Positive-Sense RNA Viruses

2016 ◽  
pp. 7-7
Keyword(s):  
Rna Viruses ◽  
Positive Sense

COVID 19, All a Radiologist Needs to Know: A Narrative Review

2020 ◽  
Vol 16 ◽  
Author(s):  
Farzaneh Shobeirian
Keyword(s):  
Computed Tomography ◽  
Rna Viruses ◽  
Imaging Findings ◽  
Protective Measures ◽  
Infection Transmission ◽  
The World ◽  
Positive Sense ◽  
Global Concern ◽  
Interlobular Septal Thickening ◽  
Radiologic Characteristics

Background: Coronaviruses are non-segmented enveloped positive-sense single-strand RNA viruses, and COVID-19 is the seventh known coronavirus, infecting humans. Objective: As the COVID-19 continued to spread the world wildly, every radiologist or clinician needs to be familiar with its imaging findings. Methods: In this study, we reviewed available studies to provide a comprehensive statement on COVID-19 imaging findings. Results: Ground-glass opacities, linear opacities, interlobular septal thickening, consolidation, and Crazy-paving patterns are the most frequent findings in computed tomography (CT) of lungs in patients with COVID-19 pneumonia, which are mostly bilateral, multifocal, and peripheral. Staff needs to follow some rules to reduce infection transmission. Conclusion: COVID-19 pneumonia is a new global concern which has many unknown features. In this article, the radiologic characteristics of COVID-19 pneumonia are discussed. We also discussed appropriate protective measures that the radiology team should be aware of.

Inhibitions of Positive-Sense (ss) RNA Viruses RNA-Dependent RNA Polymerases

2009 ◽  
Vol 5 (4) ◽  
pp. 234-244 ◽  
Author(s):  
Kajohn Boonrod ◽  
Gabriele Krczal
Keyword(s):  
Rna Viruses ◽  
Rna Polymerases ◽  
Positive Sense

scholarly journals Innate Immune DNA Sensing of Flaviviruses

Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 979
Author(s):  
Tongtong Zhu ◽  
Ana Fernandez-Sesma
Keyword(s):  
Innate Immune System ◽  
Rna Viruses ◽  
Innate Immune ◽  
Host Factors ◽  
Dna Sensing ◽  
Antiviral Responses ◽  
Sensory Pathways ◽  
Sensing System ◽  
Positive Sense ◽  
Successful Replication

Flaviviruses are arthropod-borne RNA viruses that have been used extensively to study host antiviral responses. Often selected just to represent standard single-stranded positive-sense RNA viruses in early studies, the Flavivirus genus over time has taught us how truly unique it is in its remarkable ability to target not just the RNA sensory pathways but also the cytosolic DNA sensing system for its successful replication inside the host cell. This review summarizes the main developments on the unexpected antagonistic strategies utilized by different flaviviruses, with RNA genomes, against the host cyclic GAMP synthase (cGAS)/stimulator of interferon genes (STING) cytosolic DNA sensing pathway in mammalian systems. On the basis of the recent advancements on this topic, we hypothesize that the mechanisms of viral sensing and innate immunity are much more fluid than what we had anticipated, and both viral and host factors will continue to be found as important factors contributing to the host innate immune system in the future.

scholarly journals Developing Picornaviruses for Cancer Therapy

Cancers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 685 ◽  
Author(s):  
Cormac McCarthy ◽  
Nadishka Jayawardena ◽  
Laura N. Burga ◽  
Mihnea Bostina
Keyword(s):  
Cancer Therapy ◽  
Anticancer Activity ◽  
Cancer Cells ◽  
Rna Viruses ◽  
Therapeutic Agents ◽  
Oncolytic Viruses ◽  
Wide Range ◽  
Positive Sense

Oncolytic viruses (OVs) form a group of novel anticancer therapeutic agents which selectively infect and lyse cancer cells. Members of several viral families, including Picornaviridae, have been shown to have anticancer activity. Picornaviruses are small icosahedral non-enveloped, positive-sense, single-stranded RNA viruses infecting a wide range of hosts. They possess several advantages for development for cancer therapy: Their genomes do not integrate into host chromosomes, do not encode oncogenes, and are easily manipulated as cDNA. This review focuses on the picornaviruses investigated for anticancer potential and the mechanisms that underpin this specificity.

scholarly journals Origins and Evolution of the Global RNA Virome

mBio ◽  
2018 ◽  
Vol 9 (6) ◽  
Author(s):  
Yuri I. Wolf ◽  
Darius Kazlauskas ◽  
Jaime Iranzo ◽  
Adriana Lucía-Sanz ◽  
Jens H. Kuhn ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Rna Viruses ◽  
Rna Virus ◽  
Phylogenomic Analysis ◽  
Rna Helicases ◽  
Sequence Alignments ◽  
Recent Advances ◽  
Wide Range ◽  
Positive Sense ◽  
Dsrna Viruses

ABSTRACTViruses with RNA genomes dominate the eukaryotic virome, reaching enormous diversity in animals and plants. The recent advances of metaviromics prompted us to perform a detailed phylogenomic reconstruction of the evolution of the dramatically expanded global RNA virome. The only universal gene among RNA viruses is the gene encoding the RNA-dependent RNA polymerase (RdRp). We developed an iterative computational procedure that alternates the RdRp phylogenetic tree construction with refinement of the underlying multiple-sequence alignments. The resulting tree encompasses 4,617 RNA virus RdRps and consists of 5 major branches; 2 of the branches include positive-sense RNA viruses, 1 is a mix of positive-sense (+) RNA and double-stranded RNA (dsRNA) viruses, and 2 consist of dsRNA and negative-sense (−) RNA viruses, respectively. This tree topology implies that dsRNA viruses evolved from +RNA viruses on at least two independent occasions, whereas −RNA viruses evolved from dsRNA viruses. Reconstruction of RNA virus evolution using the RdRp tree as the scaffold suggests that the last common ancestors of the major branches of +RNA viruses encoded only the RdRp and a single jelly-roll capsid protein. Subsequent evolution involved independent capture of additional genes, in particular, those encoding distinct RNA helicases, enabling replication of larger RNA genomes and facilitating virus genome expression and virus-host interactions. Phylogenomic analysis reveals extensive gene module exchange among diverse viruses and horizontal virus transfer between distantly related hosts. Although the network of evolutionary relationships within the RNA virome is bound to further expand, the present results call for a thorough reevaluation of the RNA virus taxonomy.IMPORTANCEThe majority of the diverse viruses infecting eukaryotes have RNA genomes, including numerous human, animal, and plant pathogens. Recent advances of metagenomics have led to the discovery of many new groups of RNA viruses in a wide range of hosts. These findings enable a far more complete reconstruction of the evolution of RNA viruses than was attainable previously. This reconstruction reveals the relationships between different Baltimore classes of viruses and indicates extensive transfer of viruses between distantly related hosts, such as plants and animals. These results call for a major revision of the existing taxonomy of RNA viruses.

scholarly journals An exploration of ambigrammatic sequences in narnaviruses

2019 ◽  
Author(s):  
Joseph L. DeRisi ◽  
Greg Huber ◽  
Amy Kistler ◽  
Hanna Retallack ◽  
Michael Wilkinson ◽  
...  
Keyword(s):  
De Novo ◽  
Rna Viruses ◽  
Nucleotide Substitutions ◽  
Rna Dependent Rna Polymerase ◽  
Single Nucleotide ◽  
Reading Frame ◽  
Reverse Complement ◽  
Positive Sense ◽  
Reverse Strand ◽  
Coding Strategy

ABSTRACTNarnaviruses have been described as positive-sense RNA viruses with a remarkably simple genome of ∼ 3 kb, encoding only a highly conserved RNA-dependent RNA polymerase (RdRp). Many narnaviruses, however, are ‘ambigrammatic’ and harbour an additional uninterrupted open reading frame (ORF) covering almost the entire length of the reverse complement strand. No function has been described for this ORF, yet the absence of stops is conserved across diverse narnaviruses, and in every case the codons in the reverse ORF and the RdRp are aligned. The > 3 kb ORF overlap on opposite strands, unprecedented among RNA viruses, motivates an exploration of the constraints imposed or alleviated by the codon alignment. Here, we show that only when the codon frames are aligned can all stop codons be eliminated from the reverse strand by synonymous single-nucleotide substitutions in the RdRp gene, suggesting a mechanism for de novo gene creation within a strongly conserved amino-acid sequence. It will be fascinating to explore what implications this coding strategy has for other aspects of narnavirus biology. Beyond narnaviruses, our rapidly expanding catalogue of viral diversity may yet reveal additional examples of this broadly-extensible principle for ambigrammatic-sequence development.

scholarly journals Positive-sense RNA viruses reveal the complexity and dynamics of the cellular and viral epitranscriptomes during infection

2018 ◽  
Vol 46 (11) ◽  
pp. 5776-5791 ◽  
Author(s):  
Will McIntyre ◽  
Rachel Netzband ◽  
Gaston Bonenfant ◽  
Jason M Biegel ◽  
Clare Miller ◽  
...  
Keyword(s):  
Rna Viruses ◽  
Positive Sense

scholarly journals Establishment of Neurospora crassa as a model organism for fungal virology

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Shinji Honda ◽  
Ana Eusebio-Cope ◽  
Shuhei Miyashita ◽  
Ayumi Yokoyama ◽  
Annisa Aulia ◽  
...  
Keyword(s):  
Viral Replication ◽  
Neurospora Crassa ◽  
Rna Viruses ◽  
Model Organism ◽  
Model System ◽  
Double Stranded Rna ◽  
Antiviral Responses ◽  
Positive Sense ◽  
Host Virus Interactions ◽  
Virus Interactions

Abstract The filamentous fungus Neurospora crassa is used as a model organism for genetics, developmental biology and molecular biology. Remarkably, it is not known to host or to be susceptible to infection with any viruses. Here, we identify diverse RNA viruses in N. crassa and other Neurospora species, and show that N. crassa supports the replication of these viruses as well as some viruses from other fungi. Several encapsidated double-stranded RNA viruses and capsid-less positive-sense single-stranded RNA viruses can be experimentally introduced into N. crassa protoplasts or spheroplasts. This allowed us to examine viral replication and RNAi-mediated antiviral responses in this organism. We show that viral infection upregulates the transcription of RNAi components, and that Dicer proteins (DCL-1, DCL-2) and an Argonaute (QDE-2) participate in suppression of viral replication. Our study thus establishes N. crassa as a model system for the study of host-virus interactions.

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