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American Journal of Transplantation :... Nov 2023The classical lytic infection theory along with large T antigen-mediated oncogenesis cannot explain the BK polyomavirus (BKPyV)-associated tumor secondary to...
The classical lytic infection theory along with large T antigen-mediated oncogenesis cannot explain the BK polyomavirus (BKPyV)-associated tumor secondary to BKPyV-associated nephropathy (BKVAN), viremia/DNAemia, and viruria after renal transplantation. This study performed virome capture sequencing and pathological examination on regularly collected urine sediment and peripheral blood samples, and BKVAN and tumor biopsy tissues of 20 patients with BKPyV-associated diseases of different stages. In the early noncancerous stages, well-amplified integration sites were visualized by in situ polymerase chain reaction, simultaneously with BKPyV inclusion bodies and capsid protein expression. The integration intensity, the proportion of microhomology-mediated end-joining integration, and host PARP-1 and POLQ gene expression levels increased with disease progression. Furthermore, multiomics analysis was performed on BKPyV-associated urothelial carcinoma tissues, identifying tandem-like structures of BKPyV integration using long-read genome sequencing. The carcinogenicity of BKPyV integration was proven to disturb host gene expression and increase viral oncoprotein expression. Fallible DNA double-strand break repair pathways were significantly activated in the parenchyma of BKPyV-associated tumors. Olaparib showed an antitumor activity dose-response effect in the tumor organoids without BRCA1/2 genes mutation. In conclusion, the dynamic viral integration patterns actively participate in the progression of BKPyV-associated diseases and thus could be a potential target for disease monitoring and intervention.
Topics: Humans; Kidney Transplantation; BK Virus; BRCA1 Protein; Carcinoma, Transitional Cell; BRCA2 Protein; Urinary Bladder Neoplasms; Polyomavirus Infections; Nephritis, Interstitial; Virus Integration; Tumor Virus Infections
PubMed: 37507072
DOI: 10.1016/j.ajt.2023.07.014 -
Microbiome Jan 2021Polintons are large mobile genetic elements found in the genomes of eukaryotic organisms that are considered the ancient ancestors of most eukaryotic dsDNA viruses....
BACKGROUND
Polintons are large mobile genetic elements found in the genomes of eukaryotic organisms that are considered the ancient ancestors of most eukaryotic dsDNA viruses. Originally considered as transposons, they have been found to encode virus capsid genes, suggesting they may actually be integrated viruses; however, an extracellular form has yet to be detected. Recently, circa 25 Polinton-like viruses have been discovered in environmental metagenomes and algal genomes, which shared distantly related genes to both Polintons and virophages (Lavidaviridae). These entities could be the first members of a major class of ancient eukaryotic viruses; however, owing to the lack of available genomes for analysis, information on their global diversity, evolutionary relationships, eukaryotic hosts, and status as free virus particles is limited.
RESULTS
Here, we analysed the metaviromes of an alpine lake to show that Polinton-like virus genome sequences are abundant in the water column. We identify major capsid protein genes belonging to 82 new Polinton-like viruses and use these to interrogate publicly available metagenomic datasets, identifying 543 genomes and a further 16 integrated into eukaryotic genomes. Using an analysis of shared gene content and major capsid protein phylogeny, we define large groups of Polinton-like viruses and link them to diverse eukaryotic hosts, including a new group of viruses, which possess all the core genes of virophages and infect oomycetes and Chrysophyceae.
CONCLUSIONS
Our study increased the number of known Polinton-like viruses by 25-fold, identifying five major new groups of eukaryotic viruses, which until now have been hidden in metagenomic datasets. The large enrichment (> 100-fold) of Polinton-like virus sequences in the virus-sized fraction of this alpine lake and the fact that their viral major capsid proteins are found in eukaryotic host transcriptomes support the hypothesis that Polintons in unicellular eukaryotes are viruses. In summary, our data reveals a diverse assemblage of globally distributed viruses, associated with a wide range of unicellular eukaryotic hosts. We anticipate that the methods we have developed for Polinton-like virus detection and the database of over 20,000 genes we present will allow for continued discovery and analysis of these new viral groups. Video abstract.
Topics: Aquatic Organisms; DNA Viruses; DNA, Viral; Ecosystem; Eukaryota; Genome, Viral; Lakes; Phylogeny; Virophages; Virus Integration
PubMed: 33436089
DOI: 10.1186/s40168-020-00956-0 -
Vaccine Feb 2020The bipartite genome of Vibrio cholerae is divided into two circular non-homologous chromosomes, which harbor several genetic elements like phages, plasmids,... (Review)
Review
The bipartite genome of Vibrio cholerae is divided into two circular non-homologous chromosomes, which harbor several genetic elements like phages, plasmids, transposons, integrative conjugative elements, and pathogenic islands that encode functions responsible for disease development, antimicrobial resistance, and subsistence in hostile environments. These elements are highly heterogeneous, mobile in nature, and encode their own mobility functions or exploit host-encoded enzymes for intra- and inter-cellular movements. The key toxin of V. cholerae responsible for the life-threatening diarrheal disease cholera, the cholera toxin, is coded by part of the genome of a filamentous phage, CTXϕ. The replicative genome of CTXϕ is divided into two distinct modular structures and has adopted a unique strategy for its irreversible integration into the V. cholerae chromosomes. CTXϕ exploits two host-encoded tyrosine recombinases, XerC and XerD, for its integration in the highly conserved dimer resolution site (dif) of V. cholerae chromosomes. CTXϕ can replicate only in the limited number of Vibrio species. In contrast, the phage integration into the bacterial chromosome does not rely on its replication and could integrate to the dif site of large numbers of gram-negative bacteria. Recent pangenomic analysis revealed that like CTXϕ, the bacterial dif site is the integration spot for several other mobile genetic elements such as plasmids and genomic islands. In this review we discuss about current molecular insights into CTXϕ genomics and its replication and integration mechanisms into hosts. Particular emphasis has been given on the exploitation of CTXϕ genomics knowledge in developing genetic tools and designing environmentally safe recombinant live oral cholera vaccine strains.
Topics: Bacteriophages; Cholera; Cholera Toxin; Chromosomes, Bacterial; Genome, Viral; Genomics; Humans; Vibrio cholerae; Virus Integration
PubMed: 31272871
DOI: 10.1016/j.vaccine.2019.06.034 -
Viruses Dec 2022To complete their replication cycle, retroviruses need to integrate a DNA copy of their RNA genome into a host chromosome. Integration site selection is not random and... (Review)
Review
To complete their replication cycle, retroviruses need to integrate a DNA copy of their RNA genome into a host chromosome. Integration site selection is not random and is driven by multiple viral and cellular host factors specific to different classes of retroviruses. Today, overwhelming evidence from cell culture, animal experiments and clinical data suggests that integration sites are important for retroviral replication, oncogenesis and/or latency. In this review, we will summarize the increasing knowledge of the mechanisms underlying the integration site selection of the gammaretrovirus MLV and the lentivirus HIV-1. We will discuss how host factors of the integration site selection of retroviruses may steer the development of safer viral vectors for gene therapy. Next, we will discuss how altering the integration site preference of HIV-1 using small molecules could lead to a cure for HIV-1 infection.
Topics: Animals; HIV-1; Virus Integration; Retroviridae; Lentivirus; HIV Infections; Genetic Vectors
PubMed: 36680071
DOI: 10.3390/v15010032 -
Nature Communications Apr 2023Phage-plasmids are extra-chromosomal elements that act both as plasmids and as phages, whose eco-evolutionary dynamics remain poorly constrained. Here, we show that...
Phage-plasmids are extra-chromosomal elements that act both as plasmids and as phages, whose eco-evolutionary dynamics remain poorly constrained. Here, we show that segregational drift and loss-of-function mutations play key roles in the infection dynamics of a cosmopolitan phage-plasmid, allowing it to create continuous productive infections in a population of marine Roseobacter. Recurrent loss-of-function mutations in the phage repressor that controls prophage induction leads to constitutively lytic phage-plasmids that spread rapidly throughout the population. The entire phage-plasmid genome is packaged into virions, which were horizontally transferred by re-infecting lysogenized cells, leading to an increase in phage-plasmid copy number and to heterozygosity in a phage repressor locus in re-infected cells. However, the uneven distribution of phage-plasmids after cell division (i.e., segregational drift) leads to the production of offspring carrying only the constitutively lytic phage-plasmid, thus restarting the lysis-reinfection-segregation life cycle. Mathematical models and experiments show that these dynamics lead to a continuous productive infection of the bacterial population, in which lytic and lysogenic phage-plasmids coexist. Furthermore, analyses of marine bacterial genome sequences indicate that the plasmid backbone here can carry different phages and disseminates trans-continentally. Our study highlights how the interplay between phage infection and plasmid genetics provides a unique eco-evolutionary strategy for phage-plasmids.
Topics: Bacteriophages; Plasmids; Lysogeny; Virus Activation; Mutation
PubMed: 37041135
DOI: 10.1038/s41467-023-37512-x -
Nature Communications Oct 2022Cellular proteins CPSF6, NUP153 and SEC24C play crucial roles in HIV-1 infection. While weak interactions of short phenylalanine-glycine (FG) containing peptides with...
Cellular proteins CPSF6, NUP153 and SEC24C play crucial roles in HIV-1 infection. While weak interactions of short phenylalanine-glycine (FG) containing peptides with isolated capsid hexamers have been characterized, how these cellular factors functionally engage with biologically relevant mature HIV-1 capsid lattices is unknown. Here we show that prion-like low complexity regions (LCRs) enable avid CPSF6, NUP153 and SEC24C binding to capsid lattices. Structural studies revealed that multivalent CPSF6 assembly is mediated by LCR-LCR interactions, which are templated by binding of CPSF6 FG peptides to a subset of hydrophobic capsid pockets positioned along adjoining hexamers. In infected cells, avid CPSF6 LCR-mediated binding to HIV-1 cores is essential for functional virus-host interactions. The investigational drug lenacapavir accesses unoccupied hydrophobic pockets in the complex to potently impair HIV-1 inside the nucleus without displacing the tightly bound cellular cofactor from virus cores. These results establish previously undescribed mechanisms of virus-host interactions and antiviral action.
Topics: Humans; Anti-HIV Agents; Capsid Proteins; Drugs, Investigational; Glycine; HIV Infections; HIV-1; Host Microbial Interactions; mRNA Cleavage and Polyadenylation Factors; Nuclear Pore Complex Proteins; Phenylalanine; Prions; Virus Integration
PubMed: 36202818
DOI: 10.1038/s41467-022-33662-6 -
Viruses Aug 2019Foamy viruses (FV) are retroviruses belonging to the subfamily. They are non-pathogenic viruses endemic in several mammalian hosts like non-human primates, felines,... (Review)
Review
Foamy viruses (FV) are retroviruses belonging to the subfamily. They are non-pathogenic viruses endemic in several mammalian hosts like non-human primates, felines, bovines, and equines. Retroviral DNA integration is a mandatory step and constitutes a prime target for antiretroviral therapy. This activity, conserved among retroviruses and long terminal repeat (LTR) retrotransposons, involves a viral nucleoprotein complex called intasome. In the last decade, a plethora of structural insights on retroviral DNA integration arose from the study of FV. Here, we review the biochemistry and the structural features of the FV integration apparatus and will also discuss the mechanism of action of strand transfer inhibitors.
Topics: Animals; Anti-Retroviral Agents; Catalytic Domain; DNA, Viral; HIV Infections; HIV-1; Humans; Integrase Inhibitors; Integrases; Models, Molecular; Nucleoproteins; Retroviridae; Spumavirus; Terminal Repeat Sequences; Virus Integration
PubMed: 31443391
DOI: 10.3390/v11090770 -
Genomics May 2021Race may influence vulnerability to HPV variants in viral infection and perisistence. Integrated analysis of the virus and host transcriptomes from different populations...
Race may influence vulnerability to HPV variants in viral infection and perisistence. Integrated analysis of the virus and host transcriptomes from different populations provides an unprecedented opportunity to understand these racial disparities in the prevalence of HPV and cervical cancers. We performed RNA-Seq analysis of 90 tumors and 39 adjacent normal tissues from cervical cancer patients at Zhejiang University (ZJU) in China, and conducted a comparative analysis with RNA-Seq data of 286 cervical cancers from TCGA. We found a modestly higher rate of HPV positives and HPV integrations in TCGA than in ZJU. In addition to LINC00393 and HSPB3 as new common integration hotspots in both cohorts, we found new hotspots such as SH2D3C and CASC8 in TCGA, and SCGB1A1 and ABCA1 in ZJU. We described the first, to our knowledge, virus-transcriptome-based classification of cervical cancer associated with clinical outcome. Particularly, patients with expressed E5 performed better than those without E5 expression. However, the constituents of these virus-transcriptome-based tumor subtypes differ dramatically between the two cohorts. We further characterized the immune infiltration landscapes between different HPV statuses and revealed significantly elevated levels of regulatory T cells and M0 macrophages in HPV positive tumors, which were associated with poor prognosis. These findings increase our understanding of the racial disparities in the prevalence of HPV and its associated cervical cancers between the two cohorts, and also have important implications in the classification of tumor subtypes, prognosis, and anti-cancer immunotherapy in cervical cancer.
Topics: China; Female; Humans; Papillomaviridae; Transcriptome; Uterine Cervical Neoplasms; Virus Integration
PubMed: 33785400
DOI: 10.1016/j.ygeno.2021.03.029 -
BMC Genomics Nov 2021Engineered versions of adeno-associated virus (AAV) are commonly used in gene therapy but evidence revealing a potential oncogenic role of natural AAV in hepatocellular...
BACKGROUND
Engineered versions of adeno-associated virus (AAV) are commonly used in gene therapy but evidence revealing a potential oncogenic role of natural AAV in hepatocellular carcinoma (HCC) has raised concerns. The frequency of potentially oncogenic integrations has been reported in only a few populations. AAV infection and host genome integration in another type of liver cancer, cholangiocarcinoma (CCA), has been studied only in one cohort. All reported oncogenic AAV integrations in HCC come from strains resembling the fully sequenced AAV2 and partly sequenced AAV13. When AAV integration occurs, only a fragment of the AAV genome is detectable in later DNA or RNA sequencing. The integrated fragment is typically from the 3' end of the AAV genome, and this positional bias has been only partly explained. Three research groups searched for evidence of AAV integration in HCC RNAseq samples in the Cancer Genome Atlas (TCGA) but reported conflicting results.
RESULTS
We collected and analyzed whole transcriptome and viral capture DNA sequencing in paired tumor and non-tumor samples from two liver cancer Asian cohorts from Thailand (N = 147, 47 HCC and 100 intrahepatic cholangiocarcinoma (iCCA)) and Mongolia (N = 70, all HCC). We found only one HCC patient with a potentially oncogenic integration of AAV, in contrast to higher frequency reported in European patients. There were no oncogenic AAV integrations in iCCA patients. AAV genomic segments are present preferentially in the non-tumor samples of Thai patients. By analyzing the AAV genome positions of oncogenic and non-oncogenic integrated fragments, we found that almost all the putative oncogenic integrations overlap the X gene, which is present and functional only in the strain AAV2 among all fully sequenced strains. This gene content difference could explain why putative oncogenic integrations from other AAV strains have not been reported. We resolved the discrepancies in previous analyses of AAV presence in TCGA HCC samples and extended it to CCA. There are 12 TCGA samples with an AAV segment and none are in Asian patients. AAV segments are present in preferentially in TCGA non-tumor samples, like what we observed in the Thai patients.
CONCLUSIONS
Our findings suggest a minimal AAV risk of hepatocarcinogenesis in Asian liver cancer patients. The partial genome presence and positional bias of AAV integrations into the human genome has complicated analysis of possible roles of AAV in liver cancer.
Topics: Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Carcinogenesis; Carcinoma, Hepatocellular; Dependovirus; Hepatitis B virus; Humans; Liver Neoplasms; Thailand; Virus Integration
PubMed: 34763675
DOI: 10.1186/s12864-021-08098-9 -
BMC Medical Genomics Jun 2022Hepatitis B virus (HBV) related hepatocellular carcinoma (HCC) is heterogeneous and frequently contains multifocal tumors, but how the multifocal tumors relate to each...
BACKGROUND
Hepatitis B virus (HBV) related hepatocellular carcinoma (HCC) is heterogeneous and frequently contains multifocal tumors, but how the multifocal tumors relate to each other in terms of HBV integration and other genomic patterns is not clear.
METHODS
To interrogate heterogeneity of HBV-HCC, we developed a HBV genome enriched single cell sequencing (HGE-scSeq) procedure and a computational method to identify HBV integration sites and infer DNA copy number variations (CNVs).
RESULTS
We performed HGE-scSeq on 269 cells from four tumor sites and two tumor thrombi of a HBV-HCC patient. HBV integrations were identified in 142 out of 269 (53%) cells sequenced, and were enriched in two HBV integration hotspots chr1:34,397,059 (CSMD2) and chr8:118,557,327 (MED30/EXT1). There were also 162 rare integration sites. HBV integration sites were enriched in DNA fragile sites and sequences around HBV integration sites were enriched for microhomologous sequences between human and HBV genomes. CNVs were inferred for each individual cell and cells were grouped into four clonal groups based on their CNVs. Cells in different clonal groups had different degrees of HBV integration heterogeneity. All of 269 cells carried chromosome 1q amplification, a recurrent feature of HCC tumors, suggesting that 1q amplification occurred before HBV integration events in this case study. Further, we performed simulation studies to demonstrate that the sequential events (HBV infecting transformed cells) could result in the observed phenotype with biologically reasonable parameters.
CONCLUSION
Our HGE-scSeq data reveals high heterogeneity of HCC tumor cells in terms of both HBV integrations and CNVs. There were two HBV integration hotspots across cells, and cells from multiple tumor sites shared some HBV integration and CNV patterns.
Topics: Carcinoma, Hepatocellular; DNA Copy Number Variations; DNA, Viral; Hepatitis B virus; Humans; Liver Neoplasms; Virus Integration
PubMed: 35710421
DOI: 10.1186/s12920-022-01264-2