Conselho Nacional de Desenvolvimento Científico e Tecnológico / Bovine herpesviruses 1 (BoHV-1) and 5 (BoHV-5) are genetic and antigenic closely related pathogens of cattle, historically associated with respiratory/genital and neurological disease, respectively. This thesis reports the genomic and phylogenetic analyzes based on glycoproteins C (gC) and D (gD) genes of BoHV-1 and BoHV-5. Initially, the differentiation between BoHV-1 and BoHV-5 was performed by a differential PCR based on 5 gC gene. Then, a molecular analysis based on the 3 region of the gC gene of 45 BoHV isolates from Brazil, Uruguay and Argentina (1981-2009) was described. The phylogenetic tree reconstruction provided a clear distinction between BoHV-1 and BoHV-5, and BoHV-1 into subtypes BoHV-1.1 and BoHV-1.2. The levels of nucleotide (nt) similarity ranged from 99.1 to 100% among BoHV-1 sequences (n=12); 96.2-100% among BoHV-5 sequences (n=32); and 77.7-90.3% between BoHV-1 and BoHV-5 sequences. A transmembrane domain of 24 amino-acid (aa) and the putative cytoplasmic tail of 8 aa were also identified. In addition, a phylogenetic study was performed to investigate genetic divergences at the 3 region of gD gene of respiratory/genital BoHV-1 (n=7), neurological BoHV-1 (n=7) and neurological BoHV-5 (n=7) isolates, and whether these differences would be associated with the respective neurological presentation. The phylogenetic reconstruction allowed a clear differentiation of BoHV-1 (n=14) and BoHV-5 (n=7), but BoHV-1 isolates from neurological disease grouped within BoHV-1 branch. The nt and aa similarity levels were on average 98.3% among BoHV-1; 97.8% and 95.8% among BoHV-5; 73.7% and 64.1% between viral species. These results indicate that both genes revealed a high conserved 3 region within each species and a less conserved region between BoHV-1 and BoHV-5. The phylogenetic analyzes allowed differentiation of BoHV-1 and BoHV-5 species, and even subtypes grouped in distinct branches in the 3 gC gene-based study, indicating that this region represents a better choice for phylogenetic subgrouping. So, it was concluded that these genome regions represent a suitable target for phylogenetic classification of BoHV-1 and BoHV-5 isolates, and, perhaps, for understanding evolutionary relationships. However, no conclusion of a possible association of genetic differences with phenotypes could be drawn. / Bovine herpesviruses 1 (BoHV-1) and 5 (BoHV-5) are genetic and antigenic closely related pathogens of cattle, historically associated with respiratory/genital and neurological disease, respectively. This thesis reports the genomic and phylogenetic analyzes based on glycoproteins C (gC) and D (gD) genes of BoHV-1 and BoHV-5. Initially, the differentiation between BoHV-1 and BoHV-5 was performed by a differential PCR based on 5 gC gene. Then, a molecular analysis based on the 3 region of the gC gene of 45 BoHV isolates from Brazil, Uruguay and Argentina (1981-2009) was described. The phylogenetic tree reconstruction provided a clear distinction between BoHV-1 and BoHV-5, and BoHV-1 into subtypes BoHV-1.1 and BoHV-1.2. The levels of nucleotide (nt) similarity ranged from 99.1 to 100% among BoHV-1 sequences (n=12); 96.2-100% among BoHV-5 sequences (n=32); and 77.7-90.3% between BoHV-1 and BoHV-5 sequences. A transmembrane domain of 24 amino-acid (aa) and the putative cytoplasmic tail of 8 aa were also identified. In addition, a phylogenetic study was performed to investigate genetic divergences at the 3 region of gD gene of respiratory/genital BoHV-1 (n=7), neurological BoHV-1 (n=7) and neurological BoHV-5 (n=7) isolates, and whether these differences would be associated with the respective neurological presentation. The phylogenetic reconstruction allowed a clear differentiation of BoHV-1 (n=14) and BoHV-5 (n=7), but BoHV-1 isolates from neurological disease grouped within BoHV-1 branch. The nt and aa similarity levels were on average 98.3% among BoHV-1; 97.8% and 95.8% among BoHV-5; 73.7% and 64.1% between viral species. These results indicate that both genes revealed a high conserved 3 region within each species and a less conserved region between BoHV-1 and BoHV-5. The phylogenetic analyzes allowed differentiation of BoHV-1 and BoHV-5 species, and even subtypes grouped in distinct branches in the 3 gC gene-based study, indicating that this region represents a better choice for phylogenetic subgrouping. So, it was concluded that these genome regions represent a suitable target for phylogenetic classification of BoHV-1 and BoHV-5 isolates, and, perhaps, for understanding evolutionary relationships. However, no conclusion of a possible association of genetic differences with phenotypes could be drawn.

Bovine herpesvirus type 1 (BoHV-1) is an important pathogen of cattle and causes significant economic losses to livestock industry. Monoclonal antibodies (mAbs) represent useful tools for diagnostic and research purposes. Most mAbs produced against BoHV-1 are directed to glycoprotein gC (gC), an abundant and immunodominant envelope antigen. In the present study, antigens of a BoHV-1 strain defective in the gene coding for glycoprotein C was used to immunize BALB/c mice to produce mAbs with other protein specificities. After fusion and selection of 54 hybridomas resistant to the selective medium HAT, three hybridomas secreting mAbs directed to BoHV-1 antigens were obtained (1F1, 2H4, 4D7). The mAbs belong to the IgG2a isotype and reacted in an indirect fluorescent antibody assay (IFA) and indirect immunoperoxidase staining (IPX) of BoHV-1-infected cells at dilutions up to 1:640 (culture supernatant) and 1:20,000 (ascitic fluid). The three mAbs tested reacted with 14 isolates of respiratory and/or genital disease and with 17 isolates of neurological disease and showed variable level of neutralizing activity against the most of these isolates. The protein specificity of the mAbs could not be determined, because none of them reacted with viral proteins in western immunoblot. On the other hand, the three mAbs reacted in IFA with viral antigens of BoHV-1 and BoHV-5 mutant strains defective on gC, gE, gI and US9 genes, demonstrating that they are directed against other viral antigens. Because the high reaction titer and the wide range of reactivity, these mAbs have potential use in diagnostics techniques. Also, these mAbs may be useful to map conserved neutralizing epitopes in the envelope glycoproteins / O herpesvírus bovino tipo 1 (BoHV-1) é um dos principais patógenos de bovinos e causa perdas significativas para a bovinocultura. Anticorpos monoclonais (AcMs) se constituem em importantes ferramentas para o diagnóstico e pesquisa em diversos aspectos da biologia desse agente. A maioria dos AcMs produzidos contra o BoHV-1 são direcionados contra a glicoproteína C (gC), um antígeno abundante e imunodominante do envelope viral. No presente trabalho, antígenos de uma cepa do BoHV-1 defectiva no gene da gC foram utilizados para a imunização de camundongos visando a produção de AcMs com outras especificidades protéicas. Após fusão e seleção de 54 clones resistentes ao meio seletivo HAT, foram obtidos três hibridomas secretores de AcMs contra antígenos do BoHV-1 (1F1, 2H4, 4D7). Os AcMs pertenceram ao isotipo IgG2a e reagiram em diluições de até 1:640 (sobrenadante de cultivo) e 1:20.000 (fluído ascítico) em testes de imunofluorescência indireta (IFA) e imunoperoxidase indireta (IPX). Os três AcMs reagiram na IFA com 14 isolados de doença respiratória e/ou genital e com 17 isolados de doença neurológica, e apresentaram atividade neutralizante em níveis variáveis contra a grande maioria desses isolados. A especificidade protéica dos AcMs não foi determinada, pois nenhum deles reagiu com proteínas virais na técnica de Western blot. Por outro lado, os três AcMs reagiram na IFA contra antígenos virais de cepas do BoHV-1 e BoHV-5 com deleção dos genes que codificam as proteínas gC, gE, gI e US9, demonstrando que são direcionados contra outros antígenos virais. Pelo seu alto título de reação e pelo amplo espectro de reatividade, esses AcMs possuem aplicação potencial em técnicas diagnósticas. Esses AcMs também podem ser úteis para o mapeamento de epitopos neutralizantes conservados nas glicoproteínas do envelope

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Bovine herpesvirus types 1 and 5 (BoHV-1, BoHV-5) are genetically and antigenic related viruses and have been associated with important economic losses to the cattle industry. The aim of this Thesis was to perform the molecular identification of BoHV-1 and BoHV-5 isolates. The first part describes the identification of 40 herpesviruses isolated from different clinical specimens and syndromes in central-southern Brazil, Argentina and Uruguay (1987 2006). The differentiation between BoHV-1 and BoHV-5 was performed by examining the size of the amplification product of a glycoprotein C gene-based PCR, designed for a low homology region of the gene. BoHV-1 isolates (n=16) were identified in cases of respiratory disease (n=3), vulvovaginitis and/or balanoposthitis (n=3), in semen of healthy bulls (n=5) and in cases of neurological disease (n=5). Samples identified as BoHV-5 (n=24) were isolated predominantly from cases of neurological disease (n=21), but also from semen of healthy bulls (n=2) and from a spleen of a calf with systemic disease (n=1). These results show that both BoHV-1 and BoHV-5 are not strictly associated with their respective diseases; yet are frequently involved in clinical conditions otherwise attributed to the other virus type. These findings also reinforce the need of correctly identifying the herpesvirus isolates as to better understand their pathogenesis and epidemiology. In the second part, it is reported the characterization of five Brazilian BoHV-1 isolates associated with neurological disease, an unusual finding. All five samples were isolated from the brain of cattle presenting neurological disease, yet histological evidences of meningoencephalitis were not observed in three cases. The isolated viruses were identified as BoHV-1 by a glycoprotein C gene-based PCR able to differentiate BoHV-1 from BoHV-5. The identity of the isolates was confirmed by nucleotide sequencing of the amplicons and by restriction analysis of PCR products from another gC region. Monoclonal antibody binding and cross-neutralization assays with BoHV-1 and BoHV-5 antisera showed a typical BoHV-1 antigenic profile. Inoculation of rabbits with these five BoHV-1 isolates did not result in neurological disease, contrasting with fatal meningoencephalitis produced by BoHV-5. Thus, the involvement of BoHV-1 in neurological disease of cattle is more frequent than previously reported, indicating the need for fast and precise means of differentiating it from BoHV-5. Likewise, the potential role of BoHV-1 in neurological disease in cattle should be further investigated. / Os herpesvírus bovino tipos 1 e 5 (BoHV-1, BoHV-5) são agentes geneticamente e antigenicamente relacionados que causam grandes prejuízos econômicos à bovinocultura. O objetivo desta tese foi o de realizar a identificação e diferenciação molecular de isolados de BoHV-1 e BoHV-5. Na primeira parte, foi relatada a identificação de 40 amostras de BoHV isoladas de diferentes casos clínicos na região Centro-Sul do Brasil, Argentina e Uruguai entre 1987 e 2006. A diferenciação entre BoHV-1 e BoHV-5 foi realizada pelo uso de um PCR para uma região de baixa homologia do gene da glicoproteína C, o que permitiu a diferenciação entre os tipos virais pelo tamanho do amplicon. As amostras identificadas como BoHV-1 (n=16) foram isoladas de doença respiratória (n=3), balanopostite e/ou vulvovaginite (n=3), do sêmen de touros saudáveis (n=5) e de casos doença neurológica (n=5). As amostras identificadas como BoHV-5 (n=24) foram, em sua maioria, isoladas de doença neurológica (n=21), mas também do sêmen de touros saudáveis (n=2) e do baço de um bezerro com doença sistêmica (n=1). Esses resultados demonstram que tanto o BoHV-1 como o BoHV-5 não estão estritamente associados às suas respectivas síndromes clínicas e que podem estar envolvidos em casos clínicos classicamente atribuídos ao outro tipo viral. Esses achados também reforçam a necessidade da correta identificação dos isolados de herpesvírus para um melhor conhecimento da sua patogenia e epidemiologia. Na segunda parte do trabalho, foram caracterizados cinco isolados de BoHV-1 provenientes de casos de doença neurológica. Esses vírus foram isolados do encéfalo de bovinos que apresentavam sinais neurológicos. Entretanto, evidências histológicas de meningoencefalite não foram observadas em três dos cinco casos. Os isolados foram identificados como BoHV-1 pela utilização de um PCR direcionado para o gene da gC. A identidade dos isolados foi confirmada pelo sequenciamento do amplicon e também por um segundo PCR para outra região do gene da gC, seguido de análise de restrição enzimática do amplicon. A caracterização antigênica com anticorpos monoclonais e testes de soroneutralização cruzada demostraram um perfil típico de BoHV-1. Esses cinco isolados também foram inoculados em coelhos, nos quais não produziram doença neurológica. Esses resultados demostram que o envolvimento de BoHV-1 em doença neurológica em bovinos é mais frequente do que o relatado anteriormente, evidenciando a necessidade de uma precisa diferenciação entre os tipos virais.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This dissertation reports the standardization of a monoclonal antibody (MAb)-based immunoenzymatic test (ELISA) for detection of antibodies to bovine herpesvírus types 1 and/or 5 (BoHV-1 and BoHV-5). The initial steps involved the determination of the most suitable MAb, the appropriate dilutions of viral antigen and test sera; and the cut-off value of the assay. After standardization, the ELISA was validated by testing 506 cattle serum samples previously tested for neutralizing antibodies to BoHV-1 and BoHV-5 by virus neutralizing (VN) assay. Comparing to the VN for BoHV-1 antibodies, the ELISA presented sensitivity and specificity of 96.6% and 98.3%, respectively. Positive and negative predictive values were 97.6%, the concordance between the tests was 97.6% and the coefficient of correlation k (kappa) was 0.95, demonstrating an excellent correlation. Comparing to the VN for BoHV-5 antibodies, the ELISA presented 94.3% of sensitivity, 97.9% of specificity, 97.1% of positive predictive value, 95.9% negative predictive value, concordance of 96.4% and kappa coefficient of 0.92. These results demonstrate that the ELISA presents suitable specificity and sensitivity to be used for individual and herd serological diagnosis of BoHV-1 and BoHV-5, thus, representing an alternative for VN assays and imported ELISA kits. / Essa dissertação relata a padronização de um teste imunoenzimático do tipo ELISA, com base em anticorpo monoclonal (AcM), para a detecção de anticorpos séricos que reagem contra herpesvírus bovino tipos 1 e/ou 5 (BoHV-1, BoHV-5). Inicialmente, determinou-se o AcM mais adequado para a sensibilização das placas, as diluições apropriadas do antígeno e dos soros-teste e o ponto de corte do ensaio. Após a padronização, o ensaio foi validado testando-se 506 amostras de soro bovino, previamente testadas para anticorpos neutralizantes contra o BoHV-1 e/ou BoHV-5 pela técnica de soroneutralização (SN). Comparando-se com os resultados da SN frente ao BoHV-1, o teste de ELISA apresentou sensibilidade e especificidade de 96,6% e 98,3%, respectivamente. Os valores preditivos positivo e negativo foram de 97,6%, a concordância foi de 97,6% e o índice de correlação (kappa) entre os testes foi de 0,95, o que indica uma excelente concordância. Comparando-se com os resultados da SN frente ao BoHV-5, o ELISA apresentou 94,3% de sensibilidade; 97,9% de especificidade; 97,1% de valor preditivo positivo e 95,9% de valor preditivo negativo. Para o BoHV-5, a concordância entre os testes foi de 96,4% e o índice de correlação foi de 0,92, também excelente. Esses resultados demonstram que o teste padronizado apresenta sensibilidade e especificidade adequados para o diagnóstico sorológico das infecções pelo BoHV-1 e BoHV-5 em nível individual e de rebanho. Dessa forma, o ensaio pode se constituir em alternativa para o teste de SN e para os kits de ELISA importados.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The present study describes an investigation of the attenuation/virulence and immunogenicity of a recombinant BoHV-5, a candidate vaccine strain. The recombinant BoHV-5gE/TKΔ was constructed out of a Brazilian BoHV-5 strain (SV507/99) and contains deletions in glycoprotein E (gE) gene as antigenic marker - and thymidine kinase (TK) gene for attenuation. In Chapter 1, we investigated the attenuation and immunogenicity of the recombinant in calves. Eighty-to-ninety days old calves (n=6) inoculated intranasally (IN) with the recombinant virus (titer of 107.5 TCID50) showed no clinical signs, and shed low titers of virus in nasal secretions. On day 30 post-infection (pi), all animals had neutralizing antibodies against BoHV-5, in titers from 4 to 8 and remained negative for antibodies to gE. Administration of dexamethasone (Dx) to four of these calves at day 42 pi (0.1mg/kg/day during 5 days) did not result in virus shedding or increase in antibody titers, indicating lack of viral reactivation. In a second experiment, intramuscular immunization (IM) of calves with 8 months of age (n=9) with the recombinant virus (107.5 TCID50/animal) did not result in virus shedding or clinical signs. Vaccinated animals developed neutralizing antibodies in titers from 2 to 8 at day 42 post-vaccination (PV) and remained negative for gE antibodies. Finally, 21 calves (approximately 10 months old) were vaccinated IM with the recombinant virus (107.3 TCID50). All vaccinated animals developed neutralizing antibodies in titers from 2 to 16 at day 30pv. A boost vaccination performed on those animals at day 240 pv resulted in a rapid and strong anamnestic antibody response, with VN titers reaching from 16 to 256 at day 14 post-booster. Serum samples of all animals remained negative for gE antibodies. Serum samples from vaccinated animals showed cross-neutralizing activity against nine field isolates of BoHV-5 and eight of BoHV-1. Chapter 2 describes an investigation of the immunogenicity and protection conferred by the recombinant virus against homologous (BoHV-5) and heterologous challenge (BoHV-1). A group of nine calves seronegative for BoHV-5 were vaccinated IM in a dose of 107.5 TCID50 of the recombinant virus and eight animals were maintained as non vaccinated controls. All vaccinated animals seroconverted 14 days postvaccination (pv), with neutralizing antibody titers from 2 to 4. At day 42 post-vaccination (pv), the vaccinated animals and controls were challenged by IN instillation of BoHV-5 or BoHV-1 isolates. After challenge, the length and magnitude of virus shedding was reduced in vaccinated animals compared to controls in both groups (challenged with BoHV-1 and BoHV-5). The vaccinated animals did not show systemic, respiratory or neurological clinical signs after challenge. Furthermore, the control animals challenged with BoHV-5 (n=4) developed severe neurological disease and were euthanized in extremis between days 13 and 14 post-challenge (pd). The challenge resulted in a strong and rapid anamnestic response in vaccinated animals, inducing neutralizing titers higher than in control animals. Antibodies to gE were detected only after challenge in both vaccinated and controls calves. These results indicate that recombinant BoHV-5 gE/TKΔ is an adequate candidate for a vaccine strain, with an antigenic marker, since it is attenuated and immunogenic for calves and provides homologous and heterologous (BoHV-1) protection. / O presente trabalho descreve a atenuação/virulência e imunogenicidade de uma cepa recombinante do herpesvírus bovino tipo 5 (BoHV-5) candidata a cepa vacinal. O recombinante BoHV-5gE/TKΔ foi construído a partir da cepa brasileira SV507/99 e contém deleções nos genes da glicoproteína E (gE) como marcador antigênico - e da enzima timidina quinase (TK), para atenuação. No capítulo 1, investigou-se a atenuação e imunogenicidade do recombinante em bezerros. Bezerros com 80 a 90 dias de idade (n=6), inoculados pela via intranasal (IN) com o vírus recombinante (título de 107,5 TCID50) não apresentaram sinais clínicos, e excretaram títulos baixos de vírus nas secreções nasais. No dia 30 pós-infecção (pi), todos os animais possuíam anticorpos neutralizantes contra o BoHV-5, em títulos entre 4 e 8, permanecendo soronegativos para a gE. Administração de dexametasona (Dx) a quatro desses bezerros no dia 42 pi (0.1mg/kg/dia durante 5 dias) não resultou em excreção viral ou em aumento dos títulos de anticorpos, indicando ausência de reativação viral. Em um segundo experimento, vacinação intramuscular (IM) de bezerros com 8 meses de idade (n=9) com o recombinante (107,5TCID50/animal) não resultou em excreção viral ou em manifestações clínicas. Os animais vacinados desenvolveram anticorpos neutralizantes em títulos de 2 a 8 no dia 42 pós-vacinação (PV) e permaneceram negativos para anticorpos anti-gE. Finalmente, 21 bezerros (aproximadamente 10 meses de idade) foram vacinados com o recombinante (107,3 TCID50) pela via IM. Todos os animais vacinados desenvolveram anticorpos neutralizantes em títulos de 2 a 16 no dia 30pv. Revacinação desses animais no dia 240 pv provocou uma resposta anamnéstica rápida e intensa, resultando em títulos neutralizantes entre 16 e 256 no dia 14 pós-revacinação. O soro de todos os animais permaneceu negativo para anticorpos contra a gE. Amostras de soro dos animais vacinados apresentaram atividade neutralizante cruzada frente a nove isolados de BoHV-5 e oito de BoHV-1. O capítulo 2 relata uma investigação sobre a imunogenicidade e proteção conferida pelo vírus recombinante frente a desafio homólogo (BoHV-5) e heterólogo (BoHV-1). Para isso, nove bezerros soronegativos para o BoHV-5 foram vacinados pela via intramuscular com uma dose de 107,5DICC50 do vírus recombinante e oito animais foram mantidos como controle. Todos os animais vacinados soroconverteram aos 14 dias pós-vacinação (pv), apresentando títulos de anticorpos neutralizantes entre 2 e 4. No dia 42 pós-vacinação (pv), os animais vacinados e os controles foram desafiados pela inoculação intranasal (IN) de isolados de BoHV-5 ou de BoHV-1. Após o desafio, a excreção de vírus pelos animais vacinados foi reduzida em comparação com os não vacinados, nos dois grupos (desafiados com BoHV-1 e BoHV-5). Os animais vacinados também não apresentaram sinais clínicos sistêmicos, respiratórios ou neurológicos pós desafio. Por outro lado, os animais controles inoculados com o BoHV-5 (n=4) desenvolveram doença neurológica severa e foram eutanasiados in extremis entre os dias 13 e 14 pós-desafio (pd). O desafio provocou uma resposta anamnéstica intensa e rápida nos animais vacinados, induzindo títulos neutralizantes superiores aos animais não vacinados. Anticorpos contra a gE foram detectados apenas após o desafio, tanto nos vacinados quanto nos controles. Esses resultados indicam que o recombinante BoHV-5 gE/TKΔ é um candidato adequado a cepa vacinal com marcador antigênico, pois é atenuado e imunogênico para bezerros, confere proteção homóloga e também contra o BoHV-1.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Bovine herpesvirus type 1 (BoHV-1) is distributed worldwide and produces high economic losses to the in livestock industry. BoHV-1 infection causes respiratory, reproductive and may also be associated with neurological signs. There are several tests that can diagnose the infection, however, serological techniques currently used are not able to differentiate antibodies produced by vaccination from those produced in response to natural infection. What is sought is a mean to differentiate vaccinated animals of those infected by the field strain. Vaccines with deletion in the glycoprotein E (gE) gene have been developed for this purpose. However, this also requires the development of tests capable to differentiate the serological response between infected and vaccinated animals. To this end, a 651 nucleotide fragment corresponding to the amino-terminal third (217 amino acids) of the BoHV-1 gE gene - that shares a high identity with the homologous BoHV-5 counterpart - was cloned as a 6×His-tag fusion protein in an Escherichia coli expression vector pET16b. A soluble protein of approximately 25 kDa was purified from lysates of transformed E. coli. The recombinant protein was detected in Western blot (WB) by anti-6-his tag and anti BoHV-1 gE monoclonal antibodies. Antibodies present in the sera of cattle infected with BoHV-1 and BoHV-5 reacted specifically with the 25 kDa recombinant protein in WB. Moreover, mice immunized with the purified protein developed antibodies that recognized the viral gE in lysates of cell monolayers infected with BoHV-1 and BoHV-5. An indirect ELISA for gE antibodies, based on the expressed protein, was able to differentiate serologically calves vaccinated with a gE-deleted BoHV- 5 strain from calves experimentally infected with BoHV-1 or BoHV-5. These data demonstrate that the antigen retained its immunological properties and, thus, can be used in serological tests for bovine herpesvirus infections. It has a potential use in a indirect ELISA to differentiate naturally infected animals from those vaccinated whit the recombinant, gE-negative strains. / O herpesvírus bovino tipo 1 (BoHV-1) é um vírus de distribuição mundial e produz grandes prejuízos econômicos em rebanhos de corte e de leite. A infecção pelo BoHV-1 produz manifestações respiratórias, reprodutivas e também pode cursar com sinais nervosos. Existem diversos testes laboratoriais capazes de diagnosticar a infecção. Contudo, as técnicas sorológicas empregadas atualmente não são capazes de diferenciar anticorpos produzidos pela vacinação daqueles produzidos em resposta à infecção natural. Assim, vacinas diferenciais com deleção da glicoproteína E (gE) têm sido desenvolvidas com essa finalidade. No entanto, necessita-se também de testes capazes de diferenciar a produção de anticorpos vacinais dos induzidos pelo vírus vacinal. Com essa finalidade, essa dissertação relata a expressão e caracterização de um fragmento da glicoproteína E do BoHV-1 e seu uso no desenvolvimento e padronização de um ELISA indireto para detecção de anticorpos anti-gE. Um fragmento de 651 nucleotídeos correspondente ao terço amino-terminal (217 aminoácidos) do gene da gE do BoHV-1, que possui uma alta identidade com o homólogo herpesvírus bovino tipo 5 (BoHV-5), foi clonado com proteína de fusão 6xHis-tag em Escherichia coli utilizando vetor de expressão pET16b. Uma proteína solúvel de aproximadamente 25kDa foi purificada a partir de lisados de E. coli transformadas. A proteína recombinante foi detectada por Western blot (WB) por anticorpos monoclonais anti-histidina e anti-gE do BoHV-1. Anticorpos presentes no soro de animais infectados com BoHV-1 e BoHV-5 reagiram especificamente com a proteína recombinante no WB. Além disso, camundongos imunizados com a proteína purificada desenvolveram anticorpos que reconheceram a gE viral proveniente de lisados de monocamadas celulares infectadas com BoHV-1 e BoHV-5. Um ELISA indireto para detecção de anticorpos anti-gE, baseado na proteína expressa, foi capaz de diferenciar sorologicamente animais vacinados com a cepa gE deletada do BoHV-5 dos animais experimentalmente infectados com BoHV-1 ou BoHV-5. Esses resultados demonstram que o antígeno obtido conservou suas características imunológicas e pode ser utilizado na detecção sorológica das infecções por herpesvírus bovinos. Possui potencial para uso em grande escala como antígeno em testes de ELISA para diferenciar animais naturalmente infectados de animais vacinados com a cepas defectivas na gE

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Bovine herpesvirus type 5 (BoHV-5) is the etiologic agent of neurological disease in calves. The use of recombinant differential vaccines have been proposed against the disease. This dissertation relates an investigation on the attenuation in calves of three BoHV-5 recombinants with deletions in the coding regions of glycoprotein E (BoHV-5gEΔ), thymidine kinase (BoHV-5TKΔ) or both (BoHV-5gETKΔ) for potential use in vaccines. Each of the four groups of calves was inoculated intranasally with one of the mutants or the wild type virus (wt [SV507/99]) and monitored thereafter. The calves inoculated with wt virus shed virus for an average of 12.3 days (106.8DICC50/mL), in the group BoHV-5gEΔ for 11 days (105.1DICC50/mL), in the group BoHV-5TKΔ for 9.6 (105.9DICC50/mL) and in the group BoHV-5gETKΔ for 6.2 days (104.7DICC50/mL). No respiratory or systemic signals were observed in animals inoculated with the recombinants, while two calves of the wt group presented neurologic disease and were euthanyzed in extremis. Seroconversion was verified on the 32 days post-inoculation (pi) in all animals of group wt and BoHV-5gEΔ, while 2 and 4 animals of the groups BoHV-5TKΔ e BoHV-5gETKΔ seroconverted, respectively. Aiming at reactivating latent infection, on the 42 days pi, animals were treated with dexamethasone (Dx). Reactivation was achieved in wt group while groups BoHV-5gE and BoHV-5TKΔ shed virus only for one or two days. No virus shedding was verified on group BoHV-5gETKΔ. Euthanasia was executed 30 days later and brain sections were collected for DNA viral detection. Viral DNA was detected in the brain of wt inoculated animals and in restricted brain sections in the BoHV-5gEΔ group. These results demonstrated that mutants are fully attenuated for calves during acute infection and present a reduced ability to establish and/or reactivate latent infection after Dx administration. Therefore these recombinants may be useful in vaccine formulations. / O herpesvírus bovino tipo 5 (BoHV-5) é o agente de doença neurológica grave em bovinos. A utilização de vacinas recombinantes tem sido preconizada para o controle da infecção pelo BoHV-5. O objetivo do presente trabalho foi investigar a patogenia, em bezerros, de três recombinantes do BoHV-5, com deleções nos genes da glicoproteína E (BoHV-5gEΔ), da enzima timidina quinase (BoHV-5TKΔ) ou ambos (BoHV-5gETKΔ) para uso potencial em vacinas. Para isso, quatro grupos de bezerros com 80 a 90 dias de idade foram inoculados pela via intranasal (IN) com um dos recombinantes ou com a cepa parental (SV507/99) e monitorados nos dias seguintes à inoculação. Os animais inoculados com o vírus parental (SV507/99) excretaram vírus por um período médio de 12,3 dias (título máximo 106,8DICC50/mL), no grupo BoHV-5gEΔ por 11 dias (105,1DICC50/mL), no grupo BoHV-5TKΔ por 9,6 dias (105,9DICC50/mL) e no grupo BoHV-5gETKΔ por 6,2 dias (104,7DICC50/mL). Os animais inoculados com os vírus recombinantes não desenvolveram sinais respiratórios ou sistêmicos importantes; dois animais do grupo SV507/99 apresentaram doença neurológica e foram sacrificados in extremis. No dia 32 pós-inoculação (pi), todos os animais inoculados com o SV507/99 e BoHV-5gEΔ haviam soroconvertido (títulos de 4 a 8), enquanto nos grupos BoHV-5TKΔ e BoHV-5gETKΔ, dois e quatro animais soroconverteram (títulos de 2 a 8), respectivamente. No dia 42 pi, realizou-se a administração de dexametasona (Dx) na tentativa de reativar a infecção latente. Após a administração de Dx, os animais dos grupos BoHV-5gEΔ e BoHV-5TKΔ excretaram vírus por um ou dois dias. Os animais do grupo BoHV-5gETKΔ não excretaram vírus, enquanto a excreção pelos animais do grupo inoculado com o vírus parental foi mais duradoura e em maiores títulos. No dia 30 pós-Dx, os animais foram submetidos à eutanásia para a coleta do encéfalo para a pesquisa de DNA latente por PCR. Não foi detectado DNA viral no encéfalo dos animais inoculados com o BoHV-5TKΔ e BoHV-5gETKΔ, enquanto no grupo SV507/99 foi detectado em todos os animais nas diferentes secções. Dentre os animais inoculados com o recombinante BoHV-5gEΔ, foi verificada uma distribuição de DNA viral restrita, com detecção em apenas uma secção (córtex anterior, ponte ou tálamo) em três animais. Esses resultados demonstram que os recombinantes foram atenuados durante a infecção aguda; apresentaram uma capacidade reduzida de estabelecer infecção latente e não foram facilmente reativados pela administração de Dx. Com isso, constituem-se em potenciais candidatos a cepas vacinais.

Bovine herpesvirus-1 (BoHV-1) is a pathogen of cattle, which most commonly affects the upper respiratory tract to cause infectious bovine rhinotracheitis (IBR). It can also spread systemically to cause fatalities in calves and abortion in pregnant cattle. The virally encoded mechanisms of this systemic spread are poorly understood and therefore have been addressed by comparing isolates from the respiratory form of disease with isolates that have previously demonstrated systemic spread. A survey of 400 bovine abortions in Scotland from 2007-2009 demonstrated a BoHV-1 prevalence of 2.5%. It also demonstrated the importance of real-time PCR as a diagnostic technique when analysing samples from natural cases. The study of BoHV-1 distribution in the placenta and foetal tissue provided support for a haematogenous route of viral spread. Whole genome sequencing of 11 BoHV-1 isolates using Illumina Solexa technology was completed and added significantly to the sequencing data of BoHV-1. In terms of identifying genetic variation between isolates causing respiratory infection and those causing systemic infection, no differences were observed by SNP or phylogenetic analysis. However, there were significant differences in the extent of variation between essential and non-essential genes, which may reflect the evolution of BoHV-1. An in vivo challenge of the natural host to compare two isolates representing the respiratory and systemic forms of infection showed differences in clinical presentation, histopathological analysis, viral distribution and viral transcript expression, measured throughout the infection period. In particular, it was noted that a more severe ocular infection, rather than respiratory based infection was caused by infection with the ‘systemic’ isolate. Differences in the tropism of the virus were observed early in the infection with the ‘systemic’ isolate showing more association with the nasal mucosa than the trachea. The tonsils demonstrated different responses to the virus and differences in viral transcript expression. However, this may simply represent different stages of virus infection. Both isolates demonstrated spread to the brain at day 10 post infection. In vitro methods were used to study the differences in transcript expression in more detail. In a bovine turbinate cell infection faster replication of the respiratory isolate was observed by a significantly faster development of cytopathic effect. This was also reflected in the higher gene expression levels of the respiratory isolate in the first 12 hours of infection. More isolates were studied to investigate whether these differences were consistent, or as suggested by the sequencing, random differences between isolates. Six isolates were used to infect bovine lung slices. Differences in transcript expression were minimal between the two isolate groups. Immunofluorescence did not provide the sensitivity to detect virus in all samples where PCR showed replication. This compromised the study of co-localization but did show promise as a model to study the tropism of respiratory viruses. Overall, this work has showed that systemic spread of BoHV-1 does not appear to be controlled by virally encoded mechanisms. The in vivo experimental infection suggested host factors may play a large part. Further work is also needed to consider any differences that may exist between reactivated virus and the original infecting isolate.

Bovine herpesvirus-1 (BoHV-1) causes recurrent respiratory and genital infections in cattle; and predisposes them to lethal secondary bacterial infections. Vaccination is a primary strategy to prevent and reduce the severity of disease associated with BoHV-1, and to reduce virus transmission. While modified live (MLV) or killed (KV) BoHV-1 vaccines exist, these are expensive to produce, can cause disease (MLV) or may be ineffective (KV). Development of a DNA vaccine for BoHV-1 has the potential to address these shortcomings, but the very small amount of antigen expressed after DNA immunization presents a barrier to successful immunization of large animals. Engineering the vaccine to target this limited quantity of antigen to dendritic cells (DCs), the cells that prime immune responses, by attracting immature DCs (iDCs) to the vaccination site, is one way that DNA vaccine efficacy might be improved. Beta (β)-defensins are chemotactic peptides that, in studies with mice, improve induction of immune responses to DNA vaccines and this is due, at least in part, to their ability to attract iDCs to the site of vaccination. Accordingly, the objective of the studies described in this thesis was to determine whether using a bovine β-defensin in a DNA vaccine would enhance immune responses to the vaccine and subsequently protect cattle upon challenge with BoHV-1. First I characterized the bovine iDC and then used these cells to screen a panel of synthesized bovine β-defensins for chemotactic activity. The results showed that bovine neutrophil β-defensin (BNBD) 3, BNBD9 and enteric β-defensin (EBD) were equally the most chemotactic of the fourteen synthesized peptides for bovine iDCs. Because BNBD3 is the most abundant of the thirteen BNBDs and was able to attract CD1+ DCs when injected into the skin, I chose BNBD3 as the peptide I would use for the rest of the project. Next I constructed plasmids that expressed BNBD3; either alone or as a fusion construct with the BoHV-1 antigen truncated glycoprotein D (tgD), and then tested the effects of the plasmids as vaccines in both mice and cattle. In cattle, the addition of BNBD3 as a fusion strengthened the Th1 bias and increased cell-mediated immune responses to the DNA vaccine but not antibody response or protection from BoHV-1 infection. Given that inefficient humoral immune responses have been implicated in a lack of protection from BoHV-1 challenge, these results suggested that the successful BoHV-1 DNA vaccine would need to induce a much stronger humoral response. Lastly I assessed the ability of BNBD3 to improve humoral responses to pMASIA-tgD when complexed with the DNA vaccine and found that the vaccine complexed at a nanomolar peptide to DNA ratio of 125:1 increased humoral responses of mice. In vitro, treatment of mouse bone-marrow DCs with BNBD3 induced phenotypic and functional maturation/activation. This is an important aspect for vaccination in the skin, since after uptake, the DC must “mature” in order to traffic from the site of vaccination to the draining lymph node where induction of antigen-specific responses, by activated DCs, takes place. The findings in this thesis show that bovine β-defensins are chemotactic for bovine iDCs. I also show that using a bovine β-defensin as a fusion construct in a DNA vaccine enhances cell mediated but not humoral responses of cattle and yet this vaccine is protective against BoHV-1 challenge. I demonstrate that a bovine β-defensin, when used as a peptide to complex an antigen-encoding plasmid, can increase humoral responses. My work shows a multifunctional ability of bovine β-defensins to modulate and increase immune responses and suggests that bovine β-defensins likely have further untapped potential to enhance efficacy of DNA vaccines for large animals.

O complexo respiratório bovino é um dos principais problemas encontrados em bovinos tanto confinados quanto àqueles criados a pasto, levando a importantes perdas econômicas devido aos altos índices de morbidade e mortalidade. O objetivo geral deste trabalho foi determinar a prevalência de M. bovis, M. díspar, M. mycoides subsp. mycoides SC, P. multocida, M. haemolytica, Parainfluenza Bovino tipo-3 (PIb- 3) e Influenza vírus D e a prevalência de anticorpos contra Vírus da Diarreia Viral Bovina (VDVB), Herpesvírus tipo -1 (BoHV1) e o Vírus Respiratório Sincicial Bovino (VRSB) em bezerros sadios e com broncopneumonia criados nos assentamentos de Caiuá, Presidente Epitácio e Mirante de Paranapanema - SP. Além disso, objetivase avaliar a associação destes micro-organismos com a presença da broncopneumonia e dos sinais e sintomas apresentados pelos animais durante a avaliação física. Estudou-se 141 bezerros, machos e fêmeas de até um ano de idade, os quais, após exame físico, foram classificados em sadios e com pneumonia. Foram coletadas amostras de lavado traqueobrônquico e sangue total para obtenção do soro. As amostras foram utilizadas para isolamento e identificação de M. bovis, M. díspar, M. mycoides subsp. mycoides SC, P. multocida e M. haemolytica, detecção molecular de Parainfluenza Bovino tipo-3 (PIb-3) e Influenza vírus D (IVD) e detecção de anticorpos contra Vírus da Diarreia Viral Bovina (VDVB), Herpesvírus tipo -1 (HVBo-1) e o Vírus Respiratório Sincicial Bovino (VRSB). Não houve isolamento de P. multocida e M. haemolytica. Dentre as bactérias aeróbias isoladas, observou-se maior frequência de isolamento de Bacillus sp., Staphylococcus intermedius e bactérias Gram-negativas não fermentadoras. M. díspar foi a única espécie de micoplasma identificada com os oligonucleotídeos iniciadores utilizados. Faz-se necessário a busca por outras espécies de micoplasmas que podem estar relacionadas aos casos de broncopneumonia em bovinos. Não houve detecção de Parainfluenza Bovino tipo 3 e Influenza vírus D nas amostras de lavado traqueobrônquico. Os três municípios estudados apresentaram anticorpos para os vírus estudados. Observou-se prevalência de BoHV-1, VDVB e VRSB de 31,7%, 24,6 e 38,8%, respectivamente. Não houve associação entre o status de saúde dos bezerros e os achados microbiológicos e sorológicos. Foi observada associação entre enterobactérias e a variável “desidratação leve” (p=0,033/ OR= 11,25, IC: 1,809-41,834. Observou-se associações entre Mollicutes e a variável “secreção nasal serosa” (p=0,03). Concluiu-se que a broncopneumonia é uma enfermidade multifatorial. Faz-se, necessário, portanto, a associação dos achados de exames físico, microbiológicos e características do ambiente e manejo / Bovine respiratory disease complex is one of the major problems observed in feedlot and grazing cattle, causing economic losses due to high morbidity and mortality rates. The aim of this study was to determine the prevalence of M. bovis, M. díspar, M. mycoides subsp. mycoides SC, P. multocida, M. haemolytica, Bovine Parainfluenza type-3 (bPI-3) and Influenza vírus D (IVD) and the prevalence of antibodies against Bovine Viral Diarrhea Vírus (BVDV), Bovine Herpesvírus type -1 (BoHV1) and Bovine Respiratory Syncytial Vírus (VRSB) in healthy and pneumonic calves raised in settlements located in Caiuá, Presidente Epitácio e Mirante de Paranapanema São Paulo State. Moreover, we aimed to evaluate the association between those microorganisms and antibodies and the presence of bronchopneumonia and the symptoms observed during the physical examination. We studied 141 males and females calves that were classified as healthy and pneumonic calves. We collected tracheobronchial lavage samples and total blood to obtain serum samples. Isolation and biochemical/ molecular identification were performed in order to detect M. bovis, M. díspar, M. mycoides subsp. mycoides SC, P. multocida, M. haemolytica, Bovine Parainfluenza type-3 and Influenzavírus D. Serological survey was performed to detect antibodies aginst Bovine Viral Diarrhea Vírus (BVDV), Bovine Herpesvírus type -1 (BoHV1) and Bovine Respiratory Syncytial Vírus (VRSB). There was not any isolation of P. multocida and M. haemolytica. Bacillus sp., Staphylococcus intermedius and Non-fermenter Gram-negative bacteria were higher prevalent compared to the other aerobic bacteria isolated. M. díspar was the only mycoplasma species identified by the primers used. It is necessary the identification of other mycoplasma species that could be related to the cases of bronchopneumonia in cattle. Bovine Parainfluenza type-3 and Influenza vírus D were not identified. Antibodies were detected in all municipalities. The prevalence of BoHV, BVDV e VRSB was 31.7%, 24.6 and 38.8%, respectively. The association between health status and microbial/ serological findings was not observed. Enterobacterias were associated to “mild dehydration” (p=0.033/OR=11.25; IC: 1.809-41.834). Associations between Mollicutes and “serous nasal discharge” (p=0.03) was also detected. In conclusion, S. intermedius was associated to “nasal air flow” (p=0.097). In conclusion bovine bronchopneumonia is multi-factorial disease. It is necessary, though, physical examination, microbiology and management and environment feature results