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Journal of Visualized Experiments : JoVE Aug 2022With the broad application of sequencing technologies, many novel virus-like sequences have been discovered in arthropods, including mosquitoes. The two main categories...
With the broad application of sequencing technologies, many novel virus-like sequences have been discovered in arthropods, including mosquitoes. The two main categories of these new mosquito-associated viruses are "mosquito-borne viruses (MBVs)" and "mosquito-specific viruses (MSVs)". These novel viruses might be pathogenic to both vertebrates and mosquitoes, or they could just be symbiotic with mosquitoes. Entity viruses are essential to confirm the biological characters of these viruses. Thus, a detailed protocol has been described here for virus isolation and amplification from field-collected mosquitoes. First, the mosquito samples were prepared as supernatants of mosquito homogenates. After centrifugation twice, the supernatants were then inoculated into either mosquito cell line C6/36 or vertebrate cell line BHK-21 for virus amplification. After 7 days, the supernatants were collected as the P1 supernatants and stored at -80 °C. Next, P1 supernatants were passaged twice more in C6/36 or BHK-21 cells while the cell status was being checked daily. When cytopathogenic effect (CPE) on the cells was discovered, these supernatants were collected and used to identify viruses. This protocol serves as the foundation for future research on mosquito-associated viruses, including MBVs and MSVs.
Topics: Animals; Culicidae; Flavivirus; Satellite Viruses; Vertebrates; Viruses
PubMed: 36121272
DOI: 10.3791/63852 -
Virus Research May 2019RNA virus populations are diverse due to a variety of factors, including lack of proofreading of the viral RNA-dependent RNA polymerase. These diverse viral populations... (Review)
Review
RNA virus populations are diverse due to a variety of factors, including lack of proofreading of the viral RNA-dependent RNA polymerase. These diverse viral populations include defective viruses incapable of productive infection. Recent studies have determined the existence of several modes of viral transmission outside of canonical pathways, including en bloc transmission of multiple viruses into a single host cell via membrane vesicles. Additionally, it has recently been determined that viral aggregation and bacteria can facilitate the delivery of multiple viruses to a single cell. Co-infection of RNA viruses is important since it has the potential to enhance viral fitness. Furthermore, through complementation and recombination, co-infection could potentially promote "resurrection" of otherwise defective viral genomes and has the potential to expand viral diversity.
Topics: Animals; Coinfection; Defective Viruses; Evolution, Molecular; Genome, Viral; Humans; Mice; RNA Viruses; RNA, Viral; RNA-Dependent RNA Polymerase; Recombination, Genetic; Virus Diseases; Virus Replication
PubMed: 30836113
DOI: 10.1016/j.virusres.2019.03.003 -
Viruses Dec 2018Hepatitis delta virus (HDV) is unique among animal viruses. HDV is a satellite virus of the hepatitis B virus (HBV), however it shares no sequence similarity with its... (Review)
Review
Hepatitis delta virus (HDV) is unique among animal viruses. HDV is a satellite virus of the hepatitis B virus (HBV), however it shares no sequence similarity with its helper virus and replicates independently in infected cells. HDV is the smallest human pathogenic RNA virus and shares numerous characteristics with viroids. Like viroids, HDV has a circular RNA genome which adopts a rod-like secondary structure, possesses ribozyme domains, replicates in the nucleus of infected cells by redirecting host DNA-dependent RNA polymerases (RNAP), and relies heavily on host proteins for its replication due to its small size and limited protein coding capacity. These similarities suggest an evolutionary relationship between HDV and viroids, and information on HDV could allow a better understanding of viroids and might globally help understanding the pathogenesis and molecular biology of these subviral RNAs. In this review, we discuss the host involvement in HDV replication and its implication for HDV pathogenesis.
Topics: DNA Replication; DNA-Directed RNA Polymerases; Genome, Viral; Hepatitis B virus; Hepatitis Delta Virus; Host-Pathogen Interactions; Humans; RNA; RNA, Circular; RNA, Viral; Satellite Viruses; Viroids; Virus Replication
PubMed: 30602655
DOI: 10.3390/v11010021 -
Cold Spring Harbor Perspectives in... Nov 2014HDV is a defective RNA pathogen requiring the simultaneous presence of HBV to complete its life cycle. Two major specific patterns of infection have been described: the... (Review)
Review
HDV is a defective RNA pathogen requiring the simultaneous presence of HBV to complete its life cycle. Two major specific patterns of infection have been described: the coinfection with HDV and HBV of a susceptible, anti-HBs-negative individual, or the HDV superinfection of a chronic HBV carrier. Coinfection mostly leads to the eradication of both agents, whereas the majority of patients with HDV superinfection evolve to chronic HDV infection and hepatitis. Chronic HDV infection worsens the preexisting HBV-related liver damage. HDV-associated chronic liver disease (chronic hepatitis D) is characterized by necroinflammation and the relentless deposition of collagen culminating, within a few decades, into the development of cirrhosis and hepatocellular carcinoma.
Topics: Coinfection; Disease Progression; Hepatitis B; Hepatitis D; Hepatitis D, Chronic; Hepatitis Delta Virus; Humans; Superinfection
PubMed: 25368018
DOI: 10.1101/cshperspect.a021550 -
Journal of Virology Aug 2021Ebola virus (EBOV), of the family , is an RNA virus that can cause a hemorrhagic fever with a high mortality rate. Defective viral genomes (DVGs) are truncated genomes...
Ebola virus (EBOV), of the family , is an RNA virus that can cause a hemorrhagic fever with a high mortality rate. Defective viral genomes (DVGs) are truncated genomes that have been observed during multiple RNA virus infections, including EBOV infection, and have previously been associated with viral persistence and immunostimulatory activity. As DVGs have been detected in cells persistently infected with EBOV, we hypothesized that DVGs may also accumulate during viral replication in filovirus-infected hosts. Therefore, we interrogated sequence data from serum and tissue samples using a bioinformatics tool in order to identify the presence of DVGs in nonhuman primates (NHPs) infected with EBOV, Sudan virus (SUDV), or Marburg virus (MARV). Multiple 5' copy-back DVGs (cbDVGs) were detected in NHP serum during the acute phase of filovirus infection. While the relative abundance of total DVGs in most animals was low, serum collected during acute EBOV and SUDV infections, but not MARV infections, contained a higher proportion of short trailer sequence cbDVGs than the challenge stock. This indicated an accumulation of these DVGs throughout infection, potentially due to the preferential replication of short DVGs over the longer viral genome. Using reverse transcriptase PCR (RT-PCR) and deep sequencing, we also confirmed the presence of 5' cbDVGs in EBOV-infected NHP testes, which is of interest due to EBOV persistence in semen of male survivors of infection. This work suggests that DVGs play a role in EBOV infection and that further study will lead to a better understanding of EBOV pathogenesis. The study of filovirus pathogenesis is critical for understanding the consequences of infection and for the development of strategies to ameliorate future outbreaks. Defective viral genomes (DVGs) have been detected during EBOV infections ; however, their presence in infections remains unknown. In this study, DVGs were detected in samples collected from EBOV- and SUDV-infected nonhuman primates (NHPs). The accumulation of these DVGs in the trailer region of the genome during infection indicates a potential role in EBOV and SUDV pathogenesis. In particular, the presence of DVGs in the testes of infected NHPs requires further investigation as it may be linked to the establishment of persistence.
Topics: Animals; Defective Viruses; Ebolavirus; Female; Genome, Viral; Hemorrhagic Fever, Ebola; Host-Pathogen Interactions; Macaca mulatta; Male; Virus Replication
PubMed: 34160256
DOI: 10.1128/JVI.00714-21 -
Viruses Dec 2022Defective interfering particles (DIPs) are particles containing defective viral genomes (DVGs) generated during viral replication. DIPs have been found in various RNA... (Review)
Review
Defective interfering particles (DIPs) are particles containing defective viral genomes (DVGs) generated during viral replication. DIPs have been found in various RNA viruses, especially in influenza viruses. Evidence indicates that DIPs interfere with the replication and encapsulation of wild-type viruses, namely standard viruses (STVs) that contain full-length viral genomes. DIPs may also activate the innate immune response by stimulating interferon synthesis. In this review, the underlying generation mechanisms and characteristics of influenza virus DIPs are summarized. We also discuss the potential impact of DIPs on the immunogenicity of live attenuated influenza vaccines (LAIVs) and development of influenza vaccines based on NS1 gene-defective DIPs. Finally, we review the antiviral strategies based on influenza virus DIPs that have been used against both influenza virus and SARS-CoV-2. This review provides systematic insights into the theory and application of influenza virus DIPs.
Topics: Humans; Antiviral Agents; Influenza Vaccines; Defective Interfering Viruses; Defective Viruses; COVID-19; SARS-CoV-2; Orthomyxoviridae; Virus Replication
PubMed: 36560777
DOI: 10.3390/v14122773 -
Hepatology (Baltimore, Md.) Jun 2022
Topics: Hepatitis Delta Virus; Piperidines; Pyridines
PubMed: 35229339
DOI: 10.1002/hep.32435 -
Viruses Jan 2022Treatment options for HDV have been limited to interferon alfa-based therapies with its poor efficacy to side effects ratio. Several novel therapies have now advanced... (Review)
Review
Treatment options for HDV have been limited to interferon alfa-based therapies with its poor efficacy to side effects ratio. Several novel therapies have now advanced into the clinic. As they each have a different mechanism of action, there is the potential for combination therapy. Here we review how studying the HDV life cycle has led to the development of these novel therapies, the key developments leading to, and the details of, the first combination study of novel anti-HDV therapies, and suggest what additional combinations of novel therapies can be anticipated as we enter this exciting new area of HDV treatments.
Topics: Antiviral Agents; Drug Therapy, Combination; Hepatitis D; Hepatitis D, Chronic; Hepatitis Delta Virus; Humans
PubMed: 35215860
DOI: 10.3390/v14020268 -
Drugs of Today (Barcelona, Spain : 1998) Jul 2021Hepatitis B virus (HBV) and its satellite virus hepatitis D (HDV) are common worldwide hepatotrophic infections responsible for cirrhosis and hepatocellular carcinoma...
Hepatitis B virus (HBV) and its satellite virus hepatitis D (HDV) are common worldwide hepatotrophic infections responsible for cirrhosis and hepatocellular carcinoma (HCC). The more common HBV infection has several therapeutic regimens currently available for suppression of viral replication. However, a regimen leading to an effective sustained functional cure is still not available. In contrast, HDV infection, which causes the most severe form of chronic viral hepatitis and an increased rate of HCC, currently has no Food and Drug Administration (FDA)-approved treatment. Bulevirtide is a novel virion entry inhibitor which blocks the virion's hepatocyte pathway of entry, the hepatic sodium/taurocholate cotransporting polypeptide (NTCP) receptor, and is now a promising therapy for both infections. In July 2020 bulevirtide was authorized for use in the E.U. following a positive opinion by the European Medicines Agency (EMA) for the treatment of chronic HDV infection in HDV RNA-positive adult patients with compensated liver disease. In this paper we have examined the studies that led to this approval as well as studies examining the drug's efficacy in treating HBV.
Topics: Adult; Carcinoma, Hepatocellular; Hepatitis B; Hepatitis B virus; Hepatitis Delta Virus; Humans; Liver Neoplasms
PubMed: 34268531
DOI: 10.1358/dot.2021.57.7.3283861 -
Clinics in Liver Disease Nov 2023Maternal-to-child transmission of hepatitis B virus (HBV) and hepatitis delta virus (HDV) can lead to the risk of progressive liver disease in infants, but fortunately... (Review)
Review
Maternal-to-child transmission of hepatitis B virus (HBV) and hepatitis delta virus (HDV) can lead to the risk of progressive liver disease in infants, but fortunately effective interventions exist to decrease transmission. Counseling on the risk of maternal-to-child transmission, care pathways to decrease transmission, and the implications of HBV and HDV on pregnancy outcomes are the key components of caring for pregnant people living with HBV and HDV.
Topics: Infant; Pregnancy; Female; Humans; Hepatitis B virus; Hepatitis Delta Virus; Hepatitis B; Hepatitis B Surface Antigens; Infectious Disease Transmission, Vertical
PubMed: 37778777
DOI: 10.1016/j.cld.2023.05.007