Vaccinia virus thymidine kinase and neighboring genes: mRNAs and polypeptides of wild-type virus and putative nonsense mutants.

1983 ◽  
Vol 45 (1) ◽  
pp. 62-72 ◽  
Author(s):  
G Bajszár ◽  
R Wittek ◽  
J P Weir ◽  
B Moss
Keyword(s):  
Vaccinia Virus ◽  
Thymidine Kinase ◽  
Wild Type Virus ◽  
Type Virus ◽  
Wild Type

scholarly journals Vaccinia Virus Envelope H3L Protein Binds to Cell Surface Heparan Sulfate and Is Important for Intracellular Mature Virion Morphogenesis and Virus Infection In Vitro and In Vivo

2000 ◽  
Vol 74 (7) ◽  
pp. 3353-3365 ◽  
Author(s):  
Chi-Long Lin ◽  
Che-Sheng Chung ◽  
Hans G. Heine ◽  
Wen Chang
Keyword(s):  
Cell Surface ◽  
Vaccinia Virus ◽  
Heparan Sulfate ◽  
Mutant Virus ◽  
Wild Type Virus ◽  
Type Virus ◽  
Wild Type ◽  
Virion Morphogenesis

ABSTRACT An immunodominant antigen, p35, is expressed on the envelope of intracellular mature virions (IMV) of vaccinia virus. p35 is encoded by the viral late gene H3L, but its role in the virus life cycle is not known. This report demonstrates that soluble H3L protein binds to heparan sulfate on the cell surface and competes with the binding of vaccinia virus, indicating a role for H3L protein in IMV adsorption to mammalian cells. A mutant virus defective in expression of H3L (H3L−) was constructed; the mutant virus has a small plaque phenotype and 10-fold lower IMV and extracellular enveloped virion titers than the wild-type virus. Virion morphogenesis is severely blocked and intermediate viral structures such as viral factories and crescents accumulate in cells infected with the H3L− mutant virus. IMV from the H3L− mutant virus are somewhat altered and less infectious than wild-type virions. However, cells infected by the mutant virus form multinucleated syncytia after low pH treatment, suggesting that H3L protein is not required for cell fusion. Mice inoculated intranasally with wild-type virus show high mortality and severe weight loss, whereas mice infected with H3L− mutant virus survive and recover faster, indicating that inactivation of the H3L gene attenuates virus virulence in vivo. In summary, these data indicate that H3L protein mediates vaccinia virus adsorption to cell surface heparan sulfate and is important for vaccinia virus infection in vitro and in vivo. In addition, H3L protein plays a role in virion assembly.

scholarly journals Mutations in the Vaccinia Virus A33R and B5R Envelope Proteins That Enhance Release of Extracellular Virions and Eliminate Formation of Actin-Containing Microvilli without Preventing Tyrosine Phosphorylation of the A36R Protein

2003 ◽  
Vol 77 (22) ◽  
pp. 12266-12275 ◽  
Author(s):  
Ehud Katz ◽  
Brian M. Ward ◽  
Andrea S. Weisberg ◽  
Bernard Moss
Keyword(s):  
Vaccinia Virus ◽  
Envelope Protein ◽  
Actin Polymerization ◽  
Single Amino Acid ◽  
Wild Type Virus ◽  
Virus Release ◽  
Type Virus ◽  
Wild Type ◽  
Extracellular Virus

ABSTRACT The spread of vaccinia virus in cell cultures is mediated by virions that adhere to the tips of specialized actin-containing microvilli and also by virions that are released into the medium. The use of a small plaque-forming A36R gene deletion mutant to select spontaneous second-site mutants exhibiting enhanced virus release was described previously. Two types of mutations were found: C-terminal truncations of the A33R envelope protein and a single amino acid substitution of the B5R envelope protein. In the present study, we transferred each type of mutation into a wild-type virus background in order to study their effects in vitro and in vivo. The two new mutants conserved the enhanced virus release properties of the original isolates; the A33R mutant produced considerably more extracellular virus than the B5R mutant. The extracellular virus particles contained the truncated A33R protein in one case and the mutated B5R protein in the other. Remarkably, both mutants failed to form actin tails and specialized microvilli, despite the presence of an intact A36R gene. The synthesis of the A36R protein as well as its physical association with the mutated or wild-type A33R protein was demonstrated. Moreover, the A36R protein was tyrosine phosphorylated, a step mediated by a membrane-associated Src kinase that regulates the nucleation of actin polymerization. The presence of large numbers of adherent virions on the cell surface argued against rapid dissociation as having a key role in preventing actin tail formation. Thus, the A33R and B5R proteins may be more directly involved in the formation or stabilization of actin tails than had been previously thought. When mice were inoculated intranasally, the A33R mutant was highly attenuated and the B5R mutant was mildly attenuated compared to wild-type virus. Enhanced virus release, therefore, did not compensate for the loss of actin tails and specialized microvilli.

scholarly journals Vaccinia Virus Infection Attenuates Innate Immune Responses and Antigen Presentation by Epidermal Dendritic Cells

2006 ◽  
Vol 80 (20) ◽  
pp. 9977-9987 ◽  
Author(s):  
Liang Deng ◽  
Peihong Dai ◽  
Wanhong Ding ◽  
Richard D. Granstein ◽  
Stewart Shuman
Keyword(s):  
Virus Infection ◽  
Vaccinia Virus ◽  
Poly I:C ◽  
Wild Type Virus ◽  
Type Virus ◽  
Wild Type ◽  
Vaccinia Virus Infection ◽  
Tnf Α ◽  
Infected Cells ◽  
Virus Mutant

ABSTRACT Langerhans cells (LCs) are antigen-presenting cells in the skin that play sentinel roles in host immune defense by secreting proinflammatory molecules and activating T cells. Here we studied the interaction of vaccinia virus with XS52 cells, a murine epidermis-derived dendritic cell line that serves as a surrogate model for LCs. We found that vaccinia virus productively infects XS52 cells, yet this infection displays an atypical response to anti-poxvirus agents. Whereas adenosine N1-oxide blocked virus production and viral protein synthesis during a synchronous infection, cytosine arabinoside had no effect at concentrations sufficient to prevent virus replication in BSC40 monkey kidney cells. Vaccinia virus infection of XS52 cells not only failed to elicit the production of various cytokines, including tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), IL-6, IL-10, IL-12 p40, alpha interferon (IFN-α), and IFN-γ, it actively inhibited the production of proinflammatory cytokines TNF-α and IL-6 by XS52 cells in response to exogenous lipopolysaccharide (LPS) or poly(I:C). Infection with a vaccinia virus mutant lacking the E3L gene resulted in TNF-α secretion in the absence of applied stimuli. Infection of XS52 cells or BSC40 cells with the ΔE3L virus, but not wild-type vaccinia virus, triggered proteolytic decay of IκBα. These results suggest a novel role for the E3L protein as an antagonist of the NF-κB signaling pathway. ΔE3L-infected XS52 cells secreted higher levels of TNF-α and IL-6 in response to LPS and poly(I:C) than did cells infected with the wild-type virus. XS52 cells were productively infected by a vaccinia virus mutant lacking the K1L gene. ΔK1L-infected cells secreted higher levels of TNF-α and IL-6 in response to LPS than wild-type virus-infected cells. Vaccinia virus infection of primary LCs harvested from mouse epidermis was nonpermissive, although a viral reporter protein was expressed in the infected LCs. Vaccinia virus infection of primary LCs strongly inhibited their capacity for antigen-specific activation of T cells. Our results highlight suppression of the skin immune response as a feature of orthopoxvirus infection.

scholarly journals Failure of Thymidine Kinase-Negative Herpes Simplex Virus To Reactivate from Latency following Efficient Establishment

2004 ◽  
Vol 78 (1) ◽  
pp. 520-523 ◽  
Author(s):  
Shih-Heng Chen ◽  
Angela Pearson ◽  
Donald M. Coen ◽  
Shun-Hua Chen
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Thymidine Kinase ◽  
Wild Type Virus ◽  
Trigeminal Ganglia ◽  
Type Virus ◽  
Wild Type ◽  
Viral Loads ◽  
Simplex Virus

ABSTRACT Thymidine kinase-negative mutants of herpes simplex virus did not reactivate from latency in mouse trigeminal ganglia, even when their latent viral loads were comparable to those that permitted reactivation by wild-type virus. Thus, reduced establishment of latency does not suffice to account for the failure to reactivate.

scholarly journals Blockade of Interferon Induction and Action by the E3L Double-Stranded RNA Binding Proteins of Vaccinia Virus

2002 ◽  
Vol 76 (10) ◽  
pp. 5251-5259 ◽  
Author(s):  
Ying Xiang ◽  
Richard C. Condit ◽  
Sangeetha Vijaysri ◽  
Bertram Jacobs ◽  
Bryan R. G. Williams ◽  
...  
Keyword(s):  
Vaccinia Virus ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Wild Type Virus ◽  
Rnase L ◽  
Type Virus ◽  
Wild Type ◽  
Double Stranded Rna ◽  
Interferon System

ABSTRACT The vaccinia virus E3L gene encodes two double-stranded RNA binding proteins that promote viral growth and pathogenesis through suppression of innate immunity. To explore how E3L enables vaccinia virus to evade the interferon system, cells and mice deficient in the principal interferon-regulated antiviral enzymes, PKR and RNase L, were infected with wild-type vaccinia virus and strains of vaccinia virus from which E3L had been deleted (E3L-deleted strains). While wild-type virus was unaffected by RNase L and PKR, virus lacking E3L replicated only in the deficient cells. Nevertheless, E3L-deleted virus failed to replicate to high titers or to cause significant morbidity or mortality in triply deficient mice lacking RNase L, PKR, and Mx1. To investigate the underlying cause, we determined the effect of E3L on interferon regulatory factor 3 (IRF3), a transcription factor required for viral induction of subtypes of type I interferons. Results showed that IRF3 activation and interferon-β induction occurred after infections with E3L-deleted virus but not with wild-type virus. These findings demonstrate that E3L plays an essential role in the pathogenesis of vaccinia virus by blocking the interferon system at multiple levels. Furthermore, our results indicate the existence of an interferon-mediated antipoxvirus pathway that operates independently of PKR, Mx1, or the 2-5A/RNase L system.

The URNA Genes of Herpesvirus Saimiri (Strain C488) Are Dispensable for Transformation of Human T Cells In Vitro

1999 ◽  
Vol 73 (12) ◽  
pp. 10551-10555 ◽  
Author(s):  
Armin Ensser ◽  
André Pfinder ◽  
Ingrid Müller-Fleckenstein ◽  
Bernhard Fleckenstein
Keyword(s):  
Cell Culture ◽  
Herpesvirus Saimiri ◽  
Wild Type Virus ◽  
Type Virus ◽  
Wild Type ◽  
Human T Cell ◽  
Human T Cells ◽  
Small Nuclear Rnas ◽  
T Cell Lines

ABSTRACT The herpesvirus saimiri strain C488 genome contains five genes for small nuclear RNAs, termed herpesvirus saimiri URNAs (or HSURs). Using a cosmid-based approach, all HSURs were precisely deleted from the genome. The mutant virus replicated at levels that were similar to those of wild-type viruses in OMK cells. Although the HSURs are expressed in wild-type virus-transformed human T-cell lines, the deletion does not affect viral transformation in cell culture.

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