues) and domain II (6 residues). In this study, the modified cry1Ac gene, which is constructed according to a crop-preferring codon usage, was used as a template to construct mutant B. thuringiensis cry1Ac genes based on cry1-5 gene through multi site-directed mutagenesis. Total 63 various mutant cry genes were obtained at 12 positions randomly. Among them, ten mutant cry genes, whose domain I was totally converted and domain II was randomly, were selected to express in baculovirus expression system as a polyhedrin fusion form. The recombinant proteins were 95 kDa in size and were stably activated as 65 kDa by trypsin. The expressed mutant Cry proteins were applied to bioassays against P. xylostella and S. exigua. All mutants showed high insecticidal activity both to P. xylostella and S. exigua similar to cry1-5. These results suggest that these mutant cry genes might be expected of desirable cry genes for introduction to transgenic crops.

Expression of the VP2 protein of feline panleukopenia virus in insect cells and use thereof in a hemagglutination inhibition assay

  • Yang, Dong-Kun;Park, Yeseul;Park, Yu-Ri;Yoo, Jae Young;An, Sungjun;Park, Jungwon;Hyun, Bang-Hun
    • Korean Journal of Veterinary Research
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    • v.61 no.2
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    • pp.19.1-19.7
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    • 2021
  • Feline panleukopenia virus (FPV) causes leukopenia and severe hemorrhagic diarrhea, killing 50% of naturally infected cats. Although intact FPV can serve as an antigen in the hemagglutination inhibition (HI) test, an accidental laboratory-mediated infection is concern. A non-infectious diagnostic reagent is required for the HI test. Here, we expressed the viral protein 2 (VP2) gene of the FPV strain currently prevalent in South Korea in a baculovirus expression system; VP2 protein was identified by an indirect immunofluorescence assay, electron microscopy (EM), Western blotting (WB), and a hemagglutination assay (HA). EM showed that the recombinant VP2 protein self-assembled to form virus-like particles. WB revealed that the recombinant VP2 was 65 kDa in size. The HA activity of the recombinant VP2 protein was very high at 1:215. A total of 143 cat serum samples were tested using FPV (HI-FPV test) and the recombinant VP2 protein (HI-VP2 test) as HI antigens. The sensitivity, specificity, and accuracy of the HI-VP2 test were 99.3%, 88.9%, and 99.3%, respectively, compared to the HI-FPV test. The HI-VP2 and HI-FPV results correlated significantly (r = 0.978). Thus, recombinant VP2 can substitute for intact FPV as the serological diagnostic reagent of the HI test for FPV.

Constructions of a Transfer Vector Containing the gX Signal Sequence of Pseudorabies Virus and a Recombinant Baculovirus

  • Lee, Hyung-Hoan;Kang, Hyun;Kim, Jung-Woo;Hong, Seung-Kuk;Kang, Bong-Joo;Song, Jae-Young
    • Journal of Microbiology and Biotechnology
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    • v.9 no.5
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    • pp.541-547
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    • 1999
  • Constructions of a transfer vector and a recombinant baculovirus using the thymidine kinase gene of the Herpes simplex virus type 1 strain F (HSV -1) were carried out. Newly cloned transfer vector, pHcgXIIIB, was constructed by insertion of the glycoprotein gX gene signal peptide sequence of Pseudorabies virus into the baculovirus vector pHcEV-IV. The gX sequence was inserted just downstream from the promoter for the polyhedrin gene of the Hyphantria cunea nuclear polyhedrosis virus (HcNPV). HSV-1 thymidine kinase(tk) gene (1.131 kb) was used as a candidate gene for transferring into the baculovirus expression system. The tk gene was inserted into a BamHI site downstream from the gX sequence-promoter for the polyhedrin gene in the pHcgXIIIB transfer vector and was transferred into the infectious lacZ-HcNPV expression vector. Recombinant virus was isolated and was named gX-TK-HcNPV. The recombinant virus produced a 45 kDa gX-TK fusion protein in Spodoptera frugiperda cells, which was confirmed by Western blot analysis. Microscopic examination of gX-TK-HcNPV-infected cells revealed normal multiplication. Fluorescent antibody staining indicated that the gX-TK fusion protein was present in the cytoplasm. These results indicated that the transfer vector successfully transferred the gX-tk gene into the baculovirus expression system.

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High-efficient Expression of Porcine IL-2 with Recombinant Baculovirus Infected Silkworm, Bombyx mori

  • Inumaru, Shigeki;KokuHo, Takehiro;Yada, Takashi;Kiuchi, Makoto;Miyazawa, Mitsusuhiro
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.5 no.2
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    • pp.146-149
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    • 2000
  • Biologically active porcine Interleukin-2(poIL-2) was produced from in vitro and in viva baculovirus expression system, namely the Autographa californica nuclear polyhedrosis virus (ACNPV)-cell culture system and the Hybrid nucler polthedrosis virus (HyNPV)-sillkworm larva system. The concentration of the recombinant poIL-2(rpoIL-2) in the larvae hemolymph was 1 to 3 mg/mL, which was about 7 to 20 times those of the cell culture systems. The level of this expression efficiency is equal to that with transgenic livestock, secretion products in milk.

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Expression and Characterization of Hepatitis C Virus Core Proteins: Effects of Single Amino Acid Substitution on Protein Conformation and Subcellular Localization

  • Hwang, Soon-Bong
    • BMB Reports
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    • v.31 no.3
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    • pp.281-286
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    • 1998
  • Hepatitis C virus (HCV) core proteins from two different isolates (HCV-1 and HCV-RH) were expressed in Spotioptera Jrugiperda (Sf9) insect cells. The RH core consisted of two major species of proteins (21 kDa and 19 kDa). On the other hand, the HCV-1 core was approximately 16 kDa in a SDS-PAGE gel. Both core proteins were phosphorylated in vivo on serine residues. Furthermore, the RH core but not HCV-1 core formed dimers, indicating that the protein conformation of the core in these two isolates is dfferent from one another. Immunofluorescence studies showed that the RH core was present in the cytoplasm, whereas the HCV-1 core was localized predominantly to the nucleus in recombinant baculovirus-infected insect cells. Since the major difference between the two isolates is the codon 9 of the core protein, a single amino acid substitution appears to play a major role in the protein conformation and these properties may reflect the different biological functions of core proteins in HCV-infected cells.

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