-
The Journal of General Virology Jan 2021Viruses in the family have a circular genome of 3.0 kb with three open reading frames. The packaged genome is inferred to be single-stranded DNA by analogy to related... (Review)
Review
Viruses in the family have a circular genome of 3.0 kb with three open reading frames. The packaged genome is inferred to be single-stranded DNA by analogy to related viruses. Redondoviruses were discovered through metagenomic sequencing methods in samples from human subjects and are inferred to replicate in humans. Evidence of redondovirus infection is associated with periodontitis and critical illness, but redondoviruses have not been shown to be the causative agent of any diseases. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family , which is available at ictv.global/report/redondoviridae.
Topics: DNA Viruses; DNA, Circular; DNA, Single-Stranded; DNA, Viral; Genome, Viral; Humans; Metagenomics; Open Reading Frames; Virus Replication
PubMed: 33258767
DOI: 10.1099/jgv.0.001526 -
Viruses Apr 2019Parvoviruses, infecting vertebrates and invertebrates, are a family of single-stranded DNA viruses with small, non-enveloped capsids with T = 1 icosahedral symmetry. A... (Review)
Review
Parvoviruses, infecting vertebrates and invertebrates, are a family of single-stranded DNA viruses with small, non-enveloped capsids with T = 1 icosahedral symmetry. A quarter of a century after the first parvovirus capsid structure was published, approximately 100 additional structures have been analyzed. This first structure was that of Canine Parvovirus, and it initiated the practice of structure-to-function correlation for the family. Despite high diversity in the capsid viral protein (VP) sequence, the structural topologies of all parvoviral capsids are conserved. However, surface loops inserted between the core secondary structure elements vary in conformation that enables the assembly of unique capsid surface morphologies within individual genera. These variations enable each virus to establish host niches by allowing host receptor attachment, specific tissue tropism, and antigenic diversity. This review focuses on the diversity among the parvoviruses with respect to the transcriptional strategy of the encoded VPs, the advances in capsid structure-function annotation, and therapeutic developments facilitated by the available structures.
Topics: Animals; Capsid Proteins; Cryoelectron Microscopy; Crystallography, X-Ray; Humans; Models, Molecular; Parvoviridae Infections; Parvovirus; Protein Conformation; Protein Structure, Secondary
PubMed: 31010002
DOI: 10.3390/v11040362 -
Viruses Mar 2021The SAM and HD domain-containing protein 1 (SAMHD1) is a dNTP triphosphohydrolase that plays a crucial role for a variety of different cellular functions. Besides... (Review)
Review
The SAM and HD domain-containing protein 1 (SAMHD1) is a dNTP triphosphohydrolase that plays a crucial role for a variety of different cellular functions. Besides balancing intracellular dNTP concentrations, facilitating DNA damage repair, and dampening excessive immune responses, SAMHD1 has been shown to act as a major restriction factor against various virus species. In addition to its well-described activity against retroviruses such as HIV-1, SAMHD1 has been identified to reduce the infectivity of different DNA viruses such as the herpesviruses CMV and EBV, the poxvirus VACV, or the hepadnavirus HBV. While some viruses are efficiently restricted by SAMHD1, others have developed evasion mechanisms that antagonize the antiviral activity of SAMHD1. Within this review, we summarize the different cellular functions of SAMHD1 and highlight the countermeasures viruses have evolved to neutralize the restriction factor SAMHD1.
Topics: DNA Virus Infections; DNA Viruses; Host-Pathogen Interactions; Humans; Retroviridae; Retroviridae Infections; SAM Domain and HD Domain-Containing Protein 1; Viral Interference
PubMed: 33801276
DOI: 10.3390/v13030395 -
Current Issues in Molecular Biology 2021Double-stranded (ds) DNA viruses of the family , commonly known as virophages, are a fascinating group of eukaryotic viruses that depend on a coinfecting giant dsDNA... (Review)
Review
Double-stranded (ds) DNA viruses of the family , commonly known as virophages, are a fascinating group of eukaryotic viruses that depend on a coinfecting giant dsDNA virus of the for their propagation. Instead of replicating in the nucleus, virophages multiply in the cytoplasmic virion factory of a coinfecting giant virus inside a phototrophic or heterotrophic protistal host cell. Virophages are parasites of giant viruses and can inhibit their replication, which may lead to increased survival rates of the infected host cell population. The genomes of virophages are 17-33 kilobase pairs (kbp) long and encode 16-34 proteins. Genetic signatures of virophages can be found in metagenomic datasets from various saltwater and freshwater environments around the planet. Most virophages share a set of conserved genes that code for a major and a minor capsid protein, a cysteine protease, a genome-packaging ATPase, and a superfamily 3 helicase, although the genomes are otherwise diverse and variable. Lavidaviruses share genes with other mobile genetic elements, suggesting that horizontal gene transfer and recombination have been major forces in shaping these viral genomes. Integrases are occasionally found in virophage genomes and enable these DNA viruses to persist as provirophages in the chromosomes of their viral and cellular hosts. As we watch the genetic diversity of this new viral family unfold through metagenomics, additional isolates are still lacking and critical questions regarding their infection cycle, host range, and ecology remain to be answered.
Topics: Capsid; Coinfection; DNA, Viral; Evolution, Molecular; Gene Transfer, Horizontal; Genetic Variation; Genome, Viral; Giant Viruses; Host Microbial Interactions; Host Specificity; Metagenome; Metagenomics; Phylogeny; Virophages; Virus Replication
PubMed: 32089519
DOI: 10.21775/cimb.040.001 -
Viruses Aug 2019Autophagy is a catabolic biological process in the body. By targeting exogenous microorganisms and aged intracellular proteins and organelles and sending them to the... (Review)
Review
Autophagy is a catabolic biological process in the body. By targeting exogenous microorganisms and aged intracellular proteins and organelles and sending them to the lysosome for phagocytosis and degradation, autophagy contributes to energy recycling. When cells are stimulated by exogenous pathogenic microorganisms such as viruses, activation or inhibition of autophagy is often triggered. As autophagy has antiviral effects, many viruses may escape and resist the process by encoding viral proteins. At the same time, viruses can also use autophagy to enhance their replication or increase the persistence of latent infections. Here, we give a brief overview of autophagy and DNA viruses and comprehensively review the known interactions between human and animal DNA viruses and autophagy and the role and mechanisms of autophagy in viral DNA replication and DNA virus-induced innate and acquired immunity.
Topics: Adaptive Immunity; Adenoviridae; Animals; Autophagosomes; Autophagy; DNA Viruses; Herpesviridae; Host Microbial Interactions; Humans; Immune Evasion; Immunity, Innate; Lysosomes; Papillomaviridae; Phagocytosis; Signal Transduction; Viral Proteins; Virus Replication
PubMed: 31450758
DOI: 10.3390/v11090776 -
Annual Review of Virology Sep 2018Viral DNA genomes have limited coding capacity and therefore harness cellular factors to facilitate replication of their genomes and generate progeny virions. Studies of... (Review)
Review
Viral DNA genomes have limited coding capacity and therefore harness cellular factors to facilitate replication of their genomes and generate progeny virions. Studies of viruses and how they interact with cellular processes have historically provided seminal insights into basic biology and disease mechanisms. The replicative life cycles of many DNA viruses have been shown to engage components of the host DNA damage and repair machinery. Viruses have evolved numerous strategies to navigate the cellular DNA damage response. By hijacking and manipulating cellular replication and repair processes, DNA viruses can selectively harness or abrogate distinct components of the cellular machinery to complete their life cycles. Here, we highlight consequences for viral replication and host genome integrity during the dynamic interactions between virus and host.
Topics: DNA Damage; DNA Repair; DNA Replication; DNA Viruses; DNA, Viral; Virus Replication
PubMed: 29996066
DOI: 10.1146/annurev-virology-092917-043534 -
Annual Review of Virology Sep 2018DNA viruses are linked to many infectious diseases and contribute significantly to human morbidity and mortality worldwide. Moreover, DNA viral infections are usually... (Review)
Review
DNA viruses are linked to many infectious diseases and contribute significantly to human morbidity and mortality worldwide. Moreover, DNA viral infections are usually lifelong and hard to eradicate. Under certain circumstances, these viruses can cause fatal disease, especially in children and immunocompromised patients. An efficient innate immune response against these viruses is critical, not only as the first line of host defense against viral infection but also for mounting more specific and robust adaptive immunity against the virus. Recognition of the viral DNA genome is the very first step of this whole process and is crucial for understanding viral pathogenesis as well as for preventing and treating DNA virus-associated diseases. This review focuses on the current state of our knowledge on how human DNA viruses are sensed by the host innate immune system and how viral proteins counteract this immune response.
Topics: DNA Virus Infections; DNA Viruses; Host-Pathogen Interactions; Humans; Immune Evasion; Immunity, Innate
PubMed: 30265633
DOI: 10.1146/annurev-virology-092917-043244 -
Viruses Mar 2022DNA virus infections are often lifelong and can cause serious diseases in their hosts. Their recognition by the sensors of the innate immune system represents the front... (Review)
Review
DNA virus infections are often lifelong and can cause serious diseases in their hosts. Their recognition by the sensors of the innate immune system represents the front line of host defence. Understanding the molecular mechanisms of innate immunity responses is an important prerequisite for the design of effective antivirotics. This review focuses on the present state of knowledge surrounding the mechanisms of viral DNA genome sensing and the main induced pathways of innate immunity responses. The studies that have been performed to date indicate that herpesviruses, adenoviruses, and polyomaviruses are sensed by various DNA sensors. In non-immune cells, STING pathways have been shown to be activated by cGAS, IFI16, DDX41, or DNA-PK. The activation of TLR9 has mainly been described in pDCs and in other immune cells. Importantly, studies on herpesviruses have unveiled novel participants (BRCA1, H2B, or DNA-PK) in the IFI16 sensing pathway. Polyomavirus studies have revealed that, in addition to viral DNA, micronuclei are released into the cytosol due to genotoxic stress. Papillomaviruses, HBV, and HIV have been shown to evade DNA sensing by sophisticated intracellular trafficking, unique cell tropism, and viral or cellular protein actions that prevent or block DNA sensing. Further research is required to fully understand the interplay between viruses and DNA sensors.
Topics: DNA Virus Infections; DNA, Viral; Herpesviridae; Humans; Immunity, Innate; Polyomavirus
PubMed: 35458396
DOI: 10.3390/v14040666 -
Viruses Nov 2023Oncolytic viruses (OVs) have emerged as one of the most promising cancer immunotherapy agents that selectively target and kill cancer cells while sparing normal cells.... (Review)
Review
Oncolytic viruses (OVs) have emerged as one of the most promising cancer immunotherapy agents that selectively target and kill cancer cells while sparing normal cells. OVs are from diverse families of viruses and can possess either a DNA or an RNA genome. These viruses also have either a natural or engineered tropism for cancer cells. Oncolytic DNA viruses have the additional advantage of a stable genome and multiple-transgene insertion capability without compromising infection or replication. Herpes simplex virus 1 (HSV-1), a member of the oncolytic DNA viruses, has been approved for the treatment of cancers. This success with HSV-1 was achievable by introducing multiple genetic modifications within the virus to enhance cancer selectivity and reduce the toxicity to healthy cells. Here, we review the natural characteristics of and genetically engineered changes in selected DNA viruses that enhance the tumor tropism of these oncolytic viruses.
Topics: Humans; Oncolytic Virotherapy; Neoplasms; Herpesvirus 1, Human; Oncolytic Viruses; Tropism; DNA Viruses
PubMed: 38005938
DOI: 10.3390/v15112262 -
Advances in Experimental Medicine and... 2024Poxvirus assembly has been an intriguing area of research for several decades. While advancements in experimental techniques continue to yield fresh insights, many... (Review)
Review
Poxvirus assembly has been an intriguing area of research for several decades. While advancements in experimental techniques continue to yield fresh insights, many questions are still unresolved. Large genome sizes of up to 380 kbp, asymmetrical structure, an exterior lipid bilayer, and a cytoplasmic life cycle are some notable characteristics of these viruses. Inside the particle are two lateral bodies and a protein wall-bound-biconcave core containing the viral nucleocapsid. The assembly progresses through five major stages-endoplasmic reticulum (ER) membrane alteration and rupture, crescent formation, immature virion formation, genome encapsidation, virion maturation and in a subset of viruses, additional envelopment of the virion prior to its dissemination. Several large dsDNA viruses have been shown to follow a comparable sequence of events. In this chapter, we recapitulate our understanding of the poxvirus morphogenesis process while reviewing the most recent advances in the field. We also briefly discuss how virion assembly aids in our knowledge of the evolutionary links between poxviruses and other Nucleocytoplasmic Large DNA Viruses (NCLDVs).
Topics: Poxviridae; Virus Assembly; Humans; Genome, Viral; Virion; Animals; Evolution, Molecular; Endoplasmic Reticulum
PubMed: 38801570
DOI: 10.1007/978-3-031-57165-7_3