1
|
Sun L, Yao C, Amanze C, Yin B, Huang J, Hao B. The cytoplasmic tail substitution increases the assembly efficiency of Ebola virus glycoprotein on the budded virus of Bombyx mori nucleopolyhedrovirus. Protein Expr Purif 2022; 200:106156. [PMID: 35987323 DOI: 10.1016/j.pep.2022.106156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 08/10/2022] [Accepted: 08/10/2022] [Indexed: 11/24/2022]
Abstract
Glycoprotein (GP1,2) of the Ebola virus (EBOV) is the key membrane fusion protein, which is a key candidate protein for vaccine preparations. Previously, GP1,2 was expressed by Bombyx mori nucleopolyhedrovirus (BmNPV) expression vector system; however, few GP1,2 was incorporated into budded virus (BV) of BmNPV. To improve the incorporation efficiency of GP1,2 into the virion, the GP1,2 fusion with the cytoplasmic tail of GP64 of BmNPV was expressed in BmN cells by the BmNPV expression system. The BV was purified by ultracentrifugation, and GP1,2 expression in BV was detected by the antibody. The result indicated that a 532% increase in the relative GP1,2 densitometry signal was observed in constructs utilizing the GP64 C-terminal domain; moreover, the substitution of GP1,2 native signal peptide with GP64 signal peptide increased the incorporation efficiency by 34.6% in the relative GP1,2 densitometry signal. We revealed that the application of the cytoplasmic tail of BmNPV GP64 significantly increased the incorporation rate of GP1,2 into the BV envelope. This study lays a foundation for GP1,2 vaccine development.
Collapse
Affiliation(s)
- Luping Sun
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, 212018, China
| | - Congyue Yao
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, 212018, China
| | - Charles Amanze
- School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan, 410083, China
| | - Bo Yin
- National University of Singapore (Suzhou) Research Institute, Suzhou, Jiangsu, China
| | - Jinshan Huang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, 212018, China
| | - Bifang Hao
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, 212018, China.
| |
Collapse
|
2
|
The NPC Families Mediate BmNPV Entry. Microbiol Spectr 2022; 10:e0091722. [PMID: 35867410 PMCID: PMC9430594 DOI: 10.1128/spectrum.00917-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Baculovirus is a powerful tool for biological control in agriculture and foreign gene expression and delivery in insect and mammalian cells. Baculovirus enters host cells by multiple endocytic pathways; however, the current understanding of the Bombyx mori nucleopolyhedrovirus (BmNPV) entry mechanism remains limited. Previous studies have identified NPC1 and NPC2 as important host factors for viral infection in insect cells, although their exact role in viral infection has not yet been determined. In this study, we demonstrate that the BmNPC1 protein is an important intracellular factor for BmNPV escape from the endosomal compartment, and the expression of BmNPC1 in Sf9 cells confers the virus the ability to enter into the nucleus of Sf9 cells. Additionally, the second luminal domain of BmNPC1 (BmNPC1-C) binds to the viral glycoprotein gp64, and preincubation of BmNPV with purified BmNPC1-C inhibits virus infection. Furthermore, knockout of the BmNPC2 protein results in reduced efficiency of viral fusion with the endosomal membrane, and BmNPC2 protein interacts directly with both viral envelope glycoprotein gp64 and the host BmNPC1 protein. BmNPC2 was found to be incorporated into progeny viral particles. Taken together, our results suggest that NPC2 protein incorporated into viral particles may facilitate viral infection through promoting the interaction of BmNPV and NPC1 in the endosome, thus enhancing viral fusion and escape from endosomes. These results, combined with those from previous studies, support that BmNPV hijacks two important cholesterol receptor members (NPC1 and NCP2) in the cholesterol intracellular transport pathway for viral entry into host cells. IMPORTANCE Baculovirus is an important biological factor for controlling insect populations and represents a powerful biological tool for gene delivery and expression. However, the host receptor of baculovirus is still unknown. In this study, we demonstrate that BmNPC1 protein is an important intracellular factor for BmNPV escape from the endosomal compartment, and the expression of BmNPC1 confers the ability of virus to enter into the host cell nucleus in nonpermissive Sf9 cells. BmNPC2 can bind to the virus and promote progeny virion infection through the NPC1-NPC2 endosome cholesterol transport pathway. We believe that our study on the BmNPV entry mechanism will further facilitate the application of baculovirus systems in eukaryotic gene delivery. Not only can the cholesterol transport pathway NPC1 protein be used by a variety of enveloped viruses, but the NPC2 protein can also be used by viruses to infect host cells. This will provide new insights into the study of enveloped virus infection mechanisms.
Collapse
|
3
|
Optimization of infection parameters improves Bombyx mori nucleopolyhedrovirus invasion efficiency. Biologia (Bratisl) 2021. [DOI: 10.1007/s11756-021-00931-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
4
|
Efficient Expression and Processing of Ebola Virus Glycoprotein Induces Morphological Changes in BmN Cells but Cannot Rescue Deficiency of Bombyx Mori Nucleopolyhedrovirus GP64. Viruses 2019; 11:v11111067. [PMID: 31731691 PMCID: PMC6893839 DOI: 10.3390/v11111067] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 11/13/2019] [Accepted: 11/14/2019] [Indexed: 01/08/2023] Open
Abstract
Ebola virus (EBOV) disease outbreaks have resulted in many fatalities, yet no licensed vaccines are available to prevent infection. Recombinant glycoprotein (GP) production may contribute to finding a cure for Ebola virus disease, which is the key candidate protein for vaccine preparation. To explore GP1,2 expression in BmN cells, EBOV-GP1,2 with its native signal peptide or the GP64 signal peptide was cloned and transferred into a normal or gp64 null Bombyx mori nucleopolyhedrovirus (BmNPV) bacmid via transposition. The infectivity of the recombinant bacmids was investigated after transfection, expression and localization of EBOV-GP were investigated, and cell morphological changes were analyzed by TEM. The GP64 signal peptide, but not the GP1,2 native signal peptide, caused GP1,2 localization to the cell membrane, and the differentially localized GP1,2 proteins were cleaved into GP1 and GP2 fragments in BmN cells. GP1,2 expression resulted in dramatic morphological changes in BmN cells in the early stage of infection. However, GP1,2 expression did not rescue GP64 deficiency in BmNPV infection. This study provides a better understanding of GP expression and processing in BmN cells, which may lay a foundation for EBOV-GP expression using the BmNPV baculovirus expression system.
Collapse
|
5
|
Methyl-Beta-Cyclodextrin-Induced Macropinocytosis Results in Increased Infection of Sf21 Cells by Bombyx Mori Nucleopolyhedrovirus. Viruses 2019; 11:v11100937. [PMID: 31614674 PMCID: PMC6832467 DOI: 10.3390/v11100937] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 10/10/2019] [Accepted: 10/11/2019] [Indexed: 11/22/2022] Open
Abstract
Bombyx mori nucleopolyhedrovirus (BmNPV) is closely related to Autographa californica multiple nucleopolyhedrovirus (AcMNPV) with over ~93% amino acid sequence identity. However, their host ranges are essentially nonoverlapping. The mechanism of BmNPV entry into host cells is completely different from that of AcMNPV, and whether the entry mechanism difference relates to the host range remains unclear. BmNPV produces an abortive infection in nonhost cells due to virion nuclear transportation failure. Here, we performed a detailed study by increasing BmNPV infection in Sf21 cells with the aid of methyl-beta-cyclodextrin (MβCD). We found that low-concentration MβCD incubation efficiently activates membrane ruffling in Sf21 cells, which mediates the increase in BmNPV infection. Interestingly, MβCD incubation after virion internalization also increases the infection, which suggests that macropinocytosis is involved in BmNPV infection in Sf21 cells after virion internalization. Further study revealed that clathrin-mediated endocytosis (CME) is employed by BmNPV to facilitate entry into Sf21 cells, and chlorpromazine application abolishes BmNPV infection in cells incubated both with and without MβCD. Based on these studies, we show that BmNPV enters Sf21 cells via CME and that parallel induction of macropinocytosis facilitates BmNPV infection in Sf21 cells. This study reveals the mechanism of BmNPV entry into Sf21 cells and provides clues for improving BmNPV infections in nonpermissive cells.
Collapse
|
6
|
Preincubation with a low concentration of methyl-β-cyclodextrin enhances baculovirus expression system productivity. Biotechnol Lett 2019; 41:921-928. [PMID: 31286325 DOI: 10.1007/s10529-019-02708-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 07/04/2019] [Indexed: 01/03/2023]
Abstract
OBJECTIVES To enhance the productivity of foreign protein in culture cells using baculovirus expression system. RESULTS A low concentration of MβCD, with the optimal application concentration of 0.25 mM and the appropriate preincubation time range from 10 to 120 min, can efficiently enhance expression levels in both the AcMNPV and BmNPV expression systems. CONCLUSIONS Preincubation with a low concentration MβCD enhance baculovirus infection and foreign protein expression productivity.
Collapse
|
7
|
Garretson TA, Shang H, Schulz AK, Donohue BV, Cheng XW. Expression- and genomic-level changes during passage of four baculoviruses derived from bacmids in permissive insect cell lines. Virus Res 2018; 256:117-124. [PMID: 30121326 DOI: 10.1016/j.virusres.2018.08.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 08/11/2018] [Accepted: 08/12/2018] [Indexed: 11/18/2022]
Abstract
The baculovirus-based bacmid expression vector system has been widely used for protein production in basic research and biotechnological laboratories. Since the first construction of the Autographa californica multiple nucleopolyhedrovirus bacmid (AcBacmid), three more bacmids have been created from Bombyx mori nucleopolyhedrovirus (BmBacmid), Spodoptera exigua nucleopolyhedrovirus (SeBacmid) and Helicoverpa armigera nucleopolyhedrovirus (HaBacmid). Each of these bacmid-derived viruses replicates efficiently in a range of specific and permissive cell types. Here, we investigated the relative stability of each virus derived from the bacmid during passage in permissive cell lines through assessment of their expression level and genome structure changes. Using two different reporters, the expression levels of the viruses from the AcBacmid-Sf9, AcBacmid-Tn5, BmBacmid-BmN and SeBacmid-SeE1 bacmid-cell systems were significantly reduced after five passages of the viruses, whereas the reductions were not detected in the AcBacmid-Sf21 and HaBacmid-HzAM1 systems. Pulse field gel electrophoresis (PFGE) and restriction fragment length polymorphism (RFLP) analysis of viral DNA isolated from passaged viruses from the AcBacmid-Sf21 and HaBacmid-HzAM1 systems showed no major genomic changes. In contrast, the genomes from passaged viruses in the AcBacmid-Tn5 and AcBacmid-Sf9 systems displayed reduced genome size and various mutations at individual loci, including genotypes missing one at least or more viral RNA polymerase subunits and fp25k. These genotypic changes were correlated with reduced protein expression. RFLP analysis of viral DNA from passaged viruses in the BmBacmid-BmN and SeBacmid-SeE1 systems exhibited changes in genome size, including excision of particular EcoRI fragments containing the mini-F replicon. Collectively, our data suggest that the viruses from the AcBacmid-Sf21 and HaBacmid-HzAM1 bacmid-cell systems are better for large-scale protein expression in continuous culture. Further study is needed to investigate the mechanism(s) behind the protein expression reduction in these bacmid-derived virus/cell systems.
Collapse
Affiliation(s)
| | - Hui Shang
- Department of Microbiology, Miami University, Oxford, OH 45056, USA; Graduate Program in Cell, Molecular, and Structural Biology, Miami University, Oxford, OH 45056, USA
| | - Annie K Schulz
- Department of Microbiology, Miami University, Oxford, OH 45056, USA
| | - Brian V Donohue
- Department of Microbiology, Miami University, Oxford, OH 45056, USA
| | - Xiao-Wen Cheng
- Department of Microbiology, Miami University, Oxford, OH 45056, USA; Graduate Program in Cell, Molecular, and Structural Biology, Miami University, Oxford, OH 45056, USA.
| |
Collapse
|
8
|
Entry of Bombyx mori nucleopolyhedrovirus into BmN cells by cholesterol-dependent macropinocytic endocytosis. Biochem Biophys Res Commun 2014; 453:166-71. [PMID: 25264104 DOI: 10.1016/j.bbrc.2014.09.073] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 09/18/2014] [Indexed: 11/19/2022]
Abstract
Bombyx mori nucleopolyhedrovirus (BmNPV) is a serious viral pathogen of silkworm, and no drug or specific protection against BmNPV infection is available at present time. Although functions of most BmNPV genes were depicted in recent years, knowledge on the mechanism of BmNPV entry into insect cells is still limited. Here BmNPV cell entry mechanism is investigated by different endocytic inhibitor application and subcellular analysis. Results indicated that BmNPV enters BmN cells by clathrin-independent macropinocytic endocytosis, which is mediated by cholesterol in a dose-dependent manner, and cholesterol replenishment rescued the BmNPV infection partially.
Collapse
|
9
|
Production of recombinant human DNA polymerase delta in a Bombyx mori bioreactor. PLoS One 2011; 6:e22224. [PMID: 21789240 PMCID: PMC3137619 DOI: 10.1371/journal.pone.0022224] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Accepted: 06/21/2011] [Indexed: 11/30/2022] Open
Abstract
Eukaryotic DNA polymerase δ (pol δ) plays a crucial role in chromosomal DNA replication and various DNA repair processes. It is thought to consist of p125, p66 (p68), p50 and p12 subunits. However, rigorous isolation of mammalian pol δ from natural sources has usually yielded two-subunit preparations containing only p125 and p50 polypeptides. While recombinant pol δ isolated from infected insect cells have some problems of consistency in the quality of the preparations, and the yields are much lower. To address these deficiencies, we have constructed recombinant BmNPV baculoviruses using MultiBac system. This method makes the generation of recombinant forms of pol δ containing mutations in any one of the subunits or combinations thereof extremely facile. From about 350 infected larvae, we obtained as much as 4 mg of pol δ four-subunit complex. Highly purified enzyme behaved like the one of native form by rigorous characterization and comparison of its activities on poly(dA)/oligo(dT) template-primer and singly primed M13 DNA, and its homogeneity on FPLC gel filtration. In vitro base excision repair (BER) assays showed that pol δ plays a significant role in uracil-intiated BER and is more likely to mediate LP BER, while the trimer lacking p12 is more likely to mediate SN BER. It seems likely that loss of p12 modulates the rate of SN BER and LP BER during the repair process. Thus, this work provides a simple, fast, reliable and economic way for the large-scale production of human DNA polymerase δ with a high activity and purity, setting up a new platform for our further research on the biochemical properties of pol δ, its regulation and the integration of its functions, and how alterations in pol δ function could contribute to the etiology of human cancer or other diseases that can result from loss of genomic stability.
Collapse
|
10
|
Variants of open reading frame Bm126 in wild-type Bombyx mori nucleopolyhedrovirus isolates exhibit functional differences. J Gen Virol 2009; 90:153-61. [DOI: 10.1099/vir.0.004580-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
|
11
|
Huang J, Hao B, Deng F, Sun X, Wang H, Hu Z. Open reading frame Bm21 of Bombyx mori nucleopolyhedrovirus is not essential for virus replication in vitro, but its deletion extends the median survival time of infected larvae. J Gen Virol 2008; 89:922-930. [PMID: 18343833 DOI: 10.1099/vir.0.83504-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In this report, the open reading frame 21 (Bm21) of Bombyx mori nucleopolyhedrovirus (BmNPV), one of the unique genes of group I NPVs, was characterized. Bm21 is predicted to encode a protein of 55.8 kDa and was found to contain imperfectly conserved leucine-rich repeats. 3' Rapid amplification of cDNA ends (3'RACE) showed that the transcript of Bm21 was first detected from 6 h post-infection and that it also encompassed the complete Bm20. 5'RACE revealed three transcription initiation sites, one of which mapped to the baculovirus early transcription motifs CGTGC and CAGT. Transient-expression and superinfection assays indicated that BM21 localized in the nucleus of infected BmN cells. To study the function of BM21, a Bm21-null virus was constructed using bacmid technology. Viral one-step growth curve analyses showed that the Bm21-null virus had similar budded virus production kinetics to those of the parental virus. Bioassay analyses showed that the median lethal concentration (LC(50)) of the Bm21-null virus was similar to that of the control virus; however, the median survival time (ST(50)) of the knockout virus was significantly longer than the control virus. These results indicate that BM21 is not essential for virus replication in vitro, but that deletion of the gene delays the killing of the infected larvae.
Collapse
Affiliation(s)
- Jinshan Huang
- Graduate School of the Chinese Academy of Sciences, Beijing 100039, PR China.,State Key Laboratory of Virology and Joint Lab of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Bifang Hao
- College of Animal Science and Technology, Northwest Agricultural and Forestry University, Yangling 712100, PR China.,State Key Laboratory of Virology and Joint Lab of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Fei Deng
- State Key Laboratory of Virology and Joint Lab of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Xiulian Sun
- State Key Laboratory of Virology and Joint Lab of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Hualin Wang
- State Key Laboratory of Virology and Joint Lab of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Zhihong Hu
- State Key Laboratory of Virology and Joint Lab of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| |
Collapse
|