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Упрощенная модель SARS-COV-2 демонстрирует защиту с помощью пероральной вакцины на основе mRNA.

Модель мыши SARS-COV-2, которая может быть разработана в любой лаборатории молекулярной биологии со стандартными средствами, будет иметь важное значение для оценки лекарств и вакцин. Здесь мы представляем упрощенную модель мыши SARS-COV-2 с использованием метода быстрой аденовиральной очистки. Мыши, чувствительные к инфекции SARS-COV-2, были образованы аденовичным ангиотенсином человека, предотвращающим фермент 2 (HACE2). Выражение " кинетика " HACE2 в мышах, получавших образование, оценивалось иммуногистохимией, RT-PCR и qPCR. Кроме того, была определена способность HACE2 поддержива

Совпадение в аннотации оригинала
A mouse model of SARS-CoV-2 that can be developed in any molecular biology lab with standard facilities will be valuable in evaluating drugs … tein (M) and epitopes of nsp13 of parental SARS-CoV-2. Further, Salmonella and Semliki Forest virus replicon were exploited, respectively, for gene delivery and mRNA expression. We recorded potent cross-protective neutralizing antibodies in immunized mice against the SARS-CoV-2 delta variant. The vaccine protected the mice against viral replication and SAR …

Construction of a Noninfectious SARS-CoV-2 Replicon for Antiviral-Drug Testing and Gene Function Studies.

The emerging coronavirus disease 2019 (COVID-19) outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread worldwide, resulting in global public health emergencies and economic crises. In the present study, a noninfectious and biosafety level 2 (BSL2)-compatible SARS-CoV-2 replicon expressing a nano luciferase (nLuc) reporter was constructed in a bacterial artificial chromosomal (BAC) vector by reverse genetics. The nLuc reporter is highly sensitive, easily quantifiable, and high throughput adaptable. Upon transfecting the SARS-CoV-2 replicon BAC plasmi…

Understanding the molecular mechanism of host-based statin resistance in hepatitis C virus replicon containing cells.

A number of statins, the cholesterol-lowering drugs, inhibit the in vitro replication of hepatitis C virus (HCV). In HCV-infected patients, addition of statins to the earlier standard of care therapy (pegIFN-α and ribavirin) resulted in increased sustained virological response rates. The mechanism by which statins inhibit HCV replication has not yet been elucidated. In an attempt to gain insight in the underlying mechanism, hepatoma cells carrying an HCV replicon were passaged in the presence of increasing concentrations of fluvastatin. Fluvastatin-resistant replicon containing cells could be …

Development and characterization of a replicon-based phenotypic assay for assessing HCV NS4B from clinical isolates.

The hepatitis C virus (HCV) NS4B inhibitors have shown potent inhibition of HCV replication in vitro. To assess the effect of viral diversity on the susceptibility to NS4B inhibitors, genotype (GT)-specific GT1a and GT1b replicon shuttle vectors were designed and created for cloning HCV NS4B genes from clinical isolates. For the GT1b NS4B shuttle vector, the S2204I adaptive mutation was introduced in NS5A to improve replication due to the replacement of the K1846T adaptive mutation in NS4B with NS4B from the clinical isolates. In addition to the adaptive mutations, a newly identified Huh-7 cel…

Development and characterization of the replicon system of Japanese encephalitis live vaccine virus SA14-14-2.

BACKGROUND: Viral self-replicating sub-genomic replicons represent a powerful tool for studying viral genome replication, antiviral screening and chimeric vaccine development. Many kinds of flavivirus replicons have been developed with broad applications. FINDINGS: The replicon system of JEV live vaccine strain SA14-14-2 was successfully developed in this study. Two kinds of replicons that express enhanced green fluorescent protein (EGFP) and Renilla luciferase (R.luc) were constructed under the control of SP6 promoter, respectively. Robust EGFP and R.luc signals could be detected in the repl…

A recombinant vesicular stomatitis virus replicon vaccine protects chickens from highly pathogenic avian influenza virus (H7N1).

Highly pathogenic avian influenza viruses (HPAIV) of subtypes H5 and H7 cause fatal disease in poultry (fowl plague) but also have zoonotic … ). Chickens were immunized via the intramuscular route. Following booster vaccination with the same replicons high titers of serum antibodies were induced, which neutralized avian influenza viruses of subtypes H7N1 and H7N7 but not H5N2. Vaccinated chickens were protected against a lethal dose of heterologous HPAIV A/chicken/Italy/445/99 (H7N1). Secretion …

Additive effect of ethanol and HCV subgenomic replicon expression on COX-2 protein levels and activity.

The mechanisms by which alcohol exacerbates liver injury in patients with hepatitis C are unknown. We used the hepatitis C virus (HCV) subgenomic replicon cell system to evaluate the effect of ethanol on HCV replication and viral protein synthesis. Our results demonstrate that alcohol stimulates HCV replicon expression at both HCV-RNA and protein levels. Furthermore, we observed that ethanol treatment showed an additive effect in cyclooxygenase-2 (COX-2) protein expression and activity already induced by HCV viral proteins, and in turn increased HCV viral expression. Our results suggest that C…

Vaccination of mice with gonococcal TbpB expressed in vivo from Venezuelan equine encephalitis viral replicon particles.

We investigated the immunogenicity of gonococcal transferrin binding protein B (TbpB) expressed with and without a eukaryotic secretion signal from a nonpropagating Venezuelan equine encephalitis virus replicon particle (VRP) delivery system. TbpB was successfully expressed in baby hamster kidney (BHK) cells, and the presence of the eukaryotic secretion signal not only apparently increased the protein's expression but also allowed for extracellular localization and glycosylation. Mice immunized with VRPs produced significant amounts of serum antibody although less than the amounts produced by …

Establishment of a stable replicon cell line of Tembusu virus (TMUV) for high-throughput antiviral screening.

Tembusu virus (TMUV), a member in the family Flaviviridae, induces egg-drop syndrome and fatal encephalitis in ducks, and thus threatens severely poultry industry. The development of preventive strategies against TMUV infection may contribute significantly to the viral disease control, but specific therapeutics is not currently available for TMUV infection. In this study, a novel TMUV replicon system was constructed in two cell lines by replacing viral structural genes with a Gaussia luciferase (Gluc) reporter and a blasticidin (BSD) resistance marker. Through continuous BSD selection, a stabl…

Development of a Noninfectious Japanese Encephalitis Virus Replicon for Antiviral Drug Screening and Gene Function Studies.

Viral replicons are efficient tools to understand the mechanisms of viral replication and screen antiviral drugs. In this study, a viral-cDNA-based replicon of Japanese encephalitis virus (JEV), which is the causative agent of Japanese encephalitis, was constructed by replacing the viral structural proteins with a green fluorescent protein (JEV-GFP replicon). The resulting JEV-GFP replicon was used as a tool to screen antiviral drugs targeting JEV nonstructural proteins, and the five compounds JNJ-A07, HZ-1157, NITD-2, quinine, and NITD008 were obtained, which significantly inhibited the repli…

A gH/gL-encoding replicon vaccine elicits neutralizing antibodies that protect humanized mice against EBV challenge.

Epstein-Barr virus (EBV) is associated with several malignancies, neurodegenerative disorders and is the causative agent of infectious monon … or vaccine development. Here, we developed and optimized the delivery of several alphavirus-derived replicon RNA (repRNA) vaccine candidates encoding gH/gL, gH/gL/gp42 or gp350 delivered by a cationic nanocarrier termed LION™. The lead candidate, encoding full-length gH/gL, elicited high titers of neutralizing antibodies that persisted for at least 8 month …

Japanese encephalitis virus replicon-based vaccine expressing enterovirus-71 epitope confers dual protection from lethal challenges.

BACKGROUND: To construct safer recombinant flavivirus vaccine, we exploited Japanese encephalitis virus (JEV) replicon-based platform to generate single-round infectious particles (SRIPs) that expressed heterologous neutralizing epitope SP70 derived from enterovirus-71 (EV71). Such pseudo-infectious virus particles, named SRIP-SP70, although are not genuine viable viruses, closely mimic live virus infection to elicit immune responses within one round of viral life cycle. RESULTS: We found that, besides gaining of full protection to thwart JEV lethal challenge, female outbred ICR mice, when we…

Combined alphavirus replicon particle vaccine induces durable and cross-protective immune responses against equine encephalitis viruses.

Alphavirus replicons were evaluated as potential vaccine candidates for Venezuelan equine encephalitis virus (VEEV), western equine encephalitis virus (WEEV), or eastern equine encephalitis virus (EEEV) when given individually or in combination (V/W/E) to mice or cynomolgus macaques. Individual replicon vaccines or the combination V/W/E replicon vaccine elicited strong neutralizing antibodies in mice to their respective alphavirus. Protection from either subcutaneous or aerosol challenge with VEEV, WEEV, or EEEV was demonstrated out to 12 months after vaccination in mice. Individual replicon v…

Effect of UV light on DNA chain growth and replicon initiation in xeroderma pigmentosum variant cells.

The effects of UV light on DNA replication were examined in wild-type and xeroderma pigmentosum (XP) variant cells using DNA fiber autoradio … the post-replication defect in XP variant cells involved a failure to activate alternative sites of replicon initiation, high/low specific activity labeling was performed. The results obtained indicated that XP variant cells were able to activate alternative sites of replicon initiation. Therefore the unique phenotype of the XP variant cells is probably du …

Efficient production of functional cholera toxin B subunit using geminiviral replicons in Nicotiana benthamiana.

The cholera toxin B subunit (CTB) has the potential to be a carrier molecule and an effective adjuvant for mucosal vaccines because of its ability to enhance immune responses to antigens. CTB proteins have been expressed in plant-based expression systems. In this study, we used geminiviral replicon systems to transiently express CTB in Nicotiana benthamiana. We developed a high-level expression system that uses combinations of the replication machinery of geminivirus, including tomato yellow leaf curl virus (TYLCV), honeysuckle yellow vein virus (HYVV), and beet mild curly top virus (BMCTV). T…

A Modular Hepatitis E Virus Replicon System for Studies on the Role of ORF1-Encoded Polyprotein Domains.

Zoonotic hepatitis E virus (HEV) infection is an emerging cause of acute viral hepatitis in developed countries. Known reservoirs of zoonoti … c regions responsible for HEV propagation in cell culture, we developed a modular chimeric reporter replicon system based on cell culture-adapted (Kernow-C1/p6 and 47832mc) and rabbit-derived HEV strains. Replication in HepG2 cells was monitored on the basis of a Gaussia luciferase reporter gene that was inserted in place of the open reading frame (ORF) 2 …

Use of Synthetic Hybrid Strains To Determine the Role of Replicon 3 in Virulence of the Burkholderia cepacia Complex.

The Burkholderia cepacia complex (Bcc) displays a wealth of metabolic diversity with great biotechnological potential, but the utilization of these bacteria is limited by their opportunistic pathogenicity to humans. The third replicon of the Bcc, megaplasmid pC3 (0.5 to 1.4 Mb, previously chromosome 3), is important for various phenotypes, including virulence, antifungal, and proteolytic activities and the utilization of certain substrates. Approximately half of plasmid pC3 is well conserved throughout sequenced Bcc members, while the other half is not. To better locate the regions responsible…

Generation of a DNA-Launched Reporter Replicon Based on Dengue Virus Type 2 as a Multipurpose Platform.

Dengue viruses (DENV) have become the most important arthropod-borne viruses, causing dengue and severe dengue fever in at least 50-100 million cases each year, mainly in tropical and subtropical countries. During recent years, important advances in the molecular biology concerning the life cycle of these viruses have allowed the manipulation and generation of recombinant viruses and replicons with multiple applications, mainly in viral biology and the screening of antiviral compounds. In the present study, we describe the construction of an enhanced green fluorescent protein-bearing DENV repl…

Incorporation of tick-borne encephalitis virus replicons into virus-like particles by a packaging cell line.

RNA replicons derived from flavivirus genomes show considerable potential as gene transfer and immunization vectors. A convenient and efficient encapsidation system is an important prerequisite for the practical application of such vectors. In this work, tick-borne encephalitis (TBE) virus replicons and an appropriate packaging cell line were constructed and characterized. A stable CHO cell line constitutively expressing the two surface proteins prM/M and E (named CHO-ME cells) was generated and shown to efficiently export mature recombinant subviral particles (RSPs). When replicon NdDeltaME l…