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Proceedings. Biological Sciences Jan 2015Viruses that originate in bats may be the most notorious emerging zoonoses that spill over from wildlife into domestic animals and humans. Understanding how these... (Review)
Review
Viruses that originate in bats may be the most notorious emerging zoonoses that spill over from wildlife into domestic animals and humans. Understanding how these infections filter through ecological systems to cause disease in humans is of profound importance to public health. Transmission of viruses from bats to humans requires a hierarchy of enabling conditions that connect the distribution of reservoir hosts, viral infection within these hosts, and exposure and susceptibility of recipient hosts. For many emerging bat viruses, spillover also requires viral shedding from bats, and survival of the virus in the environment. Focusing on Hendra virus, but also addressing Nipah virus, Ebola virus, Marburg virus and coronaviruses, we delineate this cross-species spillover dynamic from the within-host processes that drive virus excretion to land-use changes that increase interaction among species. We describe how land-use changes may affect co-occurrence and contact between bats and recipient hosts. Two hypotheses may explain temporal and spatial pulses of virus shedding in bat populations: episodic shedding from persistently infected bats or transient epidemics that occur as virus is transmitted among bat populations. Management of livestock also may affect the probability of exposure and disease. Interventions to decrease the probability of virus spillover can be implemented at multiple levels from targeting the reservoir host to managing recipient host exposure and susceptibility.
Topics: Animals; Chiroptera; Humans; Models, Biological; Queensland; RNA Virus Infections; RNA Viruses; Zoonoses
PubMed: 25392474
DOI: 10.1098/rspb.2014.2124 -
Viruses Feb 2023RNA viruses are known to induce a wide variety of respiratory tract illnesses, from simple colds to the latest coronavirus pandemic, causing effects on public health and... (Review)
Review
RNA viruses are known to induce a wide variety of respiratory tract illnesses, from simple colds to the latest coronavirus pandemic, causing effects on public health and the economy worldwide. Influenza virus (IV), parainfluenza virus (PIV), metapneumovirus (MPV), respiratory syncytial virus (RSV), rhinovirus (RhV), and coronavirus (CoV) are some of the most notable RNA viruses. Despite efforts, due to the high mutation rate, there are still no effective and scalable treatments that accompany the rapid emergence of new diseases associated with respiratory RNA viruses. Host-directed therapies have been applied to combat RNA virus infections by interfering with host cell factors that enhance the ability of immune cells to respond against those pathogens. The reprogramming of immune cell metabolism has recently emerged as a central mechanism in orchestrated immunity against respiratory viruses. Therefore, understanding the metabolic signature of immune cells during virus infection may be a promising tool for developing host-directed therapies. In this review, we revisit recent findings on the immunometabolic modulation in response to infection and discuss how these metabolic pathways may be used as targets for new therapies to combat illnesses caused by respiratory RNA viruses.
Topics: Humans; Coronavirus; Coronavirus Infections; Enterovirus Infections; Metapneumovirus; RNA; Respiratory Syncytial Virus, Human
PubMed: 36851739
DOI: 10.3390/v15020525 -
Viruses Jan 2022Epithelial cells are apico-basolateral polarized cells that line all tubular organs and are often targets for infectious agents. This review focuses on the release of... (Review)
Review
Epithelial cells are apico-basolateral polarized cells that line all tubular organs and are often targets for infectious agents. This review focuses on the release of human RNA virus particles from both sides of polarized human cells grown on transwells. Most viruses that infect the mucosa leave their host cells mainly via the apical side while basolateral release is linked to virus propagation within the host. Viruses do this by hijacking the cellular factors involved in polarization and trafficking. Thus, understanding epithelial polarization is essential for a clear understanding of virus pathophysiology.
Topics: Cell Polarity; Epithelial Cells; Humans; RNA Viruses; Virion; Virus Assembly; Virus Release; Virus Replication
PubMed: 35215825
DOI: 10.3390/v14020231 -
Microbes and Environments 2022Isolated RNA viruses mainly parasitize eukaryotes. RNA viruses either expand horizontally by infecting hosts (acute type) or coexist with the host and are vertically... (Review)
Review
Isolated RNA viruses mainly parasitize eukaryotes. RNA viruses either expand horizontally by infecting hosts (acute type) or coexist with the host and are vertically inherited (persistent type). The significance of persistent-type RNA viruses in environmental viromes (the main hosts are expected to be microbes) was only recently reported because they had previously been overlooked in virology. In this review, we summarize the host-virus relationships of eukaryotic microbial RNA viruses. Picornavirales and Reoviridae are recognized as representative acute-type virus families, and most of the microbial viruses in Narnaviridae, Totiviridae, and Partitiviridae are categorized as representative persistent-type viruses. Acute-type viruses have only been found in aquatic environments, while persistent-type viruses are present in various environments, including aquatic environments. Moreover, persistent-type viruses are potentially widely spread in the RNA viral sequence space. This emerging evidence provides novel insights into RNA viral diversity, host-virus relationships, and their history of co-evolution.
Topics: Ecosystem; Eukaryota; Genome, Viral; RNA; RNA Viruses; Viruses
PubMed: 35922920
DOI: 10.1264/jsme2.ME22034 -
Viruses Mar 2022Massive amounts of data from nucleic acid sequencing have changed our perspective about diversity and dynamics of marine viral communities. Here, we summarize recent... (Review)
Review
Massive amounts of data from nucleic acid sequencing have changed our perspective about diversity and dynamics of marine viral communities. Here, we summarize recent metatranscriptomic and metaviromic studies targeting predominantly RNA viral communities. The analysis of RNA viromes reaffirms the abundance of lytic (+) ssRNA viruses of the order Picornavirales, but also reveals other (+) ssRNA viruses, including RNA bacteriophages, as important constituents of extracellular RNA viral communities. Sequencing of dsRNA suggests unknown diversity of dsRNA viruses. Environmental metatranscriptomes capture the dynamics of ssDNA, dsDNA, ssRNA, and dsRNA viruses simultaneously, unravelling the full complexity of viral dynamics in the marine environment. RNA viruses are prevalent in large size fractions of environmental metatranscriptomes, actively infect marine unicellular eukaryotes larger than 3 µm, and can outnumber bacteriophages during phytoplankton blooms. DNA and RNA viruses change abundance on hourly timescales, implying viral control on a daily temporal basis. Metatranscriptomes of cultured protists host a diverse community of ssRNA and dsRNA viruses, often with multipartite genomes and possibly persistent intracellular lifestyles. We posit that RNA viral communities might be more diverse and complex than formerly anticipated and that the influence they exert on community composition and global carbon flows in aquatic ecosystems may be underestimated.
Topics: Ecosystem; Eukaryota; Genome, Viral; Genomics; Phylogeny; RNA Viruses; RNA, Double-Stranded; Transcriptome
PubMed: 35458432
DOI: 10.3390/v14040702 -
The Journal of General Virology Sep 2017The role of m6A methylation of RNA has remained elusive for decades, but recent technological advances are now allowing the mapping of the m6A methylation landscape at... (Review)
Review
The role of m6A methylation of RNA has remained elusive for decades, but recent technological advances are now allowing the mapping of the m6A methylation landscape at nucleotide level. This has spurred an explosion in our understanding of the role played by RNA epigenetics in RNA biology. m6A modifications have been tied to almost every aspect of the mRNA life cycle and it is now clear that RNA virus genomes are subject to m6A methylation. These modifications play various roles in the viral replication cycle. This review will summarize recent breakthroughs concerning m6A RNA modification and their implications for cellular and viral RNAs.
Topics: Animals; Humans; Methylation; RNA Virus Infections; RNA Viruses; RNA, Messenger; RNA, Viral
PubMed: 28869001
DOI: 10.1099/jgv.0.000910 -
Equine Veterinary Journal Jul 2018Equine populations worldwide are at increasing risk of infection by viruses transmitted by biting arthropods, including mosquitoes, biting midges (Culicoides), sandflies... (Review)
Review
Equine populations worldwide are at increasing risk of infection by viruses transmitted by biting arthropods, including mosquitoes, biting midges (Culicoides), sandflies and ticks. These include the flaviviruses (Japanese encephalitis, West Nile and Murray Valley encephalitis), alphaviruses (eastern, western and Venezuelan encephalitis) and the orbiviruses (African horse sickness and equine encephalosis). This review provides an overview of the challenges faced in the surveillance, prevention and control of the major equine arboviruses, particularly in the context of these viruses emerging in new regions of the world.
Topics: Animals; Global Health; Horse Diseases; Horses; RNA Virus Infections; RNA Viruses
PubMed: 29517814
DOI: 10.1111/evj.12829 -
Current Opinion in Virology Oct 2012In general terms, robustness is the capacity of biological systems to function in spite of genetic or environmental perturbations. The small and compacted genomes and... (Review)
Review
In general terms, robustness is the capacity of biological systems to function in spite of genetic or environmental perturbations. The small and compacted genomes and high mutation rates of RNA viruses, as well as the ever-changing environments wherein they replicate, create the conditions for robustness to be advantageous. In this review, I will enumerate possible mechanisms by which viral populations may acquire robustness, distinguishing between mechanisms that are inherent to virus replication and population dynamics and those that result from the interaction with host factors. Then, I will move to review some evidences that RNA virus populations are robust indeed. Finally, I will comment on the implications of robustness for virus evolvability, the emergence of new viruses and the efficiency of lethal mutagenesis as an antiviral strategy.
Topics: Animals; Evolution, Molecular; Humans; RNA Virus Infections; RNA Viruses; Virus Replication
PubMed: 22818515
DOI: 10.1016/j.coviro.2012.06.008 -
Wiley Interdisciplinary Reviews. RNA Sep 2016RNA virus infection in plants and invertebrates can produce virus-derived small RNAs. These RNAs share features with host endogenous small interfering RNAs (siRNAs).... (Review)
Review
RNA virus infection in plants and invertebrates can produce virus-derived small RNAs. These RNAs share features with host endogenous small interfering RNAs (siRNAs). They can potentially mediate RNA interference (RNAi) and related RNA silencing pathways, resulting in specific antiviral defense. Although most RNA silencing components such as Dicer, Ago2, and RISC are conserved among eukaryotic hosts, whether RNA virus infection in mammals can generate functional small RNAs that act in antiviral defense remains under discussion. Here, we review recent studies on the molecular and biochemical features of viral siRNAs and other virus-derived small RNAs from infected plants, arthropods, nematodes, and vertebrates and discuss the genetic pathways for their biogenesis and their roles in antiviral activity. WIREs RNA 2016, 7:575-588. doi: 10.1002/wrna.1351 For further resources related to this article, please visit the WIREs website.
Topics: Animals; Gene Silencing; Host-Pathogen Interactions; Invertebrates; Plants; RNA Viruses; RNA, Small Untranslated; RNA, Viral; Vertebrates
PubMed: 27046163
DOI: 10.1002/wrna.1351 -
Microbiology and Molecular Biology... Jun 2013The prokaryotic translation elongation factors were identified as essential cofactors for RNA-dependent RNA polymerase activity of the bacteriophage Qβ more than 40... (Review)
Review
The prokaryotic translation elongation factors were identified as essential cofactors for RNA-dependent RNA polymerase activity of the bacteriophage Qβ more than 40 years ago. A growing body of evidence now shows that eukaryotic translation elongation factors (eEFs), predominantly eEF1A, acting in partially characterized complexes sometimes involving additional eEFs, facilitate virus replication. The functions of eEF1A as a protein chaperone and an RNA- and actin-binding protein enable its "moonlighting" roles as a virus replication cofactor. A diverse group of viruses, from human immunodeficiency type 1 and West Nile virus to tomato bushy stunt virus, have adapted to use eEFs as cofactors for viral transcription, translation, assembly, and pathogenesis. Here we review the mechanisms used by viral pathogens to usurp these abundant cellular proteins for their replication.
Topics: Animals; Eukaryotic Initiation Factors; Genome, Viral; Humans; Peptide Elongation Factor 1; Protein Conformation; Protein Isoforms; Protein Subunits; RNA Viruses; RNA, Viral; Tombusvirus; Virus Assembly; Virus Replication; West Nile virus
PubMed: 23699257
DOI: 10.1128/MMBR.00059-12