Koenraad Van Doorslaer

Almost all cervical cancers are caused by human papillomaviruses (HPVs). In most cases, HPV DNA is integrated into the human genome. We found that tumor-specific, HPV-human DNA junctions are detectable in serum cell-free DNA of a fraction of cervical cancer patients at the time of initial treatment and/or at 6 months following treatment. Retrospective analysis revealed these junctions were more frequently detectable in women in whom the cancer later recurred. We also found that cervical cancers caused by HPV types outside of phylogenetic clade α9 had a higher recurrence frequency than those caused by α9 types in both our study and The Cancer Genome Atlas cervical cancer database, despite the higher prevalence ofα9 types, including HPV16, in cervical cancer. Thus, HPV-human DNA junction detection in serum cell-free DNA and HPV type determination in tumor tissue may help predict recurrence risk. Screening serum cell-free DNA for junctions may also offer an unambiguous non-invasive means to monitor absence of recurrence following treatment.

The 56th meeting of the Executive Committee (EC) of the International Committee on Taxonomy of Viruses (ICTV) was held in Bari, Italy, in July/August, 2024, and 115 submitted taxonomy proposals were reviewed. A total of 112 were subsequently ratified by the ICTV membership. An additional 9 error correction proposals were also approved in August 2025. This article lists the taxonomy proposals that have now been incorporated into release 40 version v2 of the Master Species List ( https://ictv.global/msl ), the Virus Metadata Resource ( https://ictv.global/vmr ), and associated ICTV databases. In addition to the assignments of 1,563 new virus species, 243genera, 55 families, 11 orders, and 8 classes, there were substantial additions to higher taxonomic ranks. These include the creation of a new realm ( Singelaviria ), which is based on the recognition of a separate evolutionary origin for the hallmark capsid genes of members of the kingdom Helvetiavirae. These express capsid proteins forming a single jelly-roll fold that is structurally and evolutionarily distinct from those of members of the family Bamfordvirae , assigned to the realm Varidnaviria . Furthermore, the realm Varidnaviria underwent a major reorganization, including the addition of a new kingdom, Abadenavirae . Another notable change was the classification of the vertebrate-infecting single-stranded DNA anellovirids into a new phylum Commensaviricota (kingdom Shotokuvirae , realm Monodnaviria ). Archaeal viruses infecting the hyperthermophilic Archaeoglobi were assigned to a new phylum Calorviricota , in the kingdom Trapavirae (realm Monodnaviria ), whereas RNA viruses infecting hyperthermophilic bacteria were classified into a new phylum Artimaviricota (realm Riboviria ). In recognition of his extensive and valuable contributions to virus taxonomic developments in Study Groups and over the period of his EC membership, Stuart Siddell was honoured as a new life member of the ICTV. The ICTV has created a new strategy for disseminating information on taxonomy advances through annual open-access publication of citeable taxonomy proposal summaries from each ICTV Subcommittee. A collective total of 354 co-authors of the seven summaries were drawn from members of each Subcommittee, the EC, and a very large number of contributors from the wider virology community.

The cGAS/STING pathway is an important innate immune pathway that senses and responds to foreign DNA or damaged host DNA. cGAS recognizes DNA and generates the second messenger cGAMP which activates STING. STING then creates a platform for IRF3 to be phosphorylated before pIRF3 induces a type I interferon response resulting in transcription of anti-viral genes. We examined how HPV18 infection modulates cGAS/STING activation following DNA stimulation in primary human foreskin keratinocytes from three different donors. Following exogenous activation, HPV(+) cells produced higher levels of cGAMP compared to patient-matched HPV(-) cells yet phosphorylation of STING and IRF3 was reduced in the HPV(+) cells. The reduced STING and IRF3 activation corresponded with a selective dampening of type I interferon driven antiviral genes and pro-inflammatory cytokines in HPV(+) cells. Simultaneously, HPV(+) cells had a baseline increase in genes associated with epithelial proliferation and skin development, which remained elevated following cGAMP treatment. We demonstrate that both E6 and E7 are required and sufficient to drive increased cGAMP levels and attenuate STING activation. Our results characterize cGAS/STING pathway activation across time in HPV positive and negative cells and demonstrate that the HPV oncogenes cooperate to suppress early STING activation despite higher levels of cGAMP in these HPV(+) cells. These findings indicate that HPV modulates cGAS/STING signaling to blunt antiviral defenses without impacting other arms of the cGAS/STING pathway response. Importance: In this study, we used primary human keratinocytes from multiple donors to track cGAS/STING activity over time following stimulation. We found that although HPV(+) cells produced more cGAMP, these cells showed reduced early activation of STING and IRF3. Downstream of cGAS/STING, many antiviral genes were suppressed by HPV however, epithelial proliferation-related genes had an HPV-mediated increase in baseline expression which remained higher than uninfected cells following cGAMP stimulation. We identified the HPV oncogenes E6 and E7 work together to enhance cGAMP levels and suppress parts of the downstream STING signaling response. These findings reveal that HPV attenuates cGAS/STING signaling and downstream events, selectively suppressing antiviral genes without inhibiting other parts of the pathway. Our results provide new insights into how HPV modulates innate immune responses.

Most human papillomavirus (HPV)-associated cancers harbor viral DNA integrated into the human genome as extrachromosomal circles, intrachromosomal segments, or both. Distinguishing intrachromosomal from identical-sequence extrachromosomal DNA (ecDNA) by sequencing alone is challenging, and the architecture of large-scale HPV-human DNA structures remains incompletely understood. To address this, we applied complementary genomic tools, spanning single-nucleotide to megabase resolution, to the HPV16-positive oropharyngeal cancer-cell line UM-SCC-47. These revealed that an initial integration event formed a 23 kb extrachromosomal heterocatemer circle comprising 7.5 kb of HPV16 DNA and 16 kb of the human TP63 gene. Subsequent genomic rearrangements generated heterocatemer tandem arrays extending to 0.6 megabases, plus additional large-scale rearrangements involving the HPV- TP63 structures, as revealed by long-read DNA sequencing and optical genome mapping. Fluorescent in situ Hybridization (FISH) showed that the heterocatemers were intrachromosomally localized at chromosome 3 at the TP63 locus in 100% of the cells. Long-read RNA sequencing further showed that these intrachromosomal templates produced spliced, polyadenylated transcripts. A subset of cells also harbored HPV16 ecDNA derived from the intrachromosomal HPV- TP63 DNAs. These findings define previously unrecognized higher-order architecture of integrated HPV DNA and highlight the power of FISH for distinguishing intrachromosomal from extrachromosomal DNA structures. GRAPHICAL

Taxonomic classification of cellular organisms requires the publication of descriptions and proposed names of species and the deposition of specimens. Virus taxonomy is developed through a different system of annual submission of formal taxonomy proposals (TPs) that can be submitted by anyone but are typically prepared by a study group appointed by the International Committee on Taxonomy of Viruses (ICTV) and consisting of experts on a particular group of viruses. These are initially evaluated by an expert subcommittee and by the executive committee (EC) of the ICTV. EC-approved TPs are then submitted for evaluation and a ratification vote by the wider ICTV membership. Following ratification, the new taxonomy is annually updated in the Master Species List, associated databases and bioinformatic resources. The process is consistent, creates traceability in assignments and supports a fully evaluated, hierarchical classification and nomenclature of all taxonomic ranks from species to realms. The structure also facilitates large-scale and coordinated changes to virus taxonomy, such as the recent introduction of a binomial species nomenclature. TPs are available on the ICTV website after ratification, but they are not indexed in bibliographic databases and are not easily cited. Authors of TPs do not receive citation credit for adopted proposals, and their voluntary contributions are largely invisible in the published literature. For greater visibility of TPs and their authors, the ICTV will commence the annual publication of summaries of all TPs from each ICTV subcommittee. These summaries will provide a searchable compendium of all annual taxonomy changes and additions as well as direct links to the Master Species List and other ICTV bioinformatic resources. Their publication will provide due credit and citations for their authors, form the basis for disseminating taxonomy decisions and promote greater visibility and accessibility to taxonomy changes for the virology community.

Almost all cervical cancers are caused by human papillomaviruses (HPVs). In most cases, HPV DNA is integrated into the human genome. We found that tumor-specific, HPV-human DNA junctions are detectable in serum cell-free DNA of a fraction of cervical cancer patients at the time of initial treatment and/or at six months following treatment. Retrospective analysis revealed these junctions were more frequently detectable in women in whom the cancer later recurred. We also found that cervical cancers caused by HPV types outside of phylogenetic clade α9 had a higher recurrence frequency than those caused by α9 types in both our study and The Cancer Genome Atlas cervical cancer database, despite the higher prevalence of α9 types including HPV16 in cervical cancer. Thus, HPV-human DNA junction detection in serum cell-free DNA and HPV type determination in tumor tissue may help predict recurrence risk. Screening serum cell-free DNA for junctions may also offer an unambiguous, non-invasive means to monitor absence of recurrence following treatment.

Virus taxonomy, comprising classification and nomenclature, is regulated by the International Committee on Taxonomy of Viruses (ICTV). Taxon names are standardized to facilitate recognition and communication, with defined suffixes for each rank (e.g., the names of orders, families, and genera end in -virales , - viridae, and -virus , respectively). However, until recently, a standard format for species names was lacking. In 2021, following extensive discussion and community consultation, the ICTV decided to adopt a standardized binomial (Linnaean) format for virus species names, consisting of the genus name followed by a “freeform” species epithet. Previously assigned virus species names that were non-compliant with the binomial format have been fully updated. In contrast to taxon names regulated by the ICTV, the names of viruses, or “common” names, such as yellow fever virus or human immunodeficiency virus, are not under the remit of the ICTV and have not been changed.

Urban wildlife species have the potential to serve as links in disease transmission between wildlife, humans and domestic animals at the wildland–urban interface (WUI), contributing to both sustained cross‐species transmission of pathogens and the emergence of diseases in susceptible populations. However, the relative roles of host and environmental factors in shaping the composition of pathogen communities in urban wildlife is understudied. In this study, we integrated DNA and RNA virome data with host genomic and GPS datasets to investigate factors shaping virome composition in bobcats ( Lynx rufus ) at the WUI in the Tucson Mountains, Arizona, USA. Using a hybrid‐capture approach for 31 scats and 17 buccal swabs, we identified multiple viruses that could affect carnivore health at the WUI, including canine parvovirus, feline astrovirus, Felis catus papillomaviruses 2 and 3 and Lyon‐IARC polyomavirus. Models of virome composition and distribution of viral taxa indicated contributions of host genetic relatedness and factors relating to urbanisation (such as percentages of urban land cover, road and building densities and distances to roads). Genetic associations with virome compositions were particularly influenced by females. While females exhibit significant isolation by distance, partial Mantel tests revealed a significant correlation between beta diversity and host genetic distance in females only. To our knowledge, this study represents the first assessment of factors shaping virome composition in a wild felid. Our finding of known feline and canine pathogens in bobcats underscores the potential of the WUI to facilitate cross‐species transmission between wild and domestic animals.

This article reports changes to virus taxonomy and taxon nomenclature that were approved and ratified by the International Committee on Taxonomy of Viruses (ICTV) in April 2024. The entire ICTV membership was invited to vote on 203 taxonomic proposals that had been approved by the ICTV Executive Committee (EC) in July 2023 at the 55th EC meeting in Jena, Germany, or in the second EC vote in November 2023. All proposals were ratified by online vote. Taxonomic additions include one new phylum (Ambiviricota), one new class, nine new orders, three new suborders, 51 new families, 18 new subfamilies, 820 new genera, and 3547 new species (excluding taxa that have been abolished). Proposals to complete the process of species name replacement to the binomial (genus + species epithet) format were ratified. Currently, a total of 14,690 virus species have been established.

Only persistent HPV infections lead to the development of cancer. Thus, understanding the virus-host interplay that influences the establishment of viral infection has important implications for HPV biology and human cancers. The ability of papillomaviruses to establish in cells requires the strict temporal regulation of viral gene expression in sync with cellular differentiation. This control primarily happens at the level of RNA splicing and polyadenylation. However, the details of how this spatio-temporal regulation is achieved still need to be fully understood. Until recently, it has been challenging to study the early events of the HPV lifecycle following infection. We used a single-cell genomics approach to identify cellular factors involved in viral infection and establishment. We identify protein arginine N-methyltransferase 1 (PRMT1) as an important factor in viral infection of primary human cervical cells. PRMT1 is the main cellular enzyme responsible for asymmetric dimethylation of cellular proteins. PRMT1 is an enzyme responsible for catalyzing the methylation of arginine residues on various proteins, which influences processes such as RNA processing, transcriptional regulation, and signal transduction. In this study, we show that HPV18 infection leads to increased PRMT1 levels across the viral lifecycle. PRMT1 is critical for the establishment of a persistent infection in primary cells. Mechanistically, PRMT1 inhibition leads to a highly dysregulated viral splicing pattern. Specifically, reduced PRMT1 activity leads to intron retention and a change in the E6 and E7 expression ratio. In the absence of PRMT1, viral transcripts are destabilized and subject to degradation via the nonsense-mediated decay (NMD) pathway. These findings highlight PRMT1 as a critical regulator of the HPV18 lifecycle, particularly in RNA processing, and position it as a potential therapeutic target for persistent HPV18 infections.