Consulta: creatorFacets:"Flores,E.F."
Registros recuperados: 11
Data/hora: 05/06/2024 10:32:32

Diversidade antigênica de amostras do vírus da diarréia viral bovina isoladas no Brasil: implicações para o diagnóstico e estratégias de imunização
Provedor de dados: 45
Autores: Flores,E.F.; Weiblen,R.; Gil,L.H.V.G.; Tobias,F.L.; Lima,M.; Garcez,D.C.; Botton,S.A.
Seqüenciamento e análise filogenética de 17 amostras do vírus da diarréia viral bovina (BVDV) isoladas no Brasil identificaram quatro amostras (23,5%) do genótipo 1a (BVDV-1a), nove amostras (52,9%) do genótipo 1b (BVDV tipo 1b) e quatro amostras (23,5%) do genótipo 2 (BVDV tipo 2). As amostras brasileiras de BVDV tipo 2 apresentaram-se genotipicamente distintas dos BVDV tipo 2 até então identificados na América do Norte e Europa, sugerindo pertencerem a um novo subgenótipo. A caracterização antigênica dessas amostras por neutralização cruzada revelou reatividade sorológica muito reduzida com cepas vacinais do BVDV. O anti-soro produzido contra três cepas vacinais do BVDV apresentou atividade neutralizante muito reduzida contra várias amostras brasileiras...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Vírus da diarréia viral bovina; BVDV; Diversidade antigênica; Vacina; Genótipo.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352000000100003

Inactivated Parapoxvirus ovis induces a transient increase in the expression of proinflammatory, Th1-related, and autoregulatory cytokines in mice
Provedor de dados: 56
Autores: Anziliero,D.; Weiblen,R.; Kreutz,L.C.; Spilki,F.; Flores,E.F.
The immunostimulatory properties of inactivated Parapoxvirus ovis (iPPVO) have long been investigated in different animal species and experimental settings. In this study, we investigated the effects of iPPVO on cytokine expression in mice after intraperitoneal inoculation. Spleen and sera collected from iPPVO-treated mice at intervals after inoculation were submitted to cytokine mRNA determination by real-time PCR (qPCR), serum protein concentration by ELISA, and interferon (IFN)-α/β activity by bioassay. The spleen of iPPVO-treated animals showed a significant increase in mRNA expression of all cytokines assayed, with different kinetics and magnitude. Proinflammatory cytokines interleukin (IL)-1β, tumor necrosis factor-alpha (TNF-α), and IL-8 mRNA peaked...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cytokine; MRNA; ORF virus; Immunostimulant; Innate immune response.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2014000200110

A bovine herpesvirus 5 recombinant defective in the thymidine kinase (TK) gene and a double mutant lacking TK and the glycoprotein E gene are fully attenuated for rabbits
Provedor de dados: 56
Autores: Silva,S.C.; Brum,M.C.S.; Weiblen,R.; Flores,E.F.; Chowdhury,S.I.
Bovine herpesvirus 5 (BoHV-5), the agent of herpetic meningoencephalitis in cattle, is an important pathogen of cattle in South America and several efforts have been made to produce safer and more effective vaccines. In the present study, we investigated in rabbits the virulence of three recombinant viruses constructed from a neurovirulent Brazilian BoHV-5 strain (SV507/99). The recombinants are defective in glycoprotein E (BoHV-5gEΔ), thymidine kinase (BoHV-5TKΔ) and both proteins (BoHV-5gEΔTKΔ). Rabbits inoculated with the parental virus (N = 8) developed neurological disease and died or were euthanized in extremis between days 7 and 13 post-infection (pi). Infectivity was detected in several areas of their brains. Three of 8 rabbits inoculated with the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: BoHV-5; GE and TK deletion mutants; Pathogenesis; Virulence; Vaccine candidate.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2010000200005

Antigenic characterization of Brazilian bovine viral diarrhea virus isolates by monoclonal antibodies and cross-neutralization
Provedor de dados: 56
Autores: Botton,S.A.; da-Silva,A.M.; Brum,M.C.S.; Weiblen,R.; Flores,E.F.
Nineteen Brazilian isolates of bovine viral diarrhea virus (BVDV) were characterized antigenically with a panel of 19 monoclonal antibodies (mAbs) (Corapi WV, Donis RO and Dubovi EJ (1990) American Journal of Veterinary Research, 55: 1388-1394). Eight isolates were further characterized by cross-neutralization using sheep monospecific antisera. Analysis of mAb binding to viral antigens by indirect immunofluorescence revealed distinct patterns of reactivity among the native viruses. Local isolates differed from the prototype Singer strain in recognition by up to 14 mAbs. Only two mAbs - one to the non-structural protein NS23/p125 and another to the envelope glycoprotein E0/gp48 - recognized 100% of the isolates. No isolate was recognized by more than 14...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bovine viral diarrhea virus; BVDV; Monoclonal antibodies; Cross-neutralization; Antigenic diversity.
Ano: 1998
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998001100011

Dexamethasone-induced reactivation of bovine herpesvirus type 5 latent infection in experimentally infected rabbits results in a broader distribution of latent viral DNA in the brain
Provedor de dados: 56
Autores: Mayer,S.V.; de Quadros,V.L.; Vogel,F.S.F.; Winkelmann,E.R.; Arenhart,S.; Weiblen,R.; Flores,E.F.
Bovine herpesvirus type 5 (BHV-5) is a major agent of meningoencephalitis in cattle and establishes latent infections mainly in sensory nerve ganglia. The distribution of latent BHV-5 DNA in the brain of rabbits prior to and after virus reactivation was studied using a nested PCR. Fifteen rabbits inoculated intranasally with BHV-5 were euthanized 60 days post-inoculation (group A, N = 8) or submitted to dexamethasone treatment (2.6 mg kg-1 day-1, im, for 5 days) and euthanized 60 days later (group B, N = 7) for tissue examination. Two groups of BHV-1-infected rabbits (C, N = 3 and D, N = 3) submitted to each treatment were used as controls. Viral DNA of group A rabbits was consistently detected in trigeminal ganglia (8/8), frequently in cerebellum (5/8),...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bovine herpesvirus type 5; BHV-5; BHV-1; Latent infection; Rabbits; Brain.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000300004

Sequence analysis of the 5′ third of glycoprotein C gene of South American bovine herpesviruses 1 and 5
Provedor de dados: 56
Autores: Traesel,C.K.; Bernardes,L.M.; Spilki,F.R.; Weiblen,R.; Flores,E.F.
Bovine herpesviruses 1 (BoHV-1) and 5 (BoHV-5) share high genetic and antigenic similarities, but exhibit marked differences in tissue tropism and neurovirulence. The amino-terminal region of glycoprotein C (gC), which is markedly different in each of the viruses, is involved in virus binding to cellular receptors and in interactions with the immune system. This study investigated the genetic and antigenic differences of the 5′ region of the gC (5′ gC) gene (amino-terminal) of South American BoHV-1 (n=19) and BoHV-5 (n=25) isolates. Sequence alignments of 374 nucleotides (104 amino acids) revealed mean similarity levels of 97.3 and 94.2% among BoHV-1 gC (gC1), respectively, 96.8 and 95.6% among BoHV-5 gC (gC5), and 62 and 53.3% between gC1 and gC5....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: GC amino-terminal; BoHV; Genetic diversity; Epitope prediction; Virus neutralization.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2015000500470

Construction and growth properties of bovine herpesvirus type 5 recombinants defective in the glycoprotein E or thymidine kinase gene or both
Provedor de dados: 56
Autores: Brum,M.C.S.; Weiblen,R.; Flores,E.F.; Chowdhury,S.I.
Bovine herpesvirus type 5 (BoHV-5) is an important pathogen of cattle in South America. We describe here the construction and characterization of deletion mutants defective in the glycoprotein E (gE) or thymidine kinase (TK) gene or both (gE/TK) from a highly neurovirulent and well-characterized Brazilian BoHV-5 strain (SV507/99). A gE-deleted recombinant virus (BoHV-5 gE∆) was first generated in which the entire gE open reading frame was replaced with a chimeric green fluorescent protein gene. A TK-deleted recombinant virus (BoHV-5 TK∆) was then generated in which most of the TK open reading frame sequences were deleted and replaced with a chimeric β-galactosidase gene. Subsequently, using the BoHV-5 gE∆ virus as backbone, a double gene-deleted (TK plus...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bovine herpesvirus 5; Glycoprotein E; Thymidine kinase; Deletion mutants; Vaccine candidate; Recombinant herpesvirus.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2010000200014

Production and characterization of monoclonal antibodies to a Brazilian bovine herpesvirus type 5
Provedor de dados: 56
Autores: Oldoni,I.; Weiblen,R.; Inkelmann,M.A.; Flores,E.F.
Antigens of a bovine herpesvirus type 5 (BHV-5), isolated from a cow with a neurological infection in Rio Grande do Sul State, Brazil, were used to immunize BALB/c mice to produce monoclonal antibodies (mAbs). Eleven hybridomas secreting mAbs directed at BHV-5 antigens were obtained after two fusions and screening of 356 hypoxanthine-aminopterin-thymidine-resistant clones. The mAbs reacted at dilutions up to 1:500 (hybridoma culture supernatant) and up to &gt;1:10,000 (ascitic fluid) in an indirect fluorescent antibody assay (IFA) and in immunoperoxidase staining of BHV-5-infected cells. Four mAbs (1D12, 2E2, 2G10 and 4E4) showed virus-neutralizing activity against the parental BHV-5 isolate. Five mAbs (1F3, 2A6, 2F9, 2G10 and HB24L) reacted in Western...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bovine herpesvirus type 5 and type 1; BHV-5; BHV-1; Monoclonal antibodies.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000200008

Production and characterization of monoclonal antibodies to Brazilian isolates of bovine viral diarrhea virus
Provedor de dados: 56
Autores: Kreutz,L.C.; Donis,R.; Gil,L.H.V.; Lima,M.; Hoffman,A.N.; Garcez,D.C.; Flores,E.F.; Weiblen,R.
Three Brazilian isolates of bovine viral diarrhea virus (BVDV), antigenically distinct from the standard North American isolates, were selected to immunize BALB/c mice in order to obtain hybridoma cells secreting anti-BVDV monoclonal antibodies (mAbs). Two hybridoma clones secreting mAbs, reacting specifically with BVDV-infected cells (mAbs 3.1C4 and 6.F11), were selected after five fusions and screening of 1001 hypoxanthine-aminopterin-thymidine-resistant clones. These mAbs reacted in an indirect fluorescent antibody (IFA) assay with all 39 South and North American BVDV field isolates and reference strains available in our laboratory, yet failed to recognize other pestiviruses, namely the hog cholera virus. The mAbs reacted at dilutions up to 1:25,600...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bovine viral diarrhea virus; Monoclonal antibodies; Antigenic diversity; Diagnostic reagents.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000001200010

A glycoprotein E gene-deleted bovine herpesvirus 1 as a candidate vaccine strain
Provedor de dados: 56
Autores: Weiss,M.; Brum,M.C.S.; Anziliero,D.; Weiblen,R.; Flores,E.F.
A bovine herpesvirus 1 (BoHV-1) defective in glycoprotein E (gE) was constructed from a Brazilian genital BoHV-1 isolate, by replacing the full gE coding region with the green fluorescent protein (GFP) gene for selection. Upon co-transfection of MDBK cells with genomic viral DNA plus the GFP-bearing gE-deletion plasmid, three fluorescent recombinant clones were obtained out of approximately 5000 viral plaques. Deletion of the gE gene and the presence of the GFP marker in the genome of recombinant viruses were confirmed by PCR. Despite forming smaller plaques, the BoHV-1△gE recombinants replicated in MDBK cells with similar kinetics and to similar titers to that of the parental virus (SV56/90), demonstrating that the gE deletion had no deleterious effects...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cattle pathogen; Immunization; Control; Differential vaccine.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2015000900843

A search for RNA insertions and NS3 gene duplication in the genome of cytopathic isolates of bovine viral diarrhea virus
Provedor de dados: 56
Autores: Quadros,V.L.; Mayer,S.V.; Vogel,F.S.F.; Weiblen,R.; Brum,M.C.S.; Arenhart,S.; Flores,E.F.
Calves born persistently infected with non-cytopathic bovine viral diarrhea virus (ncpBVDV) frequently develop a fatal gastroenteric illness called mucosal disease. Both the original virus (ncpBVDV) and an antigenically identical but cytopathic virus (cpBVDV) can be isolated from animals affected by mucosal disease. Cytopathic BVDVs originate from their ncp counterparts by diverse genetic mechanisms, all leading to the expression of the non-structural polypeptide NS3 as a discrete protein. In contrast, ncpBVDVs express only the large precursor polypeptide, NS2-3, which contains the NS3 sequence within its carboxy-terminal half. We report here the investigation of the mechanism leading to NS3 expression in 41 cpBVDV isolates. An RT-PCR strategy was employed...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bovine viral diarrhea virus; CpBVDV; NS3 gene; Cytopathology; RNA processing.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000700012