Localization of the non-structural protein NS3 in bluetongue virus-infected cells

Bluetongue virus (BTV), an arbovirus transmitted by Culicoides biting midges, is a major concern of wild and domestic ruminants. While BTV induces type I interferon (alpha/beta interferon [IFN-α/β]) production in infected cells, several reports have described evasion strategies elaborated by this virus to dampen this intrinsic, innate response. In the present study, we suggest that BTV VP3 is a new viral antagonist of the IFN-β synthesis. Indeed, using split luciferase and coprecipitation assays, we report an interaction between VP3 and both the mitochondrial adapter protein MAVS and the IRF3-kinase IKKε. Overall, this study describes a putative role for the BTV structural protein VP3 in the control of the antiviral response.

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NTP binding and phosphohydrolase activity associated with purified bluetongue virus non-structural protein NS2

Journal of General Virology ◽

10.1099/0022-1317-81-8-1961 ◽

2000 ◽

Vol 81 (8) ◽

pp. 1961-1965 ◽

Cited By ~ 16

Author(s):

Nigel J. Horscroft ◽

Polly Roy

Keyword(s):

Bluetongue Virus ◽

Inclusion Bodies ◽

Insect Cells ◽

Expression System ◽

Baculovirus Expression System ◽

Structural Protein ◽

Baculovirus Expression ◽

Infected Cells ◽

Viral Inclusion ◽

Hydrolysis Of

The bluetongue virus ssRNA-binding protein, NS2, is a phosphoprotein that forms viral inclusion bodies in infected cells. Recombinant NS2 was expressed in the baculovirus expression system and purified to homogeneity from insect cells. Purified NS2 bound nucleosides. Further investigation revealed that the protein bound ATP and GTP and could hydrolyse both nucleosides to their corresponding NMPs, with a higher efficiency for the hydrolysis of ATP. The increased efficiency of hydrolysis of ATP correlated with a higher binding affinity of NS2 for ATP than GTP. Ca2+, Mg2+ and Mn2+ were able to function as the required divalent cation in the reactions. The phosphohydrolase activity was not sensitive to ouabain, an inhibitor of cellular ATPases, suggesting that this activity was not the result of a cellular contaminant.

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Multiple Routes of Bluetongue Virus Egress

Microorganisms ◽

10.3390/microorganisms8070965 ◽

2020 ◽

Vol 8 (7) ◽

pp. 965

Author(s):

Thomas Labadie ◽

Edward Sullivan ◽

Polly Roy

Keyword(s):

Cell Sorting ◽

Bluetongue Virus ◽

Economic Loss ◽

Structural Protein ◽

Enveloped Virus ◽

Main Driver ◽

Multiple Routes ◽

Infected Cells ◽

Virus Egress

Bluetongue virus (BTV) is an arthropod-borne virus infecting livestock. Its frequent emergence in Europe and North America had caused significant agricultural and economic loss. BTV is also of scientific interest as a model to understand the mechanisms underlying non-enveloped virus release from mammalian and insect cells. The BTV particle, which is formed of a complex double-layered capsid, was first considered as a lytic virus that needs to lyse the infected cells for cell to cell transmission. In the last decade, however, a more in-depth focus on the role of the non-structural proteins has led to several examples where BTV particles are also released through different budding mechanisms at the plasma membrane. It is now clear that the non-structural protein NS3 is the main driver of BTV release, via different interactions with both viral and cellular proteins of the cell sorting and exocytosis pathway. In this review, we discuss the most recent advances in the molecular biology of BTV egress and compare the mechanisms that lead to lytic or non-lytic BTV release.

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Differential Localization of Structural and Non-Structural Proteins during the Bluetongue Virus Replication Cycle

Viruses ◽

10.3390/v12030343 ◽

2020 ◽

Vol 12 (3) ◽

pp. 343 ◽

Cited By ~ 1

Author(s):

Bjorn-Patrick Mohl ◽

Adeline Kerviel ◽

Thomas Labadie ◽

Eiko Matsuo ◽

Polly Roy

Keyword(s):

Virus Replication ◽

Bluetongue Virus ◽

Structured Illumination ◽

Structural Protein ◽

Structured Illumination Microscopy ◽

Virus Maturation ◽

Virus Particles ◽

Active Core ◽

Infected Cells ◽

Virus Replication Cycle

Members of the Reoviridae family assemble virus factories within the cytoplasm of infected cells to replicate and assemble virus particles. Bluetongue virus (BTV) forms virus inclusion bodies (VIBs) that are aggregates of viral RNA, certain viral proteins, and host factors, and have been shown to be sites of the initial assembly of transcriptionally active virus-like particles. This study sought to characterize the formation, composition, and ultrastructure of VIBs, particularly in relation to virus replication. In this study we have utilized various microscopic techniques, including structured illumination microscopy, and virological assays to show for the first time that the outer capsid protein VP5, which is essential for virus maturation, is also associated with VIBs. The addition of VP5 to assembled virus cores exiting VIBs is required to arrest transcriptionally active core particles, facilitating virus maturation. Furthermore, we observed a time-dependent association of the glycosylated non-structural protein 3 (NS3) with VIBs, and report on the importance of the two polybasic motifs within NS3 that facilitate virus trafficking and egress from infected cells at the plasma membrane. Thus, the presence of VP5 and the dynamic nature of NS3 association with VIBs that we report here provide novel insight into these previously less well-characterized processes.

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Umatilla Virus Association with Fibrils and Tubules in Cultured Cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600002063 ◽

1980 ◽

Vol 38 ◽

pp. 476-477

Author(s):

Neil M. Foster ◽

Ruth D. Breckon

Keyword(s):

Bluetongue Virus ◽

Linear Array ◽

Cultured Cells ◽

Intimate Association ◽

Infected Cells ◽

Dark Staining ◽

In Cells

Macrotubules have been described1 in cells infected with Umatilla virus (UMAV), an orbivirus for which bluetongue virus (BTV) is the protype. Macrotubules, often in linear array, were observed in the cytoplasm and in intimate association with viroplasms of infected cells. Macrotubules had outside and inside diameters of 20 and 15 nm and many had dark-staining centers with diameters similar to the interiors of the tubules. UMAV was 60 nm and the RNA core was 30 nm in diameter. This report describes the association of UMAV with macrotubules and two types of microtubules.

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Development of Bacteriophage Virus-Like Particle Vaccines Displaying Conserved Epitopes of Dengue Virus Non-Structural Protein 1

Vaccines ◽

10.3390/vaccines9070726 ◽

2021 ◽

Vol 9 (7) ◽

pp. 726

Author(s):

Nikole L. Warner ◽

Kathryn M. Frietze

Keyword(s):

Dengue Virus ◽

Population Based ◽

Ns1 Protein ◽

Structural Protein ◽

Denv Serotypes ◽

Conserved Regions ◽

Virus Like Particle ◽

Dependent Cell ◽

Infected Cells ◽

Plasma Leakage

Dengue virus (DENV) is a major global health problem, with over half of the world’s population at risk of infection. Despite over 60 years of efforts, no licensed vaccine suitable for population-based immunization against DENV is available. Here, we describe efforts to engineer epitope-based vaccines against DENV non-structural protein 1 (NS1). NS1 is present in DENV-infected cells as well as secreted into the blood of infected individuals. NS1 causes disruption of endothelial cell barriers, resulting in plasma leakage and hemorrhage. Immunizing against NS1 could elicit antibodies that block NS1 function and also target NS1-infected cells for antibody-dependent cell cytotoxicity. We identified highly conserved regions of NS1 from all four DENV serotypes. We generated synthetic peptides to these regions and chemically conjugated them to bacteriophage Qβ virus-like particles (VLPs). Mice were immunized two times with the candidate vaccines and sera were tested for the presence of antibodies that bound to the cognate peptide, recombinant NS1 from all four DENV serotypes, and DENV-2-infected cells. We found that two of the candidate vaccines elicited antibodies that bound to recombinant NS1, and one candidate vaccine elicited antibodies that bound to DENV-infected cells. These results show that an epitope-specific vaccine against conserved regions of NS1 could be a promising approach for DENV vaccines or therapeutics to bind circulating NS1 protein.

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Bluetongue virus non-structural protein 3 (NS3) and NS4 coordinatively antagonize type Ⅰ interferon signaling by targeting STAT1

Veterinary Microbiology ◽

10.1016/j.vetmic.2021.108986 ◽

2021 ◽

Vol 254 ◽

pp. 108986

Author(s):

Zhuoran Li ◽

Danfeng Lu ◽

Heng Yang ◽

Zhuoyue Li ◽

Pei Zhu ◽

...

Keyword(s):

Bluetongue Virus ◽

Interferon Signaling ◽

Structural Protein

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Protein synthesis in bluetongue virus-infected cells

Virology ◽

10.1016/0042-6822(79)90143-0 ◽

1979 ◽

Vol 92 (2) ◽

pp. 385-396 ◽

Cited By ~ 88

Author(s):

Hendrik Huismans

Keyword(s):

Protein Synthesis ◽

Bluetongue Virus ◽

Infected Cells

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A GFP Reporter MR766-Based Flow Cytometry Neutralization Test for Rapid Detection of Zika Virus-Neutralizing Antibodies in Serum Specimens

Vaccines ◽

10.3390/vaccines7030066 ◽

2019 ◽

Vol 7 (3) ◽

pp. 66 ◽

Cited By ~ 5

Author(s):

Frumence ◽

Viranaicken ◽

Gadea ◽

Desprès

Keyword(s):

Flow Cytometry ◽

Zika Virus ◽

Neutralizing Antibodies ◽

Neutralization Test ◽

Health Concern ◽

Structural Protein ◽

Adult Mice ◽

Gfp Reporter ◽

Infected Cells ◽

High Level

Zika virus (ZIKV) is an emerging arthropod-borne virus of major public health concern. ZIKV infection is responsible for congenital Zika disease and other neurological defects. Antibody-mediated virus neutralization is an essential component of protective antiviral immunity against ZIKV. In the present study, we assessed whether our GFP reporter ZIKV derived from African viral strain MR766 could be useful for the development of a flow cytometry neutralization test (FNT), as an alternative to the conventional plaque-reduction neutralization test (PRNT). To improve the efficacy of GFP-expressing MR766, we selected virus variant MR766GFP showing a high level of GFP signal in infected cells. A MR766GFP-based FNT was assayed with immune sera from adult mice that received ZIKBeHMR-2. The chimeric ZIKV clone ZIKBeHMR-2 comprises the structural protein region of epidemic strain BeH819015 into MR766 backbone. We reported that adult mice inoculated with ZIKBeHMR-2 developed high levels of neutralizing anti-ZIKV antibodies. Comparative analysis between MR766GFP-based FNT and conventional PRNT was performed using mouse anti-ZIKBeHMR-2 immune sera. Indistinguishable neutralization patterns were observed when compared with PRNT50 and FNT50. We consider that the newly developed MR766GFP-based FNT is a valid format for measuring ZIKV-neutralizing antibodies in serum specimens.

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