RESUMEN
Bovine viral diarrhea virus (BVDV) causes ongoing economic losses to cattle industries, directly through reduced herd performance or indirectly through control program costs. ELISA assays, one of the most widely used techniques due to their ease of implementation, have been a valuable tool for mass surveillance and detection of BVDV. In this study, we developed a new indirect ELISA (rE2-ELISA) for serologic detection of BVDV. The assay considers three recombinant E2 protein subtypes as antigens, allowing serologic diagnosis of BVDV-1b (high prevalence worldwide), BVDV-1d and 1e (high prevalence in southern Chile) sub-genotypes. Recombinant E2 (rE2) proteins were successfully expressed in stably transfected CHO cells. Conditions for rE2 ELISAs were established after determining appropriate concentrations of antigen, blocking agent, secondary antibody, and serum dilutions to achieve maximum discrimination between positive and negative serum samples. The developed rE2-ELISA showed a sensitivity of 92.86% and a specificity of 98.33%. Clinical testing of 180 serum samples from herds in southern Chile showed high accuracy (kappa > 0.8) compared to the commercial BVDV Total Ab kit (IDEXX), with 95.37% positive and 87.5% negative predictive value. In addition, the rE2 ELISA has shown the capability to detect anti-BVDV antibodies from naturally infected animals with sub-genotypes 1b, 1e, or undetermined. These results indicate that the developed indirect ELISA could serve as a valid, and efficient alternative for identifying BVDV-infected animals, thus contributing to the success of disease control and eradication programs.
Asunto(s)
Diarrea Mucosa Bovina Viral , Ensayo de Inmunoadsorción Enzimática , Sensibilidad y Especificidad , Animales , Ensayo de Inmunoadsorción Enzimática/veterinaria , Ensayo de Inmunoadsorción Enzimática/métodos , Bovinos , Diarrea Mucosa Bovina Viral/diagnóstico , Diarrea Mucosa Bovina Viral/sangre , Diarrea Mucosa Bovina Viral/virología , Chile , Genotipo , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Virus de la Diarrea Viral Bovina Tipo 1/aislamiento & purificación , Virus de la Diarrea Viral Bovina/inmunología , Virus de la Diarrea Viral Bovina/aislamiento & purificación , Proteínas del Envoltorio Viral/inmunología , Proteínas del Envoltorio Viral/genética , Antígenos Virales/inmunología , Cricetulus , Células CHO , Anticuerpos Antivirales/sangre , Proteínas Recombinantes/inmunologíaRESUMEN
Multivalent live-attenuated or inactivated vaccines are often used to control the bovine viral diarrhea disease (BVD). Still, they retain inherent disadvantages and do not provide the expected protection. This study developed a new vaccine prototype, including the external segment of the E2 viral protein from five different subgenotypes selected after a massive screening. The E2 proteins of every subgenotype (1aE2, 1bE2, 1cE2, 1dE2, and 1eE2) were produced in mammalian cells and purified by IMAC. An equimolar mixture of E2 proteins formulated in an oil-in-water adjuvant made up the vaccine candidate, inducing a high humoral response at 50, 100, and 150 µg doses in sheep. A similar immune response was observed in bovines at 50 µg. The cellular response showed a significant increase in the transcript levels of relevant Th1 cytokines, while those corresponding to the Th2 cytokine IL-4 and the negative control were similar. High levels of neutralizing antibodies against the subgenotype BVDV1a demonstrated the effectiveness of our vaccine candidate, similar to that observed in the sera of animals vaccinated with the commercial vaccine. These results suggest that our vaccine prototype could become an effective recombinant vaccine against the BVD.
Asunto(s)
Anticuerpos Antivirales , Diarrea Mucosa Bovina Viral , Vacunas de Subunidad , Vacunas Sintéticas , Vacunas Virales , Animales , Bovinos , Vacunas Virales/inmunología , Vacunas de Subunidad/inmunología , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/sangre , Vacunas Sintéticas/inmunología , Diarrea Mucosa Bovina Viral/prevención & control , Diarrea Mucosa Bovina Viral/inmunología , Diarrea Mucosa Bovina Viral/virología , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , Ovinos , Proteínas del Envoltorio Viral/inmunología , Proteínas del Envoltorio Viral/genética , Citocinas/metabolismo , Virus de la Diarrea Viral Bovina/inmunología , Virus de la Diarrea Viral Bovina/genética , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Virus de la Diarrea Viral Bovina Tipo 1/genéticaRESUMEN
Bovine viral diarrhea virus (BVDV) infection has a significant economic impact on beef and dairy industries worldwide. Fetal infection with a non-cytopathic strain may lead to the birth of persistently infected (PI) offspring, which is the main event in the epidemiological chain of BVDV infection. This report describes the birth of 99 BVDV-PI heifer calves within 52 days of birth in a regular BVDV-vaccinated Brazilian dairy cattle herd and the subgenotypes of the infecting field strains. This study was conducted in a high-yielding open dairy cattle herd that frequently acquired heifers from neighboring areas for replacement. The farm monitors the birth of PI calves by screening all calves born using an ELISA (IDEXX) for BVDV antigen detection. All calves aged 1-7 days were evaluated. For positive and suspected results, the ELISA was repeated when the calves were close to one month old. A total of 294 heifer calves were evaluated between February and March 2021. Of these, 99 (33.7 %) had positive ELISA results and were considered PI calves. To evaluate the predominant BVDV species and subgenotypes in this outbreak, whole blood samples were collected from 31 calves born during the study period. All samples were submitted to the RT-PCR assay for the partial amplification of the BVDV 5'-UTR region, and these amplicons were subjected to nucleotide sequencing. Phylogenetic analysis identified BVDV-1b and BVDV-1d in 16 and 13 heifer calves, respectively. In two calves, it was not possible to determine the BVDV-1 subgenotype. Detection of PI animals and monitoring of circulating BVDV subgenotype strains are central to disease control. This study shows that regular BVDV vaccination alone may be insufficient to prevent BVDV infection in high-yielding open dairy cattle herds. Other biosecurity measures must be adopted to avoid the purchase of cattle with acute infections by BVDV or BVDV-PI, which can cause a break in the health profile of the herd and economic losses.
Asunto(s)
Diarrea Mucosa Bovina Viral , Virus de la Diarrea Viral Bovina Tipo 1 , Virus de la Diarrea Viral Bovina , Brotes de Enfermedades , Filogenia , Animales , Bovinos , Diarrea Mucosa Bovina Viral/virología , Diarrea Mucosa Bovina Viral/epidemiología , Diarrea Mucosa Bovina Viral/prevención & control , Brotes de Enfermedades/veterinaria , Femenino , Virus de la Diarrea Viral Bovina Tipo 1/genética , Virus de la Diarrea Viral Bovina Tipo 1/clasificación , Virus de la Diarrea Viral Bovina Tipo 1/aislamiento & purificación , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Brasil/epidemiología , Virus de la Diarrea Viral Bovina/genética , Virus de la Diarrea Viral Bovina/clasificación , Virus de la Diarrea Viral Bovina/aislamiento & purificación , Virus de la Diarrea Viral Bovina/inmunología , Genotipo , Vacunas Virales/inmunología , Ensayo de Inmunoadsorción Enzimática , Industria Lechera , Vacunación/veterinaria , Anticuerpos Antivirales/sangreRESUMEN
In this communication, we report the presence of RNA of bovine viral diarrhea virus (BVDV) as a contaminant of different biological products used in Mexico for veterinary vaccine production. For this purpose, six batches of monovalent vaccines, eight cell line batches used for vaccine production, and 10 fetal bovine serum lots (FBS) commercially available in Mexico from different suppliers were tested by reverse transcription polymerase chain reaction (RT-PCR). Viral RNA was detected in 62.5% of the samples analyzed. Phylogenetic analysis revealed the presence of the subgenotypes BVDV-1a, 1b, and BVDV-2a in the tested samples. Collectively, these findings indicate that contamination by BVDV RNA occurs in commercial vaccines and reagents used in research and production of biological products. The ramifications of this contamination are discussed.
Asunto(s)
Virus de la Diarrea Viral Bovina Tipo 1/genética , Virus de la Diarrea Viral Bovina Tipo 2/genética , Vacunas Virales/genética , Animales , Diarrea Mucosa Bovina Viral/inmunología , Bovinos , Línea Celular , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Virus de la Diarrea Viral Bovina Tipo 2/inmunología , Genotipo , Síndrome Hemorrágico de los Bovinos/microbiología , México , Filogenia , ARN Viral/genética , Vacunas Virales/inmunologíaRESUMEN
Bovine viral diarrhea virus (BVDV) is a major pathogen in cattle herds. Considering the epidemiological importance of pestiviruses and the process of wild boar invasion in Brazil, this study aimed to investigate the presence of BVDV in free-living boars. Forty-nine free-living wild boars were collected by exotic wildlife controller agents in 2017 and 2018. The presence of BVDV antibodies was evaluated in 42 serum samples using the virus neutralization test, and the detection of BVDV RNA was performed from the 5'UTR genomic region by RT-PCR assay in 49 lung tissue samples followed by sequencing of amplicons. BVDV neutralizing antibodies in serum were not identified in any of the evaluated samples. However, 3/49 (6.12%) lung samples were positive for BVDV RNA and classified one as BVDV-1a and two as 1d subgenotype. This report identified BVDV RNA in free-living wild boars and these results should be considered in BVDV control programs, especially in extensive beef cattle rearing systems.
Asunto(s)
Animales Salvajes/virología , Virus de la Diarrea Viral Bovina Tipo 1/aislamiento & purificación , Sus scrofa/virología , Regiones no Traducidas 5'/genética , Animales , Anticuerpos Antivirales/sangre , Brasil , Virus de la Diarrea Viral Bovina Tipo 1/clasificación , Virus de la Diarrea Viral Bovina Tipo 1/genética , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Genotipo , Pulmón/virología , Infecciones por Pestivirus/veterinaria , Infecciones por Pestivirus/virología , Filogenia , ARN Viral/genética , Porcinos , Enfermedades de los Porcinos/virologíaRESUMEN
Interferon lambda (IFN-λ) plays an important role in inducing an antiviral state in mucosal surfaces and has been used as an effective biotherapeutic against several viral diseases. Here we performed a proof of concept study on the activity of a biologically active recombinant bovine IFN-λ (rIFN-λ) produced in eukaryotic cells against Bovine Viral Diarrhea Virus (BVDV) in cattle. We first confirmed the lack of toxicity of different concentrations of rIFN-λ in bovine peripheral blood cells and the safety of its subcutaneous application in calves in doses up to 12 IU/kg. The antiviral activity of the rIFN-λ against BVDV was assessed in calves that were inoculated with 6 IU/kg of rIFN-λ (n = 4) or mock-treated (n = 2) two days before and after challenge with a BVDV type-2 non-cytopathic strain. Mock-treated animals developed respiratory disease, shedded the virus from 4 to 7 days post-infection (dpi) and had viremia between 4 and 14 dpi. Conversely, calves treated with rIFN-λ did not develop clinical symptoms. The virus was not found in nasal secretions or sera. Only one animal had a positive viral RNA detection in serum at 7 dpi. All infected animals treated with rIFN-λ increased systemic type-I IFNs levels at 4 dpi. The antiviral treatment induced an earlier onset of the anti-BVDV neutralizing antibodies. Altogether, these results constitute the proof-of-principle of bovine IFN-λ as an antiviral biotherapeutic to protect cattle against the clinical disease caused by BVDV.
Asunto(s)
Diarrea Mucosa Bovina Viral/inmunología , Diarrea Mucosa Bovina Viral/prevención & control , Enfermedades de los Bovinos/prevención & control , Virus de la Diarrea Viral Bovina/inmunología , Diarrea/veterinaria , Inmunización Pasiva , Interferones/administración & dosificación , Factores de Edad , Animales , Bovinos , Enfermedades de los Bovinos/inmunología , Enfermedades de los Bovinos/virología , Diarrea/prevención & control , Diarrea/virología , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Virus de la Diarrea Viral Bovina Tipo 2/inmunología , Femenino , Inmunización Pasiva/veterinaria , Interferones/clasificación , Interferones/genética , Interferones/inmunología , Prueba de Estudio Conceptual , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/inmunología , Esparcimiento de VirusRESUMEN
The bovine viral diarrhea virus (BVDV-1) is a pathogen with the capacity to modulate the interferon type I system. To further investigate the effects of BVDV-1 on the production of the immune response, the Madin-Darby bovine kidney cell line was infected with the cytopathic CH001 field isolate of BVDV-1, and the IFNbeta expression profiles were analyzed. The results showed that cpBVDV-1 was able to induce the production of IFNbeta in a way similar to polyinosinic-polycytidylic acid, but with less intensity. Interestingly, all cpBVDV-1 activities were blocked by pharmacological inhibitors of the IRF-1, IRF-7, and NF-κB signaling pathway, and the level of IFNbeta decreased at the level of transcript and protein. These results, together with in silico analyses showing the presence of several regulatory consensus target motifs, suggest that cpBVDV-1 regulates IFNbeta expression in bovines through the activation of several key transcription factors. Collectively, the results suggest that during cpBVDV-1 infection, cross talk is evident between various signaling pathways involved in transcriptional activation of IFNbeta in cattle.
Asunto(s)
Diarrea Mucosa Bovina Viral/genética , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Regulación de la Expresión Génica/genética , Expresión Génica/genética , Factor 1 Regulador del Interferón/genética , Factor 7 Regulador del Interferón/genética , FN-kappa B/genética , Animales , Diarrea Mucosa Bovina Viral/virología , Bovinos , Línea Celular , Células Epiteliales/inmunología , Células Epiteliales/virología , Expresión Génica/inmunología , Regulación de la Expresión Génica/inmunología , Factor 1 Regulador del Interferón/inmunología , Factor 7 Regulador del Interferón/inmunología , FN-kappa B/inmunología , Transducción de Señal/genética , Transducción de Señal/inmunologíaRESUMEN
This study was designed to evaluate the extent of the protection for bovine viral diarrhea virus type 2 (BVDV-2) infection, afforded by vaccination with a combo inactivated vaccine, which contains bovine viral diarrhea virus type 1 (BVDV-1) and infectious bovine rhinotracheitis virus (IBRV). Five 3-4-month-old calves were intramuscularly vaccinated with a single dose of the combo vaccine and boosted with same dose three weeks after the first vaccination, with five mock immunized calves serving as a control group. Twenty-one days after the second vaccination, all calves were challenged with BVDV-2 SX08 strain by spray into nostril. The unvaccinated animals developed typical clinical signs of high rectal temperature, diarrhoea with erosions and a dramatic drop in leukocyte counts. These signs occured markedly less in all vaccinated animals, the rectal temperature, leukopenia and virarmia of which, were significantly less than the mock immunized calves. It can be concluded that vaccination with the combo inactivated vaccine affords cross-protection against clinical effects of a challenge-infection with BVDV-2 SX08 strain, although it was part protection.(AU)
Este estudo foi desenvolvido para avaliar a extensão da proteção contra a infecção pelo vírus da diarréia viral bovina tipo 2 (BVDV-2) através da vacinação com uma vacina combinada inativada contendo o vírus da diarréia viral bovina tipo 1 (BVDV-1) e vírus da rinotraqueíte de bovinos infecciosos (IBRV). Cinco bezerros com 3 a 4 meses de idade foram vacinados via intramuscular com uma dose única da vacina combinada e reforçados com a mesma dose três semanas após a primeira vacinação, com cinco bezerros imunizados em simulação servindo como grupo controle. Vinte e um dias após a segunda vacinação, todos os bezerros foram desafiados com a cepa BVDV-2 SX08 por spray na narina. Os animais não vacinados desenvolveram sinais clínicos típicos, como alta temperatura retal, diarréia com erosões e queda drástica na contagem de leucócitos. Estes sinais tiveram ocorrência significativamente menor em todos os animais vacinados, cuja temperatura retal, leucopenia e virarmia eram significativamente menores do que os bezerros simulados. É possível concluir que a vacinação com a vacina combinada inativada proporciona proteção cruzada contra os efeitos clínicos de uma infecção provocada pela cepa BVDV-2 SX08, embora tenha sido parcialmente protegida.(AU)
Asunto(s)
Animales , Bovinos , Vacunación , Vacunas Combinadas/análisis , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Virus de la Diarrea Viral Bovina Tipo 2/inmunología , Protección Cruzada , Vacunas de Productos Inactivados , Recuento de LeucocitosRESUMEN
This study was designed to evaluate the extent of the protection for bovine viral diarrhea virus type 2 (BVDV-2) infection, afforded by vaccination with a combo inactivated vaccine, which contains bovine viral diarrhea virus type 1 (BVDV-1) and infectious bovine rhinotracheitis virus (IBRV). Five 3-4-month-old calves were intramuscularly vaccinated with a single dose of the combo vaccine and boosted with same dose three weeks after the first vaccination, with five mock immunized calves serving as a control group. Twenty-one days after the second vaccination, all calves were challenged with BVDV-2 SX08 strain by spray into nostril. The unvaccinated animals developed typical clinical signs of high rectal temperature, diarrhoea with erosions and a dramatic drop in leukocyte counts. These signs occured markedly less in all vaccinated animals, the rectal temperature, leukopenia and virarmia of which, were significantly less than the mock immunized calves. It can be concluded that vaccination with the combo inactivated vaccine affords cross-protection against clinical effects of a challenge-infection with BVDV-2 SX08 strain, although it was part protection.(AU)
Este estudo foi desenvolvido para avaliar a extensão da proteção contra a infecção pelo vírus da diarréia viral bovina tipo 2 (BVDV-2) através da vacinação com uma vacina combinada inativada contendo o vírus da diarréia viral bovina tipo 1 (BVDV-1) e vírus da rinotraqueíte de bovinos infecciosos (IBRV). Cinco bezerros com 3 a 4 meses de idade foram vacinados via intramuscular com uma dose única da vacina combinada e reforçados com a mesma dose três semanas após a primeira vacinação, com cinco bezerros imunizados em simulação servindo como grupo controle. Vinte e um dias após a segunda vacinação, todos os bezerros foram desafiados com a cepa BVDV-2 SX08 por spray na narina. Os animais não vacinados desenvolveram sinais clínicos típicos, como alta temperatura retal, diarréia com erosões e queda drástica na contagem de leucócitos. Estes sinais tiveram ocorrência significativamente menor em todos os animais vacinados, cuja temperatura retal, leucopenia e virarmia eram significativamente menores do que os bezerros simulados. É possível concluir que a vacinação com a vacina combinada inativada proporciona proteção cruzada contra os efeitos clínicos de uma infecção provocada pela cepa BVDV-2 SX08, embora tenha sido parcialmente protegida.(AU)
Asunto(s)
Animales , Bovinos , Vacunación , Vacunas Combinadas/análisis , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Virus de la Diarrea Viral Bovina Tipo 2/inmunología , Protección Cruzada , Vacunas de Productos Inactivados , Recuento de LeucocitosRESUMEN
Bovine viral diarrhea virus (BVDV, Pestivirus) causes significant economic losses to the livestock industry worldwide. Although serological surveys show that BVDV exposure is widespread in cattle in Uruguay, BVDV-associated diseases are greatly underreported. The aim of this work is to describe the epidemiological, clinical, pathological, and virological findings from spontaneous outbreaks of BVDV-associated diseases in cattle in Uruguay. Diagnostic investigations were performed during 6 spontaneous disease outbreaks on beef and dairy cattle farms in the departments of Colonia, Rio Negro, and Soriano between November 2016 and April 2018. Carcasses of 8 naturally deceased cattle from these outbreaks were necropsied and subjected to histological examination and immunohistochemistry to detect BVDV antigen in the tissues. Reverse transcription real-time PCR and genomic sequencing were also performed to identify BVDV at the species and subtype levels. Other ancillary diagnostic tests, including bacterial cultures, were performed on a case-by-case basis to rule in/out differential diagnoses based on initial clinicopathological presumptive diagnoses. BVDV-associated conditions that were diagnosed in the 8 cases included mucosal disease, transient postnatal BVDV infections associated with digestive/septicemic salmonellosis by Salmonella serovar typhimurium, Histophilus somni bronchopneumonia, urinary tract coinfections with Escherichia coli and Streptococcus sp., enteric coinfection with coccidia, and transplacental fetal infections and abortions with Neospora caninum coinfection. BVDV-1a and BVDV-2b were each identified in four of the eight cases. We conclude that BVDV-1a and BVDV-2b contribute significantly to disease and mortality in cattle in Uruguay. Future research should estimate the economic impact of BVDV in the Uruguayan livestock sector.
Asunto(s)
Diarrea Mucosa Bovina Viral/complicaciones , Enfermedades de los Bovinos/virología , Coinfección , Pestivirus , Animales , Anticuerpos Antiprotozoarios , Anticuerpos Antivirales , Bacterias/aislamiento & purificación , Diarrea Mucosa Bovina Viral/epidemiología , Bronconeumonía/veterinaria , Bovinos , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/microbiología , Enfermedades de los Bovinos/parasitología , Coccidios/aislamiento & purificación , Coinfección/microbiología , Coinfección/parasitología , Enfermedades Transmisibles/complicaciones , Enfermedades Transmisibles/epidemiología , Enfermedades Transmisibles/veterinaria , Virus de la Diarrea Viral Bovina Tipo 1/genética , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Virus de la Diarrea Viral Bovina Tipo 1/aislamiento & purificación , Virus de la Diarrea Viral Bovina Tipo 2/genética , Virus de la Diarrea Viral Bovina Tipo 2/inmunología , Virus de la Diarrea Viral Bovina Tipo 2/aislamiento & purificación , Brotes de Enfermedades/veterinaria , Femenino , Inmunohistoquímica , Intestinos/microbiología , Intestinos/parasitología , Intestinos/patología , Intestinos/virología , Pulmón/microbiología , Pulmón/patología , Mortalidad , Neospora/inmunología , Neospora/aislamiento & purificación , Pasteurellaceae/aislamiento & purificación , Pestivirus/genética , Pestivirus/inmunología , Pestivirus/aislamiento & purificación , Pestivirus/patogenicidad , Embarazo , Complicaciones Infecciosas del Embarazo/parasitología , Complicaciones Infecciosas del Embarazo/veterinaria , Salmonella/aislamiento & purificación , Sepsis/veterinaria , Streptococcus/aislamiento & purificación , Sistema Urinario/microbiología , Sistema Urinario/patología , Uruguay/epidemiologíaRESUMEN
Vaccination is a strategy to the prevention and control of reproductive diseases caused by bovine viral diarrhea virus (BVDV) and bovine herpesvirus type 1 (BoHV-1), however the various compositions of commercial vaccines should be evaluated for their ability to induce protection mediated by antibodies. The objective of this research was to evaluate the production of specific neutralizing Abs against BVDV-1 and 2, and BoHV-1 induced by commercial vaccines composed by different adjuvants. Holstein heifers were vaccinated and distributed in three experimental groups: Group I (G1) was vaccinated with a commercial vaccine containing inactivated BVDV-1, BVDV-2 and BoHV-1 diluted in alum hydroxide as adjuvant (n=9); Group II (G2) was vaccinated with an product containing inactivated strains of BVDV-1, BVDV-2, BoHV-1 and BoHV-5 diluted in oil emulsion as adjuvant (n=10); Group III (G3) was vaccinated with a commercial vaccine containing inactivated BVDV-1 and BVDV-2, besides live modified thermosensitive BoHV-1, diluted in Quil A, amphigen and cholesterol (n=10); A control, non-vaccinated group (n=6) was mock vaccinated with saline. Heifers received two subcutaneous doses of 5mL of each commercial vaccine on the right side of the neck, with 21 days interval. Humoral immune response was assessed by the virus neutralization test (VN) against BVDV-1 (NADL and Singer strains), BVDV-2 (SV253 strain) and BoHV-1 (Los Angeles strain) in serum samples collected on vaccination days zero (D0), 21 (D21) and 42 (D42; 21 days after boosting). Neutralizing Abs against BVDV-1 NADL was detected only in D42, regardless of the vaccine used. Similar geometric mean titers (GMT) for BVDV-1 NADL were observed between G1 (log2=5.1) and G3 (log2=5.1). The seroconversion rate (%) was higher in G1 (78%) when compared to G2 (10%) and G3 (40%). For BVDV-1 Singer, it was also possible to detect Abs production in G1 (log2=5.8, 100% seroconversion rate) and G3 (log2=3.5, seroconversion rate = 60%), only after the booster dose (D42). Neutralizing Abs to BVDV-2 (SV253) were detected only in G3, observing 90% seroconversion associated with high titers of Abs (log2=6.7) after the 2nd dose of vaccine (D42). Heifers from G1 and G3 responded to BoHV-1 after the first dose (D21): G1 (log2=2.5, seroconversion rate = 67%) and G3 (log2=0.7, seroconversion rate = 80%). In D42, a higher magnitude response was observed in the heifers from G3 (log2=6.1, 100%) compared with G1 (log2=4.3, 100%) and G2 (log2=2.7, 60%). Based on the data obtained, it can be concluded that the commercial vaccine contained aluminum hydroxide (G1) was most effective in the induction of antibodies against BVDV-1. On the other hand, this vaccine did not induce the production of neutralizing Abs against BVDV-2. Only the heifers from G3 (Quil A, amphigen and cholesterol) generated neutralizing Abs against BVDV-2. The animals that received commercial vaccine containing oil emulsion as adjuvant (G2) had a weak/undetectable response against BVDV-1 and BVDV-2. The best protective response against BoHV-1 was observed in heifers vaccinated with the live modified thermosensitive virus.(AU)
A vacinação é utilizada como estratégia para a prevenção e controle das doenças reprodutivas, causadas pelos vírus da diarreia viral bovina (BVDV) e herpesvírus bovino tipo 1 (BoHV-1), entretanto, as diversas composições de vacinas comerciais devem ser avaliadas quanto a sua eficiência protetiva mediada por anticorpos (Acs). O objetivo desta pesquisa foi avaliar a produção Acs neutralizantes específicos para cepas de BVDV-1 e 2, e BoHV-1 induzida por vacinas comerciais contendo diferentes tipos de adjuvantes. Para tal, novilhas Holandesas foram vacinadas e distribuídas em três grupos experimentais: Grupo I (G1) foi vacinado com uma vacina comercial composta por cepas inativadas de BVDV-1, BVDV-2 e BoHV-1 diluídas em hidróxido de alumínio como adjuvante (n=9); Grupo II (G2) foi vacinado com produto contendo as cepas inativadas de BVDV-1, BVDV-2, BoHV-1 e BoHV-5 em uma emulsão oleosa como adjuvante (n=10); O Grupo III (G3) foi vacinado com uma vacina comercial contendo BVDV-1 e BVDV-2 inativado, além do BoHV-1 vivo modificado e termosensivel, diluídos em adjuvante contendo Quil A, Amphigem e colesterol (n=10); O Grupo Controle não vacinado (n=6) foi inoculado com solução salina. As novilhas receberam duas doses das respectivas vacinas ou solução salina (5mL), com intervalo de 21 dias, por via subcutânea, na tábua do pescoço do lado direito. A resposta imune humoral foi avaliada pelo teste de vírus neutralização (VN) contra o BVDV-1 (cepas NADL e Singer), BVDV-2 (cepa SV253) e BoHV-1 (cepa Los Angeles) em amostras de soro coletadas nos dias (D) de vacinação zero (D0), 21 dias após 1ª dose (D21)e 42 (D42; 21 dias após A 2ª dose). Os anticorpos neutralizantes contra o BVDV-1 NADL foram detectados apenas em D42, independentemente da vacina utilizada. Os títulos médios geométricos (GMT) de anticorpos foram semelhantes entre G1 (log2=5,1) e G3 (log2=5,1). A taxa de soroconversão foi maior no G1 (78%) quando comparado ao G2 (10%) e G3 (40%). Para o BVDV-1 Singer, somente após D42 foi observada a produção de Acs no G1 (log2=5,8; taxa de soroconversão de 100%) e G3 (log2=3,5; taxa de soroconversão = 60%). Os anticorpos contra BVDV-2 (SV253) foram detectados apenas nas novilhas do G3, observando-se taxa de soroconversão de 90% com altos títulos de anticorpos neutralizantes (log2=6,7) em D42. Novilhas G1 e G3 responderam ao BoHV-1 após a primeira dose (D21): G1 (log2=2,5; taxa de seroconversão = 67%) e G3 (log2=0,7; taxa de seroconversão = 80%). Em contrapartida, foi observada uma maior magnitude de resposta para as novilhas G3 (log2=6,1; 100%) em D42, em relação aos animais G1 (log2=4,3; 100%) e G2 (log2=2,7; 60%). Com base nos dados obtidos, foi possível concluir que a vacina composta por hidróxido de alumínio (G1) foi mais eficaz na produção de anticorpos contra o BVDV-1, em contrapartida esse produto não induziu anticorpos contra o BVDV-2. Apenas as novilhas do G3 (Quil A, amphigen e colesterol) geraram Acs neutralizantes contra o BVDV-2. Os animais que receberam a vacina em emulsão oleosa (G2) como adjuvante apresentaram uma resposta fraca/indetectável contra o BVDV-1 e BVDV-2. A melhor resposta protetiva contra o BoHV-1 foi observada nas novilhas vacinadas com a vacina viva modificada termosensível.(AU)
Asunto(s)
Animales , Bovinos , Vacunas/efectos adversos , Vacunas/inmunología , Herpesvirus Bovino 1/inmunología , Virus de la Diarrea Viral Bovina Tipo 1/inmunologíaRESUMEN
Vaccination is a strategy to the prevention and control of reproductive diseases caused by bovine viral diarrhea virus (BVDV) and bovine herpesvirus type 1 (BoHV-1), however the various compositions of commercial vaccines should be evaluated for their ability to induce protection mediated by antibodies. The objective of this research was to evaluate the production of specific neutralizing Abs against BVDV-1 and 2, and BoHV-1 induced by commercial vaccines composed by different adjuvants. Holstein heifers were vaccinated and distributed in three experimental groups: Group I (G1) was vaccinated with a commercial vaccine containing inactivated BVDV-1, BVDV-2 and BoHV-1 diluted in alum hydroxide as adjuvant (n=9); Group II (G2) was vaccinated with an product containing inactivated strains of BVDV-1, BVDV-2, BoHV-1 and BoHV-5 diluted in oil emulsion as adjuvant (n=10); Group III (G3) was vaccinated with a commercial vaccine containing inactivated BVDV-1 and BVDV-2, besides live modified thermosensitive BoHV-1, diluted in Quil A, amphigen and cholesterol (n=10); A control, non-vaccinated group (n=6) was mock vaccinated with saline. Heifers received two subcutaneous doses of 5mL of each commercial vaccine on the right side of the neck, with 21 days interval. Humoral immune response was assessed by the virus neutralization test (VN) against BVDV-1 (NADL and Singer strains), BVDV-2 (SV253 strain) and BoHV-1 (Los Angeles strain) in serum samples collected on vaccination days zero (D0), 21 (D21) and 42 (D42; 21 days after boosting). Neutralizing Abs against BVDV-1 NADL was detected only in D42, regardless of the vaccine used. Similar geometric mean titers (GMT) for BVDV-1 NADL were observed between G1 (log2=5.1) and G3 (log2=5.1). The seroconversion rate (%) was higher in G1 (78%) when compared to G2 (10%) and G3 (40%)...
A vacinação é utilizada como estratégia para a prevenção e controle das doenças reprodutivas, causadas pelos vírus da diarreia viral bovina (BVDV) e herpesvírus bovino tipo 1 (BoHV-1), entretanto, as diversas composições de vacinas comerciais devem ser avaliadas quanto a sua eficiência protetiva mediada por anticorpos (Acs). O objetivo desta pesquisa foi avaliar a produção Acs neutralizantes específicos para cepas de BVDV-1 e 2, e BoHV-1 induzida por vacinas comerciais contendo diferentes tipos de adjuvantes. Para tal, novilhas Holandesas foram vacinadas e distribuídas em três grupos experimentais: Grupo I (G1) foi vacinado com uma vacina comercial composta por cepas inativadas de BVDV-1, BVDV-2 e BoHV-1 diluídas em hidróxido de alumínio como adjuvante (n=9); Grupo II (G2) foi vacinado com produto contendo as cepas inativadas de BVDV-1, BVDV-2, BoHV-1 e BoHV-5 em uma emulsão oleosa como adjuvante (n=10); O Grupo III (G3) foi vacinado com uma vacina comercial contendo BVDV-1 e BVDV-2 inativado, além do BoHV-1 vivo modificado e termosensivel, diluídos em adjuvante contendo Quil A, Amphigem e colesterol (n=10); O Grupo Controle não vacinado (n=6) foi inoculado com solução salina. As novilhas receberam duas doses das respectivas vacinas ou solução salina (5mL), com intervalo de 21 dias, por via subcutânea, na tábua do pescoço do lado direito. A resposta imune humoral foi avaliada pelo teste de vírus neutralização (VN) contra o BVDV-1 (cepas NADL e Singer), BVDV-2 (cepa SV253) e BoHV-1 (cepa Los Angeles) em amostras de soro coletadas nos dias (D) de vacinação zero (D0), 21 dias após 1ª dose (D21)e 42 (D42; 21 dias após A 2ª dose). Os anticorpos neutralizantes contra o BVDV-1 NADL foram detectados apenas em D42, independentemente da vacina utilizada. Os títulos médios geométricos (GMT) de anticorpos foram semelhantes entre G1 (log2=5,1) e G3 (log2=5,1). A taxa de soroconversão foi maior no G1 (78%) quando comparado ao G2 (10%) e G3 (40%)...(AU)
Asunto(s)
Animales , Bovinos , Vacunas/efectos adversos , Vacunas/inmunología , Herpesvirus Bovino 1/inmunología , Virus de la Diarrea Viral Bovina Tipo 1/inmunologíaRESUMEN
Serological studies have characterized the presence of the bovine viral diarrhea virus (BVDV) infection in water buffalo herds worldwide. However, the molecular characterization of BVDV strains circulating in this animal species is uncommon. The aim of this study was to identify young water buffalo with acute infection and characterize the subgenotype of the infecting wild-type BVDV strain. Two dairy water buffalo herds from Northeastern Brazil were selected based on the results of virus neutralization test which showed high titers of anti-BVDV antibodies. To identify viremic animals, the BVDV RNA was assessed by RT-PCR assay in serum samples from 44 asymptomatic young water buffalos, where 31 serum samples from herd A and 13 from herd B. Amplicons with 288 bp of BVDV 5'UTR region were obtained in 7 (15.9%) serum samples (herd A, n = 5; herd B, n = 2). One good-quality amplicon from each herd was selected for nucleotide sequencing. The phylogenetic analysis demonstrated that the two BVDV wild-type strains clustered with BVDV strains of the subgenotype 1b. This study identified for the first time the active infection by BVDV subgenotype 1b in two dairy water buffalo herds from Brazil. These results highlight the importance of that, as well as in cattle herds, also in water buffalo herds prophylaxis measures to control BVDV infection should be intensified, mainly because these species clearly coexist in buffalo farms within Brazil.
Asunto(s)
Búfalos/virología , Virus de la Diarrea Viral Bovina Tipo 1/genética , Regiones no Traducidas 5' , Animales , Anticuerpos Antivirales/sangre , Secuencia de Bases , Diarrea Mucosa Bovina Viral/virología , Brasil/epidemiología , Bovinos , Análisis por Conglomerados , Diarrea , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Genotipo , Filogenia , ViremiaRESUMEN
Pestiviruses including Bovine viral diarrhea virus type 1 (BVDV-1), BVDV-2 and Border disease virus (BDV) have been reported in both sheep and cattle populations, together with the HoBi-like, an emerging group of pestiviruses. Pestivirus control programs in the United States have focused on the control of BVDV-1 and 2. The incidence of pestivirus infection in sheep in the United States and the risk of transmission between cattle and sheep populations are unknown. The aim of this study was to perform serological surveillance for pestivirus exposure in sheep from an important sheep producing state in the Unites States, Wyoming. For this, sera from 500 sheep, collected across the state of Wyoming (US) in 2015-2016, were examined by comparative virus neutralization assay against four species/proposed species of pestiviruses: BVDV-1, BVDV-2, BDV and HoBi-like virus. Rates of exposure varied between geographic regions within the state. The overall pestivirus prevalence of antibodies was 5.6%. Antibodies were most frequently detected against BVDV-1 (4%), and the highest antibody titers were also against BVDV-1. Data from this study highlights understanding of the dynamics of sheep pestivirus exposure, consideration of reference strains used for VN assays, transmission patterns, and potential vaccination history should be taken into account in implementation of control measures against pestiviruses in sheep and for successful BVDV control programs in cattle.
Asunto(s)
Anticuerpos Antivirales/sangre , Infecciones por Pestivirus/veterinaria , Pestivirus/inmunología , Ovinos/inmunología , Animales , Animales Domésticos/inmunología , Animales Domésticos/virología , Bovinos/virología , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/transmisión , Enfermedades de los Bovinos/virología , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Virus de la Diarrea Viral Bovina Tipo 2/inmunología , Virus de la Diarrea Viral Bovina/inmunología , Pruebas de Neutralización , Pestivirus/clasificación , Pestivirus/genética , Infecciones por Pestivirus/epidemiología , Infecciones por Pestivirus/inmunología , Infecciones por Pestivirus/transmisión , Filogenia , Estudios Seroepidemiológicos , Ovinos/virología , Encuestas y Cuestionarios , Wyoming/epidemiologíaRESUMEN
BACKGROUND: Bovine Viral Diarrhea Virus (BVDV) is the viral agent causing the most important economic losses in livestock throughout the world. Infection of fetuses before their immunological maturity causes the birth of animals persistently infected with BVDV (PI), which are the main source of infection and maintenance of this pathogen in a herd. There is evidence of susceptibility to infection with BVDV in more than 50 species of the order Artiodactyla, and the ability to establish persistent infection in wild cervid species of South America could represent an important risk in control and eradication programs of BVDV in cattle, and a threat to conservation of these wild species. In this study, a serological and virological study was performed to detect BVDV infection in a captive population of non-bovine artiodactyl species in a Chilean zoo with antecedents of abortions whose pathology suggests an infectious etiology. RESULTS: Detection of neutralizing antibodies against BVDV was performed in 112 artiodactyl animals from a zoo in Chile. Three alpacas (Vicugna pacos), one guanaco (Lama guanicoe) and seven pudús (Pudu puda) resulted seropositive, and the only seronegative pudú was suspected to be persistently infected with BVDV. Then two blood samples nine months apart were analyzed by a viral neutralization test and RT-PCR. Non-cytopathogenic BVDVs were isolated in both samples. A phylogenetic analysis showed that the virus was highly related to BVDV-1b strains circulating among Chilean cattle. CONCLUSIONS: This is the first report of a South American deer persistently infected with Bovine Viral Diarrhea Virus. Further studies are needed to determine the possible role of BVDV as a pathogen in pudús and as a threat to their conservation.
Asunto(s)
Camélidos del Nuevo Mundo/virología , Ciervos/virología , Virus de la Diarrea Viral Bovina Tipo 1/aislamiento & purificación , Infecciones por Pestivirus/epidemiología , Aborto Veterinario , Animales , Animales de Zoológico/virología , Artiodáctilos/virología , Chile/epidemiología , Ciervos/sangre , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Femenino , Pruebas de Neutralización/veterinaria , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Estudios SeroepidemiológicosRESUMEN
Saponin-based adjuvants are promising adjuvants that enhance both humoral and T-cell-mediated immunity. One of the most used natural products as vaccine adjuvants are Quillaja saponaria bark saponins and its fraction named Quil A®. Despite that, its use has been restricted for human use due to safety issues. As an alternative, our group has been studying the congener species Quillaja brasiliensis saponins and its performance as vaccine adjuvants, which have shown to trigger humoral and cellular immune responses comparable to Quil A® but with milder side effects. Here, we studied a semi purified aqueous extract (AE) and a previously little characterized saponin-enriched fraction (QB-80) from Q. brasiliensis as vaccine adjuvants and an inactivated virus (bovine viral diarrhea virus, BVDV) antigen co-formulated in experimental vaccines in mice model. For the first time, we show the spectra pattern of the Q. brasiliensis saponins by MALDI-TOF, a novel and cost-effective method that could be used to characterize different batches during saponins production. Both AE and QB-80 exhibited noteworthy chemical similarities to Quil A®. In addition, the haemolytic activity and toxicity were assessed, showing that both AE and QB-80 were less toxic than Quil A®. When subcutaneously inoculated in mice, both fractions promoted long-term strong antibody responses encompassing specific IgG1 and IgG2a, enhanced the avidity of IgG antibodies, induced a robust DTH reaction and significantly increased IFN-É£ production in T CD4+ and T CD8+ cells. Furthermore, we have proven herein that AE has the potential to promote dose-sparing, substantially reducing the dose of antigen required for the BVDV vaccines and still eliciting a mixed Th1/Th2 strong immune response. Based on these results, and considering that AE is a raw extract, easier and cheaper to produce than commercially available saponins, this product can be considered as candidate to be escalated from experimental to industrial uses.
Asunto(s)
Diarrea Mucosa Bovina Viral/inmunología , Inmunidad Celular/inmunología , Extractos Vegetales/inmunología , Quillaja/química , Saponinas/inmunología , Vacunas Virales/inmunología , Adyuvantes Inmunológicos/administración & dosificación , Adyuvantes Inmunológicos/efectos adversos , Adyuvantes Inmunológicos/química , Animales , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Formación de Anticuerpos/inmunología , Diarrea Mucosa Bovina Viral/prevención & control , Linfocitos T CD8-positivos , Bovinos , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Relación Dosis-Respuesta Inmunológica , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Ratones , Extractos Vegetales/administración & dosificación , Extractos Vegetales/efectos adversos , Extractos Vegetales/química , Hojas de la Planta/química , Saponinas de Quillaja/administración & dosificación , Saponinas de Quillaja/efectos adversos , Saponinas de Quillaja/inmunología , Saponinas/química , Saponinas/economía , Saponinas/aislamiento & purificación , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Balance Th1 - Th2 , Vacunas Virales/administración & dosificaciónRESUMEN
The immediate early response 3 (IER3) is a key regulatory factor in the immune response, particularly as related to homeostasis immunomodulation via the nuclear factor kappa B (NF-κB) signaling pathway. The IER3 gene has been identified in mammals and, more recently, in other higher vertebrates. Nevertheless, relatively little is known about this regulator in bovines. Therefore, this study explored, characterized, and compared the genetic context of bovine IER3 to homologous genes in the human, mouse, and canine chromosomes. In silico analysis identified several regions of interest preserved in phylogenetically distant species. Similar analyses were also conducted for interleukin-8, a cytokine in which several putative cis elements were identified for the inducible transcription factor NF-κB. Subsequent challenge assays against the bovine viral diarrhea virus-1 revealed NF-κB signaling pathway activation just 15min post-infection, a process blocked by the BAY-117085 inhibitor. Similarly, infection strongly increased IER3 expression. Interestingly, IER3 down-regulated interleukin-8 expression, as confirmed by IER3 gene inhibition using small interfering RNA, RT-qPCR, and luciferase assays. In conclusion, this is the first report to present data indicating that bovine IER3 is a strong regulator of immune-marker expression, specifically modulating bovine interleukin-8 activation through the NF-κB/IER3 pathway in response to the bovine viral diarrhea virus.
Asunto(s)
Proteínas Reguladoras de la Apoptosis/inmunología , Diarrea Mucosa Bovina Viral/inmunología , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Interleucina-8/inmunología , FN-kappa B/inmunología , Transducción de Señal/inmunología , Animales , Bovinos , Perros , Células de Riñón Canino Madin DarbyRESUMEN
The aims of this study were to establish the prevalence of anti-bovine viral diarrhea virus (BVDV)antibodies (Ab) in beef cattle raised in Pará state, to compare the prevalence of seropositive animals toBVDV using a commercial indirect enzyme-linked immunosorbent assay kit (iELISA) and the virusneutralization (VN) test, and finally, to determine the sensitivity (Se) and specificity (Sp) of the iELISAfor the detection of anti-BVDV Ab using VN as a gold standard. A total of 400 serum blood samplesfrom Nelore cows aged at least 24 months from five farms in the Pará state from two mesoregions(Metropolitan Region of Belem and Northeast of Pará) were analyzed. All animals were vaccinatedagainst brucellosis and foot-and-mouth disease. The examination of anti-BVDV Ab with VN wasperformed in the Laboratory of Bovine Viruses of the Biological Institute of Sao Paulo as described in theManual of Diagnostic Tests and Vaccines for Terrestrial Animals. For VN, bovine kidney epithelial cellsfrom the Madin Darby Bovine Kidney (MDBK) strain were used. The determinations of anti-BVDVAb were performed with the iELISA test at the Laboratory of Immunology and Microbiology of theFederal Rural University of Amazonia according to the manufacturers recommendations. The resultswere classified as follows: (a) correct positive diagnosis, (b) incorrect positive diagnosis, (c) correctnegative diagnosis, and (d) incorrect negative diagnosis, according to the results obtained from VN.From the values obtained from VN and iELISA, Se [(a ÷ a + d) × 100], Sp [(c ÷ c + b) × 100], positivepredictive value [(a ÷ a + B) × 100], and negative predictive value [(c ÷ c + d) × 100] were calculatedfor iELISA. The frequencies (%) of seropositive animals were determined and compared both betweenthe different tests (iELISA and VN) and between the different farms (1, 2, 3, 4, and 5). The statisticalanalysis was performed with a significance level of 5%...(AU)
Para se estabelecer a prevalência de anticorpos (Ac) anti-BVDV em rebanhos bovinos de corte noEstado do Pará e comparar a prevalência de animais soropositivos para o BVDV utilizando-se umkit comercial de ELISA-I (Enzyme-linked Immunosorbent Assay indireto) frente ao teste de VN(virusneutralização) e determinar a Se (sensibilidade) e Sp (especificidade) do ELISA-I para detecçãode Ac anti-BVDV frente a VN, foram analisadas 400 amostras de soros sanguíneos de vacas Nelorecom idade mínima superior a 24 meses, vacinadas contra brucelose e febre aftosa, provenientes de cincofazendas no estado do Pará, localizadas em duas Mesorregiões (Metropolitana de Belém e do NordesteParaense). A pesquisa de Ac anti-BVDV determinados pela VN foi realizada no Laboratório de Virosesde Bovídeos do Instituto Biológico de São Paulo, conforme descrito no Manual of Diagnostic Tests andVaccines for Terrestrial Animals. Foram utilizadas células epiteliais de rim bovino da linhagem MadinDarby Bovine Kidney MDBK). Já as determinações dos Ac anti-BVDV pelo ELISA-I foram realizadasno Laboratório de Imunologia e Microbiologia da Universidade Federal Rural da Amazônia, conformerecomendações do fabricante. Os resultados verificados foram classificados como diagnóstico positivocorreto (a), diagnóstico positivo incorreto (b), diagnóstico negativo correto (c), diagnóstico negativoincorreto (d), em função dos resultados obtidos na VN. A partir desses valores, calculou-se para oELISA-I a sensibilidade [(a / a + d) x 100], a especificidade [(c / c + b) x 100], o valor preditivo positivo[(a / a + b) x 100] e o valor preditivo negativo [(c / c + d) x 100]. Foram determinadas as frequências(%) de animais positivos, tanto entre os testes (ELISA-I e VN) como entre as diferentes fazendas (1,2, 3, 4 e 5). A estatística de inferência foi realizada com nível de significância de 5%...(AU)
Asunto(s)
Animales , Bovinos , Bovinos/inmunología , Ensayo de Inmunoadsorción Enzimática/métodos , Ensayo de Inmunoadsorción Enzimática/veterinaria , Virus de la Diarrea Viral Bovina Tipo 1/inmunologíaRESUMEN
Viruses have developed cellular strategies to ensure progeny survival. One of the most interesting is immune camouflage, where the virus triggers a controlled-intensity immune response that prevents total destruction of the infected cell, thus "winning time" for the virus. This study explored the regulatory contexts of the bovine A20 gene during bovine viral diarrhea virus (BVDV)-1 infection, using IL-8 as an immune-response sentinel molecule. Assessments were conducted through RT-qPCR, Western blotting, gene silencing/overexpression, luciferase assays, and the use of pharmacological inhibitors, among other approaches. The results demonstrated that a) BVDV-1 increased A20 levels in Madin-Darby bovine kidney cells, b) increased A20 led to decreased IL-8 expression, and c) the virus affected the NF-κB signaling pathway. Collectively, these data identify bovine A20 as a strong regulator of immune marker expression. In conclusion, this is the first report on BVDV-1 modulating bovine IL-8 activation through the NF-κB/A20 pathway.
Asunto(s)
Diarrea Mucosa Bovina Viral/inmunología , Virus de la Diarrea Viral Bovina Tipo 1/inmunología , Células Epiteliales/metabolismo , Interleucina-8/metabolismo , FN-kappa B/metabolismo , Proteína 3 Inducida por el Factor de Necrosis Tumoral alfa/metabolismo , Animales , Bovinos , Línea Celular , Células Epiteliales/patología , Células Epiteliales/virología , Regulación de la Expresión Génica , Inmunidad/genética , Inmunomodulación , Riñón/patología , ARN Interferente Pequeño/genética , Transducción de Señal , Proteína 3 Inducida por el Factor de Necrosis Tumoral alfa/genéticaRESUMEN
Hobi-like viruses comprise an unclassified group of bovine pestiviruses related to bovine viral diarrhea virus 1 (BVDV-1) and 2 (BVDV-2). These viruses were originally identified in fetal bovine serum from Brazilian origin and, subsequently, isolated from diseased animals in several countries. Herein we performed an antigenic characterization of eight Brazilian HoBi-like viruses isolated from persistently infected (PI) animals and from gastroenteric disease (2007-2015). Phylogenetic analysis based on the 5' unstranslated region (UTR) clustered these viruses with other HoBi-like viruses from European and Asiatic origin. Monoclonal antibody (MAb) binding indicated variability in the Hobi-like virus glycoprotein E2 and significant differences from the homologous BVDV-1 and BVDV-2 glycoprotein. Analysis of antigenic relatedness based on virus-neutralizing titers using virus-specific antisera revealed that HoBi-like viruses are antigenically very different from BVDV-1 and, to a lesser extent, from BVDV-2. Cross-neutralizing assays between pairs of HoBi-like viruses and their respective antisera indicated the existence of antigenic variability among these viruses, even for viruses isolated from the same herd in different occasions. Moreover, the identification of a HoBi-like isolate with low antigenic similarity with the other isolates indicates the potential existence of antigenic subgroups among HoBi-like virus isolates. Finally, sera of lambs immunized with commercial BVDV vaccines showed low or undetectable neutralizing activity against HoBi-like isolates. These results indicate significant antigenic differences between BVDV genotypes and Brazilian HoBi-like viruses and the existence of antigenic variability within this atypical group of pestiviruses. These findings extend the knowledge about the antigenic diversity of HoBi-like viruses and reinforce the need for their inclusion in current BVDV vaccines.