scholarly journals Cross-talking between baculoviruses and host insects towards a successful infection

2019 ◽  
Vol 374 (1767) ◽  
pp. 20180324 ◽  
Author(s):  
Manli Wang ◽  
Zhihong Hu
Keyword(s):  
Primary Infection ◽  
Insect Pests ◽  
Systemic Infection ◽  
Life Cycles ◽  
Theme Issue ◽  
Insect Midgut ◽  
Dna Viruses ◽  
Host Interactions ◽  
Successful Infection ◽  
Budded Virus

Baculoviridae is a family of large DNA viruses that infect insects. They have been extensively used as safe and efficient biological agents for the control of insect pests. As a result of coevolution with their hosts, baculoviruses developed unique life cycles characterized by the production of two distinctive virion phenotypes, occlusion-derived virus and budded virus, which are responsible for mediating primary infection in insect midgut epithelia and spreading systemic infection within infected insects, respectively. In this article, advances associated with virus–host interactions during the baculovirus life cycle are reviewed. We mainly focus on how baculoviruses exploit versatile strategies to overcome diverse host barriers and establish successful infections. For example, in the midgut, baculoviruses encode enzymes to degrade peritrophic membranes and use a series of per os infectivity factors to initiate primary infection. A viral fibroblast growth factor is expressed to attract tracheoblasts that spread the virus for systemic infection. Baculoviruses use different strategies to suppress host defence systems, including apoptosis, melanization and RNA interference. Additionally, baculoviruses can manipulate host physiology and induce ‘tree-top disease’ for optimal virus replication and dispersal. These advances in our understanding of baculoviruses will greatly inform the development of more effective baculoviral pesticides. This article is part of the theme issue ‘Biotic signalling sheds light on smart pest management’.

Baculovirus Entry and Egress from Insect Cells

2018 ◽  
Vol 5 (1) ◽  
pp. 113-139 ◽  
Author(s):  
Gary W. Blissard ◽  
David A. Theilmann
Keyword(s):  
Insect Cells ◽  
Critical Role ◽  
Oral Infection ◽  
Cell Recognition ◽  
Infection Cycle ◽  
Highly Pathogenic ◽  
Insect Midgut ◽  
Dna Viruses ◽  
Viral Egress ◽  
Budded Virus

Baculoviruses are large DNA viruses of insects that are highly pathogenic in many hosts. In the infection cycle, baculoviruses produce two types of virions. These virion phenotypes are physically and functionally distinct, and each serves a critical role in the biology of the virus. One phenotype, the occlusion-derived virus (ODV), is occluded within a crystallized protein that facilitates oral infection of the host. A large complex of at least nine ODV envelope proteins called per os infectivity factors are critically important for ODV infection of insect midgut epithelial cells. Viral egress from midgut cells is by budding to produce a second virus phenotype, the budded virus (BV). BV binds, enters, and replicates in most other tissues of the host insect. Cell recognition and entry by BV are mediated by a single major envelope glycoprotein: GP64 in some baculoviruses and F in others. Entry and egress by the two virion phenotypes occur by dramatically different mechanisms and reflect a life cycle in which ODV is specifically adapted for oral infection while BV mediates dissemination of the infection within the animal.

Identification of a baculovirus polyhedron formation mutant with a novel phenotype

1996 ◽  
Vol 54 ◽  
pp. 796-797
Author(s):  
James M. Slavicek ◽  
Melissa J. Mercer ◽  
Mary Ellen Kelly
Keyword(s):  
Viral Gene ◽  
Gene Products ◽  
Type Number ◽  
Infection Cycle ◽  
Wild Type ◽  
Protein Matrix ◽  
Insect Midgut ◽  
Viral Particles ◽  
Budded Virus ◽  
Viral Form

Nucleopolyhedroviruses (NPV, family Baculoviridae) produce two morphological forms, a budded virus form and a viral form that is occluded into a paracrystalline protein matrix. This structure is termed a polyhedron and is composed primarily of the protein polyhedrin. Insects are infected by NPVs after ingestion of the polyhedron and release of the occluded virions through dissolution of the polyhedron in the alkaline environment of the insect midgut. Early after infection the budded virus form is produced. It buds through the plasma membrane and then infects other cells. Later in the infection cycle the occluded form of the virus is generated (reviewed by Blissard and Rohrmann, 1990).The processes of polyhedron formation and virion occlusion are likely to involve a number of viral gene products. However, only two genes, the polyhedrin gene and 25K FP gene, have been identified to date that are necessary for the wild type number of polyhedra to be formed and viral particles occluded.

Behavior-based control of insect crop pests

2018 ◽  
Author(s):  
Sandra A. Allan
Keyword(s):  
Insect Pests ◽  
Control Strategies ◽  
Insect Behavior ◽  
Life Cycles ◽  
Economic Damage ◽  
Mass Trapping ◽  
Ecological Traits ◽  
Crop Pests ◽  
Effective Strategies ◽  
Crop Development

Manipulation of insect behavior can provide the foundation for effective strategies for control of insect crop pests. A detailed understanding of life cycles and the behavioral repertoires of insect pests is essential for development of this approach. A variety of strategies have been developed based on behavioral manipulation and include mass trapping, attract-and-kill, auto-dissemination, mating and host plant location disruption, and push-pull. Insight into application of these strategies for insect pests within Diptera, Lepidoptera, Coleoptera, and Hemiptera/Thysanoptera are provided, but first with an overview of economic damage and traditional control approaches, and overview of relevant behavioral/ecological traits. Then examples are provided of how these different control strategies are applied for each taxonomic group. The future of these approaches in the context of altered crop development for repellency or as anti-feedants, the effects of climate change and the risks of behaviorally-based methods are discussed.

scholarly journals Viruses go modular

2020 ◽  
Vol 295 (14) ◽  
pp. 4604-4616 ◽  
Author(s):  
Ariel Shepley-McTaggart ◽  
Hao Fan ◽  
Marius Sudol ◽  
Ronald N. Harty
Keyword(s):  
Hippo Pathway ◽  
Host Proteins ◽  
Dna Viruses ◽  
Ww Domain ◽  
Ww Domains ◽  
Host Interactions ◽  
New Class ◽  
Domain Interactions ◽  
Molecular Aspects ◽  
The Hippo Pathway

The WW domain is a modular protein structure that recognizes the proline-rich Pro-Pro-x-Tyr (PPxY) motif contained in specific target proteins. The compact modular nature of the WW domain makes it ideal for mediating interactions between proteins in complex networks and signaling pathways of the cell (e.g. the Hippo pathway). As a result, WW domains play key roles in a plethora of both normal and disease processes. Intriguingly, RNA and DNA viruses have evolved strategies to hijack cellular WW domain–containing proteins and thereby exploit the modular functions of these host proteins for various steps of the virus life cycle, including entry, replication, and egress. In this review, we summarize key findings in this rapidly expanding field, in which new virus-host interactions continue to be identified. Further unraveling of the molecular aspects of these crucial virus-host interactions will continue to enhance our fundamental understanding of the biology and pathogenesis of these viruses. We anticipate that additional insights into these interactions will help support strategies to develop a new class of small-molecule inhibitors of viral PPxY-host WW-domain interactions that could be used as antiviral therapeutics.

scholarly journals Response of immunocompetent and immunosuppressed Spodoptera littoralis larvae to baculovirus infection

2006 ◽  
Vol 87 (8) ◽  
pp. 2217-2225 ◽  
Author(s):  
Hadassah Rivkin ◽  
Jeremy A. Kroemer ◽  
Alexander Bronshtein ◽  
Eduard Belausov ◽  
Bruce A. Webb ◽  
...  
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Spodoptera Littoralis ◽  
Fluorescent Protein ◽  
Oral Route ◽  
Green Fluorescent Protein Gene ◽  
Successful Infection ◽  
Baculovirus Infection ◽  
Budded Virus ◽  
Green Fluorescent

The Mediterranean lepidopteran pest Spodoptera littoralis is highly resistant to infection with the Autographa californica multiple nucleopolyhedrovirus (AcMNPV) via the oral route, but highly sensitive to infection with budded virus (BV) via the intrahaemocoelic route. To study the fate of AcMNPV infection in S. littoralis, vHSGFP, an AcMNPV recombinant that expresses the reporter green fluorescent protein gene under the control of the Drosophila heat-shock promoter, and high-resolution fluorescence microscopy were utilized. S. littoralis fourth-instar larvae infected orally with vHSGFP showed melanization and encapsulation of virus-infected tracheoblast cells serving the midgut columnar cells. At 72 h post-infection, the viral foci were removed during the moult clearing the infection. Thus, oral infection was restricted by immune responses to the midgut and midgut-associated tracheal cells. By contrast, injection of BV into the haemocoel resulted in successful infection of tracheoblasts, followed by spread of the virus through the tracheal epidermis to other tissues. However, in contrast to fully permissive infections where tracheoblasts and haemocytes are equally susceptible to infection, a severe limitation to vHSGFP infection of haemocytes was observed. To investigate the resistance of S. littoralis haemocytes to BV infection with AcMNPV, the larval immune system was suppressed with the Chelonus inanitus polydnavirus or a putatively immunosuppressive polydnavirus gene, P-vank-1. Both treatments increased the susceptibility of S. littoralis larvae to AcMNPV. It is concluded that the resistance of S. littoralis to AcMNPV infection involves both humoral and cellular immune responses that act at the gut and haemocyte levels. The results also support the hypothesis that tracheolar cells mediate establishment of systemic baculovirus infections in lepidopteran larvae. The finding that polydnaviruses and their encoded genes synergize baculovirus infection also provides an approach to dissecting the responses of the lepidopteran immune system to viruses by using specific polydnavirus immunosuppressive genes.

scholarly journals Human anelloviruses: diverse, omnipresent and commensal members of the virome

2020 ◽  
Vol 44 (3) ◽  
pp. 305-313 ◽  
Author(s):  
Joanna Kaczorowska ◽  
Lia van der Hoek
Keyword(s):  
Beneficial Effect ◽  
Culture System ◽  
Human Population ◽  
Human Life ◽  
Disease Association ◽  
Viral Clearance ◽  
Early Age ◽  
Dna Viruses ◽  
Circular Dna ◽  
Host Interactions

ABSTRACT Anelloviruses are small, single stranded circular DNA viruses. They are extremely diverse and have not been associated with any disease so far. Strikingly, these small entities infect most probably the complete human population, and there are no convincing examples demonstrating viral clearance from infected individuals. The main transmission could be via fecal-oral or airway route, as infections occur at an early age. However, due to the lack of an appropriate culture system, the virus–host interactions remain enigmatic. Anelloviruses are obviously mysterious viruses, and their impact on human life is not yet known, but, with no evidence of a disease association, a potential beneficial effect on human health should also be investigated.

Induction of Cancer by DNA Viruses

1980 ◽  
Vol 89 (6) ◽  
pp. 489-496 ◽  
Author(s):  
James D. Watson
Keyword(s):  
Cell Surface ◽  
Life Cycles ◽  
Normal Cells ◽  
Dna Viruses ◽  
Tumor Virus ◽  
Cellular Dna ◽  
Virus Sv40

The life cycles of the tumor virus SV40 and polyoma are discussed with particular emphasis on the role of the viral coded proteins which mediate the transformation of normal cells into their cancerous equivalents. One or more of these proteins possibly act by stimulating directly the synthesis of cellular DNA, while others may mimic the action of polypeptide mitogens that act at the cell surface.

scholarly journals Unique structure and function of viral rhodopsins

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Dmitry Bratanov ◽  
Kirill Kovalev ◽  
Jan-Philipp Machtens ◽  
Roman Astashkin ◽  
Igor Chizhov ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Structure And Function ◽  
Proton Donor ◽  
Dna Viruses ◽  
Host Interactions ◽  
Hydrophobic Barrier ◽  
High Resolution Structure ◽  
Group 2 ◽  
Marine Protists ◽  
And Function

Abstract Recently, two groups of rhodopsin genes were identified in large double-stranded DNA viruses. The structure and function of viral rhodopsins are unknown. We present functional characterization and high-resolution structure of an Organic Lake Phycodnavirus rhodopsin II (OLPVRII) of group 2. It forms a pentamer, with a symmetrical, bottle-like central channel with the narrow vestibule in the cytoplasmic part covered by a ring of 5 arginines, whereas 5 phenylalanines form a hydrophobic barrier in its exit. The proton donor E42 is placed in the helix B. The structure is unique among the known rhodopsins. Structural and functional data and molecular dynamics suggest that OLPVRII might be a light-gated pentameric ion channel analogous to pentameric ligand-gated ion channels, however, future patch clamp experiments should prove this directly. The data shed light on a fundamentally distinct branch of rhodopsins and may contribute to the understanding of virus-host interactions in ecologically important marine protists.

scholarly journals Inoculation Period and Citrus Host Effect Establishment of New Infections of ‘Candidatus Liberibacter asiaticus’ Transmitted via Vegetative Grafting

Plant Disease ◽  
2020 ◽  
Vol 104 (7) ◽  
pp. 1894-1899
Author(s):  
Mark E. Hilf ◽  
Weiqi Luo
Keyword(s):  
Survival Analysis ◽  
Bacterial Species ◽  
Systemic Infection ◽  
Candidatus Liberibacter Asiaticus ◽  
Susceptibility To Infection ◽  
Successful Infection ◽  
Significant Difference ◽  
Candidatus Liberibacter ◽  
Liberibacter Asiaticus ◽  
Pathogen Dna

Vegetative grafting is a common method of transmitting and propagating ‘Candidatus Liberibacter asiaticus’, the bacterial species accepted as the causal agent of the citrus disease huanglongbing (HLB). Generally, infected tissue that is grafted to a receptor tree remains in place indefinitely to ensure transmission. In this study, individual HLB-symptomatic leaves were grafted as ‘Ca. L. asiaticus’ inoculum sources to receptor trees of six citrus types and removed after an inoculation period (IP) of 21, 51, or 81 days. The goal was to assess the effect of varying IPs on transmission of bacteria to the receptor tree and on the successful establishment of a new infection. Survival analysis of data from three trials showed a significantly reduced proportion of infected trees with an IP of 21 days compared with IPs of 51 and 81 days but that there was no significant difference in the proportion of infected trees between IPs of 51 and 81 days. In addition, the time to first detection of pathogen DNA in an infected tree was delayed significantly for the 21-day IP when compared with the 51- and 81-day IPs. Survival analysis showed that the probability of infection of sweet orange trees was significantly higher than for trees of five other citrus types throughout the experiment. There was no significant difference between the infection probabilities of these latter five citrus types. The data from this study show that successful infection by grafting is dependent upon the time of exposure to the inoculum, that shorter IPs increase the time needed to establish a systemic infection, and that citrus types vary in their overall susceptibility to infection by ‘Ca. L. asiaticus’.

scholarly journals Virus DNA Replication and the Host DNA Damage Response

2018 ◽  
Vol 5 (1) ◽  
pp. 141-164 ◽  
Author(s):  
Matthew D. Weitzman ◽  
Amélie Fradet-Turcotte
Keyword(s):  
Dna Damage ◽  
Dna Damage Response ◽  
Life Cycles ◽  
Dynamic Interactions ◽  
Dna Damage And Repair ◽  
Dna Viruses ◽  
Cellular Processes ◽  
Damage Response ◽  
Cellular Replication ◽  
Cellular Dna

Viral DNA genomes have limited coding capacity and therefore harness cellular factors to facilitate replication of their genomes and generate progeny virions. Studies of viruses and how they interact with cellular processes have historically provided seminal insights into basic biology and disease mechanisms. The replicative life cycles of many DNA viruses have been shown to engage components of the host DNA damage and repair machinery. Viruses have evolved numerous strategies to navigate the cellular DNA damage response. By hijacking and manipulating cellular replication and repair processes, DNA viruses can selectively harness or abrogate distinct components of the cellular machinery to complete their life cycles. Here, we highlight consequences for viral replication and host genome integrity during the dynamic interactions between virus and host.

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