-
The Journal of Biological Chemistry Sep 2023Hepatitis B virus (HBV) is a hepatotropic DNA virus that has a very compact genome. Due to this genomic density, several distinct mechanisms are used to facilitate the...
Hepatitis B virus (HBV) is a hepatotropic DNA virus that has a very compact genome. Due to this genomic density, several distinct mechanisms are used to facilitate the viral life cycle. Recently, accumulating evidence show that G-quadruplex (G4) in different viruses play essential regulatory roles in key steps of the viral life cycle. Although G4 structures in the HBV genome have been reported, their function in HBV replication remains elusive. In this study, we treated an HBV replication-competent cell line and HBV-infected cells with the G4 structure stabilizer pyridostatin (PDS) and evaluated different HBV replication markers to better understand the role played by the G4. In both models, we found PDS had no effect on viral precore RNA (pcRNA) or pre-genomic RNA (pgRNA), but treatment did increase HBeAg/HBc ELISA reads and intracellular levels of viral core/capsid protein (HBc) in a dose-dependent manner, suggesting post-transcriptional regulation. To further dissect the mechanism of G4 involvement, we used in vitro-synthesized HBV pcRNA and pgRNA. Interestingly, we found PDS treatment only enhanced HBc expression from pgRNA but not HBeAg expression from pcRNA. Our bioinformatic analysis and CD spectroscopy revealed that pgRNA harbors a conserved G4 structure. Finally, we introduced point mutations in pgRNA to disrupt its G4 structure and observed the resulting mutant failed to respond to PDS treatment and decreased HBc level in in vitro translation assay. Taken together, our data demonstrate that HBV pgRNA contains a G4 structure that plays a vital role in the regulation of viral mRNA translation.
Topics: Humans; Capsid Proteins; Hepatitis B; Hepatitis B e Antigens; Hepatitis B virus; RNA, Viral; Viral Core Proteins; Virus Replication; Cell Line; G-Quadruplexes; Protein Biosynthesis; Mutation; Aminoquinolines
PubMed: 37567479
DOI: 10.1016/j.jbc.2023.105151 -
International Journal of Molecular... May 2024While considerable attention has been devoted to respiratory manifestations, such as pneumonia and acute respiratory distress syndrome (ARDS), emerging evidence...
While considerable attention has been devoted to respiratory manifestations, such as pneumonia and acute respiratory distress syndrome (ARDS), emerging evidence underlines the significance of extrapulmonary involvement. In this study, we examined 15 hospitalized patients who succumbed to severe complications following SARS-CoV-2 infection. These patients were admitted to the Sibiu County Clinical Emergency Hospital in Sibiu, Romania, between March and October 2021. All patients were ethnic Romanians. Conducted within a COVID-19-restricted environment and adhering to national safety protocols, autopsies provided a comprehensive understanding of the disease's multisystemic impact. Detailed macroscopic evaluations and histopathological analyses of myocardial, renal, hepatic, splenic, and gastrointestinal tissues were performed. Additionally, reverse transcription-quantitative polymerase chain reaction (rt-qPCR) assays and immunohistochemical staining were employed to detect the viral genome and nucleocapsid within the tissues. Myocardial lesions, including ischemic microstructural changes and inflammatory infiltrates, were prevalent, indicative of COVID-19's cardiac implications, while renal pathology revealed the chronic alterations, acute tubular necrosis, and inflammatory infiltrates most evident. Hepatic examination identified hepatocellular necroinflammatory changes and hepatocytic cytopathy, highlighting the hepatic involvement of SARS-CoV-2 infection. Splenic parenchymal disorganization was prominent, indicating systemic immune dysregulation. Furthermore, gastrointestinal examinations unveiled nonspecific changes. Molecular analyses detected viral genes in various organs, with immunohistochemical assays confirming viral presence predominantly in macrophages and fibroblasts. These findings highlighted the systemic nature of SARS-CoV-2 infection, emphasizing the need for comprehensive clinical management strategies and targeted therapeutic approaches beyond respiratory systems.
Topics: Humans; SARS-CoV-2; COVID-19; Male; Female; Middle Aged; Genome, Viral; Aged; Kidney; Liver; Adult; Spleen; Romania; Nucleocapsid; Myocardium; Autopsy; Aged, 80 and over; Coronavirus Nucleocapsid Proteins
PubMed: 38891942
DOI: 10.3390/ijms25115755 -
Molecular Neurobiology May 2024Viral infections of the central nervous system (CNS) cause variable outcomes from acute to severe neurological sequelae with increased morbidity and mortality. Viral... (Review)
Review
Viral infections of the central nervous system (CNS) cause variable outcomes from acute to severe neurological sequelae with increased morbidity and mortality. Viral neuroinvasion directly or indirectly induces encephalitis via dysregulation of the immune response and contributes to the alteration of neuronal function and the degeneration of neuronal cells. This review provides an overview of the cellular and molecular mechanisms of virus-induced neurodegeneration. Neurotropic viral infections influence many aspects of neuronal dysfunction, including promoting chronic inflammation, inducing cellular oxidative stress, impairing mitophagy, encountering mitochondrial dynamics, enhancing metabolic rewiring, altering neurotransmitter systems, and inducing misfolded and aggregated pathological proteins associated with neurodegenerative diseases. These pathogenetic mechanisms create a multidimensional injury of the brain that leads to specific neuronal and brain dysfunction. The understanding of the molecular mechanisms underlying the neurophathogenesis associated with neurodegeneration of viral infection may emphasize the strategies for prevention, protection, and treatment of virus infection of the CNS.
Topics: Humans; Animals; Neurodegenerative Diseases; Nerve Degeneration; Virus Diseases; Oxidative Stress; Neurons
PubMed: 37946006
DOI: 10.1007/s12035-023-03761-6 -
PloS One 2024The Central African Republic (CAR) is one of the countries with the highest prevalence of viral hepatitis infection in the world. Coinfection with HIV increases the...
BACKGROUND
The Central African Republic (CAR) is one of the countries with the highest prevalence of viral hepatitis infection in the world. Coinfection with HIV increases the morbidity and mortality beyond that of mono-infection with either hepatitis or HIV. The present study describes the geographic distribution of viral hepatitis infections and molecular characterization of these viruses in the CAR.
METHODOLOGY
Out of 12,599 persons enrolled during the fourth Multiple Indicator Cluster Survey of 2010 in the CAR, 10,621 Dried Blood Spot (DBS) samples were obtained and stored at -20°C. Of these DBS, 4,317 samples were randomly selected to represent all regions of the CAR. Serological tests for hepatitis B, D, and C viruses were performed using the ELISA technique. Molecular characterization was performed to identify strains.
RESULTS
Of the 4,317 samples included, 53.2% were from men and 46.8% from women. The HBsAg prevalence among participants was 12.9% and that HBc-Ab was 19.7%. The overall prevalence of HCV was 0.6%. Co-infection of HIV/HBV was 1.1% and that of HBV/HDV was 16.6%. A total of 77 HBV, 6 HIV, and 6 HDV strains were successfully sequenced, with 72 HBV (93.5%) strains belonging to genotype E and 5 (6.5%) strains belonging to genotype D. The 6 HDV strains all belonged to clade 1, while 4 recombinants subtype were identified among the 6 strains of HIV.
CONCLUSION
Our study found a high prevalence of HBV, HBV/HDV and HBV/HIV co-infection, but a low prevalence of HCV. CAR remains an area of high HBV endemicity. This study's data and analyses would be useful for establishing an integrated viral hepatitis and HIV surveillance program in the CAR.
Topics: Humans; HIV Infections; Female; Male; Coinfection; Adult; Seroepidemiologic Studies; Central African Republic; Middle Aged; Adolescent; Young Adult; Hepatitis, Viral, Human; Hepatitis B; Hepatitis B virus; Child; Hepatitis C; Phylogeny; Child, Preschool; Prevalence
PubMed: 38722944
DOI: 10.1371/journal.pone.0291155 -
Acta Neuropathologica Apr 2024Influenza-associated encephalopathy (IAE) is extremely acute in onset, with high lethality and morbidity within a few days, while the direct pathogenesis by influenza...
Influenza-associated encephalopathy (IAE) is extremely acute in onset, with high lethality and morbidity within a few days, while the direct pathogenesis by influenza virus in this acute phase in the brain is largely unknown. Here we show that influenza virus enters into the cerebral endothelium and thereby induces IAE. Three-weeks-old young mice were inoculated with influenza A virus (IAV). Physical and neurological scores were recorded and temporal-spatial analyses of histopathology and viral studies were performed up to 72 h post inoculation. Histopathological examinations were also performed using IAE human autopsy brains. Viral infection, proliferation and pathogenesis were analyzed in cell lines of endothelium and astrocyte. The effects of anti-influenza viral drugs were tested in the cell lines and animal models. Upon intravenous inoculation of IAV in mice, the mice developed encephalopathy with brain edema and pathological lesions represented by micro bleeding and injured astrocytic process (clasmatodendrosis) within 72 h. Histologically, massive deposits of viral nucleoprotein were observed as early as 24 h post infection in the brain endothelial cells of mouse models and the IAE patients. IAV inoculated endothelial cell lines showed deposition of viral proteins and provoked cell death, while IAV scarcely amplified. Inhibition of viral transcription and translation suppressed the endothelial cell death and the lethality of mouse models. These data suggest that the onset of encephalopathy should be induced by cerebral endothelial infection with IAV. Thus, IAV entry into the endothelium, and transcription and/or translation of viral RNA, but not viral proliferation, should be the key pathogenesis of IAE.
Topics: Animals; Humans; Mice; Brain; Orthomyxoviridae Infections; Virus Internalization; Influenza A virus; Endothelial Cells; Influenza, Human; Brain Diseases; Male; Disease Models, Animal; Female; Endothelium; Mice, Inbred C57BL
PubMed: 38687393
DOI: 10.1007/s00401-024-02723-z -
Science (New York, N.Y.) Dec 2023Microbial genomes from ancient chickens uncover the drivers of pathogenicity.
Microbial genomes from ancient chickens uncover the drivers of pathogenicity.
Topics: Animals; Chickens; Virulence; Marek Disease; Mardivirus; Genome, Viral
PubMed: 38096277
DOI: 10.1126/science.adl6094 -
Journal of Virology Oct 2023This study highlights the crucial role RNA processing plays in regulating viral gene expression and replication. By targeting SR kinases, we identified harmine as a...
This study highlights the crucial role RNA processing plays in regulating viral gene expression and replication. By targeting SR kinases, we identified harmine as a potent inhibitor of HIV-1 as well as coronavirus (HCoV-229E and multiple SARS-CoV-2 variants) replication. Harmine inhibits HIV-1 protein expression and reduces accumulation of HIV-1 RNAs in both cell lines and primary CD4 T cells. Harmine also suppresses coronavirus replication post-viral entry by preferentially reducing coronavirus sub-genomic RNA accumulation. By focusing on host factors rather than viral targets, our study offers a novel approach to combating viral infections that is effective against a range of unrelated viruses. Moreover, at doses required to inhibit virus replication, harmine had limited toxicity and minimal effect on the host transcriptome. These findings support the viability of targeting host cellular processes as a means of developing broad-spectrum anti-virals.
Topics: Humans; Antiviral Agents; Coronavirus; Coronavirus Infections; Harmine; HIV-1; Virus Replication
PubMed: 37706687
DOI: 10.1128/jvi.00396-23 -
BMC Infectious Diseases Mar 2024Our aim was to examine the prevalence and characteristics of difficult-to-treat HIV in the current Swedish HIV cohort and to compare treatment outcomes between people...
BACKGROUND
Our aim was to examine the prevalence and characteristics of difficult-to-treat HIV in the current Swedish HIV cohort and to compare treatment outcomes between people with difficult and non-difficult-to-treat HIV.
METHODS
In this cross-sectional analysis of the Swedish HIV cohort, we identified all people with HIV currently in active care in 2023 from the national register InfCareHIV. We defined five categories of difficult-to-treat HIV: 1) advanced resistance, 2) four-drug regimen, 3) salvage therapy, 4) virologic failure within the past 12 months, and 5) ≥ 2 regimen switches following virologic failure since 2008. People classified as having difficult-to-treat HIV were compared with non-difficult for background characteristics as well as treatment outcomes (viral suppression and self-reported physical and psychological health).
RESULTS
Nine percent of the Swedish HIV cohort in 2023 (n = 8531) met at least one criterion for difficult-to-treat HIV. Most of them had ≥ 2 regimen switches (6%), and the other categories of difficult-to-treat HIV were rare (1-2% of the entire cohort). Compared with non-difficult, people with difficult-to-treat HIV were older, had an earlier first year of positive HIV test and lower CD4 counts, and were more often female. The viral suppression rate among people with difficult-to-treat HIV was 84% compared with 95% for non-difficult (p = 0.001). People with difficult-to-treat HIV reported worse physical (but not psychological) health, and this remained statistically significant after adjustment for age, sex, and transmission group.
CONCLUSIONS
Although 9% of the HIV cohort in Sweden in 2023 were classified as having difficult-to-treat HIV, a large proportion of these were virally suppressed, and challenges such as advanced resistance and need for salvage therapy are rare in the current Swedish cohort.
Topics: Humans; Female; Anti-HIV Agents; Cross-Sectional Studies; Sweden; HIV Infections; HIV-1; CD4 Lymphocyte Count; Viral Load; Antiretroviral Therapy, Highly Active
PubMed: 38500050
DOI: 10.1186/s12879-024-09214-2 -
PLoS Pathogens Jul 2023The genomes of positive-sense RNA viruses encode polyproteins that are essential for mediating viral replication. These viral polyproteins must undergo proteolysis (also...
The genomes of positive-sense RNA viruses encode polyproteins that are essential for mediating viral replication. These viral polyproteins must undergo proteolysis (also termed polyprotein processing) to generate functional protein units. This proteolysis can be performed by virally-encoded proteases as well as host cellular proteases, and is generally believed to be a key step in regulating viral replication. Hepatitis E virus (HEV) is a leading cause of acute viral hepatitis. The positive-sense RNA genome is translated to generate a polyprotein, termed pORF1, which is necessary and sufficient for viral genome replication. However, the mechanism of polyprotein processing in HEV remains to be determined. In this study, we aimed to understand processing of this polyprotein and its role in viral replication using a combination of in vitro translation experiments and HEV sub-genomic replicons. Our data suggest no evidence for a virally-encoded protease or auto-proteolytic activity, as in vitro translation predominantly generates unprocessed viral polyprotein precursors. However, seven cleavage sites within the polyprotein (suggested by bioinformatic analysis) are susceptible to the host cellular protease, thrombin. Using two sub-genomic replicon systems, we demonstrate that mutagenesis of these sites prevents replication, as does pharmacological inhibition of serine proteases including thrombin. Overall, our data supports a model where HEV uses host proteases to support replication and could have evolved to be independent of a virally-encoded protease for polyprotein processing.
Topics: Hepatitis E virus; Polyproteins; Thrombin; Virus Replication; Peptide Hydrolases; Viral Nonstructural Proteins
PubMed: 37478143
DOI: 10.1371/journal.ppat.1011529 -
JAMA May 2024
Topics: Humans; Acute Disease; Hepatitis D; Hepatitis D, Chronic; Hepatitis Delta Virus; Risk Factors; Hepatitis B; Coinfection; Vaccination; Viral Vaccines
PubMed: 38635231
DOI: 10.1001/jama.2024.1317