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Current Issues in Molecular Biology 2021Both the development of the mammalian innate immune system and the antagonistic strategies acquired by alphaherpesviruses to dismantle it have been shaped by co-evolving... (Review)
Review
Both the development of the mammalian innate immune system and the antagonistic strategies acquired by alphaherpesviruses to dismantle it have been shaped by co-evolving virus-host interactions over millions of years. Here, we review mechanisms employed by mammalian cells to detect pathogen molecules, such as viral glycoproteins and nucleic acids, and induce innate immune signaling upon infection with alphaherpesviruses. We further explore strategies acquired by these viruses to bypass immune detection and activation, thereby supporting virus replication and spread. Finally, we discuss the contributions of advanced 'omics' and microscopy methods to these discoveries in immune signaling and highlight emerging technologies that can help to further our understanding of the dynamic interplay between host innate immune responses and virus immune evasion.
Topics: Alphaherpesvirinae; Animals; Biological Evolution; DNA, Viral; Herpesviridae Infections; Host-Pathogen Interactions; Humans; Immune Evasion; Immunity, Innate; Signal Transduction; Viral Proteins; Virus Replication
PubMed: 33640867
DOI: 10.21775/cimb.042.635 -
Viruses May 2024Marek's disease (MD), caused by (GaAHV2) or Marek's disease herpesvirus (MDV), is a devastating disease in chickens characterized by the development of lymphomas...
Marek's disease (MD), caused by (GaAHV2) or Marek's disease herpesvirus (MDV), is a devastating disease in chickens characterized by the development of lymphomas throughout the body. Vaccine strains used against MD include 3 (GaAHV3), a non-oncogenic chicken alphaherpesvirus homologous to MDV, and homologous meleagrid alphaherpesvirus 1 (MeAHV1) or turkey herpesvirus (HVT). Previous work has shown most of the MDV gC produced during in vitro passage is secreted into the media of infected cells although the predicted protein contains a transmembrane domain. We formerly identified two alternatively spliced gC mRNAs that are secreted during MDV replication in vitro, termed gC104 and gC145 based on the size of the intron removed for each (gC) transcript. Since gC is conserved within the subfamily, we hypothesized GaAHV3 (strain 301B/1) and HVT also secrete gC due to mRNA splicing. To address this, we collected media from 301B/1- and HVT-infected cell cultures and used Western blot analyses and determined that both 301B/1 and HVT produced secreted gC. Next, we extracted RNAs from 301B/1- and HVT-infected cell cultures and chicken feather follicle epithelial (FFE) skin cells. RT-PCR analyses confirmed one splicing variant for 301B/1 gC (gC104) and two variants for HVT gC (gC104 and gC145). Interestingly, the splicing between all three viruses was remarkably conserved. Further analysis of predicted and validated mRNA splicing donor, branch point (BP), and acceptor sites suggested single nucleotide polymorphisms (SNPs) within the 301B/1 transcript sequence resulted in no gC145 being produced. However, modification of the 301B/1 gC145 donor, BP, and acceptor sites to the MDV sequences did not result in gC145 mRNA splice variant, suggesting mRNA splicing is more complex than originally hypothesized. In all, our results show that mRNA splicing of avian herpesviruses is conserved and this information may be important in developing the next generation of MD vaccines or therapies to block transmission.
Topics: Animals; Chickens; RNA Splicing; Viral Envelope Proteins; RNA, Messenger; Marek Disease; Mardivirus; Viral Proteins; Herpesvirus 2, Gallid; Alternative Splicing; Antigens, Viral
PubMed: 38793663
DOI: 10.3390/v16050782 -
Viruses Dec 2019The include the neurotropic pathogens herpes simplex virus and varicella zoster virus of humans and pseudorabies virus of swine. These viruses establish lifelong... (Review)
Review
The include the neurotropic pathogens herpes simplex virus and varicella zoster virus of humans and pseudorabies virus of swine. These viruses establish lifelong latency in the nuclei of peripheral ganglia, but utilize the peripheral tissues those neurons innervate for productive replication, spread, and transmission. Delivery of virions from replicative pools to the sites of latency requires microtubule-directed retrograde axonal transport from the nerve terminus to the cell body of the sensory neuron. As a corollary, during reactivation newly assembled virions must travel along axonal microtubules in the anterograde direction to return to the nerve terminus and infect peripheral tissues, completing the cycle. Neurotropic alphaherpesviruses can therefore exploit neuronal microtubules and motors for long distance axonal transport, and alternate between periods of sustained plus end- and minus end-directed motion at different stages of their infectious cycle. This review summarizes our current understanding of the molecular details by which this is achieved.
Topics: Alphaherpesvirinae; Animals; Axons; Biomarkers; Capsid; Cell Nucleus; Cytoplasm; Disease Susceptibility; Exocytosis; Herpesviridae Infections; Host-Pathogen Interactions; Humans; Life Cycle Stages; Microtubules; Nervous System Diseases; Neurons; Protein Transport
PubMed: 31861082
DOI: 10.3390/v11121165 -
Viruses Dec 2015Enveloped viruses employ a class of proteins known as fusogens to orchestrate the merger of their surrounding envelope and a target cell membrane. Most fusogens... (Review)
Review
Enveloped viruses employ a class of proteins known as fusogens to orchestrate the merger of their surrounding envelope and a target cell membrane. Most fusogens accomplish this task alone, by binding cellular receptors and subsequently catalyzing the membrane fusion process. Surprisingly, in herpesviruses, these functions are distributed among multiple proteins: the conserved fusogen gB, the conserved gH/gL heterodimer of poorly defined function, and various non-conserved receptor-binding proteins. We summarize what is currently known about gB from two closely related herpesviruses, HSV-1 and HSV-2, with emphasis on the structure of the largely uncharted membrane interacting regions of this fusogen. We propose that the unusual mechanism of herpesvirus fusion could be linked to the unique architecture of gB.
Topics: Herpesvirus 1, Human; Herpesvirus 2, Human; Humans; Viral Envelope Proteins; Virus Internalization
PubMed: 26690469
DOI: 10.3390/v7122957 -
Viruses Feb 2018Actin filaments, microtubules and intermediate filaments form the cytoskeleton of vertebrate cells. Involved in maintaining cell integrity and structure, facilitating... (Review)
Review
Actin filaments, microtubules and intermediate filaments form the cytoskeleton of vertebrate cells. Involved in maintaining cell integrity and structure, facilitating cargo and vesicle transport, remodelling surface structures and motility, the cytoskeleton is necessary for the successful life of a cell. Because of the broad range of functions these filaments are involved in, they are common targets for viral pathogens, including the alphaherpesviruses. Human-tropic alphaherpesviruses are prevalent pathogens carried by more than half of the world's population; comprising herpes simplex virus (types 1 and 2) and varicella-zoster virus, these viruses are characterised by their ability to establish latency in sensory neurons. This review will discuss the known mechanisms involved in subversion of and transport via the cytoskeleton during alphaherpesvirus infections, focusing on protein-protein interactions and pathways that have recently been identified. Studies on related alphaherpesviruses whose primary host is not human, along with comparisons to more distantly related beta and gammaherpesviruses, are also presented in this review. The need to decipher as-yet-unknown mechanisms exploited by viruses to hijack cytoskeletal components-to reveal the hidden cytoskeletons in the closet-will also be addressed.
Topics: Actins; Alphaherpesvirinae; Animals; Cytoskeleton; Herpesviridae Infections; Host-Pathogen Interactions; Humans; Intermediate Filaments; Microtubules; Models, Biological; Myosins; Protein Binding; Protein Transport
PubMed: 29438303
DOI: 10.3390/v10020079 -
Viruses Mar 2022The non-specific innate immunity can initiate host antiviral innate immune responses within minutes to hours after the invasion of pathogenic microorganisms. Therefore,... (Review)
Review
The non-specific innate immunity can initiate host antiviral innate immune responses within minutes to hours after the invasion of pathogenic microorganisms. Therefore, the natural immune response is the first line of defense for the host to resist the invaders, including viruses, bacteria, fungi. Host pattern recognition receptors (PRRs) in the infected cells or bystander cells recognize pathogen-associated molecular patterns (PAMPs) of invading pathogens and initiate a series of signal cascades, resulting in the expression of type I interferons (IFN-I) and inflammatory cytokines to antagonize the infection of microorganisms. In contrast, the invading pathogens take a variety of mechanisms to inhibit the induction of IFN-I production from avoiding being cleared. Pseudorabies virus (PRV) belongs to the family Herpesviridae, subfamily Alphaherpesvirinae, genus Varicellovirus. PRV is the causative agent of Aujeszky's disease (AD, pseudorabies). Although the natural host of PRV is swine, it can infect a wide variety of mammals, such as cattle, sheep, cats, and dogs. The disease is usually fatal to these hosts. PRV mainly infects the peripheral nervous system (PNS) in swine. For other species, PRV mainly invades the PNS first and then progresses to the central nervous system (CNS), which leads to acute death of the host with serious clinical and neurological symptoms. In recent years, new PRV variant strains have appeared in some areas, and sporadic cases of PRV infection in humans have also been reported, suggesting that PRV is still an important emerging and re-emerging infectious disease. This review summarizes the strategies of PRV evading host innate immunity and new targets for inhibition of PRV replication, which will provide more information for the development of effective inactivated vaccines and drugs for PRV.
Topics: Animals; Antiviral Agents; Cattle; Dogs; Herpesvirus 1, Suid; Immunity, Innate; Mammals; Pseudorabies; Sheep; Swine; Virus Replication
PubMed: 35336954
DOI: 10.3390/v14030547 -
Journal of Veterinary Diagnostic... Jul 2022Herpesviruses are found in free-living and captive chelonian populations, often in association with morbidity and mortality. To date, all known chelonian herpesviruses...
Herpesviruses are found in free-living and captive chelonian populations, often in association with morbidity and mortality. To date, all known chelonian herpesviruses fall within the subfamily . We detected a novel herpesvirus in 3 species of chelonians: a captive leopard tortoise () in western TX, USA; a steppe tortoise ( [] ) found near Fort Irwin, CA, USA; and 2 free-living, three-toed box turtles () found in Forest Park, St. Louis, MO. The leopard tortoise was coinfected with the tortoise intranuclear coccidian and had clinical signs of upper respiratory tract disease. The steppe tortoise had mucopurulent nasal discharge and lethargy. One of the three-toed box turtles had no clinical signs; the other was found dead with signs of trauma after being observed with blepharedema, tympanic membrane swelling, cervical edema, and other clinical signs several weeks prior to death. Generally, the branching order of the turtle herpesviruses mirrors the divergence patterns of their hosts, consistent with codivergence. Based on phylogenetic analysis, this novel herpesvirus clusters with a clade of viruses that infect emydid hosts and is likely of box turtle origin. Therefore, we suggest the name terrapene alphaherpesvirus 3 (TerAHV3) for the novel virus. This virus also has the ability to host-jump to tortoises, and previously documented herpesviral morbidity tends to be more common in aberrant hosts. The relationship between clinical signs and infection with TerAHV3 in these animals is unclear, and further investigation is merited.
Topics: Alphaherpesvirinae; Animals; Herpesviridae; Phylogeny; Turtles
PubMed: 35459421
DOI: 10.1177/10406387221092048 -
Viruses Jan 2023Pseudorabies virus (PRV) is the pathogen of pseudorabies (PR), which belongs to the alpha herpesvirus subfamily with a double stranded DNA genome encoding approximately... (Review)
Review
Pseudorabies virus (PRV) is the pathogen of pseudorabies (PR), which belongs to the alpha herpesvirus subfamily with a double stranded DNA genome encoding approximately 70 proteins. PRV has many non-essential regions for replication, has a strong capacity to accommodate foreign genes, and more areas for genetic modification. PRV is an ideal vaccine vector, and multivalent live virus-vectored vaccines can be developed using the gene-deleted PRV. The immune system continues to be stimulated by the gene-deleted PRVs and maintain a long immunity lasting more than 4 months. Here, we provide a brief overview of the biology of PRV, recombinant PRV construction methodology, the technology platform for efficiently constructing recombinant PRV, and the applications of recombinant PRV in vaccine development. This review summarizes the latest information on PRV usage in vaccine development against swine infectious diseases, and it offers novel perspectives for advancing preventive medicine through vaccinology.
Topics: Animals; Swine; Pseudorabies; Herpesvirus 1, Suid; Communicable Diseases; Alphaherpesvirinae; Vaccine Development; Orthopoxvirus; Vaccines, Combined
PubMed: 36851584
DOI: 10.3390/v15020370 -
Current Issues in Molecular Biology 2021Herpesviruses virions are large and complex structures that deliver their genetic content to nuclei upon entering cells. This property is not unusual as many other... (Review)
Review
Herpesviruses virions are large and complex structures that deliver their genetic content to nuclei upon entering cells. This property is not unusual as many other viruses including the adenoviruses, orthomyxoviruses, papillomaviruses, polyomaviruses, and retroviruses, do likewise. However, the means by which viruses in the subfamily accomplish this fundamental stage of the infectious cycle is tied to their defining ability to efficiently invade the nervous system. Fusion of the viral envelope with a cell membrane results in the deposition of the capsid, along with an assortment of tegument proteins, into the cytosol. Establishment of infection requires that the capsid traverse the cytosol, dock at a nuclear pore, and inject its genome into the nucleoplasm. Accumulating evidence indicates that the capsid is not the effector of this delivery process, but is instead shepherded by tegument proteins that remain capsid bound. At the same time, tegument proteins that are released from the capsid upon entry act to increase the susceptibility of the cell to the ensuing infection. Mucosal epithelial cells and neurons are both susceptible to alphaherpesvirus infection and, together, provide the niche to which these viruses have adapted. Although much has been revealed about the functions of expressed tegument proteins during the late stages of assembly and egress, this review will specifically address the roles of tegument proteins brought into the cell with the incoming virion, and our current understanding of alphaherpesvirus genome delivery to nuclei.
Topics: Alphaherpesvirinae; Animals; Capsid Proteins; Cell Nucleus; Cytoplasm; Genome, Viral; Herpesviridae Infections; Humans; Virion; Virus Assembly; Virus Internalization
PubMed: 32807747
DOI: 10.21775/cimb.041.171 -
Brain Pathology (Zurich, Switzerland) Oct 2001Herpesviruses cause various acute, subacute, and chronic disorders of the central (CNS) and peripheral (PNS) nervous systems in adults and children. Both immunocompetent... (Review)
Review
Herpesviruses cause various acute, subacute, and chronic disorders of the central (CNS) and peripheral (PNS) nervous systems in adults and children. Both immunocompetent and immunocompromised individuals may be affected. Zoster (shingles), a result of reactivation of varicella zoster virus (VZV), is the most frequent neurologic complication. Other neurological complications include encephalitis produced by type I herpes simplex virus (HSV-1), and less frequently HSV-2, as well as by VZV and cytomegalovirus (CMV). Acute meningitis is seen with VZV and HSV-2, and benign recurrent meningitis with HSV-2. Combinations of meningitis/ encephalitis and myelitis/radiculitis are associated with Epstein Barr Virus (EBV); myelitis with VZV, CMV, EBV, and HSV-2; and ventriculitis/encephalitis with VZV and CMV. Brainstem encephalitis due to HSV and VZV, and polymyeloradiculitis due to CMV are well documented. HHV-6 produces childhood exanthem subitum (roseola) and febrile convulsions. Immunocompetent and immunocompromised hosts manifest different incidences and patterns of herpesvirus infections. For example, stroke due to VZV-mediated large vessel disease (herpes zoster ophthalmicus) occurs predominantly in immunocompetent hosts, while small vessel disease (leukoencephalitis) and ventriculitis develop almost exclusively in immunocompromised patients. EBV-associated primary CNS lymphomas also are restricted to immunosuppressed individuals. Recent large CSF PCR studies have shown that VZV, EBV, and CMV more frequently produce meningitis, encephalitis, or encephalopathy in immunocompetent hosts than was formerly realized. We review herpesvirus infections of the nervous system and illustrate the expanding spectrum of disease by including examples of a 75-year-old male on steroid treatment for chronic lung disease with fatal HSV-2 meningitis and an 81-year-old male with myasthenia gravis, long-term azathioprine use, and an EBV-associated primary CNS lymphoma.
Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Cytomegalovirus; Female; Herpesviridae Infections; Herpesvirus 1, Human; Herpesvirus 2, Human; Herpesvirus 3, Human; Herpesvirus 4, Human; Herpesvirus 6, Human; Humans; Infant; Infant, Newborn; Male; Middle Aged; Nervous System
PubMed: 11556690
DOI: 10.1111/j.1750-3639.2001.tb00413.x