Journal of General Virology最新文献

Recent studies have reported a genotype 4 (G4) reassortant Eurasian avian-like (EA) H1N1 virus in swine, demonstrating a potential pandemic threat in humans. Here, we have compared the tropism, replication competence and pro-inflammatory cytokine and chemokine induction of the two G4 EA H1N1 strains in parallel with 2009 pandemic H1N1 (H1N1/pdm/09) and A/Quail/HK/G1/1997 H9N2 (G1) using ex vivo culture of the human respiratory tract and in vitro culture of human peripheral blood-derived macrophages. Our results showed that G4 strains could replicate in ex vivo cultures of human lung and bronchus with a similar replication competence to H1N1/pdm/09. The cytokine induction levels of G4 were similar to H1N1/pdm/09 in macrophages. Taken together, we could extrapolate that the G4 EA H1N1 swine influenza may pose a notable public health threat towards human and should not underestimate this threat.

The Fungal and Protist Viruses Subcommittee (SC) of the International Committee on Taxonomy of Viruses (ICTV) has received a total of eight taxonomic proposals for the 2024 annual cycle. The extent of proposed changes varied, including nomenclatural updates, creation of new taxa and reorganization of established taxa. Following the ICTV procedures, all proposals were reviewed and voted upon by the members of the Executive Committee with ratification in March 2025. As a result, a total of 52 species in the families Botourmiaviridae and Marnaviridae were renamed to comply with the mandated binomial format. A new genus has been added to the dsRNA virus family Amalgaviridae, while two new families, Splipalmiviridae (Wolframvirales) and Mycoalphaviridae (Hepelivirales), were created to classify new groups of positive-sense (+) RNA mycoviruses. The class Arfiviricetes (Cressdnaviricota) was expanded by a new order Lineavirales and a new family Oomyviridae of ssDNA viruses. Additionally, a new class Orpoviricetes was created in the kingdom Orthornavirae to classify a group of bisegmented (+)RNA viruses reported from fungi and oomycetes. Finally, the order Pimascovirales was reorganized to better depict evolutionary relationships of pithoviruses and related viruses with large dsDNA genomes. The summary of updates in the taxonomy of fungal and protist viruses presented here is limited to taxa within the remit of this Subcommittee. For information on taxonomy changes on other fungal viruses closely related to animal and/or plant viruses, please see reports from sister ICTV Subcommittees (i.e. Plant Virus SC and Animal dsRNA and ssRNA(-) Viruses SC).

As intracellular parasites, viruses must hijack and often rewire organelles, signalling pathways and the bioenergetics machinery of the infected cell to replicate their genome, produce viral proteins and assemble new viral particles. Mitochondria are key eukaryotic organelles often referred to as the cell's powerhouse. They control many fundamental cellular processes, from metabolism and energy production to calcium homeostasis and programmed cell death. Importantly, mitochondrial membranes are also critical sites for the integration and amplification of antiviral innate immune responses. Overall, mitochondria are therefore both supporting the virus life cycle by sustaining energy production, metabolism and synthesis of macromolecules and part of the cell's first line of defence against viruses. This review summarizes recent findings on viral manipulations of mitochondria and their functions. We explore the evolving understanding of how mitochondrial dynamics is targeted to regulate innate immunity, evasion strategies used to avoid mitochondrial-associated mechanisms that impair replication and the role of mitochondrial functions such as generating reactive oxygen species or regulating the electron transport chain during infection. Overall, we provide a comprehensive view of how viruses modulate mitochondrial function to promote replication.

During the 56th annual meeting of the International Committee on Taxonomy of Viruses (ICTV), held in Bari, Italy, in August 2024, two technical proposals were presented. The first called for amended versions of accepted taxonomic proposals to be named in such a way to ensure that they are readily accessible on the ICTV website (2024.001G). The second proposed a substantial reformatting of the ICTV statutes and codes to produce a more unified text after the numerous changes made to both documents in previous years (2024.002G). Finally, the ICTV Executive Committee (EC) nominated Professor Stuart Siddell as a Life Member of the ICTV for his work over four decades on virus taxonomy, including 16 years as a member of the EC (2024.003G).

Human cytomegalovirus (HCMV) genetic manipulation traditionally relies on bacterial artificial chromosome (BAC) recombineering, necessitated by its large ~236 kb genome. This approach is limited by the scarcity of HCMV strains engineered into BACs and often requires the deletion of 'non-essential' genes to accommodate the BAC cassette. We developed a novel approach using temperature-sensitive Sendai virus (SeV) vectors to deliver CRISPR/Cas9 for targeted HCMV genome editing without these constraints. This system achieves high editing efficiency (80-90%) in fibroblasts, epithelial cells and endothelial cells without BAC intermediates. As proof of principle, we targeted the HCMV (TB40/E strain) pentamer complex (PC) genes UL128 and UL130, crucial for viral entry into non-fibroblast cells. Edited viruses showed significantly reduced infectivity in epithelial cells, confirming functional disruption of the PC. Plaque purification yielded isogenic clones with phenotypes comparable to AD169, a naturally PC-deficient strain. Furthermore, multiplexed editing created precise 663 bp deletions in over 60% of viral genomes. Importantly, this method enables HCMV editing in physiologically relevant cell types without fibroblast passaging, which typically introduces mutations. This SeV-Cas9 system represents a significant advancement for studying HCMV biology in diverse cell types.

The International Committee on Taxonomy of Viruses (ICTV) holds a ratification vote annually following the review of newly proposed taxa by ICTV Study Groups and members of the virology community. This article reports changes to the taxonomy of viruses infecting archaea that were approved and ratified by the ICTV in March 2025. Six new families of head-tailed viruses expanded the order Caudoviricetes (realm Duplodnaviria); one new family of filamentous viruses was added to the order Ligamenvirales (realm Adnaviria); one new family of viruses with pleomorphic virions was included within a new phylum, new order and new class in the kingdom Trapavirae (realm Monodnaviria); finally, three new families were created for spindle-shaped viruses that remain unassigned to higher level taxa. The 25 new species represent viruses infecting a broad range of archaea, including members of the classes Archaeoglobi, Bathyarchaeia, Methanobacteria, Methanomicrobia, Nitrososphaeria and Poseidoniia. Most of these viruses have been discovered by metagenomics in samples derived from diverse environments, including ambient and extreme marine ecosystems, the gastrointestinal tract of humans and animals, anaerobic digesters and terrestrial hot springs. Following this taxonomic update, archaeal viruses are officially classified into a total of 163 virus species in 94 genera within 62 families.

RNA viruses are ubiquitous in the environment and are important pathogens of humans, animals and plants. In 2024, the International Committee on Taxonomy of Viruses Animal dsRNA and ssRNA(-) Viruses Subcommittee submitted 18 taxonomic proposals for consideration. These proposals expanded the known virosphere by classifying 9 new genera and 88 species for newly detected virus genomes. Of note, newly established species expand the large family of Rhabdoviridae to 580 species. A new species in the family Arenaviridae includes a virus detected in Antarctic fish with a unique split nucleoprotein ORF. Additionally, four new species were established for historically isolated viruses with previously unsequenced genomes. Furthermore, three species were abolished due to incomplete genome sequence information, and one family was moved from being unassigned in the phylum Negarnaviricota into a subphylum and order. Herein, we summarize the 18 ratified taxonomic proposals and the general features of the current taxonomy, thereby supporting public and animal health responses.

The International Committee on Taxonomy of Viruses (ICTV) holds a ratification vote annually after review of newly proposed taxa by ICTV Study Groups and members of the virology community. In March 2025, the vote outcome of the 11 proposals within the mandate of the Animal DNA Viruses and Retroviruses Subcommittee was made public. Here, we provide a summary of the newly accepted proposals. These include reorganization of taxa in the realm Varidnaviria, classification of the 'polinton-like' viruses into a new family (Phypoliviridae) within a new order Archintovirales; establishment of a new phylum (Commensaviricota) in the kingdom Shotokuvirae; the establishment of a new family called Filamentoviridae with two new genera and three new species; the addition of four new genera in the family Anelloviridae with 70 new species; and the addition of 85 new species in the families Adenoviridae (n=16), Baculoviridae (n=5), Circoviridae (n=5), Parvoviridae (n=55) and Polyomaviridae (n=4). Also, in the family Belpaoviridae, 11 species were renamed to comply with the binomial requirement for species names.

Coronaviruses are abundant and diverse RNA viruses with broad vertebrate host ranges. These viruses include agents of human seasonal respiratory illness, such as human coronaviruses OC43 and HKU1; important pathogens of livestock and domestic animals such as swine acute diarrhoea syndrome coronavirus and feline coronavirus; and human pathogens of epidemic potential such as SARS-CoV, MERS-CoV and SARS-CoV-2. Most coronavirus surveillance has been conducted in bat species. However, small terrestrial mammals such as rodents and eulipotyphlans are important hosts of coronaviruses as well. Although fewer studies of rodent and eulipotyphlan coronaviruses exist compared to those of bats, notable diversity of coronaviruses has been reported in the former. No literature synthesis for this area of research has been completed despite (a) growing evidence for a small mammal origin of certain human coronaviruses and (b) global abundance of small mammal species. In this review, we present an overview of the current state of coronavirus research in wild terrestrial small mammals. We conducted a literature search for studies that investigated coronaviruses infecting rodent and eulipotyphlan hosts, which returned 63 studies published up to and including 2024. We describe trends in coronavirus diversity and surveillance for these studies. To further the examination of the interrelatedness of these viruses, we conducted a phylogenetic analysis of coronavirus whole genomes recovered from rodent and eulipotyphlan hosts. We discuss important facets of terrestrial small mammal coronaviruses, including evolutionary aspects and zoonotic spillover risk. Lastly, we present important recommendations and considerations for further surveillance and viral characterization efforts in this field.

Orthotospovirus tomatomaculae [tomato spotted wilt virus (TSWV)] is a major pathogen in horticultural and row crops worldwide including the USA. In this study, tomato spotted wilt disease incidence was monitored in Arachis hypogaea (peanut; year 1990 to 2024) and Nicotiana tabacum (tobacco; year 2000 to 2024) in commercial farmers' fields in the Southeastern USA. Furthermore, nucleocapsid (N), nonstructural movement (NSm) and nonstructural silencing suppressor (NSs) protein gene sequences of TSWV global populations from North America, South America, Europe, Asia-Pacific, Africa and Australia were compared with local US population and analysed to understand the genetic variability in the virus genome. In our study, full-length sequences of 94 N, 111 NSm and 78 NSs genes were amplified from TSWV-infected A. hypogaea (peanut), Capsicum annuum (pepper), N. tabacum (tobacco) and Solanum lycopersicum (tomato). nt-based phylogenetic analysis of N, NSm and NSs genes correlated with the geographical location of the TSWV isolates, with notably higher substitution rates in the population of recent years. In addition, the least genetic variability was observed in the N gene of the local population upon comparison with other global TSWV population. The neutrality test of TSWV suggested a non-neutral evolution of the virus genome. Low variation among the selected genes might be attributed to strong purifying selection pressure in the populations. Furthermore, estimation of selection pressure (dN/dS) on small (S) segment-encoded N protein and nonstructural protein showed higher purifying selection than the movement protein encoded by the medium (M) segment of the TSWV isolates. Single-likelihood ancestor counting suggested an overall negative selection pressure on several codons of the selected genes, which indicated that natural selection and population bottleneck events might have influenced the evolution of TSWV. Our study also deciphered high gene flow and low genetic differentiation amid the different TSWV population sets. Additionally, BEAST analysis of TSWV N gene sequences from GA predicted the most common recent ancestor existed ~25 years ago. This data was further correlated with disease incidence data from peanut and tobacco crops obtained in the last three decades. These findings suggest the intermixing of TSWV isolates between peanut, pepper, tobacco and tomato crops, while the virus genome has undergone strong purifying selection.