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Archives of Virology. Supplementum 1993The family Filoviridae contains extremely pathogenic human viruses causing a fulminating, febrile hemorrhagic disease. Filoviruses are enveloped, filamentous particles... (Review)
Review
The family Filoviridae contains extremely pathogenic human viruses causing a fulminating, febrile hemorrhagic disease. Filoviruses are enveloped, filamentous particles with a nonsegmented negative-strand RNA genome showing the gene arrangement 3'-NP-VP35-VP40-GP-VP30-VP24-L-5'. Genes are flanked by highly conserved transcriptional signals and are generally separated by variable intergenic regions. They are transcribed into monocistronic polyadenylated messenger RNAs which contain relatively long 5' and 3' untranslated regions. Seven structural proteins are encoded by the genome of which four form the helical nucleocapsid (NP-VP35-VP30-L), two are membrane-associated (VP40-VP24), and one is a transmembrane glycoprotein (GP). Comparison of filovirus genomes with those of other nonsegmented negative-strand RNA viruses suggest comparable mechanisms of transcription and replication and a common evolutionary lineage for all these viruses. Sequence analyses of single genes, however, showed that filoviruses are more closely related to paramyxoviruses, particularly human respiratory syncytial virus. These data support the concept of the taxonomic order Mononegavirales for all nonsegmented negative-strand RNA viruses and the classification of Marburg virus, Ebola virus, and Reston virus in the family Filoviridae, separate from the families Paramyxoviridae and Rhabdoviridae.
Topics: Animals; Base Sequence; Biological Evolution; Filoviridae; Genes, Viral; Humans; Molecular Sequence Data; RNA, Viral; Viral Proteins
PubMed: 8219816
DOI: 10.1007/978-3-7091-9300-6_8 -
PLoS Pathogens Aug 2019
Topics: Animals; Bird Diseases; Bornaviridae; Central Nervous System Infections; Humans; Mononegavirales Infections; Prevalence
PubMed: 31369648
DOI: 10.1371/journal.ppat.1007873 -
Molecular Aspects of Medicine Jun 2008Ebolavirus and Marburgvirus (belonging to the Filoviridae family) emerged four decades ago and cause epidemics of haemorrhagic fever with high case-fatality rates. The... (Review)
Review
Ebolavirus and Marburgvirus (belonging to the Filoviridae family) emerged four decades ago and cause epidemics of haemorrhagic fever with high case-fatality rates. The genome of filoviruses encodes seven proteins. No significant homology is observed between filovirus proteins and any known macromolecule. Moreover, Marburgvirus and Ebolavirus show significant differences in protein homology. The natural maintenance cycle of filoviruses is unknown, the natural reservoir, the mode of transmission, the epidemic disease generation, and temporal dynamics are unclear. Lastly, Ebolavirus and Marburgvirus are considered as potential biological weapons. Vaccine appears the unique therapeutic frontier. Here, molecular and clinical aspects of filoviral haemorrhagic fevers are summarized.
Topics: Animals; Biological Warfare Agents; Ebolavirus; Filoviridae Infections; Humans; Marburgvirus; Viral Vaccines; Virus Assembly
PubMed: 18063023
DOI: 10.1016/j.mam.2007.09.005 -
Journal of Molecular Biology Aug 2016The host innate immune system serves as the first line of defense against viral infections. Germline-encoded pattern recognition receptors detect molecular patterns... (Review)
Review
The host innate immune system serves as the first line of defense against viral infections. Germline-encoded pattern recognition receptors detect molecular patterns associated with pathogens and activate innate immune responses. Of particular relevance to viral infections are those pattern recognition receptors that activate type I interferon responses, which establish an antiviral state. The order Mononegavirales is composed of viruses that possess single-stranded, non-segmented negative-sense (NNS) RNA genomes and are important human pathogens that consistently antagonize signaling related to type I interferon responses. NNS viruses have limited encoding capacity compared to many DNA viruses, and as a likely consequence, most open reading frames encode multifunctional viral proteins that interact with host factors in order to evade host cell defenses while promoting viral replication. In this review, we will discuss the molecular mechanisms of innate immune evasion by select NNS viruses. A greater understanding of these interactions will be critical in facilitating the development of effective therapeutics and viral countermeasures.
Topics: Animals; Host-Pathogen Interactions; Humans; Immune Evasion; Immune Tolerance; Immunity, Innate; Models, Biological; Models, Molecular; Mononegavirales
PubMed: 27487481
DOI: 10.1016/j.jmb.2016.07.017 -
Journal of Virology Jun 2006De novo generation of negative-strand RNA viruses depends on the efficient expression of antigenomic RNA (cRNA) from cDNA. To improve the rescue system of Borna disease...
RNA polymerase II-controlled expression of antigenomic RNA enhances the rescue efficacies of two different members of the Mononegavirales independently of the site of viral genome replication.
De novo generation of negative-strand RNA viruses depends on the efficient expression of antigenomic RNA (cRNA) from cDNA. To improve the rescue system of Borna disease virus (BDV), a member of the Mononegavirales with a nuclear replication phase, we evaluated different RNA polymerase (Pol) promoters for viral cRNA expression. Human and mouse Pol I promoters did not increase the recovery rate of infectious BDV from cDNA compared to the originally employed T7 RNA polymerase system. In contrast, expression of viral cRNA under the control of an RNA Pol II promoter increased the rescue efficacy by nearly 20-fold. Similarly, rescue of measles virus (MV), a member of the Mononegavirales with a cytoplasmic replication phase, was strongly improved by Pol II-controlled expression of viral cRNA. Analysis of transcription levels derived from different promoters suggested that the rescue-enhancing function of the Pol II promoter was due mainly to enhanced cRNA synthesis from the plasmid. Remarkably, correct 5'-terminal processing of Pol II-transcribed cRNA by a hammerhead ribozyme was not necessary for efficient rescue of BDV or MV. The correct 5' termini were reconstituted during replication of the artificially prolonged cRNA, indicating that the BDV and MV replicase complexes are able to recognize internal viral replication signals.
Topics: Borna disease virus; Genome, Viral; Mononegavirales; Mononegavirales Infections; Promoter Regions, Genetic; RNA Polymerase II; RNA, Antisense; RNA, Viral; RNA-Dependent RNA Polymerase; Transcription, Genetic; Virus Replication
PubMed: 16731909
DOI: 10.1128/JVI.02389-05 -
Acta Neuropathologica Jun 2019
Topics: Adult; Bornaviridae; Disease Progression; Encephalitis, Viral; Female; Guillain-Barre Syndrome; Humans; Mononegavirales Infections; Persistent Vegetative State; Real-Time Polymerase Chain Reaction
PubMed: 30953131
DOI: 10.1007/s00401-019-02005-z -
Viruses May 2020Feline morbillivirus (FeMV) was first isolated in stray cats in Hong Kong in 2012. Since its discovery, the virus has been reported in domestic cats worldwide, including... (Review)
Review
Feline morbillivirus (FeMV) was first isolated in stray cats in Hong Kong in 2012. Since its discovery, the virus has been reported in domestic cats worldwide, including in Hong Kong, Japan, Italy, US, Brazil, Turkey, UK, Germany, and Malaysia. FeMV is classified in the genus within the family. FeMV research has focused primarily on determining the host range, symptoms, and characteristics of persistent infections in vitro. Importantly, there is a potential association between FeMV infection and feline kidney diseases, such as tubulointerstitial nephritis (TIN) and chronic kidney diseases (CKD), which are known to significantly affect feline health and survival. However, the tropism and viral entry mechanism(s) of FeMV remain unknown. In this review, we summarize the FeMV studies up to date, including the discoveries of various FeMV strains, basic virology, pathogenicity, and disease signs.
Topics: Animals; Cat Diseases; Cats; Kidney Diseases; Morbillivirus; Morbillivirus Infections; Paramyxoviridae
PubMed: 32370044
DOI: 10.3390/v12050501 -
Veterinary Microbiology Aug 1999Flying foxes have been the focus of research into three newly described viruses from the order Mononegavirales, namely Hendra virus (HeV), Menangle virus and Australian... (Review)
Review
Flying foxes have been the focus of research into three newly described viruses from the order Mononegavirales, namely Hendra virus (HeV), Menangle virus and Australian Bat Lyssavirus (ABL). Early investigations indicate that flying foxes are the reservoir host for these viruses. In 1994, two outbreaks of a new zoonotic disease affecting horses and humans occurred in Queensland. The virus which was found to be responsible was called equine morbillivirus (EMV) and has since been renamed HeV. Investigation into the reservoir of HeV has produced evidence that antibodies capable of neutralising HeV have only been detected in flying foxes. Over 20% of flying foxes in eastern Australia have been identified as being seropositive. Additionally six species of flying foxes in Papua New Guinea have tested positive for antibodies to HeV. In 1996 a virus from the family Paramyxoviridae was isolated from the uterine fluid of a female flying fox. Sequencing of 10000 of the 18000 base pairs (bp) has shown that the sequence is identical to the HeV sequence. As part of investigations into HeV, a virus was isolated from a juvenile flying fox which presented with neurological signs in 1996. This virus was characterised as belonging to the family Rhabdoviridae, and was named ABL. Since then four flying fox species and one insectivorous species have tested positive for ABL. The third virus to be detected in flying foxes is Menangle virus, belonging to the family Paramyxoviridae. This virus was responsible for a zoonotic disease affecting pigs and humans in New South Wales in 1997. Antibodies capable of neutralising Menangle virus, were detected in flying foxes.
Topics: Animals; Antibodies, Viral; Australia; Chiroptera; Disease Reservoirs; Female; Horse Diseases; Horses; Humans; Mononegavirales; Mononegavirales Infections; Papua New Guinea; Swine; Swine Diseases; Zoonoses
PubMed: 10501164
DOI: 10.1016/s0378-1135(99)00063-2 -
Advances in Virus Research 2023Respiratory Syncytial Virus (RSV) is a major cause of respiratory illness in young children, elderly and immunocompromised individuals worldwide representing a severe...
Respiratory Syncytial Virus (RSV) is a major cause of respiratory illness in young children, elderly and immunocompromised individuals worldwide representing a severe burden for health systems. The urgent development of vaccines or specific antivirals against RSV is impaired by the lack of knowledge regarding its replication mechanisms. RSV is a negative-sense single-stranded RNA (ssRNA) virus belonging to the Mononegavirales order (MNV) which includes other viruses pathogenic to humans as Rabies (RabV), Ebola (EBOV), or measles (MeV) viruses. Transcription and replication of viral genomes occur within cytoplasmatic virus-induced spherical inclusions, commonly referred as inclusion bodies (IBs). Recently IBs were shown to exhibit properties of membrane-less organelles (MLO) arising by liquid-liquid phase separation (LLPS). Compartmentalization of viral RNA synthesis steps in viral-induced MLO is indeed a common feature of MNV. Strikingly these key compartments still remain mysterious. Most of our current knowledge on IBs relies on the use of fluorescence microscopy. The ability to fluorescently label IBs in cells has been key to uncover their dynamics and nature. The generation of recombinant viruses expressing a fluorescently-labeled viral protein and the immunolabeling or the expression of viral fusion proteins known to be recruited in IBs are some of the tools used to visualize IBs in infected cells. In this chapter, microscope techniques and the most relevant studies that have shed light on RSV IBs fundamental aspects, including biogenesis, organization and dynamics are being discussed and brought to light with the investigations carried out on other MNV.
Topics: Humans; Cell Line; Inclusion Bodies; Respiratory Syncytial Virus, Human; Virus Replication
PubMed: 37524479
DOI: 10.1016/bs.aivir.2023.06.001 -
Frontiers in Bioscience (Landmark... Jan 2013Matrix proteins are essential components of most negative-sense RNA, enveloped viruses. They serve a wide range of duties ranging from self-driven membrane budding and... (Review)
Review
Matrix proteins are essential components of most negative-sense RNA, enveloped viruses. They serve a wide range of duties ranging from self-driven membrane budding and coordination of other viral components to modulation of viral transcription. The functional similarity between these proteins is striking, despite major differences in their structures. Whereas biochemical and structural studies have partly been hindered by the inherent aggregation properties of these proteins, their cellular functions are beginning to be understood. In this review we summarize the current knowledge on negative-sense RNA virus matrix proteins and their interactions with other viral and cellular proteins. We also discuss the similarities and differences in matrix protein functions between the different families within the negative-sense RNA viruses.
Topics: Arenaviridae; Borna disease virus; Bunyaviridae; Filoviridae; Models, Molecular; Orthomyxoviridae; Paramyxoviridae; Rhabdoviridae; Viral Matrix Proteins; Virion
PubMed: 23276954
DOI: 10.2741/4132