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Annual Review of Phytopathology Aug 2016Twenty years ago, breakthroughs for reverse genetics analyses of negative-strand RNA (NSR) viruses were achieved by devising conditions for generation of infectious... (Review)
Review
Twenty years ago, breakthroughs for reverse genetics analyses of negative-strand RNA (NSR) viruses were achieved by devising conditions for generation of infectious viruses in susceptible cells. Recombinant strategies have subsequently been engineered for members of all vertebrate NSR virus families, and research arising from these advances has profoundly increased understanding of infection cycles, pathogenesis, and complexities of host interactions of animal NSR viruses. These strategies also permitted development of many applications, including attenuated vaccines and delivery vehicles for therapeutic and biotechnology proteins. However, for a variety of reasons, it was difficult to devise procedures for reverse genetics analyses of plant NSR viruses. In this review, we discuss advances that have circumvented these problems and resulted in construction of a recombinant system for Sonchus yellow net nucleorhabdovirus. We also discuss possible extensions to other plant NSR viruses as well as the applications that may emanate from recombinant analyses of these pathogens.
Topics: Plant Diseases; Reverse Genetics; Rhabdoviridae
PubMed: 27359368
DOI: 10.1146/annurev-phyto-080615-095909 -
The Journal of General Virology Nov 2021is a family of viruses in the order , with unsegmented (except for members of the genus ), negative-sense RNA genomes of 10-13 kb. Nyamviruses have a genome...
is a family of viruses in the order , with unsegmented (except for members of the genus ), negative-sense RNA genomes of 10-13 kb. Nyamviruses have a genome organisation and content similar to that of other mononegaviruses. includes several genera that form monophyletic clades on phylogenetic analysis of the RNA polymerase. Nyamiviruses have been found associated with diverse invertebrates as well as land- and seabirds. Members of the genera and produce enveloped, spherical virions. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family which is available at ictv.global/report/nyamiviridae.
Topics: Animals; Genome, Viral; Invertebrates; Mononegavirales; Phylogeny; RNA, Viral; Viral Proteins; Virion
PubMed: 34738886
DOI: 10.1099/jgv.0.001681 -
Jornal de Pediatria 2023To identify and assess the current evidence available about the costs of managing hospitalized pediatric patients diagnosed with Respiratory Syncytial Virus (RSV) and... (Review)
Review
OBJECTIVE
To identify and assess the current evidence available about the costs of managing hospitalized pediatric patients diagnosed with Respiratory Syncytial Virus (RSV) and Parainfluenza Virus Type 3 (PIV3) in upper-middle-income countries.
METHODS
The authors conducted a systematic review across seven key databases from database inception to July 2022. Costs extracted were converted into 2022 International Dollars using the Purchasing Power Parity-adjusted. PROSPERO identifier: CRD42020225757.
RESULTS
No eligible study for PIV3 was recovered. For RSV, cost analysis and COI studies were performed for populations in Colombia, China, Malaysia, and Mexico. Comparing the total economic impact, the lowest cost per patient at the pediatric ward was observed in Malaysia ($ 347.60), while the highest was in Colombia ($ 709.66). On the other hand, at pediatric ICU, the lowest cost was observed in China ($ 1068.26), while the highest was in Mexico ($ 3815.56). Although there is no consensus on the major cost driver, all included studies described that the medications (treatment) consumed over 30% of the total cost. A high rate of inappropriate prescription drugs was observed.
CONCLUSION
The present study highlighted how RSV infection represents a substantial economic burden to health care systems and to society. The findings of the included studies suggest a possible association between baseline risk status and expenditures. Moreover, it was observed that an important amount of the cost is destinated to treatments that have no evidence or support in most clinical practice guidelines.
Topics: Humans; Child; Infant; Developing Countries; Financial Stress; Respiratory Syncytial Virus Infections; Respiratory Syncytial Virus, Human; Parainfluenza Virus 3, Human; Hospitalization
PubMed: 37247828
DOI: 10.1016/j.jped.2023.05.003 -
The Journal of Infectious Diseases Nov 2023Ebola virus (EBOV) and Marburg virus (MARV) made headlines in the past decade, causing outbreaks of human disease in previously nonendemic yet overlapping areas. While...
Ebola virus (EBOV) and Marburg virus (MARV) made headlines in the past decade, causing outbreaks of human disease in previously nonendemic yet overlapping areas. While EBOV outbreaks can be mitigated with licensed vaccines and treatments, there is not yet a licensed countermeasure for MARV. Here, we used nonhuman primates (NHPs) previously vaccinated with vesicular stomatitis virus (VSV)-MARV and protected against lethal MARV challenge. After a resting period of 9 months, these NHPs were revaccinated with VSV-EBOV and challenged with EBOV, resulting in 75% survival. Surviving NHPs developed EBOV glycoprotein (GP)-specific antibody titers and no viremia or clinical signs of disease. The single vaccinated NHP succumbing to challenge showed the lowest EBOV GP-specific antibody response after challenge, supporting previous findings with VSV-EBOV that antigen-specific antibodies are critical in mediating protection. This study again demonstrates that VSVΔG-based filovirus vaccine can be successfully used in individuals with preexisting VSV vector immunity, highlighting the platform's applicability for consecutive outbreak response.
Topics: Animals; Humans; Hemorrhagic Fever, Ebola; Vesicular Stomatitis; Ebola Vaccines; Ebolavirus; Vesiculovirus; Vesicular stomatitis Indiana virus; Marburgvirus; Antibodies, Viral; Glycoproteins; Primates
PubMed: 37290042
DOI: 10.1093/infdis/jiad208 -
RNA (New York, N.Y.) Mar 2019A primary property of paramyxovirus bipartite promoters is to ensure that their RNA genomes are imprinted with a hexamer phase via their association with nucleoproteins,... (Review)
Review
A primary property of paramyxovirus bipartite promoters is to ensure that their RNA genomes are imprinted with a hexamer phase via their association with nucleoproteins, in part because this phase as well the editing sequence itself controls mRNA editing. The question then arises whether a similar mechanism operates for filoviruses that also contain bipartite promoters that are governed by the "rule of six," even though these genomes need not, and given Ebola virus biology, cannot always be of hexamer genome length. This review suggests that this is possible and describes how it might operate, and that RNA editing may play a role in Ebola virus genome interconversion that helps the virus adapt to different host environments.
Topics: Filoviridae; Gene Expression Regulation, Viral; Genome, Viral; Paramyxoviridae; Promoter Regions, Genetic; RNA Editing; RNA, Viral; Viral Proteins; Virus Replication
PubMed: 30587495
DOI: 10.1261/rna.068825.118 -
Virus Research May 2019Pneumoviruses represent a major public health burden across the world. Respiratory syncytial virus (RSV) and human metapneumovirus (HMPV), two of the most recognizable... (Review)
Review
Pneumoviruses represent a major public health burden across the world. Respiratory syncytial virus (RSV) and human metapneumovirus (HMPV), two of the most recognizable pediatric infectious agents, belong to this family. These viruses are enveloped with a non-segmented negative-sense RNA genome, and their replication occurs in specialized cytosolic organelles named inclusion bodies (IB). The critical role of IBs in replication of pneumoviruses has begun to be elucidated, and our current understanding suggests they are highly dynamic structures. From IBs, newly synthesized nucleocapsids are transported to assembly sites, potentially via the actin cytoskeleton, to be incorporated into nascent virions. Released virions, which generally contain one genome, can then diffuse in the extracellular environment to target new cells and reinitiate the process of infection. This is a challenging business for virions, which must face several risks including the extracellular immune responses. In addition, several recent studies suggest that successful infection may be achieved more rapidly by multiple, rather than single, genomic copies being deposited into a target cell. Interestingly, recent data indicate that pneumoviruses have several mechanisms that permit their transmission en bloc, i.e. transmission of multiple genomes at the same time. These mechanisms include the well-studied syncytia formation as well as the newly described formation of long actin-based intercellular extensions. These not only permit en bloc viral transmission, but also bypass assembly of complete virions. In this review we describe several aspects of en bloc viral transmission and how these mechanisms are reshaping our understanding of pneumovirus replication, assembly and spread.
Topics: Animals; Cell Line; Humans; Metapneumovirus; Mice; Paramyxoviridae Infections; Pneumovirus; RNA, Viral; Virion; Virus Assembly; Virus Replication
PubMed: 30844414
DOI: 10.1016/j.virusres.2019.03.002 -
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 -
Methods in Molecular Biology (Clifton,... 2024Ebola (EBOV) and Marburg (MARV) viruses cause hemorrhagic fever disease in humans and non-human primates (NHPs) with case-fatality rates as high as 90%. The 2013-2016...
Ebola (EBOV) and Marburg (MARV) viruses cause hemorrhagic fever disease in humans and non-human primates (NHPs) with case-fatality rates as high as 90%. The 2013-2016 Ebola virus disease (EVD) outbreak led to over 28,000 cases and 11,000 deaths and took an enormous toll on the economy of West African nations, in the absence of any vaccine or therapeutic options. Like EVD, there have been at least 6 outbreaks of MVD with ~88% case-fatality and the most recent cases emerging in Equatorial Guinea in February 2023. These outbreaks have spurred an unprecedented global effort to develop vaccines and therapeutics for EVD and MVD and led to an approved vaccine (ERVEBO™) and two monoclonal antibody (mAb) therapeutics for EBOV. In contrast to EVD, therapeutic options against Marburg and another Ebola-relative Sudan virus (SUDV) are lacking. The filovirus glycoprotein (GP), which mediates host cell entry and fusion, is the primary target of neutralizing antibodies. In addition to its pre- and post-fusion trimeric states, the protein is highly glycosylated making production of pure and homogeneous trimers on a large scale, a requirement for subunit vaccine development, a challenge. In efforts to address this roadblock, we have developed a unique combination of structure-based design, selection of expression system, and purification methods to produce uniform and stable EBOV and MARV GP trimers at scales appropriate for vaccine production.
Topics: Animals; Humans; Hemorrhagic Fever, Ebola; Antibodies, Viral; Ebolavirus; Marburgvirus; Glycoproteins; Vaccines
PubMed: 38315357
DOI: 10.1007/978-1-0716-3666-4_2 -
Current Opinion in Immunology Aug 2022Viral proteins fold into a variety of structures as they perform their functions. Structure-based vaccine design aims to exploit knowledge of an antigen's architecture... (Review)
Review
Viral proteins fold into a variety of structures as they perform their functions. Structure-based vaccine design aims to exploit knowledge of an antigen's architecture to stabilize it in a vulnerable conformation. We summarize the general principles of structure-based vaccine design, with a focus on the major types of sequence modifications: proline, disulfide, cavity-filling, electrostatic and hydrogen-bond substitution, as well as domain deletion. We then review recent applications of these principles to vaccine-design efforts across five viral families: Coronaviridae, Orthomyxoviridae, Paramyxoviridae, Pneumoviridae, and Filoviridae. Outstanding challenges include continued application of proven design principles to pathogens of interest, as well as development of new strategies for those pathogens that resist traditional techniques.
Topics: Coronaviridae; Filoviridae; Humans; Orthomyxoviridae; Paramyxoviridae; Pneumovirinae; Vaccine Development; Viral Proteins; Viral Vaccines
PubMed: 35598506
DOI: 10.1016/j.coi.2022.102209 -
Medecine Sciences : M/S 2018Ebola virus is an important pathogen that emerged in Central Africa where it was responsible of numerous outbreaks of haemorrhagic fevers associated with a extremely... (Review)
Review
Ebola virus is an important pathogen that emerged in Central Africa where it was responsible of numerous outbreaks of haemorrhagic fevers associated with a extremely high mortality rate (up to 90%). The filovirus pathogenicity is related to an inappropriate antiviral response. Indeed, this family of viruses has developed evasion strategies from early innate immunity mechanisms. As a result, a massive viral replication induces an unsuitable immune response causing an acute inflammatory reaction associated with the haemorrhagic syndrome. In this review, we describe the mechanisms adopted by filoviruses like Ebola virus to escape innate immunity response.
Topics: Animals; Filoviridae; Filoviridae Infections; Humans; Immune Evasion; Immunity, Innate
PubMed: 30230452
DOI: 10.1051/medsci/20183408013