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Virologica Sinica Aug 2022ISG20 is an interferon-inducible exonuclease that inhibits virus replication. Although ISG20 is thought to degrade viral RNA, the antiviral mechanism and specificity of...
ISG20 is an interferon-inducible exonuclease that inhibits virus replication. Although ISG20 is thought to degrade viral RNA, the antiviral mechanism and specificity of ISG20 remain unclear. In this study, the antiviral role of ovine ISG20 (oISG20) in bluetongue virus (BTV) infection was investigated. It was found that BTV infection up-regulated the transcription of ovine ISG20 (oISG20) in a time- and BTV multiplicity of infection (MOI)-dependent manner. Overexpression of oISG20 suppressed the production of BTV genome, proteins, and virus titer, whereas the knockdown of oISG20 increased viral replication. oISG20 was found to co-localize with BTV proteins VP4, VP5, VP6, and NS2, but only directly interacted with VP4. Exonuclease defective oISG20 significantly decreased the inhibitory effect on BTV replication. In addition, the interaction of mutant oISG20 and VP4 was weakened, suggesting that binding to VP4 was associated with the inhibition of BTV replication. The present data characterized the anti-BTV effect of oISG20, and provides a novel clue for further exploring the inhibition mechanism of double-stranded RNA virus by ISG20.
Topics: Animals; Antiviral Agents; Bluetongue; Bluetongue virus; Exonucleases; Sheep; Virus Replication
PubMed: 35513266
DOI: 10.1016/j.virs.2022.04.010 -
Frontiers in Cellular and Infection... 2024Tibet orbivirus (TIBOV) was first isolated from mosquitoes in Xizang, China, in 2009. In recent years, more TIBOV strains have been isolated in several provinces across...
Tibet orbivirus (TIBOV) was first isolated from mosquitoes in Xizang, China, in 2009. In recent years, more TIBOV strains have been isolated in several provinces across China, Japan, East Asia, and Nepal, South Asia. Furthermore, TIBOVs have also been isolated from mosquitoes, and several midge species. Additionally, TIBOV neutralizing antibodies have been detected in serum specimens from several mammals, including cattle, sheep, and pigs. All of the evidence suggests that the geographical distribution of TIBOVs has significantly expanded in recent years, with an increased number of vector species involved in its transmission. Moreover, the virus demonstrated infectivity towards a variety of animals. Although TIBOV is considered an emerging orbivirus, detailed reports on its genome and molecular evolution are currently lacking. Thus, this study performed the whole-genome nucleotide sequencing of three TIBOV isolates from mosquitoes and midges collected in China in 2009, 2011, and 2019. Furthermore, the genome and molecular genetic evolution of TIBOVs isolated from different countries, periods, and hosts (mosquitoes, midges, and cattle) was systematically analyzed. The results revealed no molecular specificity among TIBOVs isolated from different countries, periods, and vectors. Meanwhile, the time-scaled phylogenetic analysis demonstrated that the most recent common ancestor (TMRCA) of TIBOV appeared approximately 797 years ago (95% HPD: 16-2347) and subsequently differentiated at least three times, resulting in three distinct genotypes. The evolutionary rate of TIBOVs was about 2.12 × 10 nucleotide substitutions per site per year (s/s/y) (95% HPD: 3.07 × 10, 9.63 × 10), which is similar to that of the bluetongue virus (BTV), also in the genus. Structural analyses of the viral proteins revealed that the three-dimensional structures of the outer capsid proteins of TIBOV and BTV were similar. These results suggest that TIBOV is a newly discovered and rapidly evolving virus transmitted by various blood-sucking insects. Given the potential public health burden of this virus and its high infectious rate in a wide range of animals, it is significant to strengthen research on the genetic variation of TIBOVs in blood-feeding insects and mammals in the natural environment and the infection status in animals.
Topics: Cattle; Animals; Sheep; Swine; Orbivirus; Tibet; Phylogeny; Mosquito Vectors; Anopheles; Mammals; Nucleotides; Genome, Viral; Reoviridae Infections
PubMed: 38505291
DOI: 10.3389/fcimb.2024.1327780 -
Methods (San Diego, Calif.) Aug 2017Fluorescent tags constitute an invaluable tool in facilitating a deeper understanding of the mechanistic processes governing virus-host interactions. However, when... (Review)
Review
Fluorescent tags constitute an invaluable tool in facilitating a deeper understanding of the mechanistic processes governing virus-host interactions. However, when selecting a fluorescent tag for in vivo imaging of cells, a number of parameters and aspects must be considered. These include whether the tag may affect and interfere with protein conformation or localization, cell toxicity, spectral overlap, photo-stability and background. Cumulatively, these constitute challenges to be overcome. Bluetongue virus (BTV), a member of the Orbivirus genus in the Reoviridae family, is a non-enveloped virus that is comprised of two architecturally complex capsids. The outer capsid, composed of two proteins, VP2 and VP5, together facilitate BTV attachment, entry and the delivery of the transcriptionally active core in the cell cytoplasm. Previously, the significance of the endocytic pathway for BTV entry was reported, although a detailed analysis of the role of each protein during virus trafficking remained elusive due to the unavailability of a tagged virus. Described here is the successful modification, and validation, of a segmented genome belonging to a complex and large capsid virus to introduce tags for fluorescence visualization. The data generated from this approach highlighted the sequential dissociation of VP2 and VP5, driven by decreasing pH during the transition from early to late endosomes, and their retention therein as the virus particles progress along the endocytic pathway. Furthermore, the described tagging technology and methodology may prove transferable and allow for the labeling of other non-enveloped complex viruses.
Topics: Animals; Bluetongue virus; Host-Pathogen Interactions; Microbiological Techniques; Virology; Virus Internalization
PubMed: 28802715
DOI: 10.1016/j.ymeth.2017.08.004 -
Virus Research Aug 2020A novel orbivirus had been identified as a member of the Orbivirus genus, which was isolated from pooled Culex fatigans mosquitoes in Guangdong of China, named as the...
A novel orbivirus had been identified as a member of the Orbivirus genus, which was isolated from pooled Culex fatigans mosquitoes in Guangdong of China, named as the Fengkai virus (FKOV). The cytopathic effects (CPEs) on both Aedes albopictus cells (C6/36) and mammalian cell lines (Vero and BHK-21) emerged in the cell cultures inoculated above virus in. Experimental confirmation as the Orbivirus genus was conducted by the Real-time PCR and based on Ion Torrent Next-Generation in sequencing. The Identities of VP1, VP2 and VP3 in amino acid sequences between the Tibet orbivirus (TIBOV) and this strain were 98.6%, 42.9%, and 99.9%, respectively, which indicated that this strain shares the same genus (VP1, Pol) and species (VP3, T2) with TIBOV but was greatly different in VP2 and VP5 (10.3%) of TIBOV. The VP2 and VP5 diversities of both TIBOV and FKOV strains suggested both serotypes are distinct with each other. As natural evolution and circulation, this strain might expand its host ranges and infect human beings as a potential and severe pathogen.
Topics: Aedes; Animals; China; Chlorocebus aethiops; Culex; Cytopathogenic Effect, Viral; Genome, Viral; Host Specificity; Orbivirus; Phylogeny; Vero Cells; Viral Proteins
PubMed: 32437817
DOI: 10.1016/j.virusres.2020.197990 -
Revue Scientifique Et Technique... Aug 2015Many novel emerging orbiviruses have been isolated in the past 15 years. Important viruses include Peruvian horse sickness virus (PHSV) and Yunnan orbivirus (YUOV),...
Many novel emerging orbiviruses have been isolated in the past 15 years. Important viruses include Peruvian horse sickness virus (PHSV) and Yunnan orbivirus (YUOV), pathogens of equids which were originally isolated almost simultaneously from 1997 to 1999 in the People's Republic of China, Australia and Peru. YUOV has also been isolated from cattle, sheep and a dog. The isolation of YUOVfrom a dog is not the first case of an orbivirus being isolated from a carnivore. Bluetongue virus and African horse sickness virus were earlier detected in carnivores which fed on contaminated meat. PHSV and YUOV both offer an opportunity to study the emergence of a single pathogen in geographically distant locations, although the original point of emergence is still unidentified. PHSV has been isolated from horses with neurological disease both in Australia and in Peru (where it is now endemic). Serological and molecular diagnostic assays have been developed for these viruses to assist in their identification and diagnosis. Other orbiviruses, such as Palyam virus and Equine encephalosis virus, have more recently been identified outside their geographical boundaries and may represent a threat to domesticated livestock and horses, respectively. The article also reviews four zoonotic orbivirus species (Corriparta virus, Changuinola virus, Kemerovo virus and Orungo virus) which have been identified in livestock and/or wildlife.
Topics: Animals; Communicable Diseases, Emerging; Humans; Orbivirus; Reoviridae Infections; Zoonoses
PubMed: 26601440
DOI: 10.20506/rst.34.2.2362 -
Parasites & Vectors Sep 2021Bluetongue is a serious disease of ruminants caused by the bluetongue virus (BTV). BTV is transmitted by biting midges (Culicoides spp.). Serological evidence from...
BACKGROUND
Bluetongue is a serious disease of ruminants caused by the bluetongue virus (BTV). BTV is transmitted by biting midges (Culicoides spp.). Serological evidence from livestock and the presence of at least one competent vector species of Culicoides suggests that transmission of BTV is possible and may have occurred in Kazakhstan.
METHODS
We estimated the risk of transmission using a mathematical model of the reproduction number R for bluetongue. This model depends on livestock density and climatic factors which affect vector density. Data on climate and livestock numbers from the 2466 local communities were used. This, together with previously published model parameters, was used to estimate R for each month of the year. We plotted the results on isopleth maps of Kazakhstan using interpolation to smooth the irregular data. We also mapped the estimated proportion of the population requiring vaccination to prevent outbreaks of bluetongue.
RESULTS
The results suggest that transmission of bluetongue in Kazakhstan is not possible in the winter from October to March. Assuming there are vector-competent species of Culicoides endemic in Kazakhstan, then low levels of risk first appear in the south of Kazakhstan in April before spreading north and intensifying, reaching maximum levels in northern Kazakhstan in July. The risk declined in September and had disappeared by October.
CONCLUSION
These results should aid in surveillance efforts for the detection and control of bluetongue in Kazakhstan by indicating where and when outbreaks of bluetongue are most likely to occur. The results also indicate where vaccination efforts should be focussed to prevent outbreaks of disease.
Topics: Animals; Bluetongue; Bluetongue virus; Climate; Insect Vectors; Livestock; Models, Theoretical; Seasons
PubMed: 34563238
DOI: 10.1186/s13071-021-04945-6 -
Pathogens (Basel, Switzerland) Jul 2021Bluetongue (BT) and epizootic hemorrhagic disease (EHD) cases have increased worldwide, causing significant economic loss to ruminant livestock production and... (Review)
Review
Bluetongue (BT) and epizootic hemorrhagic disease (EHD) cases have increased worldwide, causing significant economic loss to ruminant livestock production and detrimental effects to susceptible wildlife populations. In recent decades, hemorrhagic disease cases have been reported over expanding geographic areas in the United States. Effective BT and EHD prevention and control strategies for livestock and monitoring of these diseases in wildlife populations depend on an accurate understanding of the distribution of BT and EHD viruses in domestic and wild ruminants and their vectors, the biting midges that transmit them. However, national maps showing the distribution of BT and EHD viruses and the presence of vectors are incomplete or not available at all. Thus, efforts to accurately describe the potential risk of these viruses on ruminant populations are obstructed by the lack of systematic and routine surveillance of their hosts and vectors. In this review, we: (1) outline animal health impacts of BT and EHD in the USA; (2) describe current knowledge of the distribution and abundance of BT and EHD and their vectors in the USA; and (3) highlight the importance of disease (BT and EHD) and vector surveillance for ruminant populations.
PubMed: 34451380
DOI: 10.3390/pathogens10080915 -
Viruses Aug 2014Maturation is an intrinsic phase of the viral life cycle and is often intertwined with egress. In this review we focus on orbivirus maturation by using Bluetongue virus... (Review)
Review
Maturation is an intrinsic phase of the viral life cycle and is often intertwined with egress. In this review we focus on orbivirus maturation by using Bluetongue virus (BTV) as a representative. BTV, a member of the genus Orbivirus within the family Reoviridae, has over the last three decades been subjected to intense molecular study and is thus one of the best understood viruses. BTV is a non-enveloped virus comprised of two concentric protein shells that encapsidate 10 double-stranded RNA genome segments. Upon cell entry, the outer capsid is shed, releasing the core which does not disassemble into the cytoplasm. The polymerase complex within the core then synthesizes transcripts from each genome segment and extrudes these into the cytoplasm where they act as templates for protein synthesis. Newly synthesized ssRNA then associates with the replicase complex prior to encapsidation by inner and outer protein layers of core within virus-triggered inclusion bodies. Maturation of core occurs outside these inclusion bodies (IBs) via the addition of the outer capsid proteins, which appears to be coupled to a non-lytic, exocytic pathway during early infection. Similar to the enveloped viruses, BTV hijacks the exocytosis and endosomal sorting complex required for trafficking (ESCRT) pathway via a non-structural glycoprotein. This exquisitely detailed understanding is assembled from a broad array of assays, spanning numerous and diverse in vitro and in vivo studies. Presented here are the detailed insights of BTV maturation and egress.
Topics: Biological Transport; Bluetongue virus; Capsid; Exocytosis; Inclusion Bodies, Viral; Virus Assembly; Virus Release
PubMed: 25196482
DOI: 10.3390/v6083250 -
Current Opinion in Virology Oct 2020Bluetongue virus (BTV) reverse genetics (RG), available since 2007, has allowed the dissection of the virus replication cycle, including discovery of a primary... (Review)
Review
Bluetongue virus (BTV) reverse genetics (RG), available since 2007, has allowed the dissection of the virus replication cycle, including discovery of a primary replication stage. This information has allowed the generation of Entry-Competent-Replication-Abortive (ECRA) vaccines, which enter cells and complete primary replication but fail to complete the later stage. A series of vaccine trials in sheep and cattle either with a single ECRA serotype or a cocktail of multiple ECRA serotypes have demonstrated that these vaccines provide complete protection against virulent virus challenge without cross-serotype interference. Similarly, an RG system developed for the related African Horse Sickness virus, which causes high mortality in equids has provided AHSV ECRA vaccines that are protective in horses. ECRA vaccines were incapable of productive replication in animals despite being competent for cell entry. This technology allows rapid generation of emerging Orbivirus vaccines and offers immunogenicity and safety levels that surpass attenuated or recombinant routes.
Topics: Animals; Antibodies, Neutralizing; Antibodies, Viral; Bluetongue; Bluetongue virus; Cattle; Orbivirus; Reoviridae Infections; Reverse Genetics; Sheep; Vaccines, Attenuated; Viral Vaccines; Virus Replication
PubMed: 32610251
DOI: 10.1016/j.coviro.2020.05.003 -
Emerging Infectious Diseases May 2023We describe the detection of epizootic hemorrhagic disease virus (EHDV) serotype 8 in cattle farms in Sardinia and Sicily in October-November 2022. The virus has a...
We describe the detection of epizootic hemorrhagic disease virus (EHDV) serotype 8 in cattle farms in Sardinia and Sicily in October-November 2022. The virus has a direct origin in North Africa; its genome is identical (>99.9% nucleotide sequence identity) to EHDV serotype 8 strains detected in Tunisia in 2021.
Topics: Animals; Cattle; Reoviridae Infections; Serogroup; Hemorrhagic Disease Virus, Epizootic; Base Sequence; Italy; Cattle Diseases
PubMed: 37081599
DOI: 10.3201/eid2905.221773