RESUMO
Bovine alphaherpesvirus 1 (BoHV-1) is a pathogen causing respiratory and reproductive clinical signs in cattle. Infected animals may develop rhinotracheitis, vulvovaginitis, balanoposthitis, and abortion. Viral latency is generally established in neuronal ganglia simultaneously to a decrease in both genes or genome expression and viral replication. Under stressful conditions, infection is reactivated leading to viral replication and the manifestation of clinical signs. In this study, we evaluated both viral reactivation and apoptosis in trigeminal ganglia cells as BoHV-1 progressed from the latent to the acute phase of infection after dexamethasone administration in experimentally infected calves. To test ganglia cell death as a consequence of BoHV-1 infection, we stained the BoHV-1 samples with TUNEL after the viral shedding by the calves. RT-qPCR of apoptotic genes was also performed, showing the upregulation of the caspase 8 gene in the trigeminal ganglia from cattle experimentally infected with BoHV-1. These results showed the occurrence of apoptosis in ganglion cells of calves infected by BoHV-1.
Assuntos
Apoptose , Doenças dos Bovinos , Infecções por Herpesviridae , Herpesvirus Bovino 1 , Animais , Bovinos , Doenças dos Bovinos/virologia , Infecções por Herpesviridae/veterinária , Herpesvirus Bovino 1/genética , Herpesvirus Bovino 1/fisiologia , Ativação Viral , Latência Viral , Replicação ViralRESUMO
A stochastic quantitative risk assessment model was developed to estimate the annual probability of introduction of bovine viral diarrhea virus (BVDV) and bovine herpesvirus 1 (BoHV-1) on 127 dairy farms through indirect contacts. Vehicles transporting calves, cattle to slaughterhouse, dead animals, and mixture of feed, as well as visits by veterinarians and hoof trimmers, farm workers and contacts with neighbors were considered in the model. Data from biosecurity questionnaires of each farm, scientific literature and expert opinion from field veterinarians, animal vehicle drivers, hoof trimmers and personnel from rendering transport companies were used to estimate values for input parameters. Results showed that the annual probability of introducing BVDV or BoHV-1 through indirect contacts was very heterogeneous. The overall distribution of median values for each farm ranged from 0.5 to 14.6% and from 1.0 to 24.9% for BVDV and BoHV-1, respectively. The model identified that providing protective clothing and boots to visits, not allowing the animal vehicle driver to come into contact with animals present on the farm and ensuring that calf vehicles arrived empty, were the measures with the highest impact on the probability of infection for most farms. This model could be a useful tool to show the impact of the measures to farmers and veterinarians, thus increasing their awareness on biosecurity. In addition, it could support decision making on which measures should be prioritized in dairy cattle herds to reduce the probability of introduction of diseases.
Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina/epidemiologia , Indústria de Laticínios/métodos , Vírus da Diarreia Viral Bovina/fisiologia , Infecções por Herpesviridae/veterinária , Herpesvirus Bovino 1/fisiologia , Animais , Doença das Mucosas por Vírus da Diarreia Viral Bovina/virologia , Bovinos , Infecções por Herpesviridae/epidemiologia , Infecções por Herpesviridae/virologia , Prevalência , Medição de Risco , Espanha/epidemiologiaRESUMO
BACKGROUND: The dairy sector is one of the leading in agricultural production sectors in the world and the bovine herpesvirus 1 (BoHV-1) is an important pathogen that causes great losses in most production systems. Moreover, BoLA DRB3 immunological gene presents different alleles related to protection against many pathogens. METHODS: Serological diagnosis was carried out to determine the BoHV-1 infection and through PCR-RFLP 506 Holstein cows from several municipalities of Antioquia were genotyped for BoLA DRB3.2 gene polymorphisms. RESULTS: Alleles 8, 16, 22, and 24 were the most common out of the 42 alleles found. By indirect ELISA technique, a 58.7% prevalence of BoHV-1 infection in this population was diagnosed and Odd ratios for found alleles were calculated by logistic regression; the only significant association was held for allele 37, which showed that it effects confers susceptibility to infection. On the other hand, by using generalized linear models, a significant association between BoLA DRB3.2 gene and milk and fat yield in primiparous and services per conception in multiparous was found, with the most favorable alleles being 11 and 28 in primiparous and 22 and 28 in multiparous; allele 37 was unfavorable only in primiparous. CONCLUSION: BoLA DRB3.2 gene polymorphisms have shown high variability and significant effects on Holstein cattle and their performance in production systems in Antioquia are at both sanitary or health and productive levels.
Assuntos
Doenças dos Bovinos/genética , Infecções por Herpesviridae/veterinária , Herpesvirus Bovino 1/fisiologia , Antígenos de Histocompatibilidade Classe II/genética , Polimorfismo Genético , Animais , Argentina/epidemiologia , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/microbiologia , Feminino , Infecções por Herpesviridae/epidemiologia , Infecções por Herpesviridae/genética , Infecções por Herpesviridae/microbiologia , Herpesvirus Bovino 1/genética , Prevalência , Estudos SoroepidemiológicosRESUMO
Artificial insemination and in vitro embryo production are increasingly used to improve the reproductive efficiency of herds, however success of these techniques depends on the sanitary quality of the semen. Insemination centers commonly use antibiotics in their routine procedure, but they are not able against viruses. In this paper, we demonstrate a new approach for disinfecting virus in bovine semen using photoimmunoinactivation, an adaptation of the photodynamic inactivation (PDI) methodology. The photosensitizers (PSs), hematoporphyrin (HP) and zinc tetracarboxy-phthalocyanine (ZnPc) were conjugated to Immunoglobulin Y (IgY) anti-bovine alphaherpesvirus 1 (BoHV-1) and used for PDI against the BoHV-1 viruses in cell culture and compared to the unconjugated PSs. Both treatments proved to be efficient, but a significant decrease in the irradiation time required to completely eliminate the virus was observed in the samples treated with the immunoconjugates. Photophysical measurements help us to understand the coupling between PSs and IgY and the evaluated production of singlet oxygen. Following the cell culture test, the same approach was applied in semen artificially infected with BoHV-1. The immunoconjugates were also efficient for complete virus inactivation up to 5â¯min of irradiation and proved to be safe using several parameters of sperm viability, demonstrating the feasibility of our strategy for disinfection viruses in semen.
Assuntos
Doenças dos Bovinos/prevenção & controle , Herpesvirus Bovino 1/efeitos da radiação , Imunoconjugados/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Sêmen/virologia , Inativação de Vírus , Animais , Bovinos , Doenças dos Bovinos/virologia , Galinhas , Feminino , Hematoporfirinas/farmacologia , Herpesvirus Bovino 1/fisiologia , Imunoglobulinas/imunologia , Indóis/farmacologia , Isoindóis , Masculino , Compostos Organometálicos/farmacologia , Processos Fotoquímicos , Espermatozoides/efeitos dos fármacos , Inativação de Vírus/efeitos dos fármacos , Inativação de Vírus/efeitos da radiação , Compostos de ZincoRESUMO
Herein we present the excited state dynamic of zinc and aluminum tetracarboxy-phthalocyanines (ZnPc and AlPc) and its application in the photodynamic inactivation (PDI) of Bovine herpesvirus type 1 (BoHV-1) in vitro. The excited state dynamic provides valuable data to describe the excited state properties of potential optical limiters and/or photosensitizers (PSs), such as: the excited state cross-sections, fluorescence lifetime and triplet state quantum yield. The excited state characterization was performed using three different Z-scan techniques: Single Pulse, White Light Continuum and Pulse Train. Considering the photodynamic inactivation of BoHV-1, an initial viral suspension containing 105.75TCID50/mL was incubated with the PSs for 1h at 37°C under agitation and protected from light. The samples were placed in microtiter plates and irradiated (180mW/cm2). During irradiation, a sample was taken every 15min and the viability of the virus was evaluated. The results show that both phthalocyanines were efficient against viruses. However, a higher photodynamic efficiency was observed by ZnPc, which can be attributed to its higher triplet and singlet quantum yields. The results presented here are important for animal health (treatment of BoHV-1) and also open up a field of studies to use AlPc and ZnPc as potential agents against a wide range of microorganisms of veterinary interest.
Assuntos
Herpesvirus Bovino 1/fisiologia , Indóis/química , Compostos Organometálicos/química , Fármacos Fotossensibilizantes/farmacologia , Inativação de Vírus/efeitos dos fármacos , Animais , Bovinos , Indóis/farmacologia , Luz , Compostos Organometálicos/farmacologia , Fármacos Fotossensibilizantes/química , Teoria Quântica , Oxigênio Singlete/química , Oxigênio Singlete/metabolismo , Inativação de Vírus/efeitos da radiaçãoRESUMO
Bovine herpesvirus type 1 (BoHV-1) and bovine herpesvirus type 5 (BoHV-5) are important pathogens of cattle. The diseases they produce are quite different, with BoHV-5 being more neuropathogenic than BoHV-1 which mainly induces respiratory symptoms. The sequencing of the entire BoHV-5 genome has shown that most of the differences between these viruses are found in the immediate early and LR (latency related) genes. The LR gene is the only viral gene abundantly expressed in latently infected neurons, is essential for viral reactivation and seems to have an anti-apoptotic function which can be observed in vivo and in vitro. This gene spans two potential ORFs (1 and 2) which can also be found as a fused version, an ORF-E protein encoded within the promoter region and two miRNAs located within the 5' UTR segment. Most of the essential functions of the LR gene seem to be located within the ORF-2 which has been found to modulate components of cell signaling/cycle pathways. In this review we present a comparative sequence analysis of the LR gene of several BoHV-5 isolates, their differences with the BoHV-1 homologue and the potential impact this may have on its function. The LR gene was found to be highly conserved in all sequenced BoHV-5 strains. ORF-1 shares 60 % homology compared to BoHV-1 whereas the BoHV-5 homologue of ORF-2 is truncated at amino acid 51. Preliminary studies analyzing the emerging transcripts from the BoHV-5 LR gene in infected cells, as well as in stably transfected cells, indicates that their products are, in fact, missing crucial components of the anti-apoptotic function when compared to the BoHV-1 LR gene. In addition these transcripts maintain a region that, similar to what is found in BoHV-1, would produce a miRNA with the potential to recognize a region within the BoHV-5 immediate early gene. All together, these BoHV-5 characteristics suggest that this virus would not possess the same repertoire of latency maintaining functions as BoHV-1. Implications for BoHV-5 neuropathogenic potential are discussed.
Assuntos
Herpesvirus Bovino 1/genética , Herpesvirus Bovino 1/fisiologia , Herpesvirus Bovino 5/genética , Herpesvirus Bovino 5/fisiologia , Interações Hospedeiro-Patógeno , Proteínas Virais/genética , Latência Viral , Sequência Conservada , Variação Genética , Análise de Sequência de DNA , Transcrição GênicaRESUMO
Bovine herpesvirus type 1 (BoHV-1) is responsible for respiratory and genital disease in cattle. BoHV-1 encephalitis is only occasionally reported. However, several cases of neurological disease have been recently attributed to BoHV-1. In this study, the distribution and pathological alterations caused by two BoHV-1 strains in the nervous system of experimentally infected calves during acute infection and reactivation are described. Calves were inoculated intranasally with BoHV-1 Los Angeles (BoHV-1.LA) or Cooper (BoHV-1.Cooper) strains. Acutely infected calves were euthanased at 6 days (BoHV-1.Cooper, n = 2) and 7 days post-inoculation (BoHV-1.LA, n = 2). Latently infected calves that were given dexamethasone to induce reactivation were euthanased at 2 days (BoHV-1.Cooper, n = 2) or 5 days (BoHV-1.LA, n = 2) after dexamethasone administration. Both BoHV-1 strains were isolated from the brains of acutely infected calves. Distribution of viral DNA in the neural tissues was similar for both strains. During reactivation, neither BoHV-1.LA nor BoHV-1.Cooper was isolated from any brain section or trigeminal ganglia in infected calves. Macroscopic lesions were not evident in any group. In BoHV-1.LA infected calves, microscopic lesions were found in the brain but not in the trigeminal ganglia. Microscopic lesions in the brain of BoHV-1.Cooper infected calves were not as evident as in BoHV-1.LA infected animals. However, mononuclear infiltrates and neuronophagia were present in trigeminal ganglia. The results of this study demonstrated that respiratory BoHV-1 strains are able to replicate and disseminate within the bovine nervous tissue and provide evidence of the neuroinvasiveness of BoHV-1 strains.
Assuntos
Infecções por Herpesviridae/veterinária , Herpesvirus Bovino 1/fisiologia , Rinotraqueíte Infecciosa Bovina/virologia , Ativação Viral , Doença Aguda , Animais , Encéfalo/virologia , Bovinos , Infecções por Herpesviridae/virologia , Herpesvirus Bovino 1/isolamento & purificação , Sistema Nervoso/virologia , Gânglio Trigeminal/virologiaRESUMO
Members of the subfamily Alphaherpesvirinae use the epithelium of the upper respiratory and/or genital tract as preferential sites for primary replication. However, bovine herpesvirus 5 (BoHV5) is neurotropic and neuroinvasive and responsible for meningoencephalitis in cattle and in animal models. A related virus, BoHV1 has also been occasionally implicated in natural cases of neurological infection and disease in cattle. The aim of the present study was to assess the in vitro effects of BoHV1 and BoHV5 replication in neuron-like cells. Overall, cytopathic effects, consisting of floating rounded cells, giant cells and monolayer lysis, induced by both viruses at 48 h postinfection (p.i.) resulted in a loss of cell viability and high virus titres (r = 0.978). The BoHV1 Cooper strain produced the lowest titres in neuron-like cells, although viral DNA was detected in infected cells during all experiments. Virus replication in infected cells was demonstrated by immunocytochemistry, flow cytometry and qPCR assays. BoHV antigens were better visualized at 48 h p.i. and flow cytometry analysis showed that SV56/90 and Los Angeles antigens were present at higher levels. In spite of the fact that BoHV titres dropped at 48 h p.i, viral DNA remained detectable until 120 h p.i. Sensitive TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling) and annexin V assays were used to identify apoptosis. BoHV5 induced death in approximately 50% of cells within 24 h p.i., similar to what has been observed for BoHV1 Los Angeles. Infection with the BoHV1 Cooper strain resulted in 26.37% of cells being in the early stages of apoptosis; 63.69% of infected cells were considered viable. Modulation of mitochondrial function, as measured by mitochondrial membrane depolarization, was synchronous with the virus replication cycle, cell viability and virus titres at 48 h p.i. Our results indicate that apoptosis plays an important role in preventing neuronal death and provides a bovine-derived in vitro system to study herpesvirus-neuron interactions.
Assuntos
Doenças dos Bovinos/virologia , Infecções por Herpesviridae/veterinária , Herpesvirus Bovino 1/fisiologia , Herpesvirus Bovino 5/fisiologia , Neurônios/virologia , Replicação Viral , Animais , Apoptose , Bovinos , Doenças dos Bovinos/fisiopatologia , Células Cultivadas , Infecções por Herpesviridae/fisiopatologia , Infecções por Herpesviridae/virologia , Herpesvirus Bovino 1/genética , Herpesvirus Bovino 5/genéticaRESUMO
The viral envelope glycoprotein D from bovine herpesviruses 1 and 5 (BoHV-1 and -5), two important pathogens of cattle, is a major component of the virion and plays a critical role in the pathogenesis of herpesviruses. Glycoprotein D is essential for virus penetration into permissive cells and thus is a major target for virus neutralizing antibodies during infection. In view of its role in the induction of protective immunity, gD has been tested in new vaccine development strategies against both viruses. Subunit, DNA and vectored vaccine candidates have been developed using this glycoprotein as the primary antigen, demonstrating that gD has the capacity to induce robust virus neutralizing antibodies and strong cell-mediated immune responses, as well as protection from clinical symptoms, in target species. This review highlights the structural and functional characteristics of BoHV-1, BoHV-5 and where appropriate, Human herpesvirus gD, as well as its role in viral entry and interactions with host cell receptors. Furthermore, the interactions of gD with the host immune system are discussed. Finally, the application of this glycoprotein in new vaccine design is reviewed, taking its structural and functional characteristics into consideration.
Assuntos
Herpesvirus Bovino 1/fisiologia , Herpesvirus Humano 1/fisiologia , Herpesvirus Humano 2/fisiologia , Herpesvirus Bovino 5/fisiologia , Proteínas do Envelope Viral/genética , Vacinas Virais/imunologia , Sequência de Aminoácidos , Animais , Herpesvirus Bovino 1/imunologia , Herpesvirus Humano 1/imunologia , Herpesvirus Humano 2/imunologia , Herpesvirus Bovino 5/imunologia , Humanos , Proteínas do Envelope Viral/químicaRESUMO
Bovine herpesvirus types 1 (BoHV-1) and 5 (BoHV-5) can both establish latency in the trigeminal ganglion. Non-neural sites of latency have been described for BoHV-1 but not for BoHV-5. The aim of this study was to determine whether peripheral blood leukocytes and tonsils are targets for BoHV-5 infection and to establish whether all stages of that virus's infectious cycle can occur in those cell types. Comparisons with BoHV-1 infection of these tissues were also made in order to better understand the pathogenesis of both viruses. BoHV-1 and BoHV-5 were isolated from tonsils of acutely-infected calves. BoHV-5 was also isolated from a tonsil homogenate after dexamethasone-induced reactivation. During latency, infectious virus was recovered from a tonsil explant of one BoHV-5-infected calf. The genomes of BoHV-5 and BoHV-1 were detected in tonsils from acutely-infected calves although were not detected in tonsils from latently-infected calves or from calves treated with dexamethasone. Virus DNA was intermittently detected in leukocytes. The study has shown that BoHV-5 can establish latency in bovine tonsils and peripheral white blood cells, and that it can be reactivated from latently-infected tonsils, which might contribute to viral transmission. The titres of BoHV-1 and BoHV-5 in tonsils were similar, suggesting that replication at this site is a common feature for both viruses.