scholarly journals Rice dwarf virus is engulfed into and released via vesicular compartments in cultured insect vector cells

2008 ◽  
Vol 89 (11) ◽  
pp. 2915-2920 ◽  
Author(s):  
Taiyun Wei ◽  
Hiroyuki Hibino ◽  
Toshihiro Omura
Keyword(s):  
Brefeldin A ◽  
Virus Multiplication ◽  
Dwarf Virus ◽  
Insect Vector ◽  
Rice Dwarf Virus ◽  
Transmission Electron ◽  
Viral Particles ◽  
Infected Cells ◽  
Vector Insect ◽  
Butanedione Monoxime

Vector insect cells infected with Rice dwarf virus had vesicular compartments containing viral particles located adjacent to the viroplasm when examined by transmission electron and confocal microscopy. Such compartments were often at the periphery of infected cells. Inhibitors of vesicular transport, brefeldin A and monensin, and an inhibitor of myosin motor activity, butanedione monoxime, abolished the formation of such vesicles and prevented the release of viral particles from infected cells without significant effects on virus multiplication. Furthermore, the actin-depolymerizing drug, cytochalasin D, inhibited the formation of actin filaments without significantly interfering with formation of vesicular compartments and the release of viruses from treated cells. These results together revealed intracellular vesicular compartments as a mode for viral transport in and release from insect vector cells infected with a plant-infecting reovirus.

scholarly journals Association of Rice Gall Dwarf Virus with Microtubules Is Necessary for Viral Release from Cultured Insect Vector Cells

2009 ◽  
Vol 83 (20) ◽  
pp. 10830-10835 ◽  
Author(s):  
Taiyun Wei ◽  
Tamaki Uehara-Ichiki ◽  
Naoyuki Miyazaki ◽  
Hiroyuki Hibino ◽  
Kenji Iwasaki ◽  
...  
Keyword(s):  
Insect Cells ◽  
Core Protein ◽  
Dwarf Virus ◽  
Insect Vector ◽  
Viral Transport ◽  
Transmission Electron ◽  
Viral Particles ◽  
The Family ◽  
Rice Gall Dwarf Virus ◽  
Vector Insect

ABSTRACT Vector insect cells infected with Rice gall dwarf virus, a member of the family Reoviridae, contained the virus-associated microtubules adjacent to the viroplasms, as revealed by transmission electron, electron tomographic, and confocal microscopy. The viroplasms, putative sites of viral replication, contained the nonstructural viral proteins Pns7 and Pns12, as well as core protein P5, of the virus. Microtubule-depolymerizing drugs suppressed the association of viral particles with microtubules and prevented the release of viruses from cells without significantly affecting viral multiplication. Thus, microtubules appear to mediate viral transport within and release of viruses from infected vector cells.

Nonstructural protein Pns12 of rice dwarf virus is a principal regulator for viral replication and infection in its insect vector

2015 ◽  
Vol 210 ◽  
pp. 54-61 ◽  
Author(s):  
Qian Chen ◽  
Hongyan Chen ◽  
Dongsheng Jia ◽  
Qianzhuo Mao ◽  
Lianhui Xei ◽  
...  
Keyword(s):  
Viral Replication ◽  
Nonstructural Protein ◽  
Dwarf Virus ◽  
Insect Vector ◽  
Rice Dwarf Virus

scholarly journals Characterization of a novel alloherpesvirus from Atlantic cod (Gadus morhua)

2011 ◽  
Vol 24 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Mar Marcos-Lopez ◽  
Thomas B. Waltzek ◽  
Ronald P. Hedrick ◽  
Dolores V. Baxa ◽  
Amber F. Garber ◽  
...  
Keyword(s):  
Gadus Morhua ◽  
Virus Isolation ◽  
Atlantic Cod ◽  
International Committee ◽  
Atpase Subunit ◽  
Transmission Electron ◽  
Viral Particles ◽  
Infected Cells

Alloherpesviruses affect freshwater and marine fish species. The aim of the current study was to characterize a novel alloherpesvirus in Atlantic cod ( Gadus morhua). Samples were processed for histopathology, transmission electron microscopy (TEM), virus isolation, molecular characterization, and in situ hybridization (ISH). Histopathology revealed that the infection was restricted to the gills and that it induced cytomegaly in infected cells. By TEM, numerous viral particles with morphology compatible with a herpesvirus were observed inside the cytomegalic cells. To characterize this new agent, polymerase chain reaction amplified regions of the ATPase subunit of the terminase, and DNA polymerase genes were sequenced. Phylogenetic analysis revealed strongest similarity with alloherpesviruses belonging to the genus Ictalurivirus and Salmonivirus. The ISH showed specific labeling of nuclear inclusions in the cytomegalic cells. While virus isolation was unsuccessful, the results obtained through different diagnostic tests in the present study confirm the discovery of a new alloherpesvirus affecting Atlantic cod. The authors propose the formal species designation Gadid herpesvirus 1 (GaHV-1) to be considered for approval by the International Committee on the Taxonomy of Viruses.

Viral burst size of heterotrophic prokaryotes in aquatic systems

2006 ◽  
Vol 86 (3) ◽  
pp. 613-621 ◽  
Author(s):  
Verónica Parada ◽  
Gerhard J. Herndl ◽  
Markus G. Weinbauer
Keyword(s):  
Large Scale ◽  
Burst Size ◽  
Aquatic Systems ◽  
The Past ◽  
Number Of Factors ◽  
Transmission Electron ◽  
Viral Particles ◽  
Infected Cells ◽  
Heterotrophic Prokaryotes

Viral burst size (BS), i.e. the number of viruses released during cell lysis, is a critical parameter for assessing the ecological and biogeochemical role of viruses in aquatic systems. Burst size is typically estimated by enumerating the viral particles in bacteria using transmission electron microscopy. Here, we review the average BS reported for different aquatic systems, present several hypotheses on the control of the BS and evaluate whether there are relationships between BS and bacterial activity parameters across systems. Based on reports from a variety of different aquatic environments, we calculated a mean BS of 24 and 34 for marine and freshwater environments, respectively. Generally, the BS increased with the trophic status of the environment and with the percentage of infected cells in marine populations. When diel dynamics were investigated or averages from large-scale environments were used, BS was positively related to bacterial production but no trend was detectable across systems. The across systems' finding that BS was significantly related to the frequency of infected cells (FIC) could be due to co-infection or superinfection. At any given site, BS seems to be influenced by a number of factors such as the size of the host cell and the viruses, the metabolic activity of the host and phage and host diversity. Thus, based on the available data collected over the past two decades on a variety of aquatic systems, some relations between BS and bacterial variables were detectable.

scholarly journals Pns12 protein of Rice dwarf virus is essential for formation of viroplasms and nucleation of viral-assembly complexes

2006 ◽  
Vol 87 (2) ◽  
pp. 429-438 ◽  
Author(s):  
Taiyun Wei ◽  
Takumi Shimizu ◽  
Kyoji Hagiwara ◽  
Akira Kikuchi ◽  
Yusuke Moriyasu ◽  
...  
Keyword(s):  
Capsid Proteins ◽  
Dwarf Virus ◽  
Post Inoculation ◽  
Rice Dwarf Virus ◽  
Cytoplasmic Inclusions ◽  
Virus Particles ◽  
Core Proteins ◽  
Intact Virus ◽  
Infected Cells ◽  
Outer Capsid

Cytoplasmic inclusion bodies, known as viroplasms or viral factories, are assumed to be the sites of replication of members of the family Reoviridae. Immunocytochemical and biochemical analyses were carried out to characterize the poorly understood viroplasms of the phytoreovirus Rice dwarf virus (RDV). Within 6 h of inoculation of cells, viroplasms, namely discrete cytoplasmic inclusions, were formed that contained the non-structural proteins Pns6, Pns11 and Pns12 of RDV, which appeared to be the constituents of the inclusions. Formation of similar inclusions in non-host insect cells upon expression of Pns12 in a baculovirus system and the association of molecules of Pns12 in vitro suggested that the inclusions observed in RDV-infected cells were composed basically of Pns12. Core proteins P1, P3, P5 and P7 and core virus particles were identified in the interior region of the inclusions. In contrast, accumulation of the outer capsid proteins P2, P8 and P9 and of intact virus particles was evident in the peripheral regions of the inclusions. These observations suggest that core particles were constructed inside the inclusions, whereas outer capsid proteins were assembled at the periphery of the inclusions. Viral inclusions were shown to be the sites of viral RNA synthesis by labelling infected cells with 5-bromouridine 5′-triphosphate. The number of viroplasms decreased with time post-inoculation as their sizes increased, suggesting that inclusions might fuse with one another during the virus-propagation process. Our results are consistent with a model, proposed for vertebrate reoviruses, in which viroplasms play a pivotal role in virus assembly.

scholarly journals The Autophagosomes Containing Dengue Virus Proteins and Full-Length Genomic RNA Are Infectious

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2034
Author(s):  
Shan-Ying Wu ◽  
Yu-Lun Chen ◽  
Ying-Ray Lee ◽  
Chiou-Feng Lin ◽  
Sheng-Hui Lan ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Full Length ◽  
Genomic Rnas ◽  
Double Membrane ◽  
Transmission Electron ◽  
Viral Particles ◽  
Autophagic Degradation ◽  
Infected Cells ◽  
Intracellular Vesicles ◽  
Secretory Autophagy

Autophagic machinery is involved in selective and non-selective recruitment as well as degradation or exocytosis of cargoes, including pathogens. Dengue virus (DENV) infectioninduces autophagy that enhances virus replication and vesicle release to evade immune systemsurveillance. This study reveals that DENV2 induces autophagy in lung and liver cancer cells andshowed that DENV2 capsid, envelope, NS1, NS3, NS4B and host cell proinflammatory high mobilitygroup box 1 (HMGB1) proteins associated with autophagosomes which were purified by gradientcentrifugation. Capsid, NS1 and NS3 proteins showing high colocalization with LC3 protein in thecytoplasm of the infected cells were detected in the purified double-membrane autophagosome byimmunogold labeling under transmission electron microscopy. In DENV infected cells, the levels ofcapsid, envelope, NS1 and HMGB1 proteins are not significantly changed compared to the dramaticaccumulation of LC3-II and p62/SQSTM1 proteins when autophagic degradation was blocked bychloroquine, indicating that these proteins are not regulated by autophagic degradation machinery.We further demonstrated that purified autophagosomes were infectious when co-cultured withuninfected cells. Notably, these infectious autophagosomes contain DENV2 proteins, negativestrandand full-length genomic RNAs, but no viral particles. It is possible that the infectivity ofthe autophagosome originates from the full-length DENV RNA. Moreover, we reveal that DENV2promotes HMGB1 exocytosis partially through secretory autophagy. In conclusion, we are the firstto report that DENV2-induced double-membrane autophagosomes containing viral proteins andfull-length RNAs are infectious and not undergoing autophagic degradation. Our novel findingwarrants further validation of whether these intracellular vesicles undergo exocytosis to becomeinfectious autophagic vesicles.

scholarly journals A Novel Iflavirus Was Discovered in Green Rice Leafhopper Nephotettix cincticeps and Its Proliferation Was Inhibited by Infection of Rice Dwarf Virus

2021 ◽  
Vol 11 ◽  
Author(s):  
Wenxi Jia ◽  
Fei Wang ◽  
Jingjing Li ◽  
Xuefei Chang ◽  
Yi Yang ◽  
...  
Keyword(s):  
Infection Rate ◽  
Rna Virus ◽  
Antagonistic Effect ◽  
Dwarf Virus ◽  
Insect Vector ◽  
Rice Dwarf Virus ◽  
Reading Frame ◽  
Green Rice Leafhopper ◽  
Laboratory Populations ◽  
Dwarf Disease

The green rice leafhopper, Nephotettix cincticeps (Hemiptera: Cicadellidae), is a key insect vector transmitting rice dwarf virus (RDV) that causes rice dwarf disease. We discovered a novel iflavirus from the transcriptomes of N. cincticeps and named it as Nephotettix cincticeps positive-stranded RNA virus-1 (NcPSRV-1). The viral genome consists of 10,524 nucleotides excluding the poly(A) tail and contains one predicted open reading frame encoding a polyprotein of 3,192 amino acids, flanked by 5' and 3' untranslated regions. NcPSRV-1 has a typical iflavirus genome arrangement and is clustered with the members of the family Iflaviridae in the phylogenetic analysis. NcPSRV-1 was detected in all tested tissues and life stages of N. cincticeps and could be transmitted horizontally and vertically. Moreover, NcPSRV-1 had high prevalence in the laboratory populations and was widely spread in field populations of N. cincticeps. NcPSRV-1 could also infect the two-striped leafhopper, Nephotettix apicalis, at a 3.33% infection rate, but was absent in the zigzag leafhopper, Recilia dorsalis, and rice Oryza sativa variety TN1. The infection of RDV altered the viral load and infection rate of NcPSRV-1 in N. cincticeps, for which it seems that RDV has an antagonistic effect on NcPSRV-1 infection in the host.

scholarly journals Nonstructural protein Pns4 of rice dwarf virus is essential for viral infection in its insect vector

2015 ◽  
Vol 12 (1) ◽  
Author(s):  
Qian Chen ◽  
Linghua Zhang ◽  
Hongyan Chen ◽  
Lianhui Xie ◽  
Taiyun Wei
Keyword(s):  
Viral Infection ◽  
Nonstructural Protein ◽  
Dwarf Virus ◽  
Insect Vector ◽  
Rice Dwarf Virus

scholarly journals The Spread of Rice Dwarf Virus among Cells of Its Insect Vector Exploits Virus-Induced Tubular Structures

2006 ◽  
Vol 80 (17) ◽  
pp. 8593-8602 ◽  
Author(s):  
Taiyun Wei ◽  
Akira Kikuchi ◽  
Yusuke Moriyasu ◽  
Nobuhiro Suzuki ◽  
Takumi Shimizu ◽  
...  
Keyword(s):  
Viral Protein ◽  
Neutralizing Antibodies ◽  
Specific Binding ◽  
Host Cells ◽  
Dwarf Virus ◽  
Insect Vector ◽  
Rice Dwarf Virus ◽  
Tubular Structures ◽  
Intercellular Spread

ABSTRACT Various cytopathological structures, known as inclusion bodies, are formed upon infection of cultured leafhopper cells by Rice dwarf virus, a member of the family Reoviridae. These structures include tubules of approximately 85 nm in diameter which are composed of the nonstructural viral protein Pns10 and contain viral particles. Such tubular structures were produced in heterologous non-host insect cells that expressed Pns10 of the virus. These tubules, when associated with actin-based filopodia, were able to protrude from the surface of cells and to penetrate neighboring cells. A binding assay in vitro revealed the specific binding of Pns10 to actin. Infection of clusters of cells was readily apparent 5 days after inoculation at a low multiplicity of infection with the virus, even in the presence of neutralizing antibodies. However, treatment of host cells with drugs that inhibited the elongation of actin filaments abolished the extension of Pns10 tubules from the surface of cells, with a significant simultaneous decrease in the extent of infection of neighboring cells. These results together revealed a previously undescribed aspect of the intercellular spread of Rice dwarf virus, wherein the virus exploits tubules composed of a nonstructural viral protein and actin-based filopodia to move into neighboring cells.

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