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Shchelkanov Miu - One of the best experts on this subject based on the ideXlab platform.
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Taxonomic status of the Burana virus (BURV) (Bunyaviridae, Nairovirus, Tamdy group) isolated from the ticks Haemaphysalis punctata Canestrini et Fanzago, 1877 and Haem. concinna Koch, 1844 (Ixodidae, Haemaphysalinae) in Kyrgyzstan
Voprosy virusologii, 2014Co-Authors: Shchelkanov MiuAbstract:Complete genome sequence of the Burana virus (BURV) was determined using the next-generation sequencing approach (ID GenBank KF801651). The prototype strain of BURV LEIV-Krg760 was originally isolated from the ticks Haemaphysalis punctata Canestrini et Fanzago, 1877 (Ixodidae, Haemaphysalinae), collected from cows in Tokmak wildlife sanctuary, eastern part of the Chu valley (43 degrees 10' N, 74 degrees 40' E) near Burana village, Kirgizia, in April 1971. Molecular genetics and phylogenetic analyses showed that the BURV belonged to the Nairovirus genus, Bunyaviridae and is related to Tamdy virus (TAMV) that is also associated with the ixodidae ticks of pasture biocenosis in Central Asia. Previous studies showed that TAMV is the prototypic virus of new phylogenetic Tamdy group in the Nairovirus genus. Thus, BURV was classified as a new virus of the Tamdy group, Nairovirus, Bunyaviridae.
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Taxonomic status of the Artashat virus (ARTSV) (Bunyaviridae, Nairovirus) isolated from the ticks Ornithodoros alactagalis Issaakjan, 1936 and O. verrucosus Olenev, Sassuchin et Fenuk, 1934 (Argasidae Koch, 1844) collected in Transcaucasia
Voprosy virusologii, 2014Co-Authors: Shchelkanov MiuAbstract:The Artashat virus (ARTSV) was originally isolated fom the Ornithodoros alactagalis Issaakjan, 1936 (Argasidae Koch, 1844), which were collected in the burrow of small five-toed jerboa (Allactaga elater Lichtenstein, 1825) in Armenia in 1972. Later, the ARTSV was isolated from the O. verrucosus Olenev, Sassuchin et Fenuk, 1934 collected in the burrows of Persian gerbil (Meriones persicus Blanford, 1875) in Azerbaijan. Based on the virion morphology, the ARTSV was assigned to the Bunyaviridae viruses. In this work, the ARTSV genome was partially sequenced (GenBank ID: KF801650) and it was shown that the ARTSV is a new member of the Nairovirus genus. ARTSV has from 42% (Issyk-Kul virus) to 58% (Raza virus, Hughes group) similarity with the Nairoviruses for nucleotide sequence of part of RNA-dependent RNA-polymerase (RdRp). The similarity on the amino acid level is 65-70%. Low level of homology and the equidistant position of the ARTSV on phylogenetic tree indicate that the ARTSV is a new prototype species of the Nairovirus genus (Bunyaviridae) forming a separate phylogenetic branch.
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Genetic characterization of the Sakhalin virus (SAKV), Paramushir virus (PMRV) (Sakhalin group, Nairovirus, Bunyaviridae), and Rukutama virus (RUKV) (Uukuniemi group, Phlebovirus, Bunyaviridae) isolated from the obligate parasites of the colonial sea
Voprosy virusologii, 2014Co-Authors: Shchelkanov MiuAbstract:Full-length genomes of the Sakhalin virus (SAKH) and Paramushir virus (PRMV) (Sakhalin group, Nairovirus, Bunyaviridae) isolated from the ticks Ixodes uriae White 1852 were sequenced using the next-generation sequencing (Genbank ID: KF801659, KF801656). SAKV and PRMV have 81% identity for the part of RNA-dependent RNA-polymerase (RdRp) on the nucleotide level and 98.5% on the amino acid level. Full-length genome comparison shows that SAKV have, in average, from 25% (N-protein, S-segment) to 50% (RdRp, L-segment) similarity with the Nairoviruses. The maximum value of the amino acid similarity (50.3% for RdRp) SAKV have with the Crimean-Congo hemorrhagic fever virus (CCHFV) and Dugbe virus (DUGV), which are also associated with the Ixodidae ticks. Another virus studied is Rukutama virus (RUKV) (isolated from ticks I. signatus Birulya, 1895) that recently was classified (based on morphology and antigenic reaction) to the Nairovirus genus, presumably to the Sakhalin group. In this work the genome of the RUKV was sequenced (KF892052-KF892054) and RUKV was classified as a member of the Uukuniemi group (Phlebovirus, Bunyaviridae). RUKV is closely related (93.0-95.5% similarity) with our previously described Komandory virus (KOMV). RUKV and KOMV form separate phylogenetic line neighbor of Manawa virus (MWAV) isolated from the ticks Argas abdussalami Hoogstraal et McCarthy, 1965 in Pakistan. The value of the similarity between RUCV and MWAV is 65-74% on the amino acid level.
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Genetic characterization of the Geran virus (GERV, Bunyaviridae, Nairovirus, Qalyub group) isolated from the ticks Ornithodoros verrucosus Olenev, Zasukhin and Fenyuk, 1934 (Argasidae) collected in the burrow of Meriones erythrourus Grey, 1842 in Aze
Voprosy virusologii, 2014Co-Authors: Shchelkanov MiuAbstract:The full-length genome of the unclassified Geran virus (GERV, strain LEIV-10899Az) isolated from the ticks (Ornithodoros verrucosus Olenev, Zasukhin and Fenyuk, 1934 (Argasidae, Ornithodorinae)) collected in the burrow of the red-tailed gerbils (Meriones (Cricedidae) erythrourus Grey, 1842) near the Geran station (Azerbaijan) was sequenced using the next-generation approach (GenBank ID: KF801649). It was shown that the GERV is a new representative of the Nairovirus genus (family Bunyaviridae). The comparative analysis of the full-length genome sequences of the GERV with other Nairoviruses showed that the highest level of homology (55.6% for N protein (S-segment) of 54.2% for the polyprotein Gn/Gc (M-segment) and 74.8% for the RNA-dependent RNA polymerase (L-segment)) GERV had with the Chim virus (CHIMV) that is also associated with the shelters biocenoses (rodent burrows) in Central Asia and was previously assigned to the Qalyub virus group (QYBV). Comparing the GERV with the QYBV sequences (partial sequence 413 n.o. of RdRp gene) revealed a high level of homology: 74.3 and 97.4% for the nucleotide and amino acid sequences, respectively. The data obtained in this work provided an opportunity to classify the GERV to the QYBV group; the Nairovirus genus, to the family Bunyaviridae.
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Genetic characterization of the Caspiy virus (CASV) (Bunyaviridae, Nairovirus) isolated from the Laridae (Vigors, 1825) and Sternidae (Bonaparte, 1838) birds and the Argasidae (Koch, 1844) ticks Ornithodoros capensis Neumann, 1901, in Western and Eas
Voprosy virusologii, 2014Co-Authors: Shchelkanov MiuAbstract:Full-genome sequencing of the Caspiy virus (CASV - Caspiy virus) (ID GenBank KF801658) revealed its attribution to the Nairovirus genus of the Bunyaviridae family as a separate species. CASV forms separate line, which is the most close to the Hughes virus (HUGV) and Sakhalin virus (SAKV) groups containing viruses linked with seabirds and ticks parasitizing on them and distributed over the shelf and island ecosystems in the Northern Eurasia, as well as the North and South America.
Scott D Pegan - One of the best experts on this subject based on the ideXlab platform.
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determining the molecular drivers of species specific interferon stimulated gene product 15 interactions with Nairovirus ovarian tumor domain proteases
PLOS ONE, 2019Co-Authors: J V Dzimianski, Florine E M Scholte, Isabelle L Williams, Caroline Langley, Brendan T Freitas, Jessica R Spengler, Eric Bergeron, Scott D PeganAbstract:Tick-borne Nairoviruses (order Bunyavirales) encode an ovarian tumor domain protease (OTU) that suppresses the innate immune response by reversing the post-translational modification of proteins by ubiquitin (Ub) and interferon-stimulated gene product 15 (ISG15). Ub is highly conserved across eukaryotes, whereas ISG15 is only present in vertebrates and shows substantial sequence diversity. Prior attempts to address the effect of ISG15 diversity on viral protein-ISG15 interactions have focused on only a single species' ISG15 or a limited selection of Nairovirus OTUs. To gain a more complete perspective of OTU-ISG15 interactions, we biochemically assessed the relative activities of 14 diverse Nairovirus OTUs for 12 species' ISG15 and found that ISG15 activity is predominantly restricted to particular Nairovirus lineages reflecting, in general, known virus-host associations. To uncover the underlying molecular factors driving OTUs affinity for ISG15, X-ray crystal structures of Kupe virus and Ganjam virus OTUs bound to sheep ISG15 were solved and compared to complexes of Crimean-Congo hemorrhagic fever virus and Erve virus OTUs bound to human and mouse ISG15, respectively. Through mutational and structural analysis seven residues in ISG15 were identified that predominantly influence ISG15 species specificity among Nairovirus OTUs. Additionally, OTU residues were identified that influence ISG15 preference, suggesting the potential for viral OTUs to adapt to different host ISG15s. These findings provide a foundation to further develop research methods to trace Nairovirus-host relationships and delineate the full impact of ISG15 diversity on Nairovirus infection.
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Sequence and structural diversity of Nairovirus vOTUs.
2019Co-Authors: John V. Dzimianski, Florine E M Scholte, Eric Bergeron, Brianna S. Beldon, Courtney M. Daczkowski, Octavia Y. Goodwin, Scott D PeganAbstract:(A) Phylogenetic tree of CLUSTALW aligned Nairovirus vOTUs. The tree was constructed utilizing the Jones-Thornton-Taylor model in the MEGA7 program [70]. Current species groupings are indicated by colored ovals, and the assigned species denoted. Previous serogroup classification, if applicable, is shown in parentheses. Virus vOTUs included in this study are denoted by red lettering. Inset is a structure-based phylogenetic tree of vOTUs, with the mammalian Cezanne, A20, and OTULIN OTUs included for comparison. The tree was constructed using PDB IDs 3PRP, 4HXD, 5JZE, 6DX1, 6DX2, 6DX3, 6DX5, 5LRV, 5LRX, and 3ZNZ in the MultiSeq module of VMD [71]. Sequence accession numbers are included in S1 Table. CCHFV, Crimean-Congo hemorrhagic fever virus; GANV, Ganjam virus; NSDV, Nairobi sheep disease virus; DUGV, Dugbe virus; KUPEV, Kupe virus; HAZV, Hazara virus; TFLV, Tofla virus; TAGV, Taggert virus; TILLV, Tillamook virus; SAKV, Sakhalin virus; PRMV, Paramushir virus; AVAV, Avalon virus; ARTSV, Artashat virus; TFAV, Thiafora virus; ERVEV, Erve virus; HUGV, Hughes virus; FARV, Farallon virus; RAZAV, Raza virus; PSV, Punta Salinas virus; ZIRV, Zirqa virus; SOLV, Soldado virus; GRSV, Great Saltee virus; CASV, Caspiy virus; AHV, Abu Hammad virus; DGKV, Dera Ghazi Khan virus; SAPV, Sapphire II virus; WzTV, Wēnzhōu tick virus; BURV, Burana virus; HpTV-1, Huángpí tick virus 1; TcTV-1, Tǎchéng tick virus 1; TDYV, Tamdy virus; YOGV, Yogue virus; LPHV, Leopards Hill virus; QYBV, Qalyub virus; GERV, Geran virus; CHIMV, Chim virus; GOSV, Gossas virus; ISKV, Issyk-kul virus; UZAV, Uzun-Agach virus; KTRV, Keterah virus. (B) Nairovirus vOTUs tested in this study aligned using the T-Coffee sequence alignment program [72]. Percentages show the sequence identity relative to CCHFV vOTU. Generic vOTU secondary structure based on Define Secondary Structure of Proteins (DSSP) algorithm calculations for the vOTUs is shown in reddish orange, with the α3 and α4 helices of FARV vOTU shown in teal. The catalytic triad is boxed in black and the selectivity pocket in orange. Mutation sites related to the selectivity pocket are shown by yellow stars, sites related to differences in how FARV vOTU engages mono-Ub by blue stars, and the DGKV vOTU catalytic triad mutant by a green star. Mutation sites for the second Ub binding site in FARV vOTU are denoted by red stars. The region deleted in the FARV vOTUΔ79–107 construct is indicated by a bracket.
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Diversity of Ubiquitin and ISG15 Specificity among Nairoviruses' Viral Ovarian Tumor Domain Proteases
Journal of Virology, 2013Co-Authors: Glenn C. Capodagli, Michelle K. Deaton, Erica A. Baker, Ryan J Lumpkin, Scott D PeganAbstract:Nairoviruses are responsible for numerous diseases that affect both humans and animal. Recent work has implicated the viral ovarian tumor domain (vOTU) as a possible Nairovirus virulence factor due to its ability to edit ubiquitin (Ub) bound to cellular proteins and, at least in the case of Crimean-Congo hemorrhagic fever virus (CCHFV), to cleave the Ub-like protein interferon-stimulated gene 15 (ISG15), a protein involved in the regulation of host immunity. The prospective roles of vOTUs in immune evasion have generated several questions concerning whether vOTUs act through a preserved specificity for Ub- and ISG15-conjugated proteins and where that specificity may originate. To gain insight into the substrate specificity of vOTUs, enzymological studies were conducted on vOTUs from Dugbe, CCHFV, and Erve Nairoviruses. These studies revealed that vOTUs originating from different Nairoviruses display a significant divergence in their preference toward Ub and ISG15. In addition, a recently identified vOTU from turnip yellow mosaic tymovirus was evaluated to elucidate any possible similarities between vOTUs originating from different viral families. Although possessing a similar preference for certain polymeric Ub moieties, its activity toward Ub in general was significantly less then those of Nairoviruses. Lastly, the X-ray crystallographic structure of the vOTU from the Dugbe Nairovirus was obtained in complex with Ub to reveal structural commonalities of vOTUs originating from Nairoviruses. The structure suggests that divergences between Nairovirus vOTUs specificity originate at the primary structural level. Comparison of this structure to that originating from CCHFV identified key residues that infer the substrate specificity of vOTUs.
John N. Barr - One of the best experts on this subject based on the ideXlab platform.
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Hazara Nairovirus Requires COPI Components in both Arf1-Dependent and Arf1-Independent Stages of Its Replication Cycle.
Journal of Virology, 2020Co-Authors: Jack Fuller, Roger Hewson, Jamel Mankouri, Beatriz Álvarez-rodríguez, Eleanor J. A. A. Todd, John N. BarrAbstract:Hazara Nairovirus (HAZV) is an enveloped trisegmented negative-strand RNA virus classified within the Nairoviridae family of the Bunyavirales order and a member of the same subtype as Crimean-Congo hemorrhagic fever virus, responsible for fatal human disease. Nairoviral subversion of cellular trafficking pathways to permit viral entry, gene expression, assembly, and egress is poorly understood. Here, we generated a recombinant HAZV expressing enhanced green fluorescent protein and used live-cell fluorescent imaging to screen an siRNA library targeting genes involved in cellular trafficking networks, the first such screen for a Nairovirus. The screen revealed prominent roles for subunits of the coat protein 1 (COPI)-vesicle coatomer, which regulates retrograde trafficking of cargo between the Golgi apparatus and the endoplasmic reticulum, as well as intra-Golgi transport. We show the requirement of COPI-coatomer subunits impacted at least two stages of the HAZV replication cycle: an early stage prior to and including gene expression and also a later stage during assembly and egress of infectious virus, with COPI-knockdown reducing titers by approximately 1,000-fold. Treatment of HAZV-infected cells with brefeldin A (BFA), an inhibitor of Arf1 activation required for COPI coatomer formation, revealed that this late COPI-dependent stage was Arf1 dependent, consistent with the established role of Arf1 in COPI vesicle formation. In contrast, the early COPI-dependent stage was Arf1 independent, with neither BFA treatment nor siRNA-mediated ARF1 knockdown affecting HAZV gene expression. HAZV exploitation of COPI components in a noncanonical Arf1-independent process suggests that COPI coatomer components may perform roles unrelated to vesicle formation, adding further complexity to our understanding of cargo-mediated transport.IMPORTANCE Nairoviruses are tick-borne enveloped RNA viruses that include several pathogens responsible for fatal disease in humans and animals. Here, we analyzed host genes involved in trafficking networks to examine their involvement in Nairovirus replication. We revealed important roles for genes that express multiple components of the COPI complex, which regulates transport of Golgi apparatus-resident cargos. COPI components influenced at least two stages of the Nairovirus replication cycle: an early stage prior to and including gene expression and also a later stage during assembly of infectious virus, with COPI knockdown reducing titers by approximately 1,000-fold. Importantly, while the late stage was Arf1 dependent, as expected for canonical COPI vesicle formation, the early stage was found to be Arf1 independent, suggestive of a previously unreported function of COPI unrelated to vesicle formation. Collectively, these data improve our understanding of Nairovirus host-pathogen interactions and suggest a new Arf1-independent role for components of the COPI coatomer complex.
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Mutagenic Analysis of Hazara Nairovirus Nontranslated Regions during Single- and Multistep Growth Identifies both Attenuating and Functionally Critical Sequences for Virus Replication.
Journal of Virology, 2020Co-Authors: Daniele F. Mega, Roger Hewson, Jamel Mankouri, Jack Fuller, Beatriz Álvarez-rodríguez, John N. BarrAbstract:Hazara Nairovirus (HAZV) is a member of the family Nairoviridae in the order Bunyavirales and closely related to Crimean-Congo hemorrhagic fever virus, which is responsible for severe and fatal human disease. The HAZV genome comprises three segments of negative-sense RNA, named S, M, and L, with nontranslated regions (NTRs) flanking a single open reading frame. NTR sequences regulate RNA synthesis and, by analogy with other segmented negative-sense RNA viruses, may direct activities such as virus assembly and innate immune modulation. The terminal-proximal nucleotides of 3' and 5' NTRs exhibit extensive terminal complementarity; the first 11 nucleotides are strictly conserved and form promoter element 1 (PE1), with adjacent segment-specific nucleotides forming PE2. To explore the functionality of NTR nucleotides within the context of the Nairovirus multiplication cycle, we designed infectious HAZV mutants bearing successive deletions throughout both S segment NTRs. Fitness of rescued viruses was assessed in single-step and multistep growth, which revealed that the 3' NTR was highly tolerant to change, whereas several deletions of centrally located nucleotides in the 5' NTR led to significantly reduced growth, indicative of functional disruption. Deletions that encroached upon PE1 and PE2 ablated virus growth and identified additional adjacent nucleotides critical for viability. Mutational analysis of PE2 suggest that its signaling ability relies solely on interterminal base pairing and is an independent cis-acting signaling module. This study represents the first mutagenic analysis of nairoviral NTRs in the context of the infectious cycle, and the mechanistic implications of our findings for Nairovirus RNA synthesis are discussed.IMPORTANCE Nairoviruses are a group of RNA viruses that include many serious pathogens of humans and animals, including one of the most serious human pathogens in existence, Crimean-Congo hemorrhagic fever virus. The ability of Nairoviruses to multiply and cause disease is controlled in major part by nucleotides that flank the 3' and 5' ends of nairoviral genes, called nontranslated regions (NTRs). NTR nucleotides interact with other virus components to perform critical steps of the virus multiplication cycle, such as mRNA transcription and RNA replication, with other roles being likely. To better understand how NTRs work, we performed the first comprehensive investigation of the importance of NTR nucleotides in the context of the entire Nairovirus replication cycle. We identified both dispensable and critical NTR nucleotides, as well as highlighting the importance of 3' and 5' NTR interactions in virus growth, thus providing the first functional map of the Nairovirus NTRs.
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Hazara Nairovirus elicits differential induction of apoptosis and nucleocapsid protein cleavage in mammalian and tick cells
Journal of General Virology, 2019Co-Authors: Jack Fuller, Rebecca Surtees, Roger Hewson, Jamel Mankouri, Thomas A. Edwards, Beatriz Álvarez-rodríguez, A. B. Shaw, Gillian S. Slack, Lesley Bell-sakyi, John N. BarrAbstract:The Nairoviridae family within the Bunyavirales order comprise tick-borne segmented negative-sense RNA viruses that cause serious disease in a broad range of mammals, yet cause a latent and lifelong infection in tick hosts. An important member of this family is Crimean-Congo haemorrhagic fever virus (CCHFV), which is responsible for serious human disease that results in case fatality rates of up to 30 %, and which exhibits the most geographically broad distribution of any tick-borne virus. Here, we explored differences in the cellular response of both mammalian and tick cells to Nairovirus infection using Hazara virus (HAZV), which is a close relative of CCHFV within the CCHFV serogroup. We show that HAZV infection of human-derived SW13 cells led to induction of apoptosis, evidenced by activation of cellular caspases 3, 7 and 9. This was followed by cleavage of the classical apoptosis marker poly ADP-ribose polymerase, as well as cellular genome fragmentation. In addition, we show that the HAZV nucleocapsid (N) protein was abundantly cleaved by caspase 3 in these mammalian cells at a conserved DQVD motif exposed at the tip of its arm domain, and that cleaved HAZV-N was subsequently packaged into nascent virions. However, in stark contrast, we show for the first time that Nairovirus infection of cells of the tick vector failed to induce apoptosis, as evidenced by undetectable levels of cleaved caspases and lack of cleaved HAZV-N. Our findings reveal that Nairoviruses elicit diametrically opposed cellular responses in mammalian and tick cells, which may influence the infection outcome in the respective hosts.
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Heat Shock Protein 70 Family Members Interact with Crimean-Congo Hemorrhagic Fever Virus and Hazara Virus Nucleocapsid Proteins and Perform a Functional Role in the Nairovirus Replication Cycle
Journal of Virology, 2016Co-Authors: Rebecca Surtees, Sd Dowall, Ja Hiscox, Amelia Shaw, Stuart D. Armstrong, Roger Hewson, Miles W. Carroll, Jamel Mankouri, Thomas A. Edwards, John N. BarrAbstract:ABSTRACT The Nairovirus genus of the Bunyaviridae family contains serious human and animal pathogens classified within multiple serogroups and species. Of these serogroups, the Crimean-Congo hemorrhagic fever virus (CCHFV) serogroup comprises sole members CCHFV and Hazara virus (HAZV). CCHFV is an emerging zoonotic virus that causes often-fatal hemorrhagic fever in infected humans for which preventative or therapeutic strategies are not available. In contrast, HAZV is nonpathogenic to humans and thus represents an excellent model to study aspects of CCHFV biology under conditions of more-accessible biological containment. The three RNA segments that form the Nairovirus genome are encapsidated by the viral nucleocapsid protein (N) to form ribonucleoprotein (RNP) complexes that are substrates for RNA synthesis and packaging into virus particles. We used quantitative proteomics to identify cellular interaction partners of CCHFV N and identified robust interactions with cellular chaperones. These interactions were validated using immunological methods, and the specific interaction between native CCHFV N and cellular chaperones of the HSP70 family was confirmed during live CCHFV infection. Using infectious HAZV, we showed for the first time that the Nairovirus N-HSP70 association was maintained within both infected cells and virus particles, where N is assembled as RNPs. Reduction of active HSP70 levels in cells by the use of small-molecule inhibitors significantly reduced HAZV titers, and a model for chaperone function in the context of high genetic variability is proposed. These results suggest that chaperones of the HSP70 family are required for Nairovirus replication and thus represent a genetically stable cellular therapeutic target for preventing Nairovirus-mediated disease. IMPORTANCE Nairoviruses compose a group of human and animal viruses that are transmitted by ticks and associated with serious or fatal disease. One member is Crimean-Congo hemorrhagic fever virus (CCHFV), which is responsible for fatal human disease and is recognized as an emerging threat within Europe in response to climate change. No preventative or therapeutic strategies against Nairovirus-mediated disease are currently available. Here we show that the N protein of CCHFV and the related Hazara virus interact with a cellular protein, HSP70, during both the intracellular and extracellular stages of the virus life cycle. The use of inhibitors that block HSP70 function reduces virus titers by up to 1,000-fold, suggesting that this interaction is important within the context of the Nairovirus life cycle and may represent a potent target for antiNairovirus therapies against which the virus cannot easily develop resistance.
Jn Barr - One of the best experts on this subject based on the ideXlab platform.
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Heat Shock Protein 70 family members interact with Crimean-Congo hemorrhagic fever virus and Hazara virus nucleocapsid proteins and perform a functional role in the Nairovirus replication cycle
'American Society for Microbiology', 2016Co-Authors: Surtees R, Sd Dowall, Shaw A, Armstrong S, Hewson R, Mw Carroll, Mankouri J, Ta Edwards, Ja Hiscox, Jn BarrAbstract:The Nairovirus genus of the Bunyaviridae family contains serious human and animal pathogens classified within multiple serogroups and species. Of these serogroups, the Crimean-Congo hemorrhagic fever virus (CCHFV) serogroup comprises sole members CCHFV and Hazara virus (HAZV). CCHFV is an emerging zoonotic virus that causes often-fatal hemorrhagic fever in infected humans for which preventative or therapeutic strategies are not available. In contrast HAZV is non-pathogenic to humans, and thus represents an excellent model to study aspects of CCHFV biology under more accessible biological containment. The three RNA segments that form the Nairovirus genome are encapsidated by the viral nucleocapsid protein (N) to form ribonucleoprotein (RNP) complexes that are substrates for RNA synthesis and packaging into virus particles. We used quantitative proteomics to identify cellular interaction partners of CCHFV N, and identified robust interactions with cellular chaperones. These interactions were validated using immunological methods, and the specific interaction between native CCHFV N and cellular chaperones of the HSP70 family was confirmed during live CCHFV infection. Using infectious HAZV we showed for the first time that the Nairovirus N-HSP70 association was maintained within both infected cells and virus particles, where N is assembled as RNPs. Reduction of active HSP70 levels in cells using small molecule inhibitors significantly reduced HAZV titres, and a model for chaperone function in the context of high genetic variability is proposed. These results suggest chaperones of the HSP70 family are required for Nairovirus replication and thus represent a genetically stable cellular therapeutic target for preventing Nairovirus-mediated disease
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Heat Shock Protein 70 Family Members Interact with Crimean-Congo Hemorrhagic Fever Virus and Hazara Virus Nucleocapsid Proteins and Perform a Functional Role in the Nairovirus Replication Cycle
'American Society for Microbiology', 2016Co-Authors: Surtees R, Sd Dowall, Shaw A, Armstrong S, Hewson R, Mw Carroll, Mankouri J, Ta Edwards, Ja Hiscox, Jn BarrAbstract:The Nairovirus genus of the Bunyaviridae family contains serious human and animal pathogens classified within multiple serogroups and species. Of these serogroups, the Crimean-Congo hemorrhagic fever virus (CCHFV) serogroup comprises sole members CCHFV and Hazara virus (HAZV). CCHFV is an emerging zoonotic virus that causes often-fatal hemorrhagic fever in infected humans for which preventative or therapeutic strategies are not available. In contrast, HAZV is nonpathogenic to humans and thus represents an excellent model to study aspects of CCHFV biology under conditions of more-accessible biological containment. The three RNA segments that form the Nairovirus genome are encapsidated by the viral nucleocapsid protein (N) to form ribonucleoprotein (RNP) complexes that are substrates for RNA synthesis and packaging into virus particles. We used quantitative proteomics to identify cellular interaction partners of CCHFV N and identified robust interactions with cellular chaperones. These interactions were validated using immunological methods, and the specific interaction between native CCHFV N and cellular chaperones of the HSP70 family was confirmed during live CCHFV infection. Using infectious HAZV, we showed for the first time that the Nairovirus N-HSP70 association was maintained within both infected cells and virus particles, where N is assembled as RNPs. Reduction of active HSP70 levels in cells by the use of small-molecule inhibitors significantly reduced HAZV titers, and a model for chaperone function in the context of high genetic variability is proposed. These results suggest that chaperones of the HSP70 family are required for Nairovirus replication and thus represent a genetically stable cellular therapeutic target for preventing Nairovirus-mediated disease
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Expression, purification and crystallization of the Crimean-Congo haemorrhagic fever virus nucleocapsid protein.
Acta crystallographica. Section F Structural biology and crystallization communications, 2012Co-Authors: S D Carter, Jn Barr, Ta EdwardsAbstract:Crimean-Congo haemorrhagic fever virus (CCHFV) is a member of the Nairovirus genus within the Bunyaviridae family of segmented negative-sense RNA viruses. This paper describes the expression, purification and crystallization of full-length CCHFV nucleocapsid (N) protein and the collection of a 2.1 Å resolution X-ray diffraction data set using synchrotron radiation. Crystals of the CCHFV N protein belonged to space group C2, with unit-cell parameters a = 150.38, b = 72.06, c = 101.23 Å, β = 110.70° and two molecules in the asymmetric unit. Circular-dichroism analysis provided insight into the secondary structure, whilst gel-filtration analysis revealed possible oligomeric states of the N protein. Structural determination is ongoing.
Stuart T. Nichol - One of the best experts on this subject based on the ideXlab platform.
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The Crimean-Congo Hemorrhagic Fever Virus NSm Protein Is Dispensable for Growth In Vitro and Disease in Ifnar-/- Mice
Microorganisms, 2020Co-Authors: Stephen R. Welch, Stuart T. Nichol, Florine E M Scholte, Jessica R Spengler, Jana M. Ritter, Joann D. Coleman-mccray, Jessica R. Harmon, Sherif R. Zaki, Christina F. Spiropoulou, Eric BergeronAbstract:Crimean-Congo hemorrhagic fever virus (CCHFV) is a tri-segmented, tick-borne Nairovirus that causes disease of ranging severity in humans. The CCHFV M segment encodes a complex glycoprotein precursor (GPC) that undergoes extensive endoproteolytic cleavage, giving rise to two structural proteins (Gn and Gc) required for virus attachment and entry, and to multiple non-structural proteins (NSm, GP160, GP85, and GP38). The functions of these non-structural proteins remain largely unclear. Here, we investigate the role of NSm during infection by generating a recombinant CCHFV lacking the complete NSm domain (10200∆NSm) and observing CCHFV ∆NSm replication in cell lines and pathogenicity in Ifnar-/- mice. Our data demonstrate that the NSm domain is dispensable for viral replication in vitro, and, despite the delayed onset of clinical signs, CCHFV lacking this domain caused severe or lethal disease in infected mice.
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Crimean–Congo hemorrhagic fever virus genome L RNA segment and encoded protein
Virology, 2004Co-Authors: Jessica E. Honig, Jane C. Osborne, Stuart T. NicholAbstract:Abstract Sequence analysis of the L RNA genome segment and predicted encoded L polymerase protein of Crimean–Congo hemorrhagic fever (CCHF) virus (genus Nairovirus, family Bunyaviridae) demonstrates that they are approximately twice the size of those found in viruses of other bunyavirus genera. The CCHF virus L segment and encoded protein (12164 nucleotides and 3944 amino acids, respectively) are similar in size and sequence to those of the Nairovirus Dugbe virus (12255/62% and 4036/62% nucleotide and amino acid length/identity, respectively). The identification of an ovarian tumor (OTU)-like protease motif in the L protein amino termini of the Nairoviruses Dugbe, CCHF, and Nairobi sheep disease (NSD) indicates these proteins are members of the recently described OTU-like protease family and suggests that these large proteins may be polyproteins that are autoproteolytically cleaved or involved in deubiquitination.
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The high genetic variation of viruses of the genus Nairovirus reflects the diversity of their predominant tick hosts.
Virology, 2004Co-Authors: Jessica E. Honig, Jane C. Osborne, Stuart T. NicholAbstract:The genus Nairovirus (family Bunyaviridae) contains seven serogroups consisting of 34 predominantly tick-borne viruses, including several associated with severe human and livestock diseases [e.g., Crimean Congo hemorrhagic fever (CCHF) and Nairobi sheep disease (NSD), respectively]. Before this report, no comparative genetic studies or molecular detection assays had been developed for this virus genus. To characterize at least one representative from each of the seven serogroups, reverse transcriptase-polymerase chain reaction (RT-PCR) primers targeting the L polymerase-encoding region of the RNA genome of these viruses were successfully designed based on conserved amino acid motifs present in the predicted catalytic core region. Sequence analysis showed the Nairoviruses to be a highly diverse group, exhibiting up to 39.4% and 46.0% nucleotide and amino acid identity differences, respectively. Virus genetic relationships correlated well with serologic groupings and with tick host associations. Hosts of these viruses include both the hard (family Ixodidae) and soft (family Argasidae) ticks. Virus phylogenetic analysis reveals two major monophyletic groups: hard tick and soft tick-vectored viruses. In addition, viruses vectored by Ornithodoros, Carios, and Argas genera ticks also form three separate monophyletic lineages. The striking similarities between tick and Nairovirus phylogenies are consistent with possible coevolution of the viruses and their tick hosts. Fossil and phylogenetic data placing the hard tick–soft tick divergence between 120 and 92 million years ago suggest an ancient origin for viruses of the genus Nairovirus.
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Nairobi sheep disease virus, an important tick-borne pathogen of sheep and goats in Africa, is also present in Asia.
Virology, 2002Co-Authors: Beate I. Marczinke, Stuart T. NicholAbstract:Nairobi sheep disease (NSD) virus is the prototype of the tick-borne NSD serogroup, genus Nairovirus, family Bunyaviridae. It is highly pathogenic for sheep and goats, causes disease in humans, and is widespread throughout East Africa. Ganjam virus has caused disease in goats and humans in India. Due to their occurrence on different continents and association with different ticks, these viruses were considered distinct despite serologic cross-reactivity. Their S RNA genome segments and encoded nucleocapsid proteins were found to be 1590 nucleotides and 482 amino acids in length and differed by only 10 and 3% at nucleotide and amino acid levels, respectively. Genetic and serologic data demonstrate that Ganjam virus is an Asian variant of NSD virus. These viruses were phylogenetically more closely related to Hazara virus than Dugbe virus.
