1
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[Anti-viral responses in insect cells]. Uirusu 2019; 69:47-60. [PMID: 32938894 DOI: 10.2222/jsv.69.47] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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2
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Jehle JA, Schulze-Bopp S, Undorf-Spahn K, Fritsch E. Evidence for a Second Type of Resistance against Cydia pomonella Granulovirus in Field Populations of Codling Moths. Appl Environ Microbiol 2017; 83:e02330-16. [PMID: 27815280 PMCID: PMC5203626 DOI: 10.1128/aem.02330-16] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 10/31/2016] [Indexed: 11/20/2022] Open
Abstract
Cydia pomonella granulovirus (CpGV) is an important biocontrol agent for the codling moth (CM) in organic and integrated apple production worldwide. Previously, Z chromosome-linked dominant resistance in at least 38 CM field populations in Europe was reported, threatening organic apple production. Growers responded by switching to a different resistance-breaking isolate of CpGV that could control these populations. Here, we report a nonuniform response of different CM field populations to CpGV isolates from CpGV genome groups A to E. Even more strikingly, one field population, NRW-WE, was resistant to all known CpGV genome groups except group B. Single-pair crossing experiments with a susceptible strain, followed by resistance testing of the F1 offspring, clearly indicated cross-resistance to CpGV isolates that had been considered to be resistance breaking. This finding provides clear evidence of a second, broader type of CpGV resistance with a novel mode of inheritance that cannot be fully explained by Z-linkage of resistance. IMPORTANCE CpGV is registered and used in virtually all commercial apple growing areas worldwide and is therefore the most widely used baculovirus biocontrol agent. Recently, resistance to CpGV products was reported in different countries in Europe, threatening organic growers who rely almost exclusively on CpGV products. This resistance appeared to be targeted against a 24-bp repeat in the pe38 gene in isolate CpGV-M of genome group A, which had been used commercially for many years. On the other hand, resistance could be broken by CpGV isolates from CpGV genome groups B to E. Here, we report clear evidence of a second type of field resistance that is also directed against resistance-breaking isolates of CpGV genome groups C, D, and E and which appears not to be targeted against CpGV pe38 Therefore, we propose to differentiate between type I resistance, which is targeted against pe38 of CpGV genome group A, and a novel type II resistance with an unknown molecular target. This finding stresses the need for further adoption of resistance management strategies for CpGV, since growers cannot rely solely on the use of resistance-breaking CpGV isolates.
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Affiliation(s)
- J A Jehle
- Institute for Biological Control, Julius Kuehn Institute, Darmstadt, Germany
- Institute for Phytopathology, Agricultural Service Center Palatinate (DLR Rheinpfalz), Neustadt an der Weinstrasse, Germany
| | - S Schulze-Bopp
- Institute for Biological Control, Julius Kuehn Institute, Darmstadt, Germany
- Institute for Phytopathology, Agricultural Service Center Palatinate (DLR Rheinpfalz), Neustadt an der Weinstrasse, Germany
| | - K Undorf-Spahn
- Institute for Biological Control, Julius Kuehn Institute, Darmstadt, Germany
| | - E Fritsch
- Institute for Biological Control, Julius Kuehn Institute, Darmstadt, Germany
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3
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Abstract
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 composition of this virus RNA polymerase is known. The virus replication process culminates in the very high level expression of both polyhedrin and p10 gene products in the latter stages of infection. It has also been realized that the insect host cell has innate defenses against baculoviruses in the form of an apoptotic response to virus invasion. Baculoviruses counter this by encoding apoptotic-suppressors, which also appear to have a role in determining the host range of the virus. Also of importance to our understanding of baculovirus expression systems is how the virus can accumulate mutations within genes that affect recombinant protein yield in cell culture. The summary in this chapter is not exhaustive, but should provide a good preparation to those wishing to use this highly successful gene expression system.
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Affiliation(s)
- Barbara J Kelly
- The Moyne Institute of Preventive Medicine, Trinity College, Dublin, Ireland
| | - Linda A King
- School of Biological and Molecular Sciences, Oxford Brookes University, Oxford, UK
| | - Robert D Possee
- NERC CEH (Oxford), Mansfield Road, Oxford, OX1, UK.
- Department of Biological and Medical Sciences, Oxford Brookes University, Gipsy Lane, Oxford, OX3 0BP, UK.
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Baculovirus resistance in codling moth is virus isolate-dependent and the consequence of a mutation in viral gene pe38. Proc Natl Acad Sci U S A 2014; 111:15711-6. [PMID: 25331863 DOI: 10.1073/pnas.1411089111] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The baculovirus Cydia pomonella granulovirus (CpGV) is widely applied as a biocontrol agent of codling moth. After field resistance of codling moth populations had been observed against the commercially used Mexican (M) isolate of CpGV, infection experiments of larvae of the resistant codling moth strain CpRR1 showed that several other naturally occurring CpGV isolates (I12, S, E2, and I07) from different geographic origins are still infectious to resistant CpRR1. Whole-genome sequencing and phylogenetic analyses of these geographic CpGV variants revealed that their genomes share only a single common difference from that of CpGV-M, which is a mutation coding for a repeat of 24 nucleotides within the gene pe38; this mutation results in an additional repeat of eight amino acids that appears to be inserted to PE38 of CpGV-M only. Deletion of pe38 from CpGV-M totally abolished virus infection in codling moth cells and larvae, demonstrating that it is an essential gene. When the CpGV-M deletion mutant was repaired with pe38 from isolate CpGV-S, which originated from the commercial product Virosoft and is infectious for the resistant codling moth strain CpRR1, the repaired CpGV-M mutant was found to be fully infectious for CpRR1. Repair using pe38 from CpGV-M restored infectivity for the virus in sensitive codling moth strains, but not in CpRR1. Therefore, we conclude that CpGV resistance of codling moth is directed to CpGV-M but not to other virus isolates. The viral gene pe38 is not only essential for the infectivity of CpGV but it is also the key factor in overcoming CpGV resistance in codling moth.
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Ardisson-Araújo DMP, Morgado FDS, Schwartz EF, Corzo G, Ribeiro BM. A new theraphosid spider toxin causes early insect cell death by necrosis when expressed in vitro during recombinant baculovirus infection. PLoS One 2013; 8:e84404. [PMID: 24349574 PMCID: PMC3862797 DOI: 10.1371/journal.pone.0084404] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Accepted: 11/20/2013] [Indexed: 11/22/2022] Open
Abstract
Baculoviruses are the most studied insect viruses in the world and are used for biological control of agricultural and forest insect pests. They are also used as versatile vectors for expression of heterologous proteins. One of the major problems of their use as biopesticides is their slow speed to kill insects. Thus, to address this shortcoming, insect-specific neurotoxins from arachnids have been introduced into the baculovirus genome solely aiming to improve its virulence. In this work, an insecticide-like toxin gene was obtained from a cDNA derived from the venom glands of the theraphosid spider Brachypelma albiceps. The mature form of the peptide toxin (called Ba3) has a high content of basic amino acid residues, potential for three possible disulfide bonds, and a predicted three-stranded β-sheetDifferent constructions of the gene were engineered for recombinant baculovirus Autographa californica multiple nuclepolyhedrovirus (AcMNPV) expression. Five different forms of Ba3 were assessed; (1) the full-length sequence, (2) the pro-peptide and mature region, (3) only the mature region, and the mature region fused to an (4) insect or a (5) virus-derived signal peptide were inserted separately into the genome of the baculovirus. All the recombinant viruses induced cell death by necrosis earlier in infection relative to a control virus lacking the toxin gene. However, the recombinant virus containing the mature portion of the toxin gene induced a faster cell death than the other recombinants. We found that the toxin construct with the signal peptide and/or pro-peptide regions delayed the necrosis phenotype. When infected cells were subjected to ultrastructural analysis, the cells showed loss of plasma membrane integrity and structural changes in mitochondria before death. Our results suggest this use of baculovirus is a potential tool to help understand or to identify the effect of insect-specific toxic peptides when produced during infection of insect cells.
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Affiliation(s)
| | | | | | - Gerardo Corzo
- Departamento de Medicina Molecular y Bioprocesos, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Bergmann Morais Ribeiro
- Departmento de Biologia Celular, Universidade de Brasília, Brasília, Brasília, DF, Brazil
- * E-mail:
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6
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Ikeda M, Yamada H, Hamajima R, Kobayashi M. Baculovirus genes modulating intracellular innate antiviral immunity of lepidopteran insect cells. Virology 2013; 435:1-13. [DOI: 10.1016/j.virol.2012.10.016] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 10/08/2012] [Accepted: 10/08/2012] [Indexed: 12/11/2022]
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7
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Peigneur S, Béress L, Möller C, Marí F, Forssmann W, Tytgat J. A natural point mutation changes both target selectivity and mechanism of action of sea anemone toxins. FASEB J 2012; 26:5141-51. [DOI: 10.1096/fj.12-218479] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Steve Peigneur
- Laboratory of ToxicologyUniversity of Leuven (Katholieke Universiteit Leuven)LeuvenBelgium
| | - László Béress
- Department of Immunology and RheumatologyHannover Medical UniversityHannoverGermany
- Pharis Biotec GmbHHannoverGermany
| | - Carolina Möller
- Department of Chemistry and BiochemistryFlorida Atlantic UniversityBoca RatonFloridaUSA
| | - Frank Marí
- Department of Chemistry and BiochemistryFlorida Atlantic UniversityBoca RatonFloridaUSA
| | - Wolf‐Georg Forssmann
- Department of Immunology and RheumatologyHannover Medical UniversityHannoverGermany
- Pharis Biotec GmbHHannoverGermany
| | - Jan Tytgat
- Laboratory of ToxicologyUniversity of Leuven (Katholieke Universiteit Leuven)LeuvenBelgium
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8
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Gandhi KM, Ohkawa T, Welch MD, Volkman LE. Nuclear localization of actin requires AC102 in Autographa californica multiple nucleopolyhedrovirus-infected cells. J Gen Virol 2012; 93:1795-1803. [PMID: 22592260 DOI: 10.1099/vir.0.041848-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Autographa californica multiple nucleopolyhedrovirus requires nuclear actin for progeny virus production and thereby encodes viral products that ensure actin's translocation to and retention within the nucleus. Current evidence suggests that the ie0-ie1 gene complex along with five nuclear localization of actin (NLA) genes are sufficient for NLA in transient transfection experiments. Here we report that, during infection, only one of the five NLA genes, Ac102, was essential for NLA, and that AC102 had at least one other activity critical for budded virus (BV) production. Viral deletion mutants in the other four NLA genes were viable, with only two having replication phenotypes different from that of the wild type. Infection with AcΔpe38 revealed a delay in both BV production and NLA. Infection with AcΔ152 revealed a delay in BV production, but no corresponding delay in NLA. Infection with either AcΔpe38 or AcΔ152 resulted in slightly reduced BV titres. Deletion of Ac004 or he65 had no impact on actin translocation kinetics, timing of BV production or BV titres. These results implicate AC102 as a key player in baculovirus manipulation of actin.
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Affiliation(s)
- Kamal M Gandhi
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3102, USA
| | - Taro Ohkawa
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3200, USA
| | - Matthew D Welch
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3200, USA
| | - Loy E Volkman
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3102, USA
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9
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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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10
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Abstract
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 composition of this virus RNA polymerase is known. The virus replication process culminates in the very high level expression of both polyhedrin and p10 gene products in the latter stages of infection. It has also been realized that the insect host cell has innate defenses against baculoviruses in the form of an apoptotic response to virus invasion. Baculoviruses counter this by encoding apoptotic-suppressors, which also appear to have a role in determining the host range of the virus. Also of importance to our understanding of baculovirus expression systems is how the virus can accumulate mutations within genes that affect recombinant protein yield in cell culture. The summary in this chapter is not exhaustive, but should provide a good preparation to those wishing to use this highly successful gene expression system.
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11
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Stewart TM, Huijskens I, Willis LG, Theilmann DA. The Autographa californica multiple nucleopolyhedrovirus ie0-ie1 gene complex is essential for wild-type virus replication, but either IE0 or IE1 can support virus growth. J Virol 2005; 79:4619-29. [PMID: 15795248 PMCID: PMC1069578 DOI: 10.1128/jvi.79.8.4619-4629.2005] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The immediate-early ie0-ie1 gene complex expresses the only baculovirus spliced gene that produces an alternate protein product. Autographa californica multiple nucleopolyhedrovirus (AcMNPV) IE1 is a potent transcriptional transactivator that is essential for viral replication in transient assays. IE1 contains 582 amino acids that are arranged into different domains, including an acidic activation domain at the N terminus, a DNA binding domain, and an oligomerization domain at the C terminus. IE0 is a 52-amino-acid N-terminally elongated form of IE1. We investigated the functions of IE0 and IE1 in virus-infected cells by constructing the first ie1 open reading frame knockout virus. An infectious AcMNPV bacmid was used to generate the ie1 knockout, and the resulting virus, AcBacIE1KO, effectively deletes both ie0 and ie1. AcBacIE1KO does not infect Spodoptera frugiperda cells, showing that the ie0-ie1 gene complex is essential for viral infection. Rescue viruses of AcBacIE1KO were constructed that express only IE1, IE1 and IE0, or only IE0. Our results show that both IE0 and IE1 can function independently, but not equivalently, to support replication, producing infectious virus. Viruses expressing predominately, or only, IE0 produced significantly fewer cells with polyhedra than either the IE1 counterpart or wild-type virus. In addition, DNA replication was prolonged and budded virus and late gene expression were delayed. Viruses expressing only IE1 also produced fewer polyhedra, but replication was slightly faster and achieved higher levels than that of the wild-type virus. Both IE0 and IE1 are therefore required and must be expressed in the correct quantitative ratios to achieve a wild-type infection.
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Affiliation(s)
- Taryn M Stewart
- Faculty of Agricultural Sciences, University of British Columbia, Vancouver, Canada V0H 1Z0
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12
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Nagamine T, Kawasaki Y, Iizuka T, Matsumoto S. Focal distribution of baculovirus IE1 triggered by its binding to the hr DNA elements. J Virol 2005; 79:39-46. [PMID: 15596799 PMCID: PMC538704 DOI: 10.1128/jvi.79.1.39-46.2005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In BmN cells infected with the baculovirus Bombyx mori nucleopolyhedrovirus (BmNPV), IE1, a principal transcriptional activator, localizes to sites of viral DNA replication. IE1 initially displays focal distribution in BmNPV-infected cells prior to DNA synthesis, whereas the protein expressed by transfection with the ie1 gene is distributed throughout the nucleoplasm instead of localized to discrete subnuclear structures. To identify the inducer of focus formation for IE1, we conducted transfection experiments with an IE1-GFP construct and found that cotransfection with genomic DNA fragments bearing the homologous region (hr) sequences caused the formation of IE1-green fluorescent protein (GFP) foci. The transfection of insect cells with a single plasmid containing exclusively the hr3 sequence and the IE1-GFP gene was sufficient to form IE1-GFP foci. These results suggest that hr elements are a primary determinant of the focal distribution of IE1. An analysis of a series of hr3 deletion mutants showed that a single copy of the direct repeat could induce the formation of IE1 foci. Targeted mutagenesis within the hr-binding domain of IE1-GFP caused impairment of the hr-dependent IE1 localization, suggesting that binding of IE1 to the hr elements is essential for the onset of IE1 focus formation. The observation of BmNPV IE1 foci in non-BmNPV-susceptible cells suggests that no species-specific factors are required for hr-dependent IE1 focus formation.
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Affiliation(s)
- Toshihiro Nagamine
- Laboratory of Molecular Entomology, RIKEN Discovery Research Institute, Wako-shi, Saitama, Japan.
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13
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Kawasaki Y, Matsumoto S, Nagamine T. Analysis of baculovirus IE1 in living cells: dynamics and spatial relationships to viral structural proteins. J Gen Virol 2004; 85:3575-3583. [PMID: 15557230 DOI: 10.1099/vir.0.80418-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
IE1, a principal transcriptional activator of the baculovirus Bombyx mori nucleopolyhedrovirus (BmNPV), is an essential factor for viral DNA replication. During viral infection, IE1 accumulates in discrete subnuclear structures where viral DNA replication occurs. To analyse the dynamic properties of IE1, we monitored green fluorescent protein-tagged IE1 (IE1-GFP) in BmNPV-infected B. mori cells by live-cell microscopy. Time-lapse imaging showed that IE1-associated structures gradually expanded and occasionally fused with one another, while photobleaching experiments revealed that IE1-GFP was relatively immobile inside the IE1-associated structures. To investigate the spatial relationships between IE1 and viral structural proteins in infected cells, three GFP-tagged viral components were expressed together with DsRed-tagged IE1. Two structural proteins that constitute the occlusion-derived virus (ODV), P91-GFP and GFP-ODV-E25, localized to the periphery of the IE1-associated structures. While local accumulations of these proteins were often in contact with the IE1-associated structures, they did not extend beyond the boundaries of the structures. In contrast, the major capsid protein VP39-GFP predominantly accumulated within the IE1-associated structures. These data indicated, in conjunction with the finding of a high DNA content in the structures, that IE1 localizes to the virogenic stroma and therefore support the prediction previously proposed that the virogenic stroma is a site for viral DNA replication as well as for the assembly of nucleocapsids.
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Affiliation(s)
- Yu Kawasaki
- Graduate School of Science and Engineering, Saitama University, Shimo-Okubo, Saitama City, Saitama 338-8570, Japan
- RIKEN Discovery Research Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
| | - Shogo Matsumoto
- RIKEN Discovery Research Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
| | - Toshihiro Nagamine
- RIKEN Discovery Research Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
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Thiem SM, Chejanovsky N. The role of baculovirus apoptotic suppressors in AcMNPV-mediated translation arrest in Ld652Y cells. Virology 2004; 319:292-305. [PMID: 14980489 DOI: 10.1016/j.virol.2003.11.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2003] [Revised: 11/05/2003] [Accepted: 11/05/2003] [Indexed: 11/17/2022]
Abstract
Infecting the insect cell line IPLB-Ld652Y with the baculovirus Autographa californica multinucleocapsid nucleopolyhedrovirus (AcMNPV) results in global translation arrest, which correlates with the presence of the AcMNPV apoptotic suppressor, p35. In this study, we investigated the role of apoptotic suppression on AcMNPV-induced translation arrest. Infecting cells with AcMNPV bearing nonfunctional mutant p35 did not result in global translation arrest. In contrast, global translation arrest was observed in cells infected with AcMNPV in which p35 was replaced with Opiap, Cpiap, or p49, baculovirus apoptotic suppressors that block apoptosis by different mechanisms than p35. These results indicated that suppressing apoptosis triggered translation arrest in AcMNPV-infected Ld652Y cells. Experiments using the DNA synthesis inhibitor aphidicolin and temperature shift experiments, using the AcMNPV replication mutants ts8 and ts8deltap35, indicated that translation arrest initiated during the early phase of infection, but events during the late phase were required for global translation arrest. Peptide caspase inhibitors could not substitute for baculovirus apoptotic suppressors to induce translation arrest in Ld652Y cells infected with a p35-null virus. However, if the p35-null-AcMNPV also carried hrf-1, a novel baculovirus host range gene, progeny virus was produced and treatment with peptide caspase inhibitors enhanced translation of a late viral gene transcript. Together, these results indicate that translation arrest in AcMNPV-infected Ld652Y cells is due to the anti-apoptotic function of p35, but suggests that rather than simply preventing caspase activation, its activity enhances signaling to a separate translation arrest pathway, possibly by stimulating the late stages of the baculovirus infection cycle.
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Affiliation(s)
- Suzanne M Thiem
- Department of Entomology, Michigan State University, East Lansing, MI 48824, USA.
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15
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Abstract
Insects, with their lack of an adaptive immune response, provide a unique animal model to examine the effects of apoptosis on viral infection. Several members of the baculovirus family of insect viruses have been shown to induce apoptosis during infection of cultured insect cells, and depending on the virus-host combination this apoptotic response can severely limit viral replication. In response to this evolutionary pressure, all baculoviruses studied to date carry antiapoptotic genes, including members of the p35 and IAP (inhibitor of apoptosis) gene families. Recent work has characterized the apoptotic response during infection of the host insect, and the results directly demonstrate the power of apoptosis as an antiviral response.
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Affiliation(s)
- Thomas E Clarke
- Molecular, Cellular, and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
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16
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Milks ML, Washburn JO, Willis LG, Volkman LE, Theilmann DA. Deletion of pe38 attenuates AcMNPV genome replication, budded virus production, and virulence in heliothis virescens. Virology 2003; 310:224-34. [PMID: 12781710 DOI: 10.1016/s0042-6822(03)00143-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The pe38 gene product of Autographa californica M nucleopolyhedrovirus (AcMNPV) has been shown to be involved in transcriptionally transactivating viral genes and augmenting viral DNA replication in transient assays. To assess the role of pe38 during infection, we generated a knockout virus, Delta pe38-E9/E9, in which the pe38 open reading frame was replaced with that of the green fluorescent protein. We compared mutant and wild-type (WT) viral replication in insect cell culture and virulence in Heliothis virescens larvae. Compared to WT, Delta pe38-E9/E9 budded virus (BV) production was delayed by at least 3 h, and BV yields were reduced over 99%. Similarly, Delta pe38-E9/E9 DNA synthesis levels were greatly reduced relative to those of WT, but onset of DNA replication was the same for both viruses. In bioassays, nearly sevenfold more Delta pe38-E9/E9 virus than WT virus was required to achieve an LD(50) when administered orally, but not hemocoelically. These results support the hypothesis that the kinetics of AcMNPV BV production greatly impact virulence in larvae infected orally (the natural route of infection) and that PE38 is an important, but not essential, factor in viral DNA synthesis and BV production.
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Affiliation(s)
- Maynard L Milks
- Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, 4200 Highway 97, Summerland, BC, Canada V0H 1Z0
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Ishikawa H, Ikeda M, Yanagimoto K, Alves CAF, Katou Y, Laviña-Caoili BA, Kobayashi M. Induction of apoptosis in an insect cell line, IPLB-Ld652Y, infected with nucleopolyhedroviruses. J Gen Virol 2003; 84:705-714. [PMID: 12604823 DOI: 10.1099/vir.0.18815-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Ld652Y cells derived from the gypsy moth, Lymantria dispar, were infected with seven different nucleopolyhedroviruses (NPVs) including those from Autographa californica, Bombyx mori (BmNPV), Hyphantria cunea (HycuNPV), Spodoptera exigua (SeMNPV), L. dispar, Orgyia pseudotsugata (OpMNPV) and Spodoptera litura (SpltMNPV). The results showed that Ld652Y cells infected with BmNPV, HycuNPV, SeMNPV, OpMNPV and SpltMNPV underwent apoptosis, displaying apoptotic bodies, characteristic DNA fragmentation and increased caspase-3-like protease activity; HycuNPV induced the most severe apoptosis. In HycuNPV-infected Ld652Y cells, a considerable amount of viral DNA was synthesized although there was no detectable yield of budded virions and polyhedrin. Northern blot and immunoblot analyses revealed that HycuNPV inhibitor of apoptosis 3 (IAP3), which has been shown to function in Sf9 cells, was expressed in HycuNPV-infected Ld652Y cells at a level higher than or comparable with that in HycuNPV-infected SpIm cells, which produced a high titre of progeny virions without any apoptotic response. These results imply that the relative ease of apoptosis induction in NPV-infected Ld652Y cells is largely dependent on inherent cellular properties rather than functions of the respective NPVs, and indicate that the defect in progeny virion production is not merely due to the virus-induced apoptosis in HycuNPV-infected Ld652Y cells.
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Affiliation(s)
- Hiroki Ishikawa
- Laboratory of Biodynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
| | - Motoko Ikeda
- Laboratory of Sericulture and Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
| | - Kenichi Yanagimoto
- Laboratory of Biodynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
| | - Cristiano A Felipe Alves
- Laboratory of Biodynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
| | - Yasuhiro Katou
- Laboratory of Biodynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
| | - Barbara A Laviña-Caoili
- Laboratory of Biodynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
| | - Michihiro Kobayashi
- Laboratory of Biodynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
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Hefferon KL. ORF98 of Autographa californica nucleopolyhedrosisvirus is an auxiliary factor in late gene expression. Can J Microbiol 2003; 49:157-63. [PMID: 12795401 DOI: 10.1139/w03-022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Autographa californica nucleopolyhedrosisvirus (AcMNPV) is the type member of the family Baculoviridae. Gene expression of AcMNPV during virus infection is temporally regulated. A series of late expression factors (LEFs) are required for late gene expression to take place. A number of additional factors have also been shown to more modestly influence late gene expression. Using the LEF transient assay, we scanned the AcMNPV genome for such factors by replacing plasmids using the LEF genes with larger clones and then looked for increases in late gene expression using a reporter plasmid under the control of a late promoter. Using this approach, ORF98 was identified as having a stimulatory effect on late gene expression. The ability of ORF98 to influence early, late, and very late gene expression was established. Furthermore, tagged versions of ORF98 were localized to the nuclei of transfected cells and were shown to interact with each other as homo-oligomers. Potential roles of ORF98 in baculovirus infection are discussed.
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Affiliation(s)
- Kathleen L Hefferon
- Cornell Research Foundation, Cornell University, 20 Thornwood Drive, Ithaca, NY 14850, USA.
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Imai N, Matsuda N, Tanaka K, Nakano A, Matsumoto S, Kang W. Ubiquitin ligase activities of Bombyx mori nucleopolyhedrovirus RING finger proteins. J Virol 2003; 77:923-30. [PMID: 12502808 PMCID: PMC140854 DOI: 10.1128/jvi.77.2.923-930.2003] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The genome of Bombyx mori nucleopolyhedrovirus (BmNPV) is predicted to contain six RING finger proteins: IAP1, ORF35, IAP2, CG30, IE2, and PE38. Several other members of the RING finger family have recently been shown to have the ubiquitin-ligase (E3) activity. We thus examined whether BmNPV RING finger proteins have the E3 activity. In vitro ubiquitination assay with the rabbit reticulocyte lysates and BmNPV RING finger proteins fused with maltose-binding protein (MBP) showed that four of them (IAP2, IE2, PE38, and CG30) were polyubiquitinated in the presence of zinc ion. Furthermore, MBP-IAP2, MBP-IE2, and MBP-PE38 were able to reconstitute ubiquitination activity in cooperation with the Ubc4/5 subfamily of ubiquitin-conjugating enzymes. Mutational analysis also showed that ubiquitination activity of MBP-IAP2, MBP-IE2, and MBP-PE38 were dependent on their RING finger motif. Therefore, these results suggest that IAP2, IE2, and PE38 may function as E3 enzymes during BmNPV infection.
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Affiliation(s)
- Noriko Imai
- Laboratory of Molecular Entomology and Baculovirology, Wako, Japan
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Ohkawa T, Rowe AR, Volkman LE. Identification of six Autographa californica multicapsid nucleopolyhedrovirus early genes that mediate nuclear localization of G-actin. J Virol 2002; 76:12281-9. [PMID: 12414968 PMCID: PMC136882 DOI: 10.1128/jvi.76.23.12281-12289.2002] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2002] [Accepted: 08/20/2002] [Indexed: 01/16/2023] Open
Abstract
Nuclear filamentous actin (F-actin) is required for nucleopolyhedrovirus (NPV) progeny production in NPV-infected, cultured lepidopteran cells. We have determined that monomeric G-actin is localized within the nuclei of host cells during the early stage of infection by Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV). With a library of cloned AcMNPV genomic fragments, along with a plasmid engineered to express enhanced green fluorescent protein-Bombyx mori G-actin in transient transfection experiments, we identified six AcMNPV early genes that mediate nuclear localization of G-actin in TN-368 cells: ie-1, pe38, he65, Ac004, Ac102, and Ac152. Within this subset, ie-1 and pe38 encode immediate-early transcriptional transactivators, he65 encodes a delayed-early product, and the products encoded by Ac004, Ac102, and Ac152 have not been characterized. We found that when driven by foreign promoters, ie-1, pe38, and Ac004 had to be expressed prior to Ac102 or he65 for nuclear G-actin to accumulate and that expression of Ac152 was no longer required. These results and others suggested that the product of Ac152 was a transactivator (directly or indirectly) of both Ac102 and he65 and that recruitment of G-actin to the nucleus was a temporally regulated process. Determining the functions of each of the six AcMNPV gene products with respect to our assay should provide valuable clues to basic cellular mechanisms of actin regulation and how AcMNPV infection affects them.
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Affiliation(s)
- Taro Ohkawa
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720-3102, USA
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Olson VA, Wetter JA, Friesen PD. Baculovirus transregulator IE1 requires a dimeric nuclear localization element for nuclear import and promoter activation. J Virol 2002; 76:9505-15. [PMID: 12186932 PMCID: PMC136476 DOI: 10.1128/jvi.76.18.9505-9515.2002] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Immediate-early protein IE1 is a principal regulator of viral transcription and a contributor to origin-specific DNA replication of the baculovirus Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV). Since these viral functions involve interaction of dimeric IE1 with palindromic homologous region (hr) enhancer-origin elements of the AcMNPV genome within the nucleus, it is presumed that proper nuclear transport of IE1 is essential for productive infection. To investigate the mechanisms of IE1 nuclear import, we analyzed the effect of site-directed mutations on IE1 subcellular distribution. As demonstrated by fluorescence microscopy and biochemical fractionation of plasmid-transfected cells, wild-type IE1 localized predominantly to the nucleus. Substitution or deletion of amino acid residues within a positively charged domain (residues 534 to 538) adjacent to IE1's oligomerization motif impaired nuclear import and caused loss of transactivation. Moreover, upon coexpression, these import-defective mutations prevented nuclear entry of wild-type IE1. In contrast, double-mutated IE1 defective for both nuclear import and dimerization failed to block nuclear entry or transactivation by wild-type IE1. Thus, import-defective IE1 dominantly interfered with wild-type IE1 by direct interaction and cytosolic trapping. Collectively, our data indicate that the small basic domain encompassing residues R(537) and R(538) constitutes a novel nuclear localization element that functions only upon IE1 dimerization. These findings support a model wherein IE1 oligomerizes within the cytosol as a prerequisite for nuclear entry and subsequent high-affinity interaction with the symmetrical binding sites comprising AcMNPV hr enhancer-origin elements.
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Affiliation(s)
- Victoria A Olson
- Institute for Molecular Virology and Department of Biochemistry, Graduate School and College of Agricultural and Life Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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de Castro ME, Ribeiro BM. Production of viral progeny in insect cells undergoing apoptosis induced by a mutant Anticarsia gemmatalis nucleopolyhedrovirus. Microbiol Res 2002; 156:369-76. [PMID: 11770855 DOI: 10.1078/0944-5013-00122] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The Anticarsia gemmatalis nucleopolyhedrovirus (AgMNPV) is the most successful viral biopesticide in use worldwide. We have demonstrated that despite widespread apoptosis and no protein synthesis at 48 h p.i., UFL-AG-286 cells infected with a mutant of AgMNPV (vApAg), produced significant amounts of budded virus (BVs) and viral DNA late in infection. However, a different susceptible cell line (BTI-Tn5B 1-4) showed no signs of apoptosis and produced 3.5 times more budded virus when infected with vApAg. A comparison of DNA from AgMNPV and vApAg digested with the same restriction enzymes showed differences in the restriction pattern, indicating that the vApAg phenotype might be due to a mutation in a gene or genes responsible for directly or indirectly inhibiting apoptosis in UFL-AG-286 cells.
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Affiliation(s)
- M E de Castro
- Embrapa Recursos Genéticos e Biotecnologia, Cx. Postal 02372, Brasília, DF, 70849-970, Brasil
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Carstens EB, Liu JJ, Dominy C. Identification and molecular characterization of the baculovirus CfMNPV early genes: ie-1, ie-2 and pe38. Virus Res 2002; 83:13-30. [PMID: 11864738 DOI: 10.1016/s0168-1702(01)00401-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Three early virus genes, ie-1, ie-2 and pe38, were identified and localized in the XbaI G region (91.2-98.6 m.u.) of the genome of Choristoneura fumiferana nucleopolyhedrovirus (CfMNPV), a baculovirus pathogenic to spruce budworm. Nucleotide sequence analysis indicated that these genes share varied sequence similarity with their homologues in other baculoviruses where they are involved in regulating virus gene expression and DNA replication. Sequence motifs characteristic of DNA binding and transactivation found in other baculovirus regulatory genes were conserved in the CfMNPV genes. Northern analysis demonstrated that all three CfMNPV genes were transcriptionally active in virus infected cells and followed the temporal expression pattern of immediate early baculovirus genes. Primer extension experiments revealed that typical baculovirus early transcription start sites (CAGT) were used for ie-1 and pe38 transcription initiation. Two regions of highly repetitive DNA were found in the odv-e56 to ie-2 and ie-2 and pe38 intergenic regions. These sequences are predicted to function as transcriptional enhancers and viral origins of DNA replication.
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Affiliation(s)
- Eric B Carstens
- Department of Microbiology and Immunology, Queen's University, Kingston Ont., Canada K7L 3N6.
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Murges D, Quadt I, Schröer J, Knebel-Mörsdorf D. Dynamic nuclear localization of the baculovirus proteins IE2 and PE38 during the infection cycle: the promyelocytic leukemia protein colocalizes with IE2. Exp Cell Res 2001; 264:219-32. [PMID: 11262179 DOI: 10.1006/excr.2000.5081] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The early gene products IE2 and PE38 of Autographa californica multicapsid nuclear polyhedrosis virus localize to distinct nuclear domains after transient expression. Here, the nuclear localization pattern and the putative association with cellular proteins have been determined during virus infection to shed light on the functional significance of the nuclear domains. IE2 was always localized to distinct nuclear structures while PE38 was partly present in nuclear dots. Confocal imaging indicated colocalization of PE38 and IE2 to common domains, prominently at 2 h p.i. The nuclear dot localization of PE38 in infected cells was different from that in transfected cells. Hence, we have performed cotransfection experiments that suggested that a viral factor influences the nuclear distribution. Since the promyelocytic leukemia protein (PML) that localizes to distinct nuclear multiprotein complexes termed ND10/PODs in mammalian cells functions as a target for some immediate early viral proteins, we have investigated whether baculovirus proteins act similarly. Transiently expressed IE2 and PE38 were found to be associated with endogenous PML in the mammalian cell line BHK21. Infection with a recombinant virus that expresses the human pml gene in insect cells reveals IE2 and PML to be colocalized during the early phase of infection followed by a redistribution of both proteins. Taken together our results provide first evidence that the early baculovirus protein IE2 associates at least with one component of mammalian PODs during virus infection, suggesting that POD-like structures can be formed in insect cells.
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Affiliation(s)
- D Murges
- Max-Planck-Institute for Neurological Research, University of Cologne, Cologne, D-50931, Germany
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Clem RJ. Baculoviruses and apoptosis: the good, the bad, and the ugly. Cell Death Differ 2001; 8:137-43. [PMID: 11313715 DOI: 10.1038/sj.cdd.4400821] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2000] [Accepted: 12/04/2000] [Indexed: 11/09/2022] Open
Abstract
Since 1991, when a baculovirus was first shown to inhibit apoptosis of its host insect cells, considerable contributions to our knowledge of apoptosis have arisen from the study of these viruses and the anti-apoptotic genes they encode. Baculovirus anti-apoptotic genes include p35, which encodes the most broadly acting caspase inhibitor protein known, and iap (inhibitor of apoptosis) genes, which were the first members of an evolutionarily conserved gene family involved in regulation of apoptosis and cytokinesis in organisms ranging from yeast to humans. Baculoviruses also provide an ideal system to study the effects of an apoptotic response on viral pathogenesis in an animal host. In this review, I discuss a number of interesting recent developments in the areas of apoptotic regulation by baculoviruses and the effects of apoptosis on baculovirus replication and pathogenesis.
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Affiliation(s)
- R J Clem
- Division of Biology, Kansas State University, Manhattan 66506, USA.
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