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Chinese Medical Journal Jun 2024Chronic hepatitis B virus (HBV) infection is a global public health concern. Existing antiviral drugs, including nucleos(t)ide analogs and interferon-α, can suppress...
Chronic hepatitis B virus (HBV) infection is a global public health concern. Existing antiviral drugs, including nucleos(t)ide analogs and interferon-α, can suppress HBV replication and improve the prognosis. However, the persistence of covalently closed circular DNA (cccDNA), the integration of HBV-DNA into the host genome, and compromised immune responses impede the successful treatment of hepatitis B. While achieving a functional cure of HBV remains elusive with the current treatment methods, this is the goal of new therapeutic approaches. Therefore, developing novel antiviral drugs is necessary for achieving a functional or complete cure for chronic hepatitis B. In recent years, substantial progress has been made in drug discovery and development for HBV infection. Direct-acting antiviral agents such as entry inhibitors, capsid assembly modulators, subviral particle release inhibitors, cccDNA silencers, and RNA interference molecules have entered clinical trials. In addition, several immunomodulatory agents, including toll-like receptor agonists, therapeutic vaccines, checkpoint inhibitors, and monoclonal antibodies, are also making their way toward clinical use. In this review, we summarize the recent progress and limitations of chronic hepatitis B treatment and discuss perspectives on approaches to achieving functional cure. Although it will take some time for these new antiviral drugs to be widely used in clinical practice, combination therapy may become a preferable treatment option in the future.
PubMed: 38945693
DOI: 10.1097/CM9.0000000000003178 -
Inorganic Chemistry Jun 2024Zwitterionic thiolate ligands have the potential to introduce novel assembly modes and functions for noble metal clusters. However, their utilization in the synthesis of...
Zwitterionic thiolate ligands have the potential to introduce novel assembly modes and functions for noble metal clusters. However, their utilization in the synthesis of silver clusters remains understudied, particularly for the clusters containing reductive Ag(0) species. In this article, we report the first synthesis of a mixed-valence silver(0/I) cluster protected by zwitterionic Tab as thiolate ligands (Tab = 4-(trimethylammonio)benzenethiolate), denoted as [Ag(Tab)](PF)·16CHOH·6EtO (·16CHOH·6EtO), alongside an Ag(I) cluster [Ag(Tab)(PhCOO)(MeCN)(HO)](PF)·11MeCN (·11MeCN). has a distinct hierarchical supratetrahedral structure with a central {Ag} kernel surrounded by four [Ag(Tab)] units. High-resolution electrospray ionization mass spectra demonstrate that has two free electrons, indicating a superatomic core. has a drum-like [Ag(Tab)(PhCOO)(HO)] inner core capped by two tetrahedral-like [Ag(Tab)(PhCOO)(MeCN)] units. can be transformed into after its reaction with NaBH in solution. Antibacterial measurements reveal that has a significantly lower minimum inhibitory concentration than that of the cluster. This work not only extends the stabilization of silver(0/I) clusters to neutral thiol ligands but also offers new materials for the development of novel antibacterial materials.
PubMed: 38943593
DOI: 10.1021/acs.inorgchem.4c01735 -
PloS One 2024Hepatitis C virus (HCV) infection remains a major cause of liver related morbidity and mortality worldwide. Epidemiologic data on seroprevalence, viremia prevalence and...
Hepatitis C virus (HCV) infection remains a major cause of liver related morbidity and mortality worldwide. Epidemiologic data on seroprevalence, viremia prevalence and risk factors remain limited in sub-Saharan Africa. In Ghana, HCV-related deaths are estimated to have increased since 2015. Risk factors associated with HCV infection in Ghana are not well described. The aim of this study was to determine the prevalence of, and risk factors associated with hepatitis C virus infection in the Upper East Region located in the northern part of Ghana. A community-based cross-sectional study was conducted in 9 communities in the Upper East region of Ghana. A total of 1,769 participants aged ≥12 years were screened for HCV antibody (anti-HCV) using rapid diagnostic testing (RDT). Seventy-four participants undertook HCV RNA testing after a positive anti-HCV result. Multivariate logistic regression was used to determine risk factors associated with HCV seropositivity. The anti-HCV prevalence was 8.4%, with 149 out of 1,769 testing anti-HCV positive. Mean age (±SD) of seropositive persons was 45.4 (±16.3) years. The highest anti-HCV seroprevalence was amongst persons aged 60 years and above. Forty-four out of 74 (59.5%) seropositive cases had viremic infection and the estimated viremic prevalence in the screened population was 5.0%. Predictors of HCV seropositivity were age (OR 1.03 95% CI 1.01-1.04), history of female genital mutilation or circumcision (OR 1.63 95% CI 1.04-2.55), sexual activity (OR 2.57 95% CI 1.38-4.79), positive maternal HCV status (OR 10.38 95% CI 4.13-26.05) and positive HIV status (OR 4.03 95% CI 1.35-12.05). In conclusion, the Upper East Region demonstrates a high Hepatitis C antibody prevalence. Almost 60% of individuals have viremic infection, however the cost of RNA testing is a barrier to virological diagnosis. There is a need to educate the population about HCV-associated risk factors to reduce HCV transmission and burden of disease.
Topics: Humans; Ghana; Female; Male; Middle Aged; Cross-Sectional Studies; Risk Factors; Adult; Hepatitis C; Prevalence; Hepacivirus; Young Adult; Seroepidemiologic Studies; Adolescent; Hepatitis C Antibodies; Aged; Child
PubMed: 38941280
DOI: 10.1371/journal.pone.0306292 -
ELife Jun 2024Genetic diversity is a hallmark of RNA viruses and the basis for their evolutionary success. Taking advantage of the uniquely large genomic database of SARS-CoV-2, we...
Genetic diversity is a hallmark of RNA viruses and the basis for their evolutionary success. Taking advantage of the uniquely large genomic database of SARS-CoV-2, we examine the impact of mutations across the spectrum of viable amino acid sequences on the biophysical phenotypes of the highly expressed and multifunctional nucleocapsid protein. We find variation in the physicochemical parameters of its extended intrinsically disordered regions (IDRs) sufficient to allow local plasticity, but also observe functional constraints that similarly occur in related coronaviruses. In biophysical experiments with several N-protein species carrying mutations associated with major variants, we find that point mutations in the IDRs can have nonlocal impact and modulate thermodynamic stability, secondary structure, protein oligomeric state, particle formation, and liquid-liquid phase separation. In the Omicron variant, distant mutations in different IDRs have compensatory effects in shifting a delicate balance of interactions controlling protein assembly properties, and include the creation of a new protein-protein interaction interface in the N-terminal IDR through the defining P13L mutation. A picture emerges where genetic diversity is accompanied by significant variation in biophysical characteristics of functional N-protein species, in particular in the IDRs.
Topics: SARS-CoV-2; Coronavirus Nucleocapsid Proteins; Mutation; COVID-19; Humans; Intrinsically Disordered Proteins; Phosphoproteins; Nucleocapsid Proteins; Thermodynamics; Protein Stability
PubMed: 38941236
DOI: 10.7554/eLife.94836 -
Plant Disease Jun 2024The first tri-segmented viruses in the family Rhabdoviridae were recently discovered by exploring publicly available plant datasets in several hosts, including alfalfa...
The first tri-segmented viruses in the family Rhabdoviridae were recently discovered by exploring publicly available plant datasets in several hosts, including alfalfa (Medicago sativa L.) (Bejerman et al. 2023). They were classified in a novel genus "Trirhavirus" within the family Rhabdoviridae. The trirhavirus identified in alfalfa was named Medicago trirhavirus 1 (MeTRV1). Here we report the first confirmation of MeTRV1 in commercial alfalfa fields in Washington State, USA. Samples were collected in 2019-2021 in Benton and Grant Counties, WA. The alfalfa leaves in which the virus was detected displayed irregular chlorotic spotting (Fig.1). Total RNA extraction, library preparation, high throughput sequencing, and bioinformatics analysis were performed as described in Nemchinov et al (2023). Raw reads were trimmed with Trimmomatic 0.39 (Bolger at al. 2014). SPAdes 3.15.5 (Bankevich et al. 2012) was used for assembly. MeTRV1 was identified in four plants out of 100 tested and three complete RNA segments were recovered from one of them. For clarity, the virus found in the alfalfa field samples was designated MeTRV1-Wa. De novo assembly resulted in three contigs, which, when subjected to BLASTn analyses, aligned to the respective RNA segments of MeTRV1. The first contig was 6,498 nucleotides (nts)-long, 99.4% identical to RNA1 of MeTRV1 (BK064256.1), and 5,922 reads mapped to it (coverage 125x). RNA1 of MeTRV1-Wa encoded a protein 2,040 amino acid (aa)-long that aligned with protein L of MeTRV1 (DBA36559.1, 99.8%). The second contig was 4,014 nts-long and 95.2% identical to the RNA2 of MetRV1 (BK064257.1) with 1,751 reads mapping (coverage 59x). It contained four open reading frames (ORFs) encoding proteins N (445 aa, 99.8%, DBA36560.1); P2 (343 aa, 99.4%, DBA36561.1); P3 (183 aa, 99.4%, DBA36562.1); and P4 (72 aa, 98.6%, DBA36563.1). Altogether, 4,653 reads mapped to the third contig (coverage 131x) that was 4,889 nts-long and 99.1% identical to the RNA 3 segment of MeTRV1 (BK064258.1). RNA3 of MeTRV1-Wa encoded four proteins: P6 (274 aa, 100%, DBA36565.1); P7 (189 aa, 99.5%, DBA36566.1); P8 (514 aa, 99 %, DBA36567.1); and P5 (303 aa, 99.7%, DBA36564.1). The 5' trailer of each RNA segment had a nearly identical 24 nts at the end. Genomic organization of the MeTRV1-Wa and the locations of its ORFs are shown in Fig.2. To confirm the virus's presence, two sets of primers were designed based on the predicted sequence of the viral RNA 3 segment. The correct-size products were amplified in RT-PCR assays with RNA extracted from infected plants (Fig.3) and verified by Sanger sequencing. Besides MeTRV1-Wa, sequences of the following viruses known to cause symptoms in alfalfa were identified in the same library: alfalfa mosaic virus, bean leafroll virus, lucerne transient streak virus, and pea streak virus. Thus, the observed symptomatology may not be clearly attributed to MeTRV1-Wa due to coinfecting organisms. However, a possible association of the disease symptoms with the virus presence could be suggested based on comparison with both asymptomatic and symptomatic plants negative for MeTRV1-Wa (Fig.1). Since plant rhabdoviruses are recognized as a cause of economic losses in alfalfa and other major crops and are transmitted by insects (Bejerman et al. 2011, 2015; Jackson et al. 2005; Man and Dietzgen 2014), this first experimental confirmation of the occurrence of the new virus in the U.S. alfalfa is important for understanding its origin, distribution, and pathogenic potential.
PubMed: 38937929
DOI: 10.1094/PDIS-05-24-1132-PDN -
Journal of Molecular Biology Jun 2024A large body of work in the last four decades has revealed the key pillars of HIV-1 transcription control at the initiation and elongation steps. Here, I provide a... (Review)
Review
A large body of work in the last four decades has revealed the key pillars of HIV-1 transcription control at the initiation and elongation steps. Here, I provide a recount of this collective knowledge starting with the genomic elements (DNA and nascent TAR RNA stem-loop) and transcription factors (cellular and the viral transactivator Tat), and later transitioning to the assembly and regulation of transcription initiation and elongation complexes, and the role of chromatin structure. Compelling evidence support a core HIV-1 transcriptional program regulated by the sequential and concerted action of cellular transcription factors and Tat to promote initiation and sustain elongation, highlighting the efficiency of a small virus to take over its host to produce the high levels of transcription required for viral replication. I summarize new advances including the use of CRISPR-Cas9, genetic tools for acute factor depletion, and imaging to study transcriptional dynamics, bursting and the progression through the multiple phases of the transcriptional cycle. Finally, I describe current challenges to future major advances and discuss areas that deserve more attention to both bolster our basic knowledge of the core HIV-1 transcriptional program and open up new therapeutic opportunities.
PubMed: 38936695
DOI: 10.1016/j.jmb.2024.168690 -
ACS Applied Bio Materials Jun 2024Protein cages are promising tools for the controlled delivery of therapeutics and imaging agents when endowed with programmable disassembly strategies. Here, we produced...
Protein cages are promising tools for the controlled delivery of therapeutics and imaging agents when endowed with programmable disassembly strategies. Here, we produced hybrid nanocomposites made of tobacco mosaic virus (TMV) and magnetic iron oxide nanoparticles (IONPs), designed to disrupt the viral protein cages using magnetically induced release of heat. We studied the effects of this magnetic hyperthermia on the programmable viral protein capsid disassembly using (1) elongated nanocomposites of TMV coated heterogeneously with magnetic iron oxide nanoparticles (TMV@IONPs) and (2) spherical nanocomposites of polystyrene (PS) on which we deposited presynthesized IONPs and TMV via layer-by-layer self-assembly (PS@IONPs/TMV). Notably, we found that the extent of the disassembly of the protein cages is contingent upon the specific absorption rate (SAR) of the magnetic nanoparticles, that is, the heating efficiency, and the relative position of the protein cage within the nanocomposite concerning the heating sources. This implies that the spatial arrangement of components within the hybrid nanostructure has a significant impact on the disassembly process. Understanding and optimizing this relationship will contribute to the critical spatiotemporal control for targeted drug and gene delivery using protein cages.
PubMed: 38934736
DOI: 10.1021/acsabm.4c00634 -
MSystems Jun 2024Hypersaline ecosystems display taxonomically similar assemblages with low diversities and highly dense accompanying viromes. The ecological implications of viral...
UNLABELLED
Hypersaline ecosystems display taxonomically similar assemblages with low diversities and highly dense accompanying viromes. The ecological implications of viral infection on natural microbial populations remain poorly understood, especially at finer scales of diversity. Here, we sought to investigate the influence of changes in environmental physicochemical conditions and viral predation pressure by autochthonous and allochthonous viruses on host dynamics. For this purpose, we transplanted two microbiomes coming from distant hypersaline systems (solar salterns of Es Trenc in Spain and the thalassohaline lake of Aran-Bidgol lake in Iran), by exchanging the cellular fractions with the sterile-filtered accompanying brines with and without the free extracellular virus fraction. The midterm exposure (1 month) of the microbiomes to the new conditions showed that at the supraspecific taxonomic range, the assemblies from the solar saltern brine more strongly resisted the environmental changes and viral predation than that of the lake. The metagenome-assembled genomes (MAGs) analysis revealed an intraspecific transition at the ecotype level, mainly driven by changes in viral predation pressure, by both autochthonous and allochthonous viruses.
IMPORTANCE
Viruses greatly influence succession and diversification of their hosts, yet the effects of viral infection on the ecological dynamics of natural microbial populations remain poorly understood, especially at finer scales of diversity. By manipulating the viral predation pressure by autochthonous and allochthonous viruses, we uncovered potential phage-host interaction, and their important role in structuring the prokaryote community at an ecotype level.
PubMed: 38934645
DOI: 10.1128/msystems.00538-24 -
Viruses Jun 2024Innate immunity, the first line of host defense against viral infections, recognizes viral components through different pattern-recognition receptors. Nucleic acids... (Review)
Review
Innate immunity, the first line of host defense against viral infections, recognizes viral components through different pattern-recognition receptors. Nucleic acids derived from viruses are mainly recognized by Toll-like receptors, nucleotide-binding domain leucine-rich repeat-containing receptors, absent in melanoma 2-like receptors, and cytosolic DNA sensors (e.g., Z-DNA-binding protein 1 and cyclic GMP-AMP synthase). Different types of nucleic acid sensors can recognize specific viruses due to their unique structures. PANoptosis is a unique form of inflammatory cell death pathway that is triggered by innate immune sensors and driven by caspases and receptor-interacting serine/threonine kinases through PANoptosome complexes. Nucleic acid sensors (e.g., Z-DNA-binding protein 1 and absent in melanoma 2) not only detect viruses, but also mediate PANoptosis through providing scaffold for the assembly of PANoptosomes. This review summarizes the structures of different nucleic acid sensors, discusses their roles in viral infections by driving PANoptosis, and highlights the crosstalk between different nucleic acid sensors. It also underscores the promising prospect of manipulating nucleic acid sensors as a therapeutic approach for viral infections.
Topics: Humans; Virus Diseases; Immunity, Innate; Nucleic Acids; Animals; DNA-Binding Proteins; Viruses; Receptors, Pattern Recognition; RNA-Binding Proteins
PubMed: 38932258
DOI: 10.3390/v16060966 -
Viruses Jun 2024Respiratory viruses significantly impact global morbidity and mortality, causing more disease in humans than any other infectious agent. Beyond pathogens, various...
BACKGROUND
Respiratory viruses significantly impact global morbidity and mortality, causing more disease in humans than any other infectious agent. Beyond pathogens, various viruses and bacteria colonize the respiratory tract without causing disease, potentially influencing respiratory diseases' pathogenesis. Nevertheless, our understanding of respiratory microbiota is limited by technical constraints, predominantly focusing on bacteria and neglecting crucial populations like viruses. Despite recent efforts to improve our understanding of viral diversity in the human body, our knowledge of viral diversity associated with the human respiratory tract remains limited.
METHODS
Following a comprehensive search in bibliographic and sequencing data repositories using keyword terms, we retrieved shotgun metagenomic data from public repositories (n = 85). After manual curation, sequencing data files from 43 studies were analyzed using EVEREST (pipEline for Viral assEmbly and chaRactEriSaTion). Complete and high-quality contigs were further assessed for genomic and taxonomic characterization.
RESULTS
Viral contigs were obtained from 194 out of the 868 FASTQ files processed through EVEREST. Of the 1842 contigs that were quality assessed, 8% (n = 146) were classified as complete/high-quality genomes. Most of the identified viral contigs were taxonomically classified as bacteriophages, with taxonomic resolution ranging from the superkingdom level down to the species level. Captured contigs were spread across 25 putative families and varied between RNA and DNA viruses, including previously uncharacterized viral genomes. Of note, airway samples also contained virus(es) characteristic of the human gastrointestinal tract, which have not been previously described as part of the lung virome. Additionally, by performing a meta-analysis of the integrated datasets, ecological trends within viral populations linked to human disease states and their biogeographical distribution along the respiratory tract were observed.
CONCLUSION
By leveraging publicly available repositories of shotgun metagenomic data, the present study provides new insights into viral genomes associated with specimens from the human respiratory tract across different disease spectra. Further studies are required to validate our findings and evaluate the potential impact of these viral communities on respiratory tract physiology.
Topics: Humans; Metagenomics; Virome; Genome, Viral; Respiratory System; Viruses; Metagenome; Computer Simulation; Phylogeny; Computational Biology; Microbiota; Bacteriophages
PubMed: 38932245
DOI: 10.3390/v16060953