RESUMO
Venezuelan equine encephalomyelitis (VEE) virus-based vectors for expression of heterologous genes have been constructed using full-length cDNA copy of the interstrain recombinant virus (Trinidad Donkey and 230 strain). Gene cassettes carrying the subgenomic mRNA promoter of VEE virus and the preS2-S gene of hepatitis B virus (HBV) were inserted before or after the genes of structural viral proteins. Live virus stocks were obtained by transfection of chick embryo fibroblasts with in vitro transcribed full-length RNA. Insertions of gene cassettes before the structural region resulted in expression of HBsAg (VEHB-25 and VEHB-361 viruses), whereas insertions in the 3' region did not. Recombinant virus VEHB-25 expressed HBsAg during 5 passages in Vero cells. VEHB-25 stimulated immune response to HBsAg and was less virulent than the parental virus.
Assuntos
Encefalomielite Equina Venezuelana/genética , Antígenos de Superfície da Hepatite B/genética , Vírus da Hepatite B/genética , Precursores de Proteínas/genética , Proteínas do Envelope Viral/genética , Animais , Linhagem Celular , Embrião de Galinha , Chlorocebus aethiops , Clonagem Molecular , Encefalomielite Equina Venezuelana/imunologia , Antígenos de Superfície da Hepatite B/ultraestrutura , Microscopia Eletrônica , Plasmídeos , Regiões Promotoras Genéticas , Precursores de Proteínas/ultraestrutura , RNA Mensageiro/genética , RNA Viral/genética , Coelhos , Recombinação Genética , Inoculações Seriadas , Células VeroRESUMO
Sequencing and computer analysis of the variola major virus strain India-1967 (VAR-IND) genome segment (53,018 bp) from the right terminal region have been carried out. Fifty nine potential open reading frames (ORFs) of over 60 amino acid residues have been identified. Structure-function organization of VAR-IND DNA segment under study was compared with the previously reported sequences from the analogous genomic regions of vaccinia virus strains Copenhagen (VAC-COP) and Western Reserve (VAC-WR) and variola virus strain Harvey (VAR-HAR). Multiple distinctions in the genetic map of VAR-IND from VAC-COP and VAC-WR have been revealed along with the high similarity to the corresponding VAR-HAR segment. Possible functions of the predicted viral proteins and the effect of their differences on the features of orthopoxviruses are discussed.
Assuntos
Genoma Viral , Vírus da Varíola/genética , Sequência de Aminoácidos , Animais , DNA Ligases/genética , DNA Viral , Dados de Sequência Molecular , Fases de Leitura Aberta , Plasmídeos , Receptores de Citocinas/genética , Homologia de Sequência de Aminoácidos , Especificidade da Espécie , Relação Estrutura-Atividade , Timidina Quinase/genéticaRESUMO
Computer analysis of variola major virus (VAR) genomic fragment bounded by open reading frames (ORFs) D1R and A33L which is 47,961 bp long revealed 46 potential ORFs. The VAR proteins were compared with the analogous proteins of vaccinia virus strain Copenhagen. The subunits of DNA-dependent RNA polymerase, as well as the transcription factors, mRNA capping enzymes, and proteins necessary for the virion morphogenesis proved to be highly conservative within orthopoxviruses. The most pronounced differences between the VAR genome fragment under study and the corresponding vaccinia virus fragment were revealed in the vicinity of the gene encoding the A-type inclusion body protein. The possible functions of the analyzed viral proteins are discussed.
Assuntos
Sequência Conservada , Vírus da Varíola/genética , Sequência de Aminoácidos , Sequência de Bases , RNA Polimerases Dirigidas por DNA/metabolismo , Desoxirribonuclease HindIII , Genoma Viral , Corpos de Inclusão Viral , Dados de Sequência Molecular , Fases de Leitura Aberta , RNA Viral/genética , Mapeamento por Restrição , Fatores de Transcrição/metabolismo , Proteínas Virais/genética , VírionRESUMO
Stable neutralization and protection escape variants of a virulent strain (Trinidad Donkey) of the VEE virus were selected by monoclonal antibodies (MAbs). Determination of nucleotide sequences of nine variants revealed a clustering of single mutations in four regions of the E1 and E2 glycoproteins. Involvement of amino acid residues 206 (site E1-1), 57 and 59 (site E2-2), 180, 182, 213, 214 and 216 (site E2-6) and 232 (site E2-3) in protective epitopes was demonstrated.
Assuntos
Capsídeo/imunologia , Vírus da Encefalite Equina Venezuelana/imunologia , Vírus da Encefalite Equina Venezuelana/patogenicidade , Epitopos/análise , Mutação Puntual , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais , Capsídeo/genética , Chlorocebus aethiops , Códon/genética , Vírus da Encefalite Equina Venezuelana/genética , Variação Genética , Camundongos , Dados de Sequência Molecular , Testes de Neutralização , Células Vero , VirulênciaRESUMO
A recombinant strain of vaccinia virus (VR26) containing a DNA-copy of the subgenomic 26S RNA of Venezuelan equine encephalomyelitis virus (VEE) inserted into the coding region of thymidine kinase (TK) gene was produced. This subgenomic RNA contained the genes for all structural proteins of the VEE virus, the strain Trinidad donkey (TRD). VR26 effectively expressed VEE virus glycoproteins on the membranes of the infected cells. Blood sera of VR26-immunized animals were found to contain VEE virus-specific antibodies. VR26-immunized mice and rabbits showed a high level of resistance to subcutaneous inoculation with the pathogenic TRD strain of VEE virus. VR26 also provided a high level of protection in animals against aerogenic infection. The absence of virus-neutralizing antibodies in most VR26-immunized animals resistant to inoculation with high doses of VEE suggests the dominant role of the cell component in the immune response. The immune response induced by the recombinant VR26 strain was stable as demonstrated by the resistance of the animals to a challenge with VEE virus 7 months after immunization. The experimental results suggest that this recombinant strain may be considered as a candidate for vaccine preparation.
Assuntos
DNA Complementar/genética , DNA Viral/genética , Vírus da Encefalite Equina Venezuelana/genética , Regulação Viral da Expressão Gênica/imunologia , RNA Mensageiro/genética , RNA Ribossômico/genética , RNA Viral/genética , Recombinação Genética/imunologia , Vaccinia virus/imunologia , Animais , Encefalomielite Equina Venezuelana/imunologia , Encefalomielite Equina Venezuelana/prevenção & controle , Regulação Viral da Expressão Gênica/genética , Soros Imunes/imunologia , Imunização/métodos , Camundongos , Coelhos , Recombinação Genética/genética , Fatores de Tempo , Vacínia/imunologia , Vacínia/prevenção & controle , Vaccinia virus/genéticaRESUMO
DNA of the variola major virus strain India-1967 in the region of HindIII M, L, I fragments has been sequenced. Analysis of this sequence of 18029 bp revealed 19 potential open reading frames (ORFs). Four proposed proteins (L2R, H9R, L5L, L6R) contain metal-binding domains. Comparison of the variola virus (VAR) and vaccinia virus strain Copenhagen (COP) sequences show that the main differences are between proteins L1R and I5R. L1R contains 6 additional amino acid residues on the C-terminus. The protein I5R of VAR contains three Ca2+ binding domains but this COP has deletions in 2 of the 3 established domains. Possible functions of the predicted viral polypeptides are discussed.
Assuntos
Genoma Viral , Vírus da Varíola/genética , Sequência de Aminoácidos , DNA Viral/genética , Metais/metabolismo , Dados de Sequência Molecular , Fases de Leitura Aberta , Conformação Proteica , Mapeamento por Restrição , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Especificidade da Espécie , Vaccinia virus/genética , Proteínas Virais/química , Proteínas Virais/genética , Proteínas Virais/metabolismoRESUMO
HindIII and XhoI genome fragments of variola major virus strain India-1967 were inserted into the bacterial plasmids and cosmid. Sequencing and computer analysis of the region of HindIII M, L, and I DNA fragments of the virus studied have been carried out.
Assuntos
DNA Viral/genética , Vírus da Varíola/genética , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Cosmídeos , Desoxirribonuclease HindIII/genética , Desoxirribonucleases de Sítio Específico do Tipo II/genética , Genes Virais , Dados de Sequência Molecular , Plasmídeos , Mapeamento por Restrição , Relação Estrutura-AtividadeAssuntos
DNA Viral/genética , Encefalomielite Equina Venezuelana/genética , Genoma Viral , Animais , Sequência de Bases , Células Cultivadas , Efeito Citopatogênico Viral , RNA Polimerases Dirigidas por DNA/genética , Cavalos , Dados de Sequência Molecular , Plasmídeos , RNA Viral/genética , RNA Viral/isolamento & purificação , Transfecção , Proteínas ViraisAssuntos
Vírus da Encefalite Equina Venezuelana/genética , Mutação , Proteínas Estruturais Virais/genética , Sequência de Aminoácidos , Animais , DNA Viral , Vírus da Encefalite Equina Venezuelana/imunologia , Vírus da Encefalite Equina Venezuelana/patogenicidade , Camundongos , Dados de Sequência Molecular , Plasmídeos , Vacinas Atenuadas , Vacinas Virais , VirulênciaAssuntos
Vírus da Encefalite Equina Venezuelana/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Embrião de Galinha , Vírus da Encefalite Equina Venezuelana/patogenicidade , Vírus da Encefalite Equina Venezuelana/fisiologia , Genes Virais , Cavalos , Dados de Sequência Molecular , RNA Viral/genética , RNA Viral/isolamento & purificação , Homologia de Sequência do Ácido Nucleico , Células Vero/microbiologia , Replicação ViralRESUMO
The complete primary structure of cDNA for hemagglutinin gene of influenza virus A/FPV/weybridge/27 subtype H7 has been determined. Its comparison with the structures of analogous genes from other strains of the same subtype has shown 75% of base changes resulting in silent mutations. This suggests the weak immunological pressing in course of evolution of this subtype strains. The reason for apathogenicity of this avian strain is supposed to be elimination of a glycosylation site present in the strain A/FPV/Rostock/34. The possibility of using the obtained data for construction of the new generation of vaccines is discussed.
Assuntos
Genes Virais , Hemaglutininas Virais/genética , Vírus da Influenza A/genética , Sequência de Aminoácidos , Sequência de Bases , Dados de Sequência MolecularRESUMO
The effects of the glucocorticoid hydrocortisone on the synthesis of specific template RNA coding tyrosine aminotransferase (TAT) in rat liver during hormonal induction were studied. Using hybridization of complementary DNA (cDNA-TAT) with polysomal liver poly-A-mRNA, the content of specific mRNA-TAT in liver polysomes during and after hormonal induction, i. e. 4 and 16 hrs after hydrocortisone injection, respectively, was estimated. It was shown that 4 hrs after the hormone injection that mRNA-TAT content in liver polysomes is increased 3-4-fold, showing a return to the initial level after 16 hrs. Thus, transcription is the main link in the realization of glucocorticoid induction.