Anthropogenic influences on emergence of vector-borne plant viruses: the persistent problem of Potato virus Y
Publication date: December 2018Source: Current Opinion in Virology, Volume 33Author(s): Stewart M Gray, Alison G PowerPotato virus Y (PVY) has reemerged as a serious impediment to seed potato production, responsible for reduced yields and tuber quality, as well as the majority of seed lot rejections by certification programs due to excessive virus incidence. This has led to seed shortages, especially in cultivars highly susceptible to infection. While seed certification programs have been effective at managing many virus diseases below economic thresholds, PVY has rapidly evolved in recent decades to become a complex of st...
Source: Current Opinion in Virology - November 12, 2018 Category: Virology Source Type: research
HDV evolution—will viral resistance be an issue in HDV infection?
Publication date: October 2018Source: Current Opinion in Virology, Volume 32Author(s): David Tabernero, Maria Francesca Cortese, Maria Buti, Francisco Rodriguez-FriasHepatitis D virus (HDV) is a hepatotropic subviral infectious agent, obligate satellite of the Hepatitis B virus (HBV) and is highly related to viroids. HDV affects around 5% of the 257 million chronic HBV-carriers worldwide, leading to the most severe form of chronic viral hepatitis. Interferon alpha is the only approved treatment for chronic hepatitis D, albeit with low response rates (around 20%–30%). New antiviral strategies are currently under study. Du...
Source: Current Opinion in Virology - November 9, 2018 Category: Virology Source Type: research
Dissection of RNAi-based antiviral immunity in plants
Publication date: October 2018Source: Current Opinion in Virology, Volume 32Author(s): Zhirui Yang, Yi LiRNA interference (RNAi)-based antiviral defense is a small RNA-dependent repression mechanism of plants to against viruses. Although the core components of antiviral RNAi are well known, it is unclear whether additional factors exist that regulate RNAi. Recently, a forward genetic screen identified two novel components of antiviral RNAi, providing important insights into the antiviral RNAi mechanism. Meanwhile, it was discovered that microRNAs make important contributions to host antiviral RNAi. On the other hand, to co...
Source: Current Opinion in Virology - November 1, 2018 Category: Virology Source Type: research
Hepatitis E virus treatment and ribavirin therapy: viral mechanisms of nonresponse
Publication date: October 2018Source: Current Opinion in Virology, Volume 32Author(s): Daniel Todt, Toni Luise Meister, Eike SteinmannHepatitis E virus (HEV) can cause chronic infections in immunosuppressed patients with adverse clinical outcomes. Intervention strategies are limited with ribavirin (RBV) being the only main therapeutic option as off-label drug. Recent reports on RBV monotherapy failures show a coherence with the presence of certain single nucleotide variants (SNVs) and in-frame insertions in the hypervariable region of open reading frame 1 in the HEV genome. Importantly, some of the alterations were present...
Source: Current Opinion in Virology - October 30, 2018 Category: Virology Source Type: research
Phage assembly and the special role of the portal protein
Publication date: Available online 28 September 2018Source: Current Opinion in VirologyAuthor(s): Peter E Prevelige, Juliana R CortinesVirus infections are ultimately dependent on a successful viral genome delivery to the host cell. The bacteriophage family Caudovirales evolved specialized machinery that fulfills this function: the portal proteins complex. The complexes are arranged as dodecameric rings and are a structural part of capsids incorporated at a five-fold vertex. They are involved in crucial aspects of viral replication, such as virion assembly, DNA packaging and DNA delivery. This review focuses on the organiz...
Source: Current Opinion in Virology - October 4, 2018 Category: Virology Source Type: research
Contribution of the KSHV and EBV lytic cycles to tumourigenesis
Publication date: October 2018Source: Current Opinion in Virology, Volume 32Author(s): Oliver Manners, James C Murphy, Alex Coleman, David J Hughes, Adrian WhitehouseKaposi’s Sarcoma-associated herpesvirus (KSHV) and Epstein Barr virus (EBV) are the causative agents of several malignancies. Like all herpesviruses, KSHV and EBV undergo distinct latent and lytic replication programmes. The transition between these states allows the establishment of a lifelong persistent infection, dissemination to sites of disease and the spread to new hosts. Latency-associated viral proteins have been well characterised in transformation ...
Source: Current Opinion in Virology - October 4, 2018 Category: Virology Source Type: research
Ubiquitination at the interface of tumor viruses and DNA damage responses
Publication date: October 2018Source: Current Opinion in Virology, Volume 32Author(s): Joseph M Dybas, Christin Herrmann, Matthew D WeitzmanViruses exploit cellular ubiquitination machinery to shape the host proteome and promote productive infection. Among the cellular processes influenced by viral manipulation of ubiquitination is the DNA damage response (DDR), a network of cellular signaling pathways that sense and respond to genomic damage. This host–pathogen interaction is particularly important during virus replication and transformation by DNA tumor viruses. Manipulating DDR pathways can promote virus replication b...
Source: Current Opinion in Virology - October 4, 2018 Category: Virology Source Type: research
More than just oncogenes: mechanisms of tumorigenesis by human viruses
Publication date: October 2018Source: Current Opinion in Virology, Volume 32Author(s): Marta M Gaglia, Karl MungerMost humans are infected with at least one of the known human cancer viruses during their lifetimes. While the initial infection with these viruses does not cause major disease, infected cells can acquire cancer hallmarks, particularly upon immunosuppression or exposure to co-carcinogenic stimuli. Even though cancer formation represents a rare outcome of a viral infection, approximately one out of eight human cancers has a viral etiology. Viral cancers present unique opportunities for prophylaxis, diagnosis, an...
Source: Current Opinion in Virology - October 4, 2018 Category: Virology Source Type: research
Mechanisms of persistence by small DNA tumor viruses
Publication date: October 2018Source: Current Opinion in Virology, Volume 32Author(s): Nathan A Krump, Wei Liu, Jianxin YouVirus infection contributes to nearly 15% of human cancers worldwide. Many of the oncogenic viruses tend to cause cancer in immunosuppressed individuals, but maintain asymptomatic, persistent infection for decades in the general population. In this review, we discuss the tactics employed by two small DNA tumor viruses, Human papillomavirus (HPV) and Merkel cell polyomavirus (MCPyV), to establish persistent infection. We will also highlight recent key findings as well as outstanding questions regarding ...
Source: Current Opinion in Virology - October 4, 2018 Category: Virology Source Type: research
Insect cuticular proteins and their role in transmission of phytoviruses
Publication date: December 2018Source: Current Opinion in Virology, Volume 33Author(s): Maëlle Deshoux, Baptiste Monsion, Marilyne UzestMany viruses of agricultural importance are transmitted to host plants via insect vectors. Characterizing virus–vector interactions at the molecular level is essential if we are to fully understand the transmission mechanisms involved and develop new strategies to control viral spread. Hitherto, insect proteins involved in virus transmission have been characterized only poorly. Recent advances in this topic, however, have significantly filled this knowledge gap. Among the vector molecul...
Source: Current Opinion in Virology - September 21, 2018 Category: Virology Source Type: research
Whitefly-transmitted viruses threatening cassava production in Africa
Publication date: December 2018Source: Current Opinion in Virology, Volume 33Author(s): Alana Lynn Jacobson, Siobain Duffy, Peter SseruwagiEmerging plant viruses are one of the greatest problems facing crop production worldwide, and have severe consequences in the developing world where subsistence farming is a major source of food production, and knowledge and resources for management are limited. In Africa, evolution of two viral disease complexes, cassava mosaic begomoviruses (CMBs) (Geminiviridae) and cassava brown streak viruses (CBSVs) (Potyviridae), have resulted in severe pandemics that continue to spread and threa...
Source: Current Opinion in Virology - September 20, 2018 Category: Virology Source Type: research
Immune-based therapeutic approaches to virus-associated cancers
Publication date: October 2018Source: Current Opinion in Virology, Volume 32Author(s): Corey Smith, Rajiv KhannaIt is estimated that 60–70% of cancers associated with infectious agents are linked to viral infections. Both RNA and DNA viruses that can establish persistent infection exploit various mechanisms including host cell immortalization through genomic instability, chronic inflammation and immune escape, to promote oncogenic transformation of human cells. Expression of selected viral proteins in malignant cells provides a unique opportunity to employ targeted therapies that can disrupt the cellular proliferation an...
Source: Current Opinion in Virology - September 19, 2018 Category: Virology Source Type: research
Strategies for immune evasion by human tumor viruses
Publication date: October 2018Source: Current Opinion in Virology, Volume 32Author(s): Kendra A Bussey, Melanie M BrinkmannImmune evasion is a hallmark of viral persistence. For the seven human tumor viruses to establish lifelong infection in their hosts, they must successfully control the host response to them. Viral inhibition of immune responses occurs at many levels. While some viruses directly target the pattern recognition receptors (PRR) of the innate immune system, they may also antagonize downstream effectors of PRR signaling cascades or activation of transcription, which would otherwise induce a type I interferon...
Source: Current Opinion in Virology - September 19, 2018 Category: Virology Source Type: research
Notes on recombination and reassortment in multipartite/segmented viruses
Publication date: December 2018Source: Current Opinion in Virology, Volume 33Author(s): Arvind Varsani, Pierre Lefeuvre, Philippe Roumagnac, Darren MartinBesides evolving through nucleotide substitution, viruses frequently also evolve by genetic recombination which can occur when related viral variants co-infect the same cells. Viruses with segmented or multipartite genomes can additionally evolve via the reassortment of genomic components. Various computational techniques are now available for identifying and characterizing recombination and reassortment. While these techniques have revealed both that all well studied seg...
Source: Current Opinion in Virology - September 18, 2018 Category: Virology Source Type: research
Epigenetic crossroads of the Epstein-Barr virus B-cell relationship
Publication date: October 2018Source: Current Opinion in Virology, Volume 32Author(s): Thomas C Frost, Benjamin E GewurzEpstein-Barr virus (EBV) is a gamma-herpesvirus that establishes lifelong infection in the majority of people worldwide. EBV uses epigenetic reprogramming to switch between multiple latency states in order to colonize the memory B-cell compartment and to then periodically undergo lytic reactivation upon plasma cell differentiation. This review focuses on recent advances in the understanding of epigenetic mechanisms that EBV uses to control its lifecycle and to subvert the growth and survival pathways that...
Source: Current Opinion in Virology - September 16, 2018 Category: Virology Source Type: research
