ABSTRACT
OBJECTIVES: To estimate the shape of the causal relationship between body mass index (BMI) and mortality risk in a Mendelian randomisation framework. DESIGN: Mendelian randomisation analyses of two prospective population-based cohorts. SETTING: Individuals of European ancestries living in Norway or the UK. PARTICIPANTS: 56 150 participants from the Trøndelag Health Study (HUNT) in Norway and 366 385 participants from UK Biobank recruited by postal invitation. OUTCOMES: All-cause mortality and cause-specific mortality (cardiovascular, cancer, non-cardiovascular non-cancer). RESULTS: A previously published non-linear Mendelian randomisation analysis of these data using the residual stratification method suggested a J-shaped association between genetically predicted BMI and mortality outcomes with the lowest mortality risk at a BMI of around 25 kg/m2. However, the 'constant genetic effect' assumption required by this method is violated. The reanalysis of these data using the more reliable doubly-ranked stratification method provided some indication of a J-shaped relationship, but with much less certainty as there was less precision in estimates at the lower end of the BMI distribution. Evidence for a harmful effect of reducing BMI at low BMI levels was only present in some analyses, and where present, only below 20 kg/m2. A harmful effect of increasing BMI for all-cause mortality was evident above 25 kg/m2, for cardiovascular mortality above 24 kg/m2, for cancer mortality above 30 kg/m2 and for non-cardiovascular non-cancer mortality above 26 kg/m2. In UK Biobank, the association between genetically predicted BMI and mortality at high BMI levels was stronger in women than in men. CONCLUSION: This research challenges findings from previous conventional observational epidemiology and Mendelian randomisation investigations that the lowest level of mortality risk is at a BMI level of around 25 kg/m2. Our results provide some evidence that reductions in BMI will increase mortality risk for a small proportion of the population, and clear evidence that increases in BMI will increase mortality risk for those with BMI above 25 kg/m2.
Subject(s)
Body Mass Index , Mendelian Randomization Analysis , Humans , United Kingdom/epidemiology , Female , Male , Middle Aged , Aged , Prospective Studies , Norway/epidemiology , Biological Specimen Banks , Neoplasms/mortality , Neoplasms/genetics , Cardiovascular Diseases/mortality , Cardiovascular Diseases/genetics , Adult , Cause of Death , Mortality , Risk Factors , UK BiobankABSTRACT
The initial objective of this study was to shed light on the evolution of small DNA tumor viruses by analyzing de novo assemblies of publicly available deep sequencing datasets. The survey generated a searchable database of contig snapshots representing more than 100,000 Sequence Read Archive records. Using modern structure-aware search tools, we iteratively broadened the search to include an increasingly wide range of other virus families. The analysis revealed a surprisingly diverse range of chimeras involving different virus groups. In some instances, genes resembling known DNA-replication modules or known virion protein operons were paired with unrecognizable sequences that structural predictions suggest may represent previously unknown replicases and novel virion architectures. Discrete clades of an emerging group called adintoviruses were discovered in datasets representing humans and other primates. As a proof of concept, we show that the contig database is also useful for discovering RNA viruses and candidate archaeal phages. The ancillary searches revealed additional examples of chimerization between different virus groups. The observations support a gene-centric taxonomic framework that should be useful for future virus-hunting efforts.
ABSTRACT
Here, we announce the complete genome of a previously undescribed papillomavirus from a betta fish, Betta splendens. The genome is 5,671 bp with a GC content of 38.2%. Variants were detected in public databases. This genome is most similar to papillomaviruses that infect sea bass (52.9 % nucleotide identity).
ABSTRACT
BACKGROUND: Major Trauma Code 1 (TC1) activations require significant resources to provide immediate treatment to potentially unstable, critically ill, patients. The Cribari Matrix Method (CMM) and Need For Trauma Intervention (NFTI) are two ways to determine over and undertriage in trauma. We studied the overtriage rate at a community level 1 trauma center using these two methods to determine the efficacy of the triage criteria in TC1 activations. METHOD: A retrospective review of all patients in the trauma registry of a level 1 American College of Surgeons trauma program from May to October 2021 was performed. Overtriage rates were determined using CMM and NFTI criteria. RESULTS: The overtriage rate of 552 activations using CMM alone was 73%. CMM combined with NFTI resulted in a 56% overtriage rate. CONCLUSION: The Cribari method can be used to determine the effectiveness of a system's trauma code 1 criteria but cannot delineate which criteria should be reviewed.
Subject(s)
Trauma Centers , Wounds and Injuries , Humans , Triage/methods , Retrospective Studies , Registries , Wounds and Injuries/diagnosis , Wounds and Injuries/therapy , Injury Severity ScoreABSTRACT
Several human polyomaviruses (HPyVs) have been described in the last 15 years. This work aimed to characterize a novel HPyV with cutaneous tropism. Swabs of healthy skin (forehead) of 75 immunocompetent individuals from Argentina were screened for HPyV through sequence amplification techniques. Publicly available metagenomic data sets were also analyzed. A previously unknown polyomavirus sequence was detected in two skin swab samples. A nearly identical sequence was detected in public data sets representing metagenomic surveys of human skin and feces. Further analyses showed that the new polyomavirus diverges from its nearest relative, human polyomavirus 6 (HPyV6), by 17.3%-17.7% (in nucleotides for the large T antigen), which meets criteria for a new species designation in the genus Deltapolyomavirus. The screening also revealed more distant HPyV6 relatives in macaque genital and chimpanzee fecal data sets. Since polyomaviruses are generally thought to cospeciate with mammalian hosts, the high degree of similarity to HPyV6 suggests the new polyomavirus species is human-tropic. Therefore, a novel polyomavirus was identified and characterized from samples of distinct populations and tissues. We suggest the common name human polyomavirus 16 (HPyV16).
Subject(s)
Polyomavirus Infections , Polyomavirus , Humans , Argentina , Polyomavirus/genetics , SkinABSTRACT
BACKGROUNDWarts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome is a primary immunodeficiency disorder caused by heterozygous gain-of-function CXCR4 mutations. Myelokathexis is a kind of neutropenia caused by neutrophil retention in bone marrow and in WHIM syndrome is associated with lymphopenia and monocytopenia. The CXCR4 antagonist plerixafor mobilizes leukocytes to the blood; however, its safety and efficacy in WHIM syndrome are undefined.METHODSIn this investigator-initiated, single-center, quadruple-masked phase III crossover trial, we compared the total infection severity score (TISS) as the primary endpoint in an intent-to-treat manner in 19 patients with WHIM who each received 12 months treatment with plerixafor and 12 months treatment with granulocyte CSF (G-CSF, the standard of care for severe congenital neutropenia). The treatment order was randomized for each patient.RESULTSPlerixafor was nonsuperior to G-CSF for TISS (P = 0.54). In exploratory endpoints, plerixafor was noninferior to G-CSF for maintaining neutrophil counts of more than 500 cells/µL (P = 0.023) and was superior to G-CSF for maintaining lymphocyte counts above 1,000 cells/µL (P < 0.0001). Complete regression of a subset of large wart areas occurred on plerixafor in 5 of 7 patients with major wart burdens at baseline. Transient rash occurred on plerixafor, and bone pain was more common on G-CSF. There were no significant differences in drug preference or quality of life or the incidence of drug failure or serious adverse events.CONCLUSIONPlerixafor was not superior to G-CSF in patients with WHIM for TISS, the primary endpoint. Together with wart regression and hematologic improvement, the infection severity results support continued study of plerixafor as a potential treatment for WHIM syndrome.TRIAL REGISTRATIONClinicaltrials.gov NCT02231879.FUNDINGThis study was funded by the Division of Intramural Research, National Institute of Allergy and Infectious Diseases.
Subject(s)
Heterocyclic Compounds , Immunologic Deficiency Syndromes , Primary Immunodeficiency Diseases , Warts , Humans , Immunologic Deficiency Syndromes/drug therapy , Immunologic Deficiency Syndromes/genetics , Granulocyte Colony-Stimulating Factor/therapeutic use , Hematopoietic Stem Cell Mobilization/adverse effects , Cross-Over Studies , Quality of Life , Heterocyclic Compounds/adverse effects , Primary Immunodeficiency Diseases/drug therapy , Primary Immunodeficiency Diseases/genetics , Warts/drug therapy , Warts/genetics , Receptors, CXCR4/geneticsABSTRACT
FGFR3 and PIK3CA are among the most frequently mutated genes in bladder tumors. We hypothesized that recurrent mutations in these genes might be caused by common carcinogenic exposures such as smoking and other factors. We analyzed 2,816 bladder tumors with available data on FGFR3 and/or PIK3CA mutations, focusing on the most recurrent mutations detected in ≥10% of tumors. Compared to tumors with other FGFR3/PIK3CA mutations, FGFR3-Y375C was more common in tumors from smokers than never-smokers (P = 0.009), while several APOBEC-type driver mutations were enriched in never-smokers: FGFR3-S249C (P = 0.013) and PIK3CA-E542K/PIK3CA-E545K (P = 0.009). To explore possible causes of these APOBEC-type mutations, we analyzed RNA sequencing (RNA-seq) data from 798 bladder tumors and detected several viruses, with BK polyomavirus (BKPyV) being the most common. We then performed IHC staining for polyomavirus (PyV) Large T-antigen (LTAg) in an independent set of 211 bladder tumors. Overall, by RNA-seq or IHC-LTAg, we detected PyV in 26 out of 1,010 bladder tumors with significantly higher detection (P = 4.4 × 10-5), 25 of 554 (4.5%) in non-muscle-invasive bladder cancers (NMIBC) versus 1 of 456 (0.2%) of muscle-invasive bladder cancers (MIBC). In the NMIBC subset, the FGFR3/PIK3CA APOBEC-type driver mutations were detected in 94.7% (18/19) of PyV-positive versus 68.3% (259/379) of PyV-negative tumors (P = 0.011). BKPyV tumor positivity in the NMIBC subset with FGFR3- or PIK3CA-mutated tumors was also associated with a higher risk of progression to MIBC (P = 0.019). In conclusion, our results support smoking and BKPyV infection as risk factors contributing to bladder tumorigenesis in the general patient population through distinct molecular mechanisms. PREVENTION RELEVANCE: Tobacco smoking likely causes one of the most common mutations in bladder tumors (FGFR3-Y375C), while viral infections might contribute to three others (FGFR3-S249C, PIK3CA-E542K, and PIK3CA-E545K). Understanding the causes of these mutations may lead to new prevention and treatment strategies, such as viral screening and vaccination.
Subject(s)
Urinary Bladder Neoplasms , Virus Diseases , Humans , Urinary Bladder Neoplasms/genetics , Urinary Bladder Neoplasms/pathology , Mutation , Urinary Bladder/pathology , Class I Phosphatidylinositol 3-Kinases/geneticsABSTRACT
The number of identified human polyomaviruses (HPyVs) has increased steadily over the last decade. Some of the novel HPyVs have been shown to cause disease in immunocompromised individuals. The Lyon-IARC polyomavirus (LIPyV) belonging to species Alphapolyomavirus quardecihominis was identified in 2017 in skin and saliva samples from healthy individuals. Since its initial discovery, LIPyV has rarely been detected in human clinical samples but has been detected in faeces from cats with diarrhoea. Serological studies show low LIPyV seroprevalence in human populations. To investigate the possibility that LIPyV is a feline rather than a human polyomavirus, we compared serum IgG responses against the VP1 major capsid protein of LIPyV and 13 other HPyVs among cats (n = 40), dogs (n = 38) and humans (n = 87) using an in-house immunoassay. Seropositivity among cats was very high (92.5%) compared to dogs (31.6%) and humans (2.3%). Furthermore, the median antibody titres against LIPyV were 100-10,000x higher in cats compared to dogs and humans. In conclusion, the high prevalence and intensity of measured seroresponses suggest LIPyV to be a feline rather than a human polyomavirus. Whether LIPyV infection induces diarrhoea or other symptoms in cats remains to be established.
Subject(s)
Polyomavirus Infections , Polyomavirus , Humans , Cats , Animals , Dogs , Seroepidemiologic Studies , Polyomavirus Infections/diagnosis , Skin , ImmunoassayABSTRACT
Recent lines of evidence suggest the intriguing hypothesis that consuming common culinary herbs of the mint family might help prevent or treat Covid. Individual citizens could easily explore the hypothesis using ordinary kitchen materials. I offer a philosophical framework to account for the puzzling lack of public health messaging about this interesting idea.
ABSTRACT
A small percentage of bladder cancers in the general population have been found to harbor DNA viruses. In contrast, up to 25% of tumors of solid organ transplant recipients, who are at an increased risk of developing bladder cancer and have an overall poorer outcomes, harbor BK polyomavirus (BKPyV). To better understand the biology of the tumors and the mechanisms of carcinogenesis from potential oncoviruses, we performed whole genome and transcriptome sequencing on bladder cancer specimens from 43 transplant patients. Nearly half of the tumors from this patient population contained viral sequences. The most common were from BKPyV (N=9, 21%), JC polyomavirus (N=7, 16%), carcinogenic human papillomaviruses (N=3, 7%), and torque teno viruses (N=5, 12%). Immunohistochemistry revealed variable Large T antigen expression in BKPyV-positive tumors ranging from 100% positive staining of tumor tissue to less than 1%. In most cases of BKPyV-positive tumors, the viral genome appeared to be clonally integrated into the host chromosome consistent with microhomology-mediated end joining and coincided with focal amplifications of the tumor genome similar to other virus-mediated cancers. Significant changes in host gene expression consistent with the functions of BKPyV Large T antigen were also observed in these tumors. Lastly, we identified four mutation signatures in our cases, with those attributable to APOBEC3 and SBS5 being the most abundant. Mutation signatures associated with an antiviral drug, ganciclovir, and aristolochic acid, a nephrotoxic compound found in some herbal medicines, were also observed. The results suggest multiple pathways to carcinogenesis in solid organ transplant recipients with a large fraction being virus-associated.
Subject(s)
BK Virus , Organ Transplantation , Polyomavirus Infections , Urinary Bladder Neoplasms , Humans , Polyomavirus Infections/complications , Polyomavirus Infections/epidemiology , BK Virus/genetics , Carcinogenesis , Urinary Bladder Neoplasms/genetics , Antigens, Viral, Tumor , Organ Transplantation/adverse effectsABSTRACT
In 2019, there were about 100,000 kidney transplants globally, with more than a quarter of them performed in the United States. Unfortunately, some engrafted organs are lost to polyomavirus-associated nephropathy (PyVAN) caused by BK and JC viruses (BKPyV and JCPyV). Both viruses cause brain disease and possibly bladder cancer in immunosuppressed individuals. Transplant patients are routinely monitored for BKPyV viremia, which is an accepted hallmark of nascent nephropathy. If viremia is detected, a reduction in immunosuppressive therapy is standard care, but the intervention comes with increased risk of immune rejection of the engrafted organ. Recent reports have suggested that transplant recipients with high levels of polyomavirus-neutralizing antibodies are protected against PyVAN. Virus-like particle (VLP) vaccines, similar to approved human papillomavirus vaccines, have an excellent safety record and are known to induce high levels of neutralizing antibodies and long-lasting protection from infection. In this study, we demonstrate that VLPs representing BKPyV genotypes I, II, and IV, as well as JCPyV genotype 2 produced in insect cells elicit robust antibody titers. In rhesus macaques, all monkeys developed neutralizing antibody titers above a previously proposed protective threshold of 10,000. A second inoculation, administered 19 weeks after priming, boosted titers to a plateau of ≥ 25,000 that was maintained for almost two years. No vaccine-related adverse events were observed in any macaques. A multivalent BK/JC VLP immunogen did not show inferiority compared to the single-genotype VLP immunogens. Considering these encouraging results, we believe a clinical trial administering the multivalent VLP vaccine in patients waiting to receive a kidney transplant is warranted to evaluate its ability to reduce or eliminate PyVAN.
Subject(s)
BK Virus , Kidney Diseases , Polyomavirus Infections , Polyomavirus , Tumor Virus Infections , Vaccines, Virus-Like Particle , Animals , Humans , Macaca mulatta , Viremia/prevention & control , Antibodies, NeutralizingABSTRACT
Polyomaviruses are oncogenic viruses that are generally thought to have co-evolved with their hosts. While primate and rodent polyomaviruses are increasingly well-studied, less is known about polyomaviruses that infect other mammals. In an effort to gain insight into polyomaviruses associated with carnivores, we surveyed fecal samples collected in the USA from bobcats (Lynx rufus), pumas (Puma concolor), Canada lynxes (Lynx canadensis), and grizzly bears (Ursus arctos). Using a viral metagenomic approach, we identified six novel polyomavirus genomes. Surprisingly, four of the six genomes showed a phylogenetic relationship to polyomaviruses found in prey animals. These included a putative rabbit polyomavirus from a bobcat fecal sample and two possible deer-trophic polyomaviruses from Canada lynx feces. One polyomavirus found in a grizzly bear sample was found to be phylogenetically distant from previously identified polyomaviruses. Further analysis of the grizzly bear fecal sample showed that it contained anelloviruses that are known to infect pigs, suggesting that the bear might have preyed on a wild or domestic pig. Interestingly, a polyomavirus genome identified in a puma fecal sample was found to be closely related both to raccoon polyomavirus 1 and to Lyon-IARC polyomavirus, the latter of which was originally identified in human saliva and skin swab specimens but has since been found in samples from domestic cats (Felis catus).
Subject(s)
Deer , Lynx , Polyomavirus , Puma , Ursidae , Rabbits , Animals , Cats , Humans , Swine , Polyomavirus/genetics , Phylogeny , FecesABSTRACT
Fish papillomaviruses form a newly discovered group broadly recognized as the Secondpapillomavirinae subfamily. This study expands the documented genomes of the fish papillomaviruses from six to 16, including one from the Antarctic emerald notothen, seven from commercial market fishes, one from data mining of sea bream sequence data, and one from a western gull cloacal swab that is likely diet derived. The genomes of secondpapillomaviruses are â¼6 kilobasepairs (kb), which is substantially smaller than the â¼8 kb of terrestrial vertebrate papillomaviruses. Each genome encodes a clear homolog of the four canonical papillomavirus genes, E1, E2, L1, and L2. In addition, we identified open reading frames (ORFs) with short linear peptide motifs reminiscent of E6/E7 oncoproteins. Fish papillomaviruses are extremely diverse and phylogenetically distant from other papillomaviruses suggesting a model in which terrestrial vertebrate-infecting papillomaviruses arose after an evolutionary bottleneck event, possibly during the water-to-land transition.
Subject(s)
Fishes/virology , Papillomaviridae/classification , Animals , Antarctic Regions , Biological Evolution , Charadriiformes/virology , DNA, Viral , Genome, Viral , High-Throughput Nucleotide Sequencing , Open Reading Frames , Papillomaviridae/genetics , Papillomavirus E7 Proteins/genetics , Papillomavirus Infections/virology , Phylogeny , Sequence Analysis, DNAABSTRACT
Polintons (also known as Mavericks) were initially identified as a widespread class of eukaryotic transposons named for their hallmark type B DNA polymerase and retrovirus-like integrase genes. It has since been recognized that many polintons encode possible capsid proteins and viral genome-packaging ATPases similar to those of a diverse range of double-stranded DNA viruses. This supports the inference that at least some polintons are actually viruses capable of cell-to-cell spread. At present, there are no polinton-associated capsid protein genes annotated in public sequence databases. To rectify this deficiency, we used a data-mining approach to investigate the distribution and gene content of polinton-like elements and related DNA viruses in animal genomic and metagenomic sequence datasets. The results define a discrete family-like clade of viruses with two genus-level divisions. We propose the family name Adintoviridae, connoting similarities to adenovirus virion proteins and the presence of a retrovirus-like integrase gene. Although adintovirus-class PolB sequences were detected in datasets for fungi and various unicellular eukaryotes, sequences resembling adintovirus virion proteins and accessory genes appear to be restricted to animals. Degraded adintovirus sequences are endogenized into the germlines of a wide range of animals, including humans.
ABSTRACT
Human papillomavirus (HPV) infections underlie a wide spectrum of both benign and malignant epithelial diseases. In this report, we describe the case of a young man who had encephalitis caused by herpes simplex virus during adolescence and currently presented with multiple recurrent skin and mucosal lesions caused by HPV. The patient was found to have a pathogenic germline mutation in the X-linked interleukin-2 receptor subunit gamma gene (IL2RG), which was somatically reverted in T cells but not in natural killer (NK) cells. Allogeneic hematopoietic-cell transplantation led to restoration of NK cytotoxicity, with normalization of the skin microbiome and persistent remission of all HPV-related diseases. NK cytotoxicity appears to play a role in containing HPV colonization and the ensuing HPV-related hyperplastic or dysplastic lesions. (Funded by the National Institutes of Health and the Herbert Irving Comprehensive Cancer Center Flow Cytometry Shared Resources.).
Subject(s)
Germ-Line Mutation , Hematopoietic Stem Cell Transplantation , Killer Cells, Natural/physiology , Papillomavirus Infections/therapy , Cytotoxicity, Immunologic , Encephalitis/virology , Female , Humans , Killer Cells, Natural/drug effects , Male , Microbiota/drug effects , Natural Killer T-Cells/physiology , Papillomaviridae , Papillomavirus Infections/genetics , Papillomavirus Infections/immunology , Pedigree , Skin/microbiology , Transplantation, Homologous , Young AdultABSTRACT
Polyomaviruses are non-enveloped viruses with circular double-stranded DNA genomes (~4-7 kb). Initially identified in mammals, polyomaviruses have now been identified in birds and a few fish species. Although fragmentary polyomavirus-like sequences have been detected as apparent 'hitchhikers' in shotgun genomics datasets of various arthropods, the possible diversity of these viruses in invertebrates remains unclear. Scorpions are predatory arachnids that are among the oldest terrestrial animals. Using high-throughput sequencing and traditional molecular techniques we determine the genome sequences of eight novel polyomaviruses in scorpions (Centruroides sculpturatus) from the greater Phoenix area, Arizona, USA. Analysis of Centruroides transcriptomic datasets elucidated the splicing of the viral late gene array, which is more complex than that of vertebrate polyomaviruses. Phylogenetic analysis provides further evidence of co-divergence of polyomaviruses with their hosts, suggesting that at least one ancestral species of polyomaviruses was circulating amongst the primitive common ancestors of arthropods and chordates.
Subject(s)
Phylogeny , Polyomavirus/genetics , Scorpions/virology , Animals , Genome, Viral , Polyomavirus/classification , Recombination, GeneticABSTRACT
Despite remarkable strides in microbiome research, the viral component of the microbiome has generally presented a more challenging target than the bacteriome. This gap persists, even though many thousands of shotgun sequencing runs from human metagenomic samples exist in public databases, and all of them encompass large amounts of viral sequence data. The lack of a comprehensive database for human-associated viruses has historically stymied efforts to interrogate the impact of the virome on human health. This study probes thousands of datasets to uncover sequences from over 45,000 unique virus taxa, with historically high per-genome completeness. Large publicly available case-control studies are reanalyzed, and over 2,200 strong virus-disease associations are found.
Subject(s)
Chronic Disease , Metagenome , Viruses/genetics , Adolescent , Adult , CRISPR-Cas Systems , Case-Control Studies , Clustered Regularly Interspaced Short Palindromic Repeats , DNA Viruses/genetics , Data Management , Genome, Viral , Genomics , Humans , Metagenomics , Microbiota , Parkinson Disease , Virome , Young AdultABSTRACT
Circular RNAs (circRNAs) are a conserved class of RNAs with diverse functions, including serving as messenger RNAs that are translated into peptides. Here we describe circular RNAs generated by human polyomaviruses (HPyVs), some of which encode variants of the previously described alternative large T antigen open reading frame (ALTO) protein. Circular ALTO RNAs (circALTOs) can be detected in virus positive Merkel cell carcinoma (VP-MCC) cell lines and tumor samples. CircALTOs are stable, predominantly located in the cytoplasm, and N6-methyladenosine (m6A) modified. The translation of MCPyV circALTOs into ALTO protein is negatively regulated by MCPyV-generated miRNAs in cultured cells. MCPyV ALTO expression increases transcription from some recombinant promoters in vitro and upregulates the expression of multiple genes previously implicated in MCPyV pathogenesis. MCPyV circALTOs are enriched in exosomes derived from VP-MCC lines and circALTO-transfected 293T cells, and purified exosomes can mediate ALTO expression and transcriptional activation in MCPyV-negative cells. The related trichodysplasia spinulosa polyomavirus (TSPyV) also expresses a circALTO that can be detected in infected tissues and produces ALTO protein in cultured cells. Thus, human polyomavirus circRNAs are expressed in human tumors and infected tissues and express proteins that have the potential to modulate the infectious and tumorigenic properties of these viruses.
Subject(s)
Antigens, Viral, Tumor/genetics , Carcinoma, Merkel Cell/virology , Merkel cell polyomavirus/genetics , Polyomavirus Infections/virology , RNA, Circular/genetics , Tumor Virus Infections/virology , Exosomes , Gene Expression Regulation, Viral , HEK293 Cells , Humans , MicroRNAs/genetics , RNA, Messenger/genetics , RNA, Viral/geneticsABSTRACT
An unusual feature of papillomaviruses is that their genomes are packaged into virions along with host histones. Viral minichromosomes were visualized as "beads on a string" by electron microscopy in the 1970s but, to date, little is known about the posttranslational modifications of these histones. To investigate this, we analyzed the histone modifications in HPV16/18 quasivirions, wart-derived bovine papillomavirus (BPV1), and wart-derived human papillomavirus type 1 (HPV1) using quantitative mass spectrometry. The chromatin from all three virion samples had abundant posttranslational modifications (acetylation, methylation, and phosphorylation). These histone modifications were verified by acid urea polyacrylamide electrophoresis and immunoblot analysis. Compared to matched host cell controls, the virion minichromosome was enriched in histone modifications associated with active chromatin and depleted for those commonly found in repressed chromatin. We propose that the viral minichromosome acquires specific histone modifications late in infection that are coupled to the mechanisms of viral replication, late gene expression, and encapsidation. We predict that, in turn, these same modifications benefit early stages of infection by helping to evade detection, promoting localization of the viral chromosome to beneficial regions of the nucleus, and promoting early transcription and replication.IMPORTANCE A relatively unique feature of papillomaviruses is that the viral genome is associated with host histones inside the virion. However, little is known about the nature of the epigenome within papillomavirions or its biological relevance to the infectious viral cycle. Here, we define the epigenetic signature of the H3 and H4 histones from HPV16 virions generated in cell culture and native human papillomavirus type 1 (HPV1) and bovine papillomavirus 1 (BPV1) virions isolated from bovine and human wart tissue. We show that native virions are enriched in posttranslational modifications associated with active chromatin and depleted with those associated with repressed chromatin compared to cellular chromatin. Native virions were also enriched in the histone variant H3.3 compared to the canonical histone H3.1. We propose that the composition of virion-packaged chromatin reflects the late stages of the viral life cycle and promotes the early stages of infection by being primed for viral transcription.
Subject(s)
Chromosomes/metabolism , Histone Code , Histones/metabolism , Papillomaviridae/genetics , Papillomaviridae/metabolism , Virion/genetics , Virion/metabolism , Animals , Cattle , Chromosomes/genetics , HEK293 Cells , Human papillomavirus 16/genetics , Human papillomavirus 16/metabolism , Human papillomavirus 18/genetics , Human papillomavirus 18/metabolism , Humans , Keratinocytes/virology , Methylation , Protein Processing, Post-Translational , Virus ReplicationABSTRACT
Viruses, despite their great abundance and significance in biological systems, remain largely mysterious. Indeed, the vast majority of the perhaps hundreds of millions of viral species on the planet remain undiscovered. Additionally, many viruses deposited in central databases like GenBank and RefSeq are littered with genes annotated as 'hypothetical protein' or the equivalent. Cenote-Taker 2, a virus discovery and annotation tool available on command line and with a graphical user interface with free high-performance computation access, utilizes highly sensitive models of hallmark virus genes to discover familiar or divergent viral sequences from user-input contigs. Additionally, Cenote-Taker 2 uses a flexible set of modules to automatically annotate the sequence features of contigs, providing more gene information than comparable tools. The outputs include readable and interactive genome maps, virome summary tables, and files that can be directly submitted to GenBank. We expect Cenote-Taker 2 to facilitate virus discovery, annotation, and expansion of the known virome.