Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2018-11-13T12:15:03Z No. of bitstreams: 1 texto completo.pdf: 1654335 bytes, checksum: bce0b05d7832cce3f6841e6c11b57384 (MD5) / Made available in DSpace on 2018-11-13T12:15:03Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1654335 bytes, checksum: bce0b05d7832cce3f6841e6c11b57384 (MD5) Previous issue date: 2018-07-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O bovine herpesvirus 1 (BoHV-1) é de fácil disseminação, difícil controle e está amplamente disseminado nos rebanhos bovinos no mundo. Essa infecção viral é responsável por prejuízos à pecuária principalmente quanto aos aspectos reprodutivos. Estudos prévios envolvendo infecção experimental com o BoHV-1 em um sistema de produção in vitro de embriões reportou que a presença do vírus afetou o desenvolvimento embrionário. Neste trabalho, foi avaliada a interferência do BoHV-1 sobre a maturação in vitro de complexos cumulus-ovócito (COCs) e ovócitos desnudados com células do cumulus em suspensão (DOs). Foram coletados sangue e os ovários de fêmeas bovinas sabidamente não vacinadas contra o BoHV-1. Após o teste de soroneutralização, os animais soropositivos foram classificados de acordo com a sua titulação de anticorpos. Os ovócitos recuperados após aspiração folicular foram divididos em COCs e DOs e avaliados através da sua capacidade de maturação nuclear associado a detecção viral pela microscopia confocal de varredura a laser. Dois experimentos foram realizados: (I) maturação após infecção in vitro de COCs e DOs de animais soronegativos; (II) maturação in vitro de COCs e DOs de animais soropositivos. No experimento I, diferença (P<0,01) foi observada entre as taxas de maturação do grupo COCs controle (78,2%) e os grupos infectados dos COCs (43,6%). No experimento II verificou-se diferença (P<0,01) na taxa de maturação entre os animais de titulação de anticorpos ≥ 16 (56,9%) e o grupo controle (79,4%). Os ensaios de imunofluorescência permitiram a identificação do BoHV-1 nos COCs e DOs. Diante disso, conclui-se que o BoHV-1 foi capaz de afetar o processo de maturação in vitro tanto nas condições de infecção in vitro e em condições naturais de infecção. / Bovine herpesvirus 1 (BoHV-1) disseminates easily, is difficult to control, and is widely spread in cattle herds worldwide. BoHV-1 causes a broad range of losses to the cattle industry, mainly concerning reproduction. Previous studies involving experimental infection of BoHV-1 in an in vitro embryo production system have reported impairment of embryonic development by BoHV-1. In this study, we evaluated the interference of BoHV-1 in the in vitro maturation system of cumulus- oocyte complexes (COCs) and denuded oocytes (DOs) cultured with a cumulus cell suspension. Blood samples and ovaries were collected from slaughterhouse cows unvaccinated against BoHV-1. Using virus neutralization assays, the seropositive animals were classified according to their antibody titers. The oocytes were recovered by follicular aspiration and divided into two groups, COCs and DOs, which were evaluated for their nuclear maturation capacity using immunofluorescence assays by laser scanning confocal microscopy. Two experiments were carried out: (I) in vitro maturation of COCs and DOs after artificial infection of seronegative animals and (II) in vitro maturation of COCs and DOs of seropositive animals. In experiment I, a difference (P <0.01) was observed between the maturation rates of the control group COCs (78.2%) and the infected COCs (43.6%). In experiment II, there was a difference (P <0.01) in the maturation rate between animals with antibody titers ≥ 16 (56.9%) and the control group (79.4%). Immunofluorescence assays identified BoHV-1 in the COCs and DOs. Therefore, it was concluded that BoHV-1 affects the in vitro maturation process in both in vitro and natural infections.

Bovine Respiratory Disease Complex is a multifactorial disease affecting cattle worldwide resulting in high mortality and morbidity rates in the cattle farming industry. This complex is caused by multiple viral and bacterial pathogens such as Bovine Herpesvirus-1, Bovine Respiratory Syncytial Virus, Mannheimia haemolytica, and Pasteurella multocida; two of the main contributors to the initiation of this disease are Bovine Herpesvirus-1 and the bacteria, Mannheimia haemolytica. Together, these microbes co-infect immunocompromised cattle during times of increased stress and induce a severe pneumonic response along with other health complications. Research has been primarily focused on these microorganisms individually or their effect on the host, however there is a need to study them together due to the increased mortality rate associated with co-infections. In this study, we used Bovine Herpesvirus-1, Mannheimia haemolytica, Pasteurella multocida, and Bovine Respiratory Syncytial Virus to co-infect bovine tissue cultures to determine how they affect each other.

O objetivo geral desta pesquisa foi avaliar a resposta imune (RI) humoral e celular de bezerros recém-nascidos mediante imunização passiva e ativa, usando como modelo o Vírus da Diarreia Viral Bovina (BVDV) e o Herpesvírus Bovino tipo-1 (BoHV-1). Esta pesquisa foi dividida em duas etapas e seus dados estão apresentados em dois capítulos. Capítulo 1- Acompanhou-se a imunização passiva de bezerros do nascimento até os seis meses de idade e a influência da vacinação materna no período pré-parto nessa resposta. Os animais foram distribuídos em dois grupos experimentais que receberam colostro de mães não imunizadas (G1, n=4) e (G2, n=6) de mães imunizadas no período pré-parto para o BVDV e BoHV-1. A colostragem foi feita pela administração de seis litros de colostro nas primeiras doze horas de vida, distribuídas em duas mamadas. Nesta etapa foi possível verificar: (1) a presença de títulos de ACs neutralizantes apenas no grupo de bezerros que receberam colostro de mães imunizadas, obtendo soroconversão após a mamada de colostro em 2/6 (33%) bezerros para o BVDV e 6/6 (100%) para o BoHV-1; (2) manutenção dos títulos de ACs protetores até os três meses de vida. Em relação a RI celular: (3) observou-se maior proporção de células T auxiliares CD4+ (P=0,05) no grupo de bezerros que receberam colostro de mães imunizadas no período pré-parto; (4) o leucograma dos bezerros demonstrou respostas inflamatórias em alguns momentos desta pesquisa, mais intensa nos animais que ingeriram colostro proveniente de mães nãoimunizadas. Capítulo 2- Acompanhou-se a imunização de bezerros para BVDV e BoHV-1 aos seis meses de idade. Dez bezerros foram distribuídos em dois grupos de bezerros não vacinados (VAC-, n=5) e vacinados para o BVDV e BoHV-1 (VAC+, n=5), as análises foram realizadas antes da imunização aos 180 dias (T0), após a 1°dose aos 210 dias (T1) e após a 2° dose aos 240 dias (T2). Os resultados obtidos para avaliação da RI humoral foram: (1) soroconversão de 2/5 (40%) animais no momento T1 e 3/5 (60%) no T2 para o BVDV; (2) soroconversão em 2/5 (40%) no T1 e 5/5 (100%) no T2 para o BoHV-1. Para a RI celular observou-se: (3) maior expressão de CD25+ pelas subpopulações de linfócitos T gama-delta WC1+ no VAC+, observando-se diferença estatística no momento T1 (P=0,0016). Com base nos resultados obtidos nas duas etapas experimentais desta pesquisa pode-se concluir que a vacinação materna é uma estratégia para melhorar a qualidade do colostro e as repostas imunes humoral e celular dos bezerros para BVDV e BoHV-1; a duração da imunidade materna considerando-se níveis protetores de Acs foi de três meses; os componentes do colostro influenciaram na resposta inflamatória dos bezerros à exposição natural aos patógenos; a vacinação dos bezerros aos seis meses de idade estimulou a resposta imune humoral para BoHV-1 e parcial para BVDV. / The aim of this research was to evaluate the humoral and cellular immune response (IR) of newborn calves by active and passive immunization, using by model the Bovine Viral Diarrhea Virus (BVDV) and Bovine Herpesvirus type-1 (BoHV-1). This research was divided in two stages and the datas are presented in two chapters. Chapter 1: Was followed the passive immunization of calves from birth until six months old and the maternal vaccination influence on pre-partum period on this response. The animals were divided in two experimental groups that received colostrum from unvaccinated mothers (G1, n = 4) and (G2, n=6) from immunized mothers in the pre-partum period to BVDV and BoHV-1. The calves received six liters of colostrums on the first twelve hours of life, divided in two feedings. At this stage was verified: (1) the presence of neutralizing titers antibodies (Abs) only in group of calves that received colostrum from immunized mothers, getting seroconversion after feeding in 2/6 (33%) of calves for BVDV and 6/6 (100%) for BoHV-1, (2) maintenance of Abs titers protectors up to three months of life. In relation to immune cellular response: (3) was observed higher proportion of helper T cells CD4+ (P = 0.05) in the group of calves that received colostrum from immunized mothers during pre-partum; (4) the leukogram of calves showed inflammatory responses in some moments of this research, more intense in animals that ingested colostrums from non-immunized mothers. Chapter 2: Was followed the immunization of calves for BVDV and BoHV-1 at six months old. Ten calves were divided in two groups of calves non-vaccinated (VAC-, n = 5) and vaccinated for BVDV and BoHV-1 (VAC +, n = 5). The analyzes were performed before immunization at 180 days (T0), after the 1st dose at 210 days (T1) and after the 2nd dose at 240 days (T2). The results for evaluation of immune humoral response were: (1) seroconversion 2/5 (40%) animals at the T1 moment and 3/5 (60%) of T2 for BVDV, (2) soroconversion on 2/5 (40 %) in the T1 to 5/5 (100%) at T2 for BoHV-1. For the immune cellular response was observed: (3) increased expression of CD25+ subpopulations of T lymphocytes by gamma-delta WC1+ in VAC+, observing statistical difference in T1 moment (P = 0.0016). Based on the results obtained in the two experimental stages of this research can be concluded that maternal vaccination is a strategy to improve the quality of colostrum and humoral and cellular immune response of calves to BVDV and BoHV-1, the duration of maternal immunity considering protective levels of Abs was three months. The components of colostrum influence the inflammatory response of calves to natural exposure to pathogens. The vaccination of calves at six months old stimulated the humoral immune response to BoHV-1 and partial for BVDV.

Bovine herpesvirus-1 (BoHV-1) is an important pathogen of cattle associated with respiratory and reproductive disease and is the most common viral agent implicated in the bovine respiratory disease complex (BRDC). BRDC is an economically significant multifactorial disease of feedlot cattle estimated to cost Australian feedlot producers $AU60 million/year in lost production, therapeutics and disease management. Worldwide BRDC is attributed to cost $US2 billion to cattle industries. In an effort to limit the associated economic costs and enhance animal health and welfare of feedlot cattle, the concerted use of vaccination and diseased animal management are practiced. Numerous vaccines are available in North America and Canada however, in Australia, feedlot producers are reliant on three vaccines. These vaccines target either the bacterial or viral agents of the BRDC and encompass antibody, subunit and attenuated live BoHV-1 preparations. Live attenuated vaccines are developed by numerous methods including, deletion or disruption of certain genes. The development of an attenuated live virus vaccine was traditionally a laborious task requiring numerous rounds of in vitro purification. Contrastingly, technological advances introduced this decade, allowing the stable maintenance of the complete herpesvirus genome in bacteria as a bacterial artificial chromosome (BAC), has advanced herpes virology exponentially in that investigation and manipulation of the herpesvirus genome can be conducted independent of a cell culture system. With respect to BRDC and the generation of vaccines to combat the disease, the tools to fully utilise the potential of BoHV-1 as a live vaccine vector are now routine. It is now possible to vii construct BoHV-1 as a delivery vector by inserting appropriate antigens of those bacterial and viral pathogens implicated in the BRDC into a BAC maintained BoHV-1 genome. However, there is a significant lack of genetic information regarding BoHV-1 and inserting several antigenic sequences would expand the genome of BoHV-1 inducing non-viability. Therefore, to further develop BoHV-1 as a vaccine vector, a study was conducted to identify the essential and nonessential genes required for the in vitro viability of BoHV-1. Identifying the essential and nonessential genes will establish which genes may be preferentially deleted or replaced with exogenous antigenic sequences in a BoHV-1 derived vaccine vector. To define the requirement of genes encoded by BoHV-1, random-insertion mutagenesis utilising a Tn5 transposition system and targeted gene deletion catalysed by GET recombination was employed to construct gene disruption and gene deletion libraries, respectively, of an infectious clone of BoHV-1. Transposon insertion position and confirmation of gene deletion was determined by direct sequencing. with the essential or nonessential requirement of either transposed or deleted open reading frames (ORFs) assessed by transfection of respective BoHV- 1 BAC DNA into host cells. Of the 73 recognised ORFs encoded by the BoHV-1 genome, 33 were determined to be essential and 36 to be nonessential for virus viability in cell culture with the requirement of the two dual copy ORFs inconclusive. The majority of ORFs were shown to conform to the in vitro requirements of BoHV-1 homologues encoded by Human herpesvirus 1. However, ORFs encoding for glycoprotein K (UL53), regulatory, membrane, tegument and capsid proteins (UL54, UL49.5, UL49, UL35, UL20, UL16 and UL7) were shown to differ in requirement when compared to Human herpesvirus-1 encoded homologues. Further analysis of clones encompassing restriction digestion profiling, one-step growth and replication kinetic analysis defined the genetic constitution and replicative capacity of the mutant clones. Thirty-three individual ORFs of the 36 defined nonessential ORF were identified as being amenable to deletion without causing significant replicative detriment to a potential BoHV-1 vaccine vector. This study has provided the foundational information required for the future development of BoHV-1 as a multivalent vaccine vector for the protection of feedlot cattle from BRDC. Furthermore, the genetic information generated in this study contributes to the general knowledge of the prototype ruminant herpesvirus, BoHV-1, and contributes to the comparative study of gene function between the large and diverse family that is Herpesviridae.

Bovine herpesvirus-1 (BoHV-1) is an important pathogen of cattle associated with respiratory and reproductive disease and is the most common viral agent implicated in the bovine respiratory disease complex (BRDC). BRDC is an economically significant multifactorial disease of feedlot cattle estimated to cost Australian feedlot producers $AU60 million/year in lost production, therapeutics and disease management. Worldwide BRDC is attributed to cost $US2 billion to cattle industries. In an effort to limit the associated economic costs and enhance animal health and welfare of feedlot cattle, the concerted use of vaccination and diseased animal management are practiced. Numerous vaccines are available in North America and Canada however, in Australia, feedlot producers are reliant on three vaccines. These vaccines target either the bacterial or viral agents of the BRDC and encompass antibody, subunit and attenuated live BoHV-1 preparations. Live attenuated vaccines are developed by numerous methods including, deletion or disruption of certain genes. The development of an attenuated live virus vaccine was traditionally a laborious task requiring numerous rounds of in vitro purification. Contrastingly, technological advances introduced this decade, allowing the stable maintenance of the complete herpesvirus genome in bacteria as a bacterial artificial chromosome (BAC), has advanced herpes virology exponentially in that investigation and manipulation of the herpesvirus genome can be conducted independent of a cell culture system. With respect to BRDC and the generation of vaccines to combat the disease, the tools to fully utilise the potential of BoHV-1 as a live vaccine vector are now routine. It is now possible to vii construct BoHV-1 as a delivery vector by inserting appropriate antigens of those bacterial and viral pathogens implicated in the BRDC into a BAC maintained BoHV-1 genome. However, there is a significant lack of genetic information regarding BoHV-1 and inserting several antigenic sequences would expand the genome of BoHV-1 inducing non-viability. Therefore, to further develop BoHV-1 as a vaccine vector, a study was conducted to identify the essential and nonessential genes required for the in vitro viability of BoHV-1. Identifying the essential and nonessential genes will establish which genes may be preferentially deleted or replaced with exogenous antigenic sequences in a BoHV-1 derived vaccine vector. To define the requirement of genes encoded by BoHV-1, random-insertion mutagenesis utilising a Tn5 transposition system and targeted gene deletion catalysed by GET recombination was employed to construct gene disruption and gene deletion libraries, respectively, of an infectious clone of BoHV-1. Transposon insertion position and confirmation of gene deletion was determined by direct sequencing. with the essential or nonessential requirement of either transposed or deleted open reading frames (ORFs) assessed by transfection of respective BoHV- 1 BAC DNA into host cells. Of the 73 recognised ORFs encoded by the BoHV-1 genome, 33 were determined to be essential and 36 to be nonessential for virus viability in cell culture with the requirement of the two dual copy ORFs inconclusive. The majority of ORFs were shown to conform to the in vitro requirements of BoHV-1 homologues encoded by Human herpesvirus 1. However, ORFs encoding for glycoprotein K (UL53), regulatory, membrane, tegument and capsid proteins (UL54, UL49.5, UL49, UL35, UL20, UL16 and UL7) were shown to differ in requirement when compared to Human herpesvirus-1 encoded homologues. Further analysis of clones encompassing restriction digestion profiling, one-step growth and replication kinetic analysis defined the genetic constitution and replicative capacity of the mutant clones. Thirty-three individual ORFs of the 36 defined nonessential ORF were identified as being amenable to deletion without causing significant replicative detriment to a potential BoHV-1 vaccine vector. This study has provided the foundational information required for the future development of BoHV-1 as a multivalent vaccine vector for the protection of feedlot cattle from BRDC. Furthermore, the genetic information generated in this study contributes to the general knowledge of the prototype ruminant herpesvirus, BoHV-1, and contributes to the comparative study of gene function between the large and diverse family that is Herpesviridae.

Thesis (M. Sc.) Uppsala : Sveriges lantbruksuniv., 2007.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2006. / Härtill 5 uppsatser.

Os herpesvírus bovino tipo 1 (BoHV-1) e 5 (BoHV-5) são alfaherpesvírus freqüentemente associados a meningoencefalites. Por outro lado, o vírus da raiva é o agente mais frequentemente identificado como causador de encefalites virais em bovinos no Brasil. O objetivo do presente estudo foi examinar a ocorrência de infecções por BoHV-1 e/ou BoHV-5 em amostras de tecido encefálico bovino submetidas ao diagnóstico de raiva e avaliar seu possível envolvimento nos quadros de encefalite que originaram a suspeita de raiva. Para tanto, 101 amostras desses tecidos, sendo 39 positivas para raiva e 62 negativas, recebidas pelo órgão oficial responsável pelo diagnóstico de raiva no Estado do Rio Grande do Sul (IPVDF) no período de 2009- 2010, foram submetidas a exames buscando o isolamento viral e amplificação de genomas de herpesvírus bovinos. Ao isolamento viral, todas as amostras foram negativas para vírus infeccioso após a realização de três passagens cegas em células MDBK. As mesmas foram submetidas à amplificação por “nested PCR” (nPCR) para a pesquisa de genomas de BoHV-1 e BoHV-5. Das 101 amostras totais analisadas esta técnica revelou que 25,7% (26/101) continham genomas de BoHV-1 e 21,8% (22/101) continham genomas de BoHV-5. Genomas de ambos os tipos foram identificadas em 30 (29,7%) amostras. Entre as amostras que foram também positivas para raiva em 23% (9/39) foram detectados genomas de BoHV-1 e em 15,4% (6/39) continham genomas de BoHV-5. Em 16 destas 39 amostras (41%) foram detectados genomas de BoHV-1 e BoHV-5. Em contrapartida, nas amostras negativas para o vírus rábico, 27,4% (17/62) também foram positivas para BoHV-1, 25,8% (16/62) foram positivas para BoHV-5. Detectaram-se os genomas de ambos BoHVs em 22,6% (14/62) dos animais. Estas diferenças não foram estatisticamente significativas, indicando não haver correlação entre a ocorrência de raiva e infecções por herpesvírus na amostragem realizada. Estes resultados indicam que, embora as infecções por BoHV-1 e BoHV-5 tenham apresentado elevada incidência nessas amostras, não havia vírus infeccioso nas mesmas, sugerindo infecções latentes sem envolvimento aparente nos quadros de encefalite que originaram a suspeita inicial de raiva. / Bovine herpesvirus type 1 (BoHV-1) and 5 (BoHV-5) are alphaherpesviruses associated with a number of clinical manifestations in cattle, including encephalitis. On the other hand, rabies virus is the agent most frequently identified as cause of viral encephalitis in cattle in Brazil. The aim of this study was to examine the occurrence of BoHV-1 and / or BoHV-5 in bovine brain tissue samples submitted to rabies diagnosis. The search was carried out by virus isolation and nested polymerase chain reaction (PCR) in brain tissues of cattle submitted to rabies diagnosis in the state of Rio Grande do Sul in the period 2009-2010. One hundred and one brain samples from cattle with signs of neurological disease, of which 39 were positive and 62 negative for rabies, were used in this study. At virus isolation, all samples were negative for the presence of infectious herpesviruses after three successive passages in MDBK cells. Of the 101 total samples analyzed, this test revealed that 25.7% (26/101) of cattle were infected with BoHV-1 and 21.8% (22/101) were infected with BoHV-5. Genomes of both types were detected in 29.7% (30/101) samples. With the 39 samples positive for rabies virus, BoHV-1 genome was detected in 23% (9/39) and 15.4% (6/39) were positive for BoHV-5 as well as in 41% (16/39) of these samples, which were positive for both BoHVs. On the other hand, the negative samples for rabies virus, 27.4% (17/62) also were positive for BoHV-1, as well and 25.8% (16/62) were positive for BoHV-5. Genomes of both BoHVs were detected in 22.6% (14/62) of the specimens. These differences were not statistically significant indicating no correlation between the occurrence of rabies and herpesvirus infections in the animals. These results do not imply that the herpesviruses detected, even showing a high incidence, were the causative agents of meningoencephalitis in the samples tested, once it was not possible to isolate virus in its infectious form, however it suggests a latent infection in the animals involved with neurological signs of meningoencephalitis whose primary suspicion was rabies.

O herpesvírus bovino tipo 1 (BoHV-1) é um dos principais agentes causadores de prejuízos econômicos em criações de bovinos. A vacinação tem sido amplamente utilizada para minimizar as perdas causadas por infecções pelo BoHV-1. Dentre as vacinas disponíveis, as vacinas desenvolvidas a partir de amostras virais recombinantes apresentam a vantagem de permitirem a diferenciação entre animais infectados e imunizados. Anteriormente, foi desenvolvida uma vacina recombinante diferencial com uma amostra de BoHV-1 brasileira baseada na deleção do gene que codifica a glicoproteína E (gE). No primeiro capítulo do presente trabalho, a segurança e imunogenicidade desta vacina recombinante inativada foi avaliada. Os experimentos de imunização, desafio e reativação da vacina diferencial em animais experimentalmente inoculados demonstraram que a vacina recombinante foi segura e eficiente ao minimizar ou mesmo prevenir os efeitos da infecção pelo BoHV-1. No segundo capítulo, a segurança da vacina gE- foi avaliada, através da imunização intramuscular (IM) de 22 vacas (14 BoHV-1 soronegativas e 8 soropositivas) prenhes. Foi observada soroconverão, mas não abortos e nem anormalidades fetais nos animais imunizados. Na segunda parte do mesmo estudo foi analizada a capacidade do vírus recombinante difundir-se em um rebanho bovino. Quatro terneiros foram inoculados pela rota intranasal (IN) com a amostra recombinante gE- e, posteriormente, adicionados a outros 16 animais com mesma idade e semelhante condição corporal durante 180 dias. Todos os animais foram monitorados diariamente em busca de sintomatologia clínica. Foi observada soroconversão apenas nos animais imunizados. Estes resultados indicam que, nas condições deste estudo, a amostra recombinante não causou nenhum dano nas vacas prenhes ou em seus terneiros e não foi capaz de difundir-se horizontalmente no rebanho. No terceiro capítulo foi avaliada a patogenicidade de uma amostra recombinante de BoHV-1 com deleção no gene Us9, utilizando coelhos como modelo experimental. Coelhos com quatro semanas de idade foram divididos em quatro grupos (A, B, C, D). Dois grupos (A e B) foram infectados via intranasal (IN) e dois (C e D) infectados via intraocular (IO). Em cada via de infecção, um grupo foi infectado com o vírus recombinante e o outro com o vírus selvagem (wt). Após a infecção IO, todos os animais, de ambos os grupos, desenvolveram intensa conjuntivite entre os dias 3 a 10 pós-inoculação (pi). Vírus infeccioso foi consistentemente isolado a partir dos suabes oculares entre os dias 1 a 10 pi chegando a um título máximo de 103,05 TCID50/mL. Nos grupos infectados pela via IN com BoHV-1 wt, 4/4 coelhos apresentaram sintomatologia característica da doença, tais como: pirexia, apatia, anorexia, tosse, secreção nasal severa (entre os dias 2 e 8 pi). Animais inoculados com o recombinante apresentaram apatia, anorexia e descarga nasal (entre os dias 3 e 7 pi). Vírus infeccioso foi isolado em diversos tecidos tanto nos animais inoculados com o vírus wt como recombinante. Ambos os vírus foram capazes de replicar nas mucosas. Análises histológicas dos tecidos dos animais demonstraram lesões em ambos os grupos. Este estudo apresentou que a proteína Us9 não tem um papel significante na patogenicidade in vivo. / Bovine herpesvirus type 1 (BoHV-1) is an the major cause of losses in cattle. Vaccination has been widely applied to minimize losses induced by BoHV-1 infections. Vacines developed from recombinant strains have the advantage of allow the differentiation between immunized and infected animals. Previously, a recombinant differential BoHV-1 vaccine based on a glycoprotein E deleted (gE) virus was developed. In the first chapter of the present work, the safety and immunogenicity of such recombinant, as a inactivate vaccine, was evaluated. The experiments showed that the DIVA vaccinne was safe and efficient in order to minimize or even prevent the clinical signs of the infection by BoHV- 1. In the second chapter of the present study, the safety of the gE- vaccine during pregnancy was evaluated by the intramuscular inoculation into 22 pregnant dams (14 BoHV-1 seronegative; 8 seropositive). Seroconversion was detected but no abortions, stillbirths or fetal abnormalities were seen after vaccination. In the second part of the same study, the potential of the gE- vaccine virus to spread among beef cattle under field conditions was examined. Four heifers were inoculated intranasally (IN) with the gE- vaccine and mixed with other 16 animals at the same age and body conditions, for 180 days. All animals were daily monitored for clinical signs.. Seroconversion was observed only in vaccinated heifers. These results indicate that, under the conditions of the present study, the gE vaccine virus did not cause any noticeable harmful effect on pregnant dams and on its offspring and did not spread horizontally among cattle. In the third chapter the pathogenicity of a US9 negative recombinant strain BoHV-1 using rabbits as an experimental model was avaluated. Rabbits four weeks old were divided in four groups (A, B, C, D) within four rabbits per group. Two groups were infected IN route and two via intraocular (IO). In each route, one group was infected by recombinant virus and the other infected by wild type (wt) virus. After IO infection, all rabbits developed intense conjunctivitis between days 3 to 10 pos infection (pi). Infective virus was consistently isolated from ocular swabs on days 1 to 10, reaching a maximum of 103.05 TCID50/mL. Animals infected in the IN rote with BoHV-1 wt, 4/4 rabbits showed characteristic signs of disease, which included pyrexia, apathy, anorexia, cough, severe nasal secretion between days 2 to 8. Rabbits inoculated with recombinant virus showed apathy, anorexia, nasal secretion (between days 3 and 7pi). Infectious virus was isolated in differents tissues as much as animals inoculated with wt and recombinant virus. Both virus were capable of replication in the mucosa nasal and ocular of the inoculated rabbits. Histopatological lesions were evident in both groups. In the present study showed which the US9 protein have not significantly in the pathogenicity in vivo.

O herpesvírus bovino tipo 1 (BoHV-1) é um dos principais agentes causadores de prejuízos econômicos em criações de bovinos. A vacinação tem sido amplamente utilizada para minimizar as perdas causadas por infecções pelo BoHV-1. Dentre as vacinas disponíveis, as vacinas desenvolvidas a partir de amostras virais recombinantes apresentam a vantagem de permitirem a diferenciação entre animais infectados e imunizados. Anteriormente, foi desenvolvida uma vacina recombinante diferencial com uma amostra de BoHV-1 brasileira baseada na deleção do gene que codifica a glicoproteína E (gE). No primeiro capítulo do presente trabalho, a segurança e imunogenicidade desta vacina recombinante inativada foi avaliada. Os experimentos de imunização, desafio e reativação da vacina diferencial em animais experimentalmente inoculados demonstraram que a vacina recombinante foi segura e eficiente ao minimizar ou mesmo prevenir os efeitos da infecção pelo BoHV-1. No segundo capítulo, a segurança da vacina gE- foi avaliada, através da imunização intramuscular (IM) de 22 vacas (14 BoHV-1 soronegativas e 8 soropositivas) prenhes. Foi observada soroconverão, mas não abortos e nem anormalidades fetais nos animais imunizados. Na segunda parte do mesmo estudo foi analizada a capacidade do vírus recombinante difundir-se em um rebanho bovino. Quatro terneiros foram inoculados pela rota intranasal (IN) com a amostra recombinante gE- e, posteriormente, adicionados a outros 16 animais com mesma idade e semelhante condição corporal durante 180 dias. Todos os animais foram monitorados diariamente em busca de sintomatologia clínica. Foi observada soroconversão apenas nos animais imunizados. Estes resultados indicam que, nas condições deste estudo, a amostra recombinante não causou nenhum dano nas vacas prenhes ou em seus terneiros e não foi capaz de difundir-se horizontalmente no rebanho. No terceiro capítulo foi avaliada a patogenicidade de uma amostra recombinante de BoHV-1 com deleção no gene Us9, utilizando coelhos como modelo experimental. Coelhos com quatro semanas de idade foram divididos em quatro grupos (A, B, C, D). Dois grupos (A e B) foram infectados via intranasal (IN) e dois (C e D) infectados via intraocular (IO). Em cada via de infecção, um grupo foi infectado com o vírus recombinante e o outro com o vírus selvagem (wt). Após a infecção IO, todos os animais, de ambos os grupos, desenvolveram intensa conjuntivite entre os dias 3 a 10 pós-inoculação (pi). Vírus infeccioso foi consistentemente isolado a partir dos suabes oculares entre os dias 1 a 10 pi chegando a um título máximo de 103,05 TCID50/mL. Nos grupos infectados pela via IN com BoHV-1 wt, 4/4 coelhos apresentaram sintomatologia característica da doença, tais como: pirexia, apatia, anorexia, tosse, secreção nasal severa (entre os dias 2 e 8 pi). Animais inoculados com o recombinante apresentaram apatia, anorexia e descarga nasal (entre os dias 3 e 7 pi). Vírus infeccioso foi isolado em diversos tecidos tanto nos animais inoculados com o vírus wt como recombinante. Ambos os vírus foram capazes de replicar nas mucosas. Análises histológicas dos tecidos dos animais demonstraram lesões em ambos os grupos. Este estudo apresentou que a proteína Us9 não tem um papel significante na patogenicidade in vivo. / Bovine herpesvirus type 1 (BoHV-1) is an the major cause of losses in cattle. Vaccination has been widely applied to minimize losses induced by BoHV-1 infections. Vacines developed from recombinant strains have the advantage of allow the differentiation between immunized and infected animals. Previously, a recombinant differential BoHV-1 vaccine based on a glycoprotein E deleted (gE) virus was developed. In the first chapter of the present work, the safety and immunogenicity of such recombinant, as a inactivate vaccine, was evaluated. The experiments showed that the DIVA vaccinne was safe and efficient in order to minimize or even prevent the clinical signs of the infection by BoHV- 1. In the second chapter of the present study, the safety of the gE- vaccine during pregnancy was evaluated by the intramuscular inoculation into 22 pregnant dams (14 BoHV-1 seronegative; 8 seropositive). Seroconversion was detected but no abortions, stillbirths or fetal abnormalities were seen after vaccination. In the second part of the same study, the potential of the gE- vaccine virus to spread among beef cattle under field conditions was examined. Four heifers were inoculated intranasally (IN) with the gE- vaccine and mixed with other 16 animals at the same age and body conditions, for 180 days. All animals were daily monitored for clinical signs.. Seroconversion was observed only in vaccinated heifers. These results indicate that, under the conditions of the present study, the gE vaccine virus did not cause any noticeable harmful effect on pregnant dams and on its offspring and did not spread horizontally among cattle. In the third chapter the pathogenicity of a US9 negative recombinant strain BoHV-1 using rabbits as an experimental model was avaluated. Rabbits four weeks old were divided in four groups (A, B, C, D) within four rabbits per group. Two groups were infected IN route and two via intraocular (IO). In each route, one group was infected by recombinant virus and the other infected by wild type (wt) virus. After IO infection, all rabbits developed intense conjunctivitis between days 3 to 10 pos infection (pi). Infective virus was consistently isolated from ocular swabs on days 1 to 10, reaching a maximum of 103.05 TCID50/mL. Animals infected in the IN rote with BoHV-1 wt, 4/4 rabbits showed characteristic signs of disease, which included pyrexia, apathy, anorexia, cough, severe nasal secretion between days 2 to 8. Rabbits inoculated with recombinant virus showed apathy, anorexia, nasal secretion (between days 3 and 7pi). Infectious virus was isolated in differents tissues as much as animals inoculated with wt and recombinant virus. Both virus were capable of replication in the mucosa nasal and ocular of the inoculated rabbits. Histopatological lesions were evident in both groups. In the present study showed which the US9 protein have not significantly in the pathogenicity in vivo.