Current opinion in virology最新文献

Picobirnaviruses are small double-stranded RNA viruses first discovered in 1988 in stool samples from patients with diarrhea. It has generally been assumed that picobirnaviruses infect animal hosts and that they are potential agents of diarrhea, but there is still no direct evidence demonstrating that picobirnaviruses infect animals. In the metagenomic era, virome studies have broadened our understanding of picobirnavirus genetic diversity and genome organization, expanded the types of animals in which they have been detected, and identified novel associations with human disease. Most importantly, from the wealth of new sequencing data and comparative genomic analyses, a provocative new hypothesis has emerged that picobirnaviruses may not infect animals, but rather that they may infect evolutionarily simpler denizens of the gastrointestinal tract: bacteria and/or fungi. Depending on whether the true hosts of picobirnaviruses are animals, fungi, or bacteria, the mechanisms by which they impact animal biology will vary dramatically.

Asymmetric structural elements are typically not readily visualized in icosahedral viruses that have other obvious symmetrical features and most asymmetry has gone unresolved for decades. Asymmetric features may be incorporated during assembly or maturation or develop during key steps in the infectious cycle of the virus. However, resolving asymmetric features requires abandoning capsid-wide symmetry averaging and relying on special applications during single-particle cryogenic electron microscopy (cryo-EM) analysis. Thanks to the advances in the cryo-EM field, we are learning more about asymmetry of viruses. Here we summarize some of what is currently known about asymmetric structural features using as examples members of the Togaviridae, Flaviviridae, Herpesviridae, Parvoviridae, and Papillomaviridae.

Ebola virus (EBOV) outbreaks can claim thousands of lives, cripple healthcare systems and local economies. Effective vaccines and treatments against EBOV are therefore needed to limit the impact of this deadly disease. In 2019, a hallmark clinical trial demonstrated the efficacy of monoclonal antibody (mAb) against EBOV. Despite, this recent success, survival of individuals with high viremia remains low. Effective immunotherapies against other Ebolavirus species are still under pre-clinical development. More importantly, the cost of immunotherapies is prohibitive to most individual and affected countries. Novel manufacturing and administration strategies of mAb protein or genetic information could substantially reduce the cost of immunotherapies; hence making them valuable tools against EBOV and other infectious agents.

Bats are the natural reservoir host for a number of zoonotic viruses, including Hendra and Nipah viruses of Henipavirus genus, which are highly pathogenic in humans and numerous other mammalian species. Despite being infected, bats present limited signs of disease but still retain the ability to transmit the infection to other susceptible hosts, presenting thus a permanent source of new viral outbreaks. Different mechanisms have evolved in fruit bats permitting them to efficiently control the Henipavirus infection. These mechanisms likely allow bats to establish an adequate equilibrium between viral tolerance and antiviral defense, enabling them thus to avoid both uncontrollable virus expansion as well as immunopathology linked to excessive antiviral responses.

The ease with which bacteria can evolve resistance to phages is a key consideration for development of phage therapy. Here, we review recent work on the different evolutionary and ecological approaches to mitigate the problem. The approaches are broadly categorised into two areas: Minimising evolved phage resistance; and Directing phage-resistance evolution towards therapeutically beneficial outcomes.

Viruses are diverse biological entities that influence all life. Even with limited genome sizes, viruses can manipulate, drive, steal from, and kill their hosts. The field of virus genomics, using sequencing data to understand viral capabilities, has seen significant innovations in recent years. However, with advancements in metagenomic sequencing and related technologies, the bottleneck to discovering and employing the virosphere has become the analysis of genomes rather than generation. With metagenomics rapidly expanding available data, vital components of virus genomes and features are being overlooked, with the issue compounded by lagging databases and bioinformatics methods. Despite the field moving in a positive direction, there are noteworthy points to keep in mind, from how software-based virus genome predictions are interpreted to what information is overlooked by current standards. In this review, we discuss conventions and ideologies that likely need to be revised while continuing forward in the study of virus genomics.

Influenza viruses cause occasional pandemics and annual epidemics, thus persist as a threat to human society. The high variability of viral envelope proteins resulting from antigenic shift and antigenic drift allows influenza viruses to escape human herd immunity. During the past decade, along with the breakthroughs of human monoclonal antibody technologies, many broad reactive monoclonal antibodies (mAbs) that neutralize diverse influenza subtypes have been isolated and characterized. The achievements in this field have provided potential candidates of anti-influenza therapeutics and shed light on the design of universal influenza vaccines. Here, we review the broad neutralizing antibodies (bnAbs) targeting the virus surface proteins, summarize their epitopes, broad spectrum and immunological mechanisms of action and discuss the design of universal influenza vaccines inspired by bnAbs.

A hallmark feature of lentiviruses, which separates them from other members of the retrovirus family, is their ability to infect non-dividing cells by traversing the nuclear pore complex. The viral determinant that mediates HIV-1 nuclear import is the viral capsid (CA) protein, which forms the conical core protecting the HIV-1 genome in a mature virion. Recently, a series of novel approaches developed to monitor post-fusion events in infection have challenged previous textbook models of the viral life cycle, which envisage reverse transcription and disassembly of the capsid core as events that complete in the cytoplasm. In this review, we summarize these recent findings and describe their implications on our understanding of the spatiotemporal staging of HIV-1 infection with a focus on the nuclear import and its implications in other aspects of the viral lifecycle.