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Proceedings of the National Academy of... Oct 1996
Review
Topics: Animals; Chlorocebus aethiops; Defective Viruses; Gene Transfer Techniques; Genes, Viral; Genetic Vectors; Herpesvirus 1, Human; Humans; Promoter Regions, Genetic; Simplexvirus; Vero Cells; Virus Integration; Virus Replication
PubMed: 8876133
DOI: 10.1073/pnas.93.21.11319 -
Annual Review of Virology Sep 2019Defective viral genomes (DVGs) are generated during viral replication and are unable to carry out a full replication cycle unless coinfected with a full-length virus.... (Review)
Review
Defective viral genomes (DVGs) are generated during viral replication and are unable to carry out a full replication cycle unless coinfected with a full-length virus. DVGs are produced by many viruses, and their presence correlates with alterations in infection outcomes. Historically, DVGs were studied for their ability to interfere with standard virus replication as well as for their association with viral persistence. More recently, a critical role for DVGs in inducing the innate immune response during infection was appreciated. Here we review the role of DVGs of RNA viruses in shaping outcomes of experimental as well as natural infections and explore the mechanisms by which DVGs impact infection outcome.
Topics: Animals; Defective Viruses; Genome, Viral; Humans; Immunity, Innate; RNA Viruses; Virus Diseases; Virus Replication
PubMed: 31082310
DOI: 10.1146/annurev-virology-092818-015652 -
Current Opinion in Virology Dec 2018Particles containing degenerate forms of the viral genome which interfere with virus replication and are non-replicative per se are known as defective interfering... (Review)
Review
Particles containing degenerate forms of the viral genome which interfere with virus replication and are non-replicative per se are known as defective interfering particles (DIPs). DIPs are likely to be produced upon infection by any virus in vitro and in nature. Until recently, roles of these non-viable particles as members of a multi-component viral system have been overlooked. In this review, we cover the most recent studies that shed light on critical roles of DIPs during the course of infection, including: the modulation of virus replication, innate immune responses, disease outcome and virus persistence, as well as the evolution of the viral population. Together, these reports allow us to conceive a more complete picture of the virion population, and highlight the fact that DIPs are not a negligible subset of this population but instead can greatly influence the fate of infection.
Topics: Defective Viruses; Evolution, Molecular; Genetics, Population; Population Dynamics; Virus Replication; Viruses
PubMed: 30099321
DOI: 10.1016/j.coviro.2018.07.014 -
The Journal of General Virology Aug 1978The formation of defective herpes simplex virus (HSV) in BSC-1 cells and the synthesis of defective virus DNA was studied. The fourth consecutive passage of undiluted...
The formation of defective herpes simplex virus (HSV) in BSC-1 cells and the synthesis of defective virus DNA was studied. The fourth consecutive passage of undiluted virus yielded defective DNA that was 0.008 g/ml more dense than wild type (w.t.) virus DNA. The amount of defective DNA increased at passage 6 concomitantly with the decrease in infectious virus progeny. The synthesis of defective DNA was always accompanied by w.t. virus DNA synthesis. Defective DNA from both infected nuclei and defective virions had a mol. wt. of 100 X 10(6) and was linear as determined by electron microscopy. Electron microscopy of defective virus DNA at passage 6 revealed circular molecules varying in size in addition to linear DNA molecules with the length of intact virion DNA. The circular DNA molecules had contour lengths of 10, 5, 2.5 and less than 2.5 micron. The smallest circular DNA molecules had a contour length of 0.3 micron, possibly one virus gene. In addition, circular-linear DNA molecules were observed in which both the circular and the linear components varied in length. Most of these DNA molecules had circular components of either 2.5 or 5.0 micron, and linear components varying in length from less than 1 to 50 micron. Based on the present study, it is proposed that the S component of w.t. virus DNA is fragmented into small circular molecules that serve as templates for DNA synthesis, possibly by the rolling circle mechanism.
Topics: Cell Line; Cell Nucleus; DNA, Circular; DNA, Viral; Defective Viruses; Microscopy, Electron; Molecular Weight; Simplexvirus; Virus Replication
PubMed: 211183
DOI: 10.1099/0022-1317-40-2-319 -
Journal of Virology Oct 2021Here, we examine the infection dynamics and interactions of two Zika virus (ZIKV) genomes: one is the full-length ZIKV genome (wild type [WT]), and the other is one of...
Here, we examine the infection dynamics and interactions of two Zika virus (ZIKV) genomes: one is the full-length ZIKV genome (wild type [WT]), and the other is one of the naturally occurring defective viral genomes (DVGs), which can replicate in the presence of the WT genome, appears under high-MOI (multiplicity of infection) passaging conditions, and carries a deletion encompassing part of the structural and NS1 protein-coding region. Ordinary differential equations (ODEs) were used to simulate the infection of cells by virus particles and the intracellular replication of the WT and DVG genomes that produce these particles. For each virus passage in Vero and C6/36 cell cultures, the rates of the simulated processes were fitted to two types of observations: virus titer data and the assembled haplotypes of the replicate passage samples. We studied the consistency of the model with the experimental data across all passages of infection in each cell type separately as well as the sensitivity of the model's parameters. We also determined which simulated processes of virus evolution are the most important for the adaptation of the WT and DVG interplay in these two disparate cell culture environments. Our results demonstrate that in the majority of passages, the rates of DVG production are higher inC6/36 cells than in Vero cells, which might result in tolerance and therefore drive the persistence of the mosquito vector in the context of ZIKV infection. Additionally, the model simulations showed a slower accumulation of infected cells under higher activation of the DVG-associated processes, which indicates a potential role of DVGs in virus attenuation. One of the ideas for lessening Zika pathogenicity is the addition of its natural or engineered defective virus genomes (DVGs) (have no pathogenicity) to the infection pool: a DVG is redirecting the wild-type (WT)-associated virus development resources toward its own maturation. The mathematical model presented here, attuned to the data from interplays between WT Zika viruses and their natural DVGs in mammalian and mosquito cells, provides evidence that the loss of uninfected cells is attenuated by the DVG development processes. This model enabled us to estimate the rates of virus development processes in the WT/DVG interplay, determine the key processes, and show that the key processes are faster in mosquito cells than in mammalian ones. In general, the presented model and its detailed study suggest in what important virus development processes the therapeutically efficient DVG might compete with the WT; this may help in assembling engineered DVGs for ZIKV and other flaviviruses.
Topics: Aedes; Animals; Chlorocebus aethiops; Defective Viruses; Host Microbial Interactions; Vero Cells; Virus Replication; Zika Virus; Zika Virus Infection
PubMed: 34468175
DOI: 10.1128/JVI.00977-21 -
Science (New York, N.Y.) Aug 1965Small, DNA-containing particles were separated from preparations of a simian adenovirus. These particles differed antigenically from the adenovirus. Replication of the...
Small, DNA-containing particles were separated from preparations of a simian adenovirus. These particles differed antigenically from the adenovirus. Replication of the particles in cell cultures was obtained only when theywere inoculated simultaneously with adenoviruses. This suggests that these adenovirus-associated particles behave as defective viruses.
Topics: Adenoviridae; Animals; Antigens; DNA; DNA, Viral; Defective Viruses; Electrons; Haplorhini; Immunologic Tests; Microscopy; Microscopy, Electron; Research; Satellite Viruses; Tissue Culture Techniques; Virion; Virus Cultivation
PubMed: 14325163
DOI: 10.1126/science.149.3685.754 -
Journal of Virological Methods Mar 2003Naturally produced defective influenza virus has antiviral activity and, in sufficient amount, can protect mice from lethal influenza, irrespective of the virus subtype...
Naturally produced defective influenza virus has antiviral activity and, in sufficient amount, can protect mice from lethal influenza, irrespective of the virus subtype causing the disease. However, such defective virus preparations contain many undefined defective RNA sequences, and it is thus not possible to establish dose-response relationships. To address this situation, we have transfected DNA encoding a cloned defective RNA into Vero cells along with the 17 A/WSN (H1N1) plasmids required for infectious helper virus, and produced molecularly cloned defective virus. Here we used POLI-220 that expresses a 445 nt defective RNA isolated from a mouse-protective defective equine H3N8 virus, and POLI-317 that expresses a 585 nt defective RNA from an avian H7N7 virus. Both originate from genomic segment 1. Virus preparations were UV-irradiated selectively to destroy virus infectivity but not the activity of the defective RNAs, and adult mice were inoculated intranasally with defective virus and WSN (H1N1) challenge virus (10 LD(50)). Defective POLI-220 and POLI-317 RNAs were detected readily in infected lung tissue by RT-PCR, but these Vero cell preparations did not modulate disease. However, after a single passage in embryonated eggs, defective POLI-220 and POLI-317 viruses significantly delayed the onset of disease and death in WSN-infected mice, although did not affect final mortality. Direct PCR sequencing confirmed the identity of mouse-passaged defective RNAs and showed that none had undergone any sequence changes. With this advance it will now be possible to study the interference phenomenon in vivo with defective viruses carrying a defined defective RNA.
Topics: Animals; Chick Embryo; Chlorocebus aethiops; Defective Viruses; Female; Gene Expression; Influenza A virus; Lung; Male; Mice; Mice, Inbred C3H; Orthomyxoviridae Infections; Plasmids; RNA, Viral; Reverse Transcriptase Polymerase Chain Reaction; Transfection; Vero Cells; Virology
PubMed: 12565156
DOI: 10.1016/s0166-0934(02)00260-4 -
The Journal of General Virology Feb 1992In an attempt to isolate conditional lethal amber nonsense mutants of Bunyamwera virus, five variants were found which produced small plaques on BHK and mouse L cells....
In an attempt to isolate conditional lethal amber nonsense mutants of Bunyamwera virus, five variants were found which produced small plaques on BHK and mouse L cells. Characterization of these variants by Northern blotting showed that they synthesized defective (subgenomic) RNAs derived from the L RNA segment. No subgenomic M or S segment RNAs were detected. The defective L RNAs were shown to be packaged into virus particles, and four of five preparations caused interference with the multiplication of standard virus. When defective-containing preparations were mixed with standard virus and grown in doubly infected cells a reduction in titre of standard virus of up to 400-fold was observed. Hence these preparations most probably contained defective interfering (DI) particles. Novel DI-specific polypeptides were synthesized in DI virus-infected cells. These novel proteins could be precipitated by antisera raised against either the N or C terminus, or both, of the L protein. Nucleotide sequence analysis of cloned cDNA to prominent DI RNAs in three different defective virus preparations revealed that the DI RNA in each case had suffered a single internal deletion of the L segment while retaining the 5'- and 3'-terminal sequences. The extent of the deletion ranged between 72% and 77% of the L RNA segment. Our results suggest that these DI particles may have arisen during the attempted isolation of Bunyamwera virus amber mutants on mouse L cells, since defective/subgenomic RNAs derived from the L and M segments were readily generated in mouse L cells but not in BHK cells, following infection with wild-type virus.
Topics: Animals; Base Sequence; Blotting, Northern; Bunyamwera virus; Cell Line; DNA Probes; DNA, Viral; Defective Viruses; L Cells; Mice; Molecular Sequence Data; Nucleic Acid Hybridization; Peptides; RNA, Viral; Viral Proteins; Virus Replication
PubMed: 1538195
DOI: 10.1099/0022-1317-73-2-389 -
Cell Aug 1982We have employed repeat units of herpes simplex virus (HSV) defective genomes to derive a cloning-amplifying vector (amplicon) that can replicate in eucaryotic cells in...
We have employed repeat units of herpes simplex virus (HSV) defective genomes to derive a cloning-amplifying vector (amplicon) that can replicate in eucaryotic cells in the presence of standard HSV helper virus. The design of the HSV amplicon system is based on the previous observation that cotransfection of cells with helper virus DNA and seed monomeric repeat units of HSV defective genomes results in the regeneration of concatemeric defective genomes composed of multiple reiterations of the seed repeats. Cotransfection of cells with helper virus DNA and chimeric repeat units containing bacterial plasmid pKC7 DNA resulted in the generation of defective genomes composed of reiterations of the seed HSV-pKC7 repeats. These chimeric defective genomes were packaged into virus particles and could be propagated in virus stocks, with the most enriched passages containing more than 90% chimeric defective genomes. Furthermore, monomeric chimeric repeat units could be transferred back and forth between bacteria and eucaryotic cells. A derivative vector constructed so as to contain several unique restriction enzyme sites could be potentially employed in the introduction of additional viral or eucaryotic DNA sequences into eucaryotic cells.
Topics: Animals; Cell Line; Chimera; Cloning, Molecular; Defective Viruses; Escherichia coli; Gene Amplification; Genes, Viral; Genetic Vectors; Humans; Plasmids; Repetitive Sequences, Nucleic Acid; Simplexvirus; Transfection
PubMed: 6290080
DOI: 10.1016/0092-8674(82)90035-6 -
Annual Review of Microbiology 1973
Review
Topics: Centrifugation, Density Gradient; Culture Techniques; DNA Viruses; DNA, Viral; Defective Viruses; Lipids; Models, Biological; Nucleoproteins; Plant Viruses; Poliovirus; RNA Viruses; RNA, Viral; Vesicular stomatitis Indiana virus; Viral Interference; Virus Replication
PubMed: 4356530
DOI: 10.1146/annurev.mi.27.100173.000533