Ancient Gene Capture and Recent Gene Loss Shape the Evolution of Orthopoxvirus-Host Interaction Genes

Orthopoxviruses (ORPV) include smallpox (variola) virus, one of the most devastating human pathogens, and vaccinia virus, comprising the vaccine used for smallpox eradication. Among roughly 200 ORPV genes, about half are essential for genome replication and expression as well as virion morphogenesis, whereas the remaining half consists of accessory genes counteracting the host immune response.

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Low-Resolution Structure of Vaccinia Virus DNA Replication Machinery

Journal of Virology ◽

10.1128/jvi.01533-12 ◽

2012 ◽

Vol 87 (3) ◽

pp. 1679-1689 ◽

Cited By ~ 19

Author(s):

Céleste Sèle ◽

Frank Gabel ◽

Irina Gutsche ◽

Ivan Ivanov ◽

Wim P. Burmeister ◽

...

Keyword(s):

Vaccinia Virus ◽

Recombinant Expression ◽

Rotational Symmetry ◽

Vaccination Campaign ◽

Virus Genome ◽

Genome Replication ◽

Variola Virus ◽

Replication Machinery ◽

Content Type ◽

Rolling Circle

ABSTRACTSmallpox caused by the poxvirus variola virus is a highly lethal disease that marked human history and was eradicated in 1979 thanks to a worldwide mass vaccination campaign. This virus remains a significant threat for public health due to its potential use as a bioterrorism agent and requires further development of antiviral drugs. The viral genome replication machinery appears to be an ideal target, although very little is known about its structure. Vaccinia virus is the prototypic virus of theOrthopoxvirusgenus and shares more than 97% amino acid sequence identity with variola virus. Here we studied four essential viral proteins of the replication machinery: the DNA polymerase E9, the processivity factor A20, the uracil-DNA glycosylase D4, and the helicase-primase D5. We present the recombinant expression and biochemical and biophysical characterizations of these proteins and the complexes they form. We show that the A20D4 polymerase cofactor binds to E9 with high affinity, leading to the formation of the A20D4E9 holoenzyme. Small-angle X-ray scattering yielded envelopes for E9, A20D4, and A20D4E9. They showed the elongated shape of the A20D4 cofactor, leading to a 150-Å separation between the polymerase active site of E9 and the DNA-binding site of D4. Electron microscopy showed a 6-fold rotational symmetry of the helicase-primase D5, as observed for other SF3 helicases. These results favor a rolling-circle mechanism of vaccinia virus genome replication similar to the one suggested for tailed bacteriophages.

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Clustered Charge-to-Alanine Mutagenesis of the Vaccinia Virus H5 Gene: Isolation of a Dominant, Temperature-Sensitive Mutant with a Profound Defect in Morphogenesis

Journal of Virology ◽

10.1128/jvi.74.5.2393-2405.2000 ◽

2000 ◽

Vol 74 (5) ◽

pp. 2393-2405 ◽

Cited By ~ 54

Author(s):

Joseph DeMasi ◽

Paula Traktman

Keyword(s):

Gene Expression ◽

Vaccinia Virus ◽

Viral Gene Expression ◽

Gene Isolation ◽

Viral Gene ◽

Temperature Sensitive ◽

Genome Replication ◽

Nonpermissive Temperature ◽

Viral Yield ◽

Virion Morphogenesis

ABSTRACT The vaccinia virus H5 gene encodes a 22.3-kDa phosphoprotein that is expressed during both the early and late phases of viral gene expression. It is a major component of virosomes and has been implicated in viral transcription and, as a substrate of the B1 kinase, may participate in genome replication. To enable a genetic analysis of the role of H5 during the viral life cycle, we used clustered charge-to-alanine mutagenesis in an attempt to create a temperature-sensitive (ts) virus with a lesion in the H5 gene. Five mutant viruses were isolated, with one of them,tsH5-4, having a strong ts phenotype as assayed by plaque formation and measurements of 24-h viral yield. Surprisingly, no defects in genome replication or viral gene expression were detected at the nonpermissive temperature. By electron microscopy, we observed a profound defect in the early stages of virion morphogenesis, with arrest occurring prior to the formation of crescent membranes or immature particles. Nonfunctional, “curdled” virosomes were detected in tsH5-4 infections at the nonpermissive temperature. These structures appeared to revert to functional virosomes after a temperature shift to permissive conditions. We suggest an essential role for H5 in normal virosome formation and the initiation of virion morphogenesis. By constructing recombinant genomes containing two H5 alleles, wild type and H5-4, we determined that H5-4 exerted a dominant phenotype. tsH5-4 is the first example of a dominant ts mutant isolated and characterized in vaccinia virus.

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Genetic variation analyses indicate conserved SARS‐CoV‐2‐host interaction and varied genetic adaptation in immune‐response factors in modern human evolution

Development Growth & Differentiation ◽

10.1111/dgd.12717 ◽

2021 ◽

Author(s):

Ji‐Won Lee ◽

In‐Hee Lee ◽

Takanori Sato ◽

Sek Won Kong ◽

Tadahiro Iimura

Keyword(s):

Immune Response ◽

Genetic Variation ◽

Human Evolution ◽

Modern Human ◽

Genetic Adaptation ◽

Response Factors ◽

Host Interaction

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Characterization of a Novel Thermobifida fusca Bacteriophage P318

Viruses ◽

10.3390/v11111042 ◽

2019 ◽

Vol 11 (11) ◽

pp. 1042

Author(s):

Cheepudom ◽

Lin ◽

Lee ◽

Meng

Keyword(s):

Plant Cell Wall ◽

Hydrolytic Enzymes ◽

Thermobifida Fusca ◽

Genome Replication ◽

Putative Orfs ◽

Base Pairs ◽

Double Stranded Dna ◽

Virion Morphogenesis ◽

Genome Information

Thermobifida fusca is of biotechnological interest due to its ability to produce an array of plant cell wall hydrolytic enzymes. Nonetheless, only one T. fusca bacteriophage with genome information has been reported to date. This study was aimed at discovering more relevant bacteriophages to expand the existing knowledge of phage diversity for this host species. With this end in view, a thermostable T. fusca bacteriophage P318, which belongs to the Siphoviridae family, was isolated and characterized. P318 has a double-stranded DNA genome of 48,045 base pairs with 3′-extended COS ends, on which 52 putative ORFs are organized into clusters responsible for the order of genome replication, virion morphogenesis, and the regulation of the lytic/lysogenic cycle. In comparison with T. fusca and the previously discovered bacteriophage P1312, P318 has a much lower G+C content in its genome except at the region encompassing ORF42, which produced a protein with unknown function. P1312 and P318 share very few similarities in their genomes except for the regions encompassing ORF42 of P318 and ORF51 of P1312 that are homologous. Thus, acquisition of ORF42 by lateral gene transfer might be an important step in the evolution of P318.

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Temporal regulation of influenza hemagglutinin expression in vaccinia virus recombinants and effects on the immune response

European Journal of Immunology ◽

10.1002/eji.1830161203 ◽

1986 ◽

Vol 16 (12) ◽

pp. 1479-1487 ◽

Cited By ~ 95

Author(s):

Barbara E. H. Coupar ◽

Marion E. Andrew ◽

Gerald W. Both ◽

David B. Boyle

Keyword(s):

Immune Response ◽

Vaccinia Virus ◽

Temporal Regulation ◽

Influenza Hemagglutinin

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Immunological Memory after Exposure to Variola Virus, Monkeypox Virus, and Vaccinia Virus

The Journal of Infectious Diseases ◽

10.1086/512161 ◽

2007 ◽

Vol 195 (8) ◽

pp. 1151-1159 ◽

Cited By ~ 11

Author(s):

Sumathi Sivapalasingam ◽

Jeffrey S. Kennedy ◽

William Borkowsky ◽

Fred Valentine ◽

Ming‐Xia Zhan ◽

...

Keyword(s):

Vaccinia Virus ◽

Immunological Memory ◽

Variola Virus ◽

Monkeypox Virus

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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

Journal of Virology ◽

10.1128/jvi.74.7.3353-3365.2000 ◽

2000 ◽

Vol 74 (7) ◽

pp. 3353-3365 ◽

Cited By ~ 183

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.

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Evaluation of Anti-HBs Antibody Immune Response against Hepatitis B virus in Vaccinated People in а North-eastern Bulgaria Region

Folia Medica ◽

10.3897/folmed.61.e47760 ◽

2019 ◽

Vol 61 (4) ◽

pp. 572-578

Author(s):

Denitsa T. Tsaneva-Damyanova ◽

Liliya I. Ivanova ◽

Silviya N. Pavlova ◽

Svetlana B. Todorova ◽

Tsvetelina K. Popova

Keyword(s):

Immune Response ◽

Hepatitis B Virus ◽

Hepatitis B ◽

Age Groups ◽

University Hospital ◽

Human Pathogens ◽

Serum Samples ◽

Post Vaccination ◽

B Virus ◽

Mass Immunization

Introduction: Hepatitis B virus (HBV) is one of the most significant human pathogens responsible for a huge number of acute and chronic liver infectious diseases worldwide. Aim: To find the duration of post-vaccination immune response in individuals allocated to five age groups from 6 months to 20 years. Materials and methods: All tested subjects were born between 1999 and 2018 and therefore covered by the compulsory vaccination program against hepatitis B. For the serological marker anti-HBs Ab we investigated 449 serum samples taken from ambulatory people and patients of St Marina University Hospital in Varna. Results: A positive antibody response (anti-HBs Ab > 10 mIU/ml) was reported in 79.7% (n = 51) of the group of subjects up to one year old, in 70.0% (n = 196) of the subjects in the age range 1 year/1 month to 15 years, and in 39.3% (n = 33) of the subjects 15 years/1 month to 20 years old. Female sex had a better post-vaccination response than male sex with statistically significant relationship between sex and anti-HBs Ab titer (χ2 = 24.76, p <0.01). Conclusions: Regardless of the mass immunization against HBV in Bulgaria, the relative share of chronic HBV infections does not show a downward trend. Therefore, it is very important to study the duration of the post-vaccination immune response by demonstrating the anti-HBs antibodies and to apply a booster dose from the vaccine if needed.

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Neutralization Assay Using a Modified Vaccinia Virus Ankara Vector Expressing the Green Fluorescent Protein Is a High-Throughput Method To Monitor the Humoral Immune Response against Vaccinia Virus

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.11.2.406-410.2004 ◽

2004 ◽

Vol 11 (2) ◽

pp. 406-410 ◽

Cited By ~ 18

Author(s):

Antonio Cosma ◽

Silja Bühler ◽

Rashmi Nagaraj ◽

Caroline Staib ◽

Anna-Lena Hammarin ◽

...

Keyword(s):

Immune Response ◽

Green Fluorescent Protein ◽

Vaccinia Virus ◽

High Throughput ◽

Neutralizing Antibodies ◽

Fluorescent Protein ◽

Safety Concern ◽

Neutralization Assay ◽

Modified Vaccinia Virus Ankara ◽

Green Fluorescent

ABSTRACT Vaccination against smallpox is again considered in order to face a possible bioterrorist threat, but the nature and the level of the immune response needed to protect a person from smallpox after vaccination are not totally understood. Therefore, simple, rapid, and accurate assays to evaluate the immune response to vaccinia virus need to be developed. Neutralization assays are usually considered good predictors of vaccine efficacy and more informative with regard to protection than binding assays. Currently, the presence of neutralizing antibodies to vaccinia virus is measured using a plaque reduction neutralization test, but this method is time-consuming and labor-intensive and has a subjective readout. Here, we describe an innovative neutralization assay based on a modified vaccinia virus Ankara (MVA) vector expressing the green fluorescent protein (MVA-gfp). This MVA-gfp neutralization assay is rapid and sensitive and has a high-throughput potential. Thus, it is suitable to monitor the immune response and eventually the efficacy of a large campaign of vaccination against smallpox and to study the vector-specific immune response in clinical trials that use genetically engineered vaccinia viruses. Most importantly, application of the highly attenuated MVA eliminates the safety concern in using the replication-competent vaccinia virus in the standard clinical laboratory.

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