Publications by authors named "Kachko A"

In this study, we evaluated the immunogenicity and protective immunity of in vitro transcribed Venezuelan equine encephalitis virus (VEEV TC-83 strain) self-amplifying RNA (saRNA) encoding the SARS-CoV-2 spike (S) protein in wild type (S-WT) and stabilized pre-fusion conformations (S-PP). Immunization with S-WT and S-PP saRNA induced specific neutralizing antibody responses in both K18-Tg hACE2 (K18) and BALB/c mice, as assessed using SARS-CoV-2 pseudotyped viruses. Protective immunity was assessed in challenge experiments.

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Introduction: A hepatitis B vaccination (HepB) series with an initial dose of hepatitis B immune globulin (HBIG) is the recommended prophylaxis for infants born to mothers with chronic hepatitis B virus (HBV) infection and for HBV-exposed persons without known protection. The HepB and HBIG are administered at different sites (limbs). Instances of HepB and HBIG administered at the same site are documented but the impact on immune responses to HepB remains unanswered.

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The major route of hepatitis C virus (HCV) transmission in the United States is injection drug use. We hypothesized that if an HCV vaccine were available, vaccination could affect HCV transmission among people who inject drugs by reducing HCV titers after viral exposure without necessarily achieving sterilizing immunity. To investigate this possibility, we developed a mathematical model to determine transmission probabilities relative to the HCV RNA titers of needle/syringe-sharing donors.

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Hepatitis C virus (HCV) is the leading cause of chronic hepatitis in humans. Several host molecules participate in HCV cell entry, but this process remains unclear. The complete unraveling of the HCV entry process is important to further understand viral pathogenesis and develop therapeutics.

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T-cell based vaccines have been considered as attractive candidates for prevention of hepatitis C virus (HCV) infections. In this study we compared the magnitude and phenotypic characteristics of CD8+ T-cells induced by three commonly used viral vectors, Adenovirus-5 (Ad5), Vaccinia virus (VV) and Modified Vaccinia Ankara (MVA) expressing the HCV NS3/4A protein. C57/BL6 mice were primed with DNA expressing NS3/4A and boosted with each of the viral vectors in individual groups of mice.

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Unlabelled: Vaccine reverse engineering is emerging as an important approach to vaccine antigen identification, recently focusing mainly on structural characterization of interactions between neutralizing monoclonal antibodies (mAbs) and antigens. Using mAbs that bind unknown antigen structures, we sought to probe the intrinsic features of antibody antigen-binding sites with a high complexity peptide library, aiming to identify conformationally optimized mimotope antigens that capture mAb-specific epitopes. Using a high throughput sequencing-enhanced messenger ribonucleic acid (mRNA) display approach, we identified high affinity binding peptides for a hepatitis C virus neutralizing mAb.

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Unlabelled: Hepatitis C virus (HCV) neutralization occurring at the E2 region 412-426 (EP-I) could be enhanced when antibodies directed specifically to the E2 region 434-446 (EP-II) were removed from serum samples of persistently infected patients and vaccinated chimpanzees, a phenomenon of so-called antibody interference. Here, we show that this type of interference can be observed in individuals after immunization with recombinant E1E2 proteins. One hundred twelve blinded serum samples from a phase I, placebo-controlled, dose escalation trial using recombinant HCV E1E2 with MF59C.

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Plant or microbial lectins are known to exhibit potent antiviral activities against viruses with glycosylated surface proteins, yet the mechanism(s) by which these carbohydrate-binding proteins exert their antiviral activities is not fully understood. Hepatitis C virus (HCV) is known to possess glycosylated envelope proteins (gpE1E2) and to be potently inhibited by lectins. Here, we tested in detail the antiviral properties of the newly discovered Microcystis viridis lectin (MVL) along with cyanovirin-N (CV-N) and Galanthus nivalis agglutinin (GNA) against cell culture HCV, as well as their binding properties toward viral particles, target cells, and recombinant HCV glycoproteins.

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Antibodies to epitopes in the E2 protein of hepatitis C virus (HCV) reduce the viral infectivity in vivo and in vitro. However, the virus can persist in patients in the presence of neutralizing antibodies. In this study, we generated a panel of monoclonal antibodies that bound specifically to the region between residues 427 and 446 of the E2 protein of HCV genotype 1a, and we examined their capacity to neutralize HCV in a cell culture system.

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One of the greatest challenges to HCV vaccine development is the induction of effective immune responses using recombinant proteins or vectors. In order to better understand which vaccine-induced antibodies contribute to neutralization of HCV the quality of polyclonal anti-E1E2 antibody responses in immunized mice and chimpanzees was assessed at the level of epitope recognition using peptide scanning and neutralization of chimeric 1a/2a, 1b/2a and 2a HCVcc after blocking or affinity elution of specific antibodies. Mice and chimpanzees were immunized with genotype 1a (H77) HCV gpE1E2; all samples contained cross-neutralizing antibody against HCVcc.

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Zaire ebolavirus (ZEBOV) causes severe hemorrhagic fever in primates, whereas in guinea pigs it induces a nonlethal infection with a mild fever and subsequent recovery. We performed 7 selective passages in guinea pigs resulted in obtaining of guinea pig-adapted strain (GPA-P7) strain. By the 7th passage, the infection with EBOV induced a lethal disease in animals accompanied by the characteristic hematological changes: leukocytosis (primarily due to neutrophilia) as well as pronounced deficiencies in platelets, lymphocytes, monocytes and significant decrease of blood neutrophils phagocytic capacity.

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Recombinant polypeptide containing the 260-466 amino acid sequence of West Nile virus (WNV) strain LEIV-Vlg99-27889-human glycoprotein E (gpE, E(260-466)) was constructed. Immunochemical similarity between the E(260-466) and gpE of WNV was proven by enzyme immunoassay (EIA), immunoblot, competitive EIA, hemagglutination inhibition, and neutralization tests using polyclonal and monoclonal antibodies against the viral gpE and recombinant E(260-466). Polypeptide E(260-466) induced formation of virus neutralizing and cross-reactive antibodies that were interactive with various epitopes of this recombinant protein.

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A prime/boost vaccine strategy that transfects antigen-presenting cells using ligand-modified immunoliposomes to efficiently deliver plasmid DNA, followed by boosting with non-replicating recombinant adenovirus was used in chimpanzees to generate HCV-specific memory T-cells. Three chimpanzees (two vaccines, one control) were immunized with immunoliposomes complexed with DNA expressing NS3-NS5B or complexed with empty vector. Animals were boosted with adenovirus expressing NS3-NS5B, or non-recombinant adenovirus (control).

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Using human immune globulins made from antihepatitis C virus (HCV)-positive plasma, we recently identified two antibody epitopes in the E2 protein at residues 412-426 (epitope I) and 434-446 (epitope II). Whereas epitope I is highly conserved among genotypes, epitope II varies. We discovered that epitope I was implicated in HCV neutralization whereas the binding of non-neutralizing antibody to epitope II disrupted virus neutralization mediated by antibody binding at epitope I.

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The level of laminin-binding protein (LBP) expression on cellular membranes was studied in three cell lines including 293 cells transformed by plasmide with human LBP gene. Vero cells show a high level of LBP on the cell surfaces and demonstrate a high level of the Venezuelan equine encephalomyelitis (VEE) virus replication. The inhibition of VEE virus replication was more than 200 times as much after treatment of Vero cell surfaces with monoclonal antibodies to human LBP.

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Two novel databases, GenSensor and ConSensor, have been developed. GenSensor accumulates information on the sensitivities of the prokaryotic genes to external stimuli and may facilitate designing of novel genosensors; ConSensor contains data about the structure and efficiency of the available genosensor plasmid constructs. Using these databases, candidate genes for the design of novel multiple functional genosensors were searched, and the Escherichia coli dps gene was chosen as the candidate.

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Complementary DNA fragments (nucleotides 466-966 and 878-1088) encoding prM protein and polypeptide M31-75-E1-30 of West Nile virus (WNV), strain LEIV-Vlg99-27889-human, were obtained and cloned. Recombinant polypeptides prM and M3175-E1-30 having amino acid sequences corresponding to the cloned cDNA fragments were purified by affinity chromatography. According to ELISA and Western blotting prM protein interacted with polyclonal antibodies against WNV.

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The paper describes the structure and functions of Ebola virus properties. It also presents information on the role of structural (NP, VP40, VP35, GP, VP30, VP24, and L) and secreted (sGP, delta-peptide, GP1, GP(1,2delta), ssGP) proteins in the viral replication cycle and in the pathogenesis of Ebola hemorrhagic fever.

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Fragments cDNA (nt 935-1475, 1091-1310, 935-1193) encoding N-terminal part of protein E of West Nile virus (WNV), strain LEIV-Vlg99-27889-human were obtained and cloned. Recombinant polypeptides of glycoprotein E (E1-86, E53-126, E1-180) of the WNV with corresponding amino acid sequence to the cloned fragments of cDNA and modeling the epitopes of domains I and II of surface glycoprotein E were purified by affinity chromatography. Twelve types of monoclonal antibodies (MAbs) created in our laboratory against recombinant polypeptide E1-180 interact with glycoprotein E of the WNV as results of Western blot and ELISA that is demonstrating an similarity of chemical structure of short recombinant polypeptides and corresponding amino acid sequence regions of WNV protein E.

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We have developed a panel of 16 hybridomas secreting neutralizing monoclonal antibodies (Nt- MAbs) to Russian isolate (LEIV-Vlg99-27889-human) of the West Nile virus (WNV). Most of the Nt-Mabs were either IgG1 or IgG3 subtypes. Nine of the 16 neutralizing MAbs detected WNV protein E in Western blot.

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The occurrence rate of HGV/GBV-C RNA, genotypic variety of isolates and various risk factors of infection with HGV/GBV-C were evaluated in 500 patients of the narcological dispensary of Novosibirsk. The occurrence rate of HGV/GBV-C RNA among all examined blood sera was 33.6%.

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It was demonstrated by subtractive hybridization that the infection of a human embryonic kidney cell line with tick-borne encephalitis virus causes an approximately tenfold transcription activation of the RIG-1 gene, which encodes a protein of the DExH/D-box-containing RNA helicase family. A possible involvement of the protein in antiviral cell systems is discussed. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2004, vol.

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The results of polymerase chain reaction and of DNA sequencing of the Adel2 mutant variant of adenovirus serotype 5, passaged 10 times and capable of selectively infecting and lysing the p53-deficient human tumor cells, are indicative of a high stability of its genotype and of the phenotypic properties acquired by it in successive passage on 293 cells. The absence of admixtures of wild-type adenovirus was clearly shown in the cultivation and passage processes. It was revealed in an experimental analysis of virus-productive properties of the studied continuous cell culture 293 by using the method of multilayer cultivation, that the maximal Adel2 yield is obtained at the 50% cytopathic effect.

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