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Shang H, Garretson TA, Kumar CS, Dieter RF, Cheng XW. Improved pFastBac™ donor plasmid vectors for higher protein production using the Bac-to-Bac® baculovirus expression vector system. J Biotechnol 2017. [DOI: 10.1016/j.jbiotec.2017.06.397] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Cao MY, Kuang XX, Li HQ, Lei XJ, Xiao WF, Dong ZQ, Zhang J, Hu N, Chen TT, Lu C, Pan MH. Screening and optimization of an efficient Bombyx mori nucleopolyhedrovirus inducible promoter. J Biotechnol 2016; 231:72-80. [PMID: 27245143 DOI: 10.1016/j.jbiotec.2016.05.037] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 05/25/2016] [Accepted: 05/27/2016] [Indexed: 12/25/2022]
Abstract
Pathogen-inducible promoters have been studied extensively and widely used in resistance breeding and gene therapy. However, few reports have been published that explore the efficacy of Bombyx mori nucleopolyhedrovirus (BmNPV)-inducible promoters in antiviral research in the Bombyx mori (Lepidoptera). Here, we screened BmNPV promoters (VP1054, P33, Bm21, Bm122, 39K, P143, and P6.9) and found that the 39K promoter had the highest BmNPV-induced transcriptional activity by dual-luciferase reporter assays system. By 5' truncation analysis, two regions of 39K promoter were critical for optimal virus-inducible activity, indicated that they could serve as a candidate to produce synthetic pathogen-induced promoters. Furthermore, we enhanced the virus-inducible activity of BmNPV 39K promoter using a hybrid enhancer comprising hr3 and polh-up (designated as HP39K). Finally, we showed that RNAi regulated by HP39K promoter could significantly inhibit the proliferation of BmNPV in silkworm cells. Taken together, our results have practical value in antiviral research of silkworm and baculovirus expression system.
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Affiliation(s)
- Ming-Ya Cao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
| | - Xiu-Xiu Kuang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
| | - Hai-Qing Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
| | - Xue-Jiao Lei
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
| | - Wen-Fu Xiao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
| | - Zhan-Qi Dong
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
| | - Jun Zhang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China; Institute of Life Sciences, Chongqing Medical University, Chongqing 400716, China
| | - Nan Hu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
| | - Ting-Ting Chen
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
| | - Cheng Lu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China; Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing 400716, China.
| | - Min-Hui Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China; Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing 400716, China.
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Tanzer FL, Shephard EG, Palmer KE, Burger M, Williamson AL, Rybicki EP. The porcine circovirus type 1 capsid gene promoter improves antigen expression and immunogenicity in a HIV-1 plasmid vaccine. Virol J 2011; 8:51. [PMID: 21299896 PMCID: PMC3041773 DOI: 10.1186/1743-422x-8-51] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Accepted: 02/07/2011] [Indexed: 12/02/2022] Open
Abstract
Background One of the promising avenues for development of vaccines against Human immunodeficiency virus type 1 (HIV-1) and other human pathogens is the use of plasmid-based DNA vaccines. However, relatively large doses of plasmid must be injected for a relatively weak response. We investigated whether genome elements from Porcine circovirus type 1 (PCV-1), an apathogenic small ssDNA-containing virus, had useful expression-enhancing properties that could allow dose-sparing in a plasmid vaccine. Results The linearised PCV-1 genome inserted 5' of the CMV promoter in the well-characterised HIV-1 plasmid vaccine pTHgrttnC increased expression of the polyantigen up to 2-fold, and elicited 3-fold higher CTL responses in mice at 10-fold lower doses than unmodified pTHgrttnC. The PCV-1 capsid gene promoter (Pcap) alone was equally effective. Enhancing activity was traced to a putative composite host transcription factor binding site and a "Conserved Late Element" transcription-enhancing sequence previously unidentified in circoviruses. Conclusions We identified a novel PCV-1 genome-derived enhancer sequence that significantly increased antigen expression from plasmids in in vitro assays, and improved immunogenicity in mice of the HIV-1 subtype C vaccine plasmid, pTHgrttnC. This should allow significant dose sparing of, or increased responses to, this and other plasmid-based vaccines. We also report investigations of the potential of other circovirus-derived sequences to be similarly used.
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Affiliation(s)
- Fiona L Tanzer
- Department of Molecular and Cell Biology, Faculty of Science, University of Cape Town, Rondebosch, Cape Town, 7701 South Africa
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Autographa californica multiple nucleopolyhedrovirus LEF-2 is a capsid protein required for amplification but not initiation of viral DNA replication. J Virol 2010; 84:5015-24. [PMID: 20219928 DOI: 10.1128/jvi.02423-09] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The late expression factor 2 gene (lef-2) of baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) has been identified as one of the factors essential for origin-dependent DNA replication in transient expression assays and has been shown to be involved in late/very late gene expression. To study the function of lef-2 in the life cycle of AcMNPV, lef-2 knockout and repair bacmids were generated by homologous recombination in Escherichia coli. Growth curve analysis showed that lef-2 was essential for virus production. Interestingly, a DNA replication assay indicated that lef-2 is not required for the initiation of viral DNA replication and that, rather, it is required for the amplification of DNA replication. lef-2 is also required for the expression of late and very late genes, as the expression of these genes was abolished by lef-2 deletion. Temporal and spatial distributions of LEF-2 protein in infected cells were also analyzed, and the data showed that LEF-2 protein was localized to the virogenic stroma in the nuclei of the infected cells. Analysis of purified virus particles revealed that LEF-2 is a viral protein component of both budded and occlusion-derived virions, predominantly in the nucleocapsids of the virus particles. This observation suggests that LEF-2 may be required immediately after virus entry into host cells for efficient viral DNA replication.
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Santos S, Silva J, Balani V, Seixas F, Fernandez M. Conserved baculoviral ORFs 10 and 14 from Bombyx mori multiple nucleopolyhedrovirus. GENETICS AND MOLECULAR RESEARCH 2010; 9:457-70. [DOI: 10.4238/vol9-1gmr723] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Cohen DPA, Marek M, Davies BG, Vlak JM, van Oers MM. Encyclopedia of Autographa californica nucleopolyhedrovirus genes. Virol Sin 2009. [DOI: 10.1007/s12250-009-3059-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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Wu CP, Wang JY, Huang TY, Lo HR, Chao YC. Identification of baculoviral factors required for the activation of enhancer-like polyhedrin upstream (pu) sequence. Virus Res 2008; 138:7-16. [PMID: 18760315 DOI: 10.1016/j.virusres.2008.07.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2008] [Revised: 07/31/2008] [Accepted: 07/31/2008] [Indexed: 11/30/2022]
Abstract
Previously, we identified a novel enhancer-like element, the polyhedrin upstream (pu) sequence, in the genome of the baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV), which activates several early promoters. The activation requires co-infection of AcMNPV, suggesting that viral gene products are needed for pu-mediated promoter activation. DNA replication assay showed that the pu sequence did not assist in DNA replication and suggested its involvement in activated transcription from target promoters. In order to identify the viral genes responsible for pu-dependent activation of early promoters, a set of overlapping cosmid clones covering the entire 134-kb AcMNPV genome were constructed and screened. Our results identified three viral genes ie1, ie2, and pe38, which function in concert with pu to activate target promoters. In addition, these three viral factors can substitute for the entire virus for the synergistic promoter activation mediated by pu and the known baculovirus enhancer, the homologous region.
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Affiliation(s)
- Carol P Wu
- Department of Chemistry, National Tsing-Hua University, Hsinchu 300, Taiwan, ROC
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Acharya A, Gopinathan K. Transcriptional analysis and preliminary characterization of ORF Bm42 from Bombyx mori nucleopolyhedrovirus. Virology 2002; 299:213-24. [PMID: 12202224 DOI: 10.1006/viro.2002.1525] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Clusters of closely spaced genes are frequently present in baculovirus genomes. We report here the detailed transcriptional mapping of one such gene cluster from Bombyx mori nucleopolyhedrovirus (BmNPV) comprising five ORFs, viz., Bm42, Lef-10, VP1054, Bm44, and Bm45, which are closely spaced and transcribed in the same orientation. This region is homologous to ORFs 53, 53a, 54, 55, and 56, respectively, on the AcMNPV genome. Multiple, overlapping sets of polycistronic transcripts from this region, that initiate independently but terminate at a common 3' end, were detected following BmNPV infection. Expression of these genes followed a temporal pattern where the shorter transcripts initiating downstream appeared early, and with the progress of infection the longer transcripts initiated from upstream. The first ORF in this cluster, Bm42, is conserved in almost all baculoviruses, but has not been characterized so far. The protein was localized in the cytosol, predominantly near the nucleus-cytoplasm boundary in BmNPV-infected BmN cells. Bm42 was present in the budded virions and was not associated with occluded virus particles or the polyhedral matrix.
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Affiliation(s)
- Asha Acharya
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
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Acharya A, Gopinathan KP. Characterization of late gene expression factors lef-9 and lef-8 from Bombyx mori nucleopolyhedrovirus. J Gen Virol 2002; 83:2015-2023. [PMID: 12124466 DOI: 10.1099/0022-1317-83-8-2015] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Late gene expression factors, LEF-4, LEF-8, LEF-9 and P47 constitute the primary components of the Autographa californica multinucleocapsid polyhedrovirus (AcMNPV)-encoded RNA polymerase, which initiates transcription from late and very late promoters. Here, characterization of lef-9 and lef-8, which encode their corresponding counterparts, from Bombyx mori NPV is reported. Transcription of lef-9 initiated at two independent sites: from a GCACT sequence located at -38 nt and a CTCTT sequence located at -50 nt, with respect to the +1 ATG of the open reading frame. The 3' end of the transcript was mapped to a site 17 nt downstream of a canonical polyadenylation signal located 7 nt downstream of the first of the two tandem translational termination codons. Maximum synthesis of LEF-9 was seen from 36 h post-infection (p.i.). The transcription of lef-8 initiated early in infection from a GTGCAAT sequence that differed in the corresponding region from its AcMNPV counterpart (GCGCAGT), with consequent elimination of the consensus early transcription start site motif (underlined). Peak levels of lef-8 transcripts were attained by 24 h p.i. Immunocopurification analyses suggested that there was an association between LEF-8 and LEF-9 in vivo.
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Affiliation(s)
- Asha Acharya
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India1
| | - Karumathil P Gopinathan
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India1
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