Polyhedrin promoter

The Autographa californica multiple nucleopolyhedrovirus (AcMNPV)-based Bac-to-Bac® expression system consists of a bacmid and five pFastBac™ donor transfer vectors. It has been widely used for eukaryotic gene expression in insect cells to elucidate gene function in biotechnology laboratories. The pFastBac™ vectors contain a 50bp AcMNPV polyhedrin (polh) promoter and a 127bp SV40 polyadenylation (pA) signal for cloning a gene of interest into the bacmid, resulting in unsolved lower gene expression levels than the wild type (wt) AcMNPV in insect cells...

The relatively low infectivity of baculoviruses to their host larvae limits their use as insecticidal agents on a larger scale. In the present study, a novel strategy was developed to efficiently embed foreign proteins into Autographa californica multiple nucleopolyhedrovirus (AcMNPV) occlusion bodies (OBs) to achieve stable expression of foreign proteins and to improve viral infectivity. A recombinant AcMNPV bacmid was constructed by expressing the 150-amino-acid (aa) N-terminal segment of polyhedrin under the control of the p10 promoter and the remaining C-terminal 95-aa segment under the control of the polyhedrin promoter...

Recombinant proteins produced in insect cells and insects, unlike those produced in mammalian cells, have pauci-mannose-type N-glycans. In this study, we examined complex-type N-glycans on recombinant proteins via coexpression of human β-1,2-N-acetylglucosaminyltransferase II (hGnT II) and human β1,4-galactosyltransferase (hGalT I) in silkworm pupae, by using the Bombyx mori nucleopolyhedrovirus (BmNPV) bacmid system. The actin A3 promoter from B. mori and the polyhedrin promoter from Autographa californica multiple nucleopolyhedroviruses (AcMNPVs) were used to coexpress hGnT II and hGalT I...

The baculovirus expression vector system (BEVS) has been widely used to produce a large number of recombinant proteins, and is becoming one of the most powerful, robust, and cost-effective systems for the production of eukaryotic proteins. Nevertheless, as in any other protein expression system, it is important to improve the production capabilities of this vector. The orf46 viral gene was identified among the most highly abundant sequences in the transcriptome of Spodoptera exigua larvae infected with its native baculovirus, the S...

A newly isolated Pacific white shrimp (Litopenaeus vannamei) beta-actin promoter SbaP and its derivative compact construct SbaP (ENX) have recently been demonstrated to promote ectopic gene expression in vitro and in vivo. To further explore the potential transduction application, this newly isolated shrimp promoter SbaP was comparatively tested with cytomegalovirus (CMV), simian virus 40 (SV40), polyhedrin (Polh), and white spot syndrome virus immediate early gene 1 (WSSV ie1) four constitutive promoters and a beta-actin promoter (TbaP) from tilapia fish to characterize its promoting function in eight different cell lines...

Grass carp hemorrhagic disease is a common fish disease and often results in significant economic losses in grass carp aquaculture in China. This study was aimed to develop a novel oral vaccine against grass carp reovirus (GCRV). GCRV vp6 and vp7 genes with β-actin promoter of Megalobrama amblycephala and polyhedrin promoter (Ph10) of baculovirus, respectively, were cloned into plasmid pFast™-Dual to construct a vector pFast-PHVP7-AVP6, which was used to generate a recombinant baculovirus BacFish-vp6/vp7 via Bac-to-Bac system...

The hemichannel and gap junction channel are major portals for the release of factors responsible for the effects of apoptotic cells on the spread of apoptosis to neighboring cells and apoptotic corpse clearance, typically by phagocytes. The N-terminal cytoplasmic domain in the connexins, gap junction proteins in vertebrate, has been implicated in regulating channel closure. However, little is known about how the hemichannel close responds to apoptotic signaling transduction leading to the reduction of neighboring cellular apoptosis in an invertebrate...

Although there are several different methods available of making recombinant baculovirus expression vectors (reviewed in Chapter 3 ), all require a stage in which insect cells are transfected with either the virus genome alone (Bac-to-Bac(®) or BaculoDirect™, Invitrogen) or virus genome and transfer vector. In the latter case, this allows the natural process of homologous recombination to transfer the foreign gene, under control of the polyhedrin or other baculovirus gene promoter, from the transfer vector to the virus genome to create the recombinant virus...

The development of baculovirus expression vector systems has accompanied a rapid expansion of our knowledge about the genes, their function and regulation in insect cells. Classification of these viruses has also been refined as we learn more about differences in gene content between isolates, how this affects virus structure and their replication in insect larvae. Baculovirus gene expression occurs in an ordered cascade, regulated by early, late and very late gene promoters. There is now a detailed knowledge of these promoter elements and how they interact first with host cell-encoded RNA polymerases and later with virus-encoded enzymes...

The simian virus 40 polyadenylation signal (SV40 polyA) has been routinely inserted downstream of the polyhedrin promoter in many baculovirus expression vector systems (BEVS). In the baculovirus prototype Autographa californica multiple nucleopolyhedrovirus (AcMNPV), the polyhedrin promoter (very late promoter) transcribes its gene by a viral RNA polymerase therefore there is no supporting evidence that SV40 polyA is required for the proper gene expression under the polyhedrin promoter. Moreover, the effect of the SV40 polyA sequence on the polyhedrin promoter activity has not been tested either at its natural polyhedrin locus or in other loci in the viral genome...

In the baculovirus shuttle vector (bacmid) system, a helper plasmid and a donor plasmid are employed to insert heterologous genes into a cloned baculovirus genome via Tn7 transposition in Escherichia coli. The helper and donor plasmids are usually cotransfected with constructed bacmids into insect cells, which will lead to integration of these plasmids into the viral genome, and hence to the production of defective virions. In this study, to facilitate the preparation of plasmid-free recombinant bacmids, we modified a set of helper and donor plasmids by replacing their replication origins with that of a temperature-sensitive (ts) plasmid, pSIM6...

Vaccines based on virus-like particles (VLPs) have proven effective in humans and animals. In this regard, the baculovirus expression vector system (BEVS) is one of the technologies of choice to generate such highly immunogenic vaccines. The extended use of these vaccines for human and animal populations is constrained because of high production costs, therefore a significant improvement in productivity is crucial to ensure their commercial viability. Here we describe the use of the previously described baculovirus expression cassette, called TB, to model the production of two VLP-forming vaccine antigens in insect cells...

To improve the expression of heterologous genes using baculovirus expression system, we constructed a novel shuttle vector based on the Bm-Bacmid. In the Bm-Bacmid, partial sequences of Chitinase and Cystein Protease were replaced with a tandem cassette of Cm and egfp through homologous recombination. Bombyx mori bidensovirus (BmBDV) ns1 under the control of polyhedrin promoter was inserted into the modified Bm-bacmid by transposition. For comparison, BmBDV ns1 under the control of polyhedrin promoter was also cloned in the wild type Bm-bacmid...

A recombinant Helicoverpa armigera nucleopolyhedrovirus (HearNPV), Ar1b-HearNPV, was constructed and identified as an improved bio-control agent of Helicoverpa armigera larvae. The HearNPV polyhedrin promoter was used to express the insect-specific neurotoxin gene, ar1b, which was originally isolated from the Australian funnel-web spider (Atrax robustus). RT-PCR and Western blotting analysis showed that both the ar1b transcript and protein were produced successfully in Ar1b-HearNPV-infected HzAM1 cells. In order to investigate the influence of foreign gene insertion in HearNPV, including the ar1b gene, chloramphenicol resistance gene, lacZ, kanamycin resistance gene, and the gentamicin resistance gene, two virus strains (HZ8-HearNPV and wt-HearNPV) were used as controls in the cell transfection analysis...

The recombinant baculoviruses were constructed to investigate the necessity of VSV-G pseudotyping for mammalian cell transduction. The viruses were designed to express green fluorescent protein (GFP) gene under the control of cytomegalovirus promoter, with or without pseudotyping with VSV-G. VSV-G was placed under the control of polyhedrin promoter that is recognized by insect cells, allowing the formation of pseudotyped baculovirus. The study findings demonstrate that the pseudotyping of baculovirus significantly enhanced transduction efficiency compared to non-pseudotyped baculovirus, resulting in consequent distinction in the expression of GFP in mammalian cells...

ns1 gene of Bombyx mori bidensovirus (BmBDV) consisted of 951 nucleotides encoding a deduced 316-amino aicd protein. In this study, the gene was cloned and fused in frame with a N-terminal 6×His tag under control of the polyhedrin promoter, which was transposed into the mini-attTn7 locus of a modified baculovirus vector. Transfection of Sf-9 cells with the resulting recombinant DNA was performed to prepare recombinant virus and the resultant supernatant of transfection with fluorescent signal was harvested...

In our previous study, Orf101 (Bm101) of Bombyx mori nucleopolyhedrovirus (BmNPV) was identified as a component of the budded virions important for viral late gene expression. In this study we demonstrate that Bm101 is actually a previously unrecognized core gene and that it is essential for mediating budded virus production. To determine the role of Bm101 in the baculovirus life cycle, a Bm101 knockout bacmid containing the BmNPV genome was generated through homologous recombination in Escherichia coli. Furthermore, a Bm101 repair bacmid was constructed by transposing the Bm101 open reading frame with its native promoter region into the polyhedrin locus of the Bm101 knockout bacmid...

In December 1983, a seminal paper appeared on the overexpression of human IFN-β in insect cells with a genetically engineered baculovirus. The finding that baculoviruses produced massive amounts of two proteins (polyhedrin and p10) by means of two very strong promoters and that the corresponding genes were dispensable for virus propagation in insect cells was crucial in the development of this expression system. During the next 30 years, major improvements were achieved over the original baculovirus expression vector (BEV) system, facilitating the engineering of the baculovirus vectors, the modification of the sugar moieties of glycoproteins expressed in insect cells and the scale-up of the cell culture process...

We previously established the first Bombyx mori macula-like virus (BmMLV)-free cell line (BmVF cells) from a B. mori embryo. In this study, we evaluated the expression of recombinant proteins in BmVF cells using a B. mori nucleopolyhedrovirus (BmNPV)-derived expression vector. Our results showed that BmVF cells are susceptible to BmNPV, and both the promoter activity of the polyhedrin gene and the post-translated modifications of a recombinant protein are equivalent between BmMLV-negative BmVF and -positive BmN4 cells...

UNLABELLED: The p143 gene from Autographa californica multinucleocapsid nucleopolyhedrovirus (AcMNPV) has been found to increase the expression of luciferase, which is driven by the polyhedrin gene promoter, in a plasmid with virus coinfection. Further study indicated that this is due to the presence of a replication origin (ori) in the coding region of this gene. Transient DNA replication assays showed that a specific fragment of the p143 coding sequence, p143-3, underwent virus-dependent DNA replication in Spodoptera frugiperda IPLB-Sf-21 (Sf-21) cells...