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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 -
Frontiers in Immunology 2021
Topics: Animals; DNA Virus Infections; DNA Viruses; DNA, Viral; Humans; Immunity, Innate
PubMed: 34276645
DOI: 10.3389/fimmu.2021.644310 -
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 -
Reviews in Medical Virology 2002TT virus (TTV) was found in 1997 from a hepatitis patient without virus markers. However, the real impact of TTV on liver diseases remains uncertain to date. Due to the... (Review)
Review
TT virus (TTV) was found in 1997 from a hepatitis patient without virus markers. However, the real impact of TTV on liver diseases remains uncertain to date. Due to the lack of suitable cell systems to support the growth of TTV, the biology of TTV is still obscure. This review tries to summarise the current status of TTV on aspects other than the taxonomic diversity of TTV. TTV was the first human virus with a single stranded circular DNA genome. TTV was considered to be a member of Circoviridae, but others suggested it conformed to a new family. TTV is distinct from ambisense viruses in the genus Circovirus, since the former genome is negative stranded. The genome structure of TTV is more related to chicken anaemia virus in the genus Gyrovirus, however, the sequence similarity is minimal except for a short stretch at 3816-3851 of TA278. Currently the working group is proposing the full name for TTV as TorqueTenoVirus and the TTV-like mini virus as TorqueTenoMiniVirus (TTMV) in a new genus Anellovirus (ring). TTVs are prevalent in non-human primates and human TTV can cross-infect chimpanzees. Furthermore, TTV sequences have been detected in chickens, pigs, cows and sheep. TTV can be transmitted by mother-to-child infection. However, within a year after birth, the prevalence reaches the same level for children born to both TTV-positive and TTV-negative mothers even without breast-feeding. The non-coding region surrounding a short 113 nt GC-rich stretch and occupying approximately one-third of the genome is considered to contain the putative replication origin. Three mRNAs are expressed by TTV, 3.0 and 1.2 and 1.0 kb species. A protein translated from the 3.0 kb mRNA is considered to be the major capsid protein as well as replicase. The nature of the proteins translated by the other two mRNAs are still putative.
Topics: Animals; Base Sequence; DNA Virus Infections; DNA Viruses; DNA, Circular; DNA, Single-Stranded; Genome, Viral; Humans; Molecular Sequence Data; Pan troglodytes
PubMed: 11987140
DOI: 10.1002/rmv.351 -
PloS One 2011Little is known about the viruses infecting most species. Even in groups as well-studied as Drosophila, only a handful of viruses have been well-characterized. A viral...
Little is known about the viruses infecting most species. Even in groups as well-studied as Drosophila, only a handful of viruses have been well-characterized. A viral metagenomic approach was used to explore viral diversity in 83 wild-caught Drosophila innubila, a mushroom feeding member of the quinaria group. A single fly that was injected with, and died from, Drosophila C Virus (DCV) was added to the sample as a control. Two-thirds of reads in the infected sample had DCV as the best BLAST hit, suggesting that the protocol developed is highly sensitive. In addition to the DCV hits, several sequences had Oryctes rhinoceros Nudivirus, a double-stranded DNA virus, as a best BLAST hit. The virus associated with these sequences was termed Drosophila innubila Nudivirus (DiNV). PCR screens of natural populations showed that DiNV was both common and widespread taxonomically and geographically. Electron microscopy confirms the presence of virions in fly fecal material similar in structure to other described Nudiviruses. In 2 species, D. innubila and D. falleni, the virus is associated with a severe (∼80-90%) loss of fecundity and significantly decreased lifespan.
Topics: Amino Acid Sequence; Animals; DNA Virus Infections; DNA Viruses; Drosophila; Feces; Female; Genetic Fitness; Genomics; Infectious Disease Transmission, Vertical; Laboratories; Male; Metagenome; Sequence Homology, Amino Acid; Survival Analysis
PubMed: 22053195
DOI: 10.1371/journal.pone.0026564 -
Frontiers in Bioscience : a Journal and... Feb 2002The cellular components engaged in entry of viruses has been an area of intense investigation in recent years. We examine the entry and receptors used for well-studied... (Review)
Review
The cellular components engaged in entry of viruses has been an area of intense investigation in recent years. We examine the entry and receptors used for well-studied and prevalent human DNA viruses adenoviruses, poxviruses and two herpesviruses- herpes simplex virus and Epstein-Barr virus. Little is yet known about the entry or early events for other human DNA viruses. Common themes that emerge for entry of these prevalent human DNA viruses include engagement of multiple receptors, use of cell surface molecules that are prominent and, in most cases, conserved on cells, and interactions with proteins that can alter morphology of the cytoskeleton or modulate intracellular signaling for gene expression. Where available, we provide evidence that entry not only transports the capsid and genome across a cell membrane, but that these events also can set up the cell for subsequent events that contribute to successful viral replication.
Topics: Adenoviridae; DNA Virus Infections; DNA Viruses; Endocytosis; Herpesvirus 4, Human; Humans; Kinetics; Models, Biological; Poxviridae; Receptors, Virus; Simplexvirus; Viral Proteins
PubMed: 11815295
DOI: 10.2741/A783 -
Journal of Medical Microbiology Jan 1998
Review
Topics: Antiviral Agents; DNA Viruses; Humans; Nucleosides; Phosphorylation; Retroviridae; Retroviridae Infections; Virus Diseases
PubMed: 9449944
DOI: 10.1099/00222615-47-1-1 -
Clinical Pharmacology and Therapeutics Nov 2010All the currently available antiviral agents used in the treatment of double-stranded (ds) DNA viruses, with the exception of interferon-α, inhibit the same target, the... (Review)
Review
All the currently available antiviral agents used in the treatment of double-stranded (ds) DNA viruses, with the exception of interferon-α, inhibit the same target, the viral DNA polymerase. With increasing reports of the development of resistance of herpes simplex virus (HSV), cytomegalovirus (CMV), and hepatitis B virus (HBV) to some of these drugs, new antiviral agents are needed to treat these infections. Additionally, no drugs have been approved to treat several DNA virus infections, including those caused by adenovirus, smallpox, molluscum contagiosum, and BK virus. We report the status of 10 new antiviral drugs for the treatment of dsDNA viruses. CMX-001 has broad activity against dsDNA viruses; 3 helicase-primase inhibitors, maribavir, and FV-100 have activity against certain herpesviruses; ST-246 inhibits poxviruses; GS-9191 inhibits papillomaviruses; and clevudine and emtricitabine are active against HBV. Most of these drugs have completed at least phase I trials in humans, and many are in additional clinical trials.
Topics: Animals; Antiviral Agents; Clinical Trials as Topic; DNA Virus Infections; DNA Viruses; DNA, Viral; Disease Models, Animal; Drug Design; Humans; Nucleic Acid Conformation; Treatment Outcome
PubMed: 20881959
DOI: 10.1038/clpt.2010.178 -
Intervirology 1999In 1997, a novel DNA virus was isolated from the serum of a patient with posttransfusion hepatitis of unknown etiology in Japan, and it was named TT virus (TTV) after... (Review)
Review
In 1997, a novel DNA virus was isolated from the serum of a patient with posttransfusion hepatitis of unknown etiology in Japan, and it was named TT virus (TTV) after the initials of the index patient. TTV is a nonenveloped, single-stranded and circular DNA virus, and its entire sequence of approximately 3.9 kb has been determined. For being a DNA virus, TTV has a wide range of sequence divergence, allowing the classification into at least 16 genotypes separated by a sequence difference of >30% from one another. The nucleotide sequence of the noncoding region of the TTV genome is conserved, whereas that of the coding region is highly variable. TTV strains with extremely high sequence divergence are common in the same individuals, thereby indicating a mixed infection of TTV strains of different genotypes. An association is found between hepatitis of unknown etiology and the TTV genotypes which are detectable by PCR with primers deduced from the N22 region (genotype 1) in the open reading frame 1 encoding the capsid protein. It would be important to select the primers for specific detection of the TTV genotypes associated with clinical diseases, to further evaluate the capacity of TTV to induce acute and chronic liver disease as well as extrahepatic manifestations.
Topics: Base Sequence; DNA Viruses; Genome, Viral; Hepatitis, Viral, Human; Humans; Liver; Molecular Sequence Data; Open Reading Frames; Polymerase Chain Reaction
PubMed: 10516475
DOI: 10.1159/000024961 -
Frontiers in Cellular and Infection... 2022
Topics: Humans; Neoplasms; DNA Viruses
PubMed: 36569205
DOI: 10.3389/fcimb.2022.1103505