Publications by authors named "Boris Gavrilov"

10 Publications

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Development of an inactivated combined vaccine for protection of cattle against lumpy skin disease and bluetongue viruses.

Vet Microbiol 2021 May 23;256:109046. Epub 2021 Mar 23.

Research and Development, MCI Santé Animale, ZI Sud-Ouest B.P: 278, Mohammedia, 28810, Morocco.

Lumpy Skin Disease (LSD) and Bluetongue (BT) are the main ruminants viral vector-borne diseases. LSD is endemic in Africa and has recently emerged in Europe and central Asia as a major threat to cattle industry. BT caused great economic damage in Europe during the last decade with a continuous spread to other countries. To control these diseases, vaccination is the only economically viable tool. For LSD, only live-attenuated vaccines (LAVs) are commercially available, whilst for BT both LAVs and inactivated vaccines are available with a limited number of serotypes. In this study, we developed an inactivated, oil adjuvanted bivalent vaccine against both diseases based on LSDV Neethling strain and BTV4. The vaccine was tested for safety and immunogenicity on cattle during a one-year period. Post-vaccination monitoring was carried out by VNT and ELISA. The vaccine was completely safe and elicited high neutralizing antibodies starting from the first week following the second injection up to one year. Furthermore, a significant correlation (R = 0.9040) was observed when comparing VNT and competitive ELISA in BTV4 serological response. Following BTV4 challenge, none of vaccinated and unvaccinated cattle were registered clinical signs, however vaccinated cattle showed full protection from viraemia. In summary, this study highlights the effectiveness of this combined vaccine as a promising solution for both LSD and BT control. It also puts an emphasis on the need for the development of other multivalent inactivated vaccines, which could be greatly beneficial for improving vaccination coverage in endemic countries and prophylaxis of vector-borne diseases.
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http://dx.doi.org/10.1016/j.vetmic.2021.109046DOI Listing
May 2021

Development and Evaluation of an Inactivated Lumpy Skin Disease Vaccine for Cattle.

Vet Microbiol 2020 Jun 18;245:108689. Epub 2020 Apr 18.

Research and development Virology, Multi-Chemical Industry, Lot. 157, ZI Sud-Ouest (ERAC) B.P: 278, Mohammedia 28810, Morocco.

Lumpy skin disease (LSD) of cattle is caused by a virus within Capripoxvirus genus. It leads to huge economic losses in addition to trade and animal movement limitation. Vaccination is the only economically feasible way to control this vector-borne disease. Only live attenuated vaccines have been used so far and no inactivated vaccine has been developed nor tested in cattle. In this study, we developed an inactivated oily adjuvanted vaccine based on Neethling strain and tested it on cattle. Selected criteria of appreciation were safety, antibody response by Virus Neutralization and protection through challenge. A field trial was also performed in Bulgaria. The vaccine was safe and did not cause any adverse reaction, high level of specific antibodies was obtained starting from day 7 post-vaccination and protection against virulent challenge strain that caused typical disease in control animals was total. Induced protection was similar to that obtained with live vaccine, without any adverse effect. In addition, the field study confirmed safety and efficacy of the vaccine, which did not show any adverse reaction and induced a high level of antibodies for up to one year. General prophylaxis based on inactivated vaccine could be of great benefit in endemic countries or at risk regions.
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http://dx.doi.org/10.1016/j.vetmic.2020.108689DOI Listing
June 2020

Structural characterization of the PCV2d virus-like particle at 3.3 Å resolution reveals differences to PCV2a and PCV2b capsids, a tetranucleotide, and an N-terminus near the icosahedral 3-fold axes.

Virology 2019 11 3;537:186-197. Epub 2019 Sep 3.

CUNY School of Medicine, City College of New York, NY, 10031, USA.

Porcine circovirus 2 (PCV2) has a major impact on the swine industry. Eight PCV2 genotypes (a-h) have been identified using capsid sequence analysis. PCV2d has been designated as the emerging genotype. The cryo-electron microscopy molecular envelope of PCV2d virus-like particles identifies differences between PCV2a, b and d genotypes that accompany the emergence of PCV2b from PCV2a, and PCV2d from PCV2b. These differences indicate that sequence analysis of genotypes is insufficient, and that it is important to determine the PCV2 capsid structure as the virus evolves. Structure-based sequence comparison demonstrate that each genotype possesses a unique combination of amino acids located on the surface of the capsid that undergo substitution. We also demonstrate that the capsid N-terminus moves in response to increasing amount of nucleic acid packaged into the capsid. Furthermore, we model a tetranucleotide between the 5- and 2-fold axes of symmetry that appears to be responsible for capsid stability.
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http://dx.doi.org/10.1016/j.virol.2019.09.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6958667PMC
November 2019

Recognition of heparan sulfate by clinical strains of dengue virus serotype 1 using recombinant subviral particles.

Virus Res 2013 Sep 22;176(1-2):69-77. Epub 2013 May 22.

Program in Applied Biological Sciences: Environmental Health, Chulabhorn Graduate Institute, Bangkok, Thailand.

Dengue is the most important arthropod-borne viral disease in humans, with an estimated 3.6 billion people at risk for infection and more than 200 million infections per year. Identification of the cellular receptors for dengue virus (DV), the causative agent of dengue, is important toward understanding the pathogenesis of the disease. Heparan sulfate (HS) has been characterized as a DV receptor in multiple model systems, however the physiological relevance of these findings has been questioned by observations that flaviviruses, including DV, can undergo cell culture adaptation changes resulting in increased binding to HS. It thus remains unclear whether HS is utilized by clinical, non-cell culture-adapted strains of DV. To address this question, herein we describe a set of methodologies using recombinant subviral particles (RSPs) to determine the utilization of HS by clinical strains of DV serotype 1 (DV1). RSPs of clinically isolated strains with low cell culture passage histories were used to study HS interaction. Biochemically characterized RSPs showed dose-dependent binding to immobilized heparin, which could be competed by heparin and HS but not structurally related glycosaminoglycans chondroitin sulfate A and hyaluronic acid. The relevance of heparin and HS biochemical interactions was demonstrated by competition of RSP and DV binding to cells with soluble heparin and HS. Our results demonstrate that clinical strains of DV1 can specifically interact with heparin and HS. Together, these data support the possibility that HS on cell surfaces is utilized in the DV-human infection process.
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http://dx.doi.org/10.1016/j.virusres.2013.04.017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4145673PMC
September 2013

Effects of glycosylation on antigenicity and immunogenicity of classical swine fever virus envelope proteins.

Virology 2011 Nov 2;420(2):135-45. Epub 2011 Oct 2.

Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, CT 06269, USA.

Classical swine fever virus (CSFV) harbors three envelope glycoproteins (E(rns), E1 and E2). Previous studies have demonstrated that removal of specific glycosylation sites within these proteins yielded attenuated and immunogenic CSFV mutants. Here we analyzed the effects of lack of glycosylation of baculovirus-expressed E(rns), E1, and E2 proteins on immunogenicity. Interestingly, E(rns), E1, and E2 proteins lacking proper post-translational modifications, most noticeable lack of glycosylation, failed to induce a detectable virus neutralizing antibody (NA) response and protection against CSFV. Similarly, no NA or protection was observed in pigs immunized with E1 glycoprotein. Analysis of E(rns) and E2 proteins with single site glycosylation mutations revealed that detectable antibody responses, but not protection against lethal CSFV challenge is affected by removal of specific glycosylation sites. In addition, it was observed that single administration of purified E(rns) glycoprotein induced an effective protection against CSFV infection.
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http://dx.doi.org/10.1016/j.virol.2011.08.025DOI Listing
November 2011

Identification of an NTPase motif in classical swine fever virus NS4B protein.

Virology 2011 Mar 13;411(1):41-9. Epub 2011 Jan 13.

Plum Island Animal Disease Center, ARS, USDA, Greenport, NY 11944, USA.

Classical swine fever (CSF) is a highly contagious and often fatal disease of swine caused by CSF virus (CSFV), a positive-sense single-stranded RNA virus within the Pestivirus genus of the Flaviviridae family. Here, we have identified conserved sequence elements observed in nucleotide-binding motifs (NBM) that hydrolyze NTPs within the CSFV non-structural (NS) protein NS4B. Expressed NS4B protein hydrolyzes both ATP and GTP. Substitutions of critical residues within the identified NS4B NBM Walker A and B motifs significantly impair the ATPase and GTPase activities of expressed proteins. Similar mutations introduced into the genetic backbone of a full-length cDNA copy of CSFV strain Brescia rendered no infectious viruses or viruses with impaired replication capabilities, suggesting that this NTPase activity is critical for the CSFV cycle. Recovered mutant viruses retained a virulent phenotype, as parental strain Brescia, in infected swine. These results have important implications for developing novel antiviral strategies against CSFV infection.
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http://dx.doi.org/10.1016/j.virol.2010.12.028DOI Listing
March 2011

Human herpesvirus-6 in patients with Crohn's disease.

APMIS 2010 May;118(5):394-400

Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs-Mansfield, CT, USA.

Human herpesvirus-6 (HHV-6) infections are usually asymptomatic reactivations in immunocompetent persons, but may be severe in immunocompromised individuals. Although primary HHV-6 infection is mainly associated with roseola infantum, it has also been associated with gastroenteritis, diarrhea, and nausea in children. In this study, we investigated the potential role of HHV-6 in Crohn's disease (CD). Evidence of HHV-6 infection in CD patients and controls was determined by immunohistochemistry (IHC), polymerase chain reaction (PCR), and quantitative real-time PCR (qPCR). Fifty-one tissue blocks from 23 CD patients and 20 tissue blocks from 20 controls were examined. Quantitativereal-time PCR was used to assess HHV-6 viral loads. IHC, PCR and qPCR indicated the presence of HHV-6 in both CD patients and controls. Immunohistochemistry of tissues revealed an almost equal frequency and distribution of positive cells; however, non-specific immunostaining confounded interpretation. HHV-6 DNA was detected in 52% (12/23) of CD and 55% (11/20) of control patients by PCR and in 69.5% (16/23) of CD cases and 65% (13/20) of controls by qPCR. Mean viral load in intestinal tissues was similar in CD and controls (33.4 and 57.9 copies microg(-1) DNA, respectively). Finding equal evidence of HHV-6 in patients and controls by multiple methods suggests that this virus is ubiquitous and probably not a cause of CD.
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http://dx.doi.org/10.1111/j.1600-0463.2010.02613.xDOI Listing
May 2010

Diversified reassortant H9N2 avian influenza viruses in chicken flocks in northern and eastern China.

Virus Res 2010 Jul 25;151(1):26-32. Epub 2010 Mar 25.

Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Science, 10 Sang Yuan Road, Jinan, Shandong 250001, China.

According to our previous study of the M genes of H9N2 avian influenza viruses (AIV) in infected chickens, A/Quail/Hong Kong/G1/97 (G1 97)-like M genes newly emerged in northern and eastern China in addition to the existing A/chicken/Hong Kong/Y280/97 (Y280)-like lineage M genes. To systematically track the genesis and evolution of H9N2 viruses in this region, whole genome sequences of seventeen H9N2 isolates were obtained and their phylogenetic properties were determined. Phylogenetic analysis revealed several newly emerged lineages of gene segments in addition to the Y280-like and A/chicken/Shanghai/F/98(F 98)-like lineages, which are prevailing in northern and eastern China according to previous reports. Reassortments among these gene segments generated five novel genotypes of H9N2 viruses that have not been reported before in China. The emerging genotypes of H9N2 viruses in this region indicate that H9N2 virus genes undergo active evolution, particularly their internal genes, which raises concern for their likely contribution to gene reassortment and production of AIVs with new properties. Our study provides valuable insight into the prevalence of H9N2 viruses in northern and eastern China and demonstrates the need of long-term monitoring of the evolution of H9N2 AIV.
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http://dx.doi.org/10.1016/j.virusres.2010.03.010DOI Listing
July 2010

Slow elimination of phosphorylated histone gamma-H2AX from DNA of terminally differentiated mouse heart cells in situ.

Biochem Biophys Res Commun 2006 Sep 12;347(4):1048-52. Epub 2006 Jul 12.

Institute of Cytology, Russian Academy of Sciences, 194064 St. Petersburg, Russian Federation.

Phosphorylation of replacement histone H2AX occurs in megabase chromatin domains around double-strand DNA breaks (DSBs) and this modification (called gamma-H2AX) may serve as a useful marker of genome damage and repair in terminally differentiated cells. Here using immunohistochemistry we studied kinetics of gamma-H2AX formation and elimination in the X-irradiated mouse heart and renal epithelial tissues in situ. Unirradiated tissues have 3-5% gamma-H2AX-positive cells and in tissues fixed 1h after X-irradiation gamma-H2AX-positive nuclei are induced in a dose-dependent manner approaching 20-30% after 3 Gy of IR. Analysis of mouse tissues at different times after 3 Gy of IR showed that maximal induction of gamma-H2AX in heart is observed 20 min after IR and then is decreased slowly with about half remaining 23 h later. In renal epithelium maximum of the gamma-H2AX-positive cells is observed 40 min after IR and then decreases to control values in 23 h. This indicates that there are significant variations between non-proliferating mammalian tissues in the initial H2AX phosphorylation rate as well as in the rate of gamma-H2AX elimination after X-irradiation, which should be taken into account in the analysis of radiation responses.
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http://dx.doi.org/10.1016/j.bbrc.2006.07.005DOI Listing
September 2006

Downregulation of peroxiredoxin V stimulates formation of etoposide-induced double-strand DNA breaks.

FEBS Lett 2004 Aug;572(1-3):75-9

Institute of Cytology, Russian Academy of Sciences, Tikchoretskii Av.4, 194064 St. Petersburg, Russia.

Antioxidant protein Peroxiredoxin V (PrxV) is located in mitochondria and peroxisomes but is also present in the nucleus. Here, we show that nuclear PrxV associates with coilin-containing bodies suggesting possible interaction of this protein with transcription complexes. We also studied etoposide-induced phosphorylation of histone H2AX (gamma-H2AX) in human cells in which PrxV activity was downregulated (knockdown, KD-clones) or compromised by overexpression of redox-negative (RD) protein. In KD clones, but not in RD-clones, formation of etoposide-induced gamma-H2AX was increased, indicating that PrxV inhibits conversion of topoisomerase II cleavage complexes into double-strand DNA breaks but this inhibition is not caused by its antioxidant activity.
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http://dx.doi.org/10.1016/j.febslet.2004.07.011DOI Listing
August 2004
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