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1.
BMC Vet Res ; 15(1): 342, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31619295

RESUMO

BACKGROUND: The objective of this study was to assess the efficacy of a trivalent vaccine mixture and compare it to the respective monovalent vaccines against Mycoplasma hyopneumoniae, porcine circovirus type 2 (PCV2), and porcine reproductive and respiratory syndrome virus (PRRSV). RESULTS: Pigs that were triple challenged with M. hyopneumoniae, PCV2, and PRRSV following vaccination with the trivalent vaccine mixture exhibited a significantly better growth performance when compared to unvaccinated and challenged pigs. A statistical difference was not found when comparing pig populations which were vaccinated with the trivalent vaccine followed by a triple challenge and pigs vaccinated with monovalent M hyopneumoniae vaccine followed by mycoplasmal single challenge in the following areas: M. hyopneumoniae nasal shedding, the number of M. hyopneumoniae-specific interferon-γ secreting cells (IFN-γ-SC), and mycoplasmal lung lesion scores. Pigs vaccinated with the trivalent vaccine mixture followed by a triple challenge resulted in a similar reduction of PCV2 viremia, an increase in the number of PCV2-specific IFN-γ-SC and reduction in interstitial lung lesion scores when compared to pigs vaccinated with a PCV-2 vaccine and challenged with PCV2 only. Lastly, there was a significant difference in the reduction of PRRSV viremia, an increase in PRRSV-specific IFN-γ-SC and a reduction of interstitial lung lesion scores between pigs vaccinated with the trivalent vaccine mixture followed by a triple challenge and pigs vaccinated with a monovalent PRRSV vaccine followed by PRRSV challenge only. CONCLUSION: The trivalent vaccine mixture was efficacious against a triple challenge of M. hyopneumoniae, PCV2, and PRRSV. The trivalent vaccine mixture, however, did not result in equal protection when compared against each respective monovalent vaccine, with the largest vaccine occurring within PRRSV.


Assuntos
Circovirus/imunologia , Mycoplasma hyopneumoniae/imunologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Doenças dos Suínos/prevenção & controle , Vacinação/veterinária , Animais , Vacinas Bacterianas/imunologia , Infecções por Circoviridae/imunologia , Infecções por Circoviridae/prevenção & controle , Feminino , Masculino , Pneumonia Suína Micoplasmática/imunologia , Pneumonia Suína Micoplasmática/prevenção & controle , Síndrome Respiratória e Reprodutiva Suína/imunologia , Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Sus scrofa , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/microbiologia , Doenças dos Suínos/virologia , Vacinas Combinadas/administração & dosagem , Vacinas Combinadas/imunologia , Vacinas Virais/imunologia
2.
J Vet Sci ; 20(4): e35, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31364320

RESUMO

The major immunogenic protein capsid (Cap) of porcine circovirus type 2 (PCV2) is critical to induce neutralizing antibodies and protective immune response against PCV2 infection. This study was conducted to investigate the immune response of recombinant adenovirus expressing PCV2b Cap and C-terminal domain of Yersinia pseudotuberculosis invasin (Cap-InvC) fusion protein in pigs. The recombinant adenovirus rAd-Cap-InvC, rAd-Cap and rAd were generated and used to immunize pigs. The phosphate-buffered saline was used as negative control. The specific antibodies levels in rAd-Cap-InvC and ZJ/C-strain vaccine groups were higher than that of rAd-Cap group (p < 0.05), and the neutralization antibody titer in rAd-Cap-InvC group was significantly higher than those of other groups during 21-42 days post-immunization (DPI). Moreover, lymphocyte proliferative level, interferon-γ and interleukin-13 levels in rAd-Cap-InvC group were increased compared to rAd-Cap group (p < 0.05). After virulent challenge, viruses were not detected from the blood samples in rAd-Cap-InvC and ZJ/C-strain vaccine groups after 49 DPI. And the respiratory symptom, rectal temperature, lung lesion and lymph node lesion were minimal and similar in the ZJ/C-strain and rAd-Cap-InVC groups. In conclusion, our results demonstrated that rAd-Cap-InvC was more efficiently to stimulate the production of antibody and protect pigs from PCV2 infection. We inferred that InvC is a good candidate gene for further development and application of PCV2 genetic engineering vaccine.


Assuntos
Vacinas contra Adenovirus/administração & dosagem , Proteínas do Capsídeo/imunologia , Infecções por Circoviridae/veterinária , Circovirus/imunologia , Imunização/veterinária , Doenças dos Suínos/prevenção & controle , Adesinas Bacterianas/genética , Adesinas Bacterianas/imunologia , Animais , Infecções por Circoviridae/prevenção & controle , Infecções por Circoviridae/virologia , Feminino , Proteínas Recombinantes/imunologia , Sus scrofa , Suínos , Doenças dos Suínos/virologia , Vacinas Sintéticas/administração & dosagem , Yersinia pseudotuberculosis/genética
3.
Vet Microbiol ; 235: 86-92, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31282383

RESUMO

Although PCV2 infections generally cause mild disease in pigs, concurrent co-infections with other pathogens can damage the immune system and cause more severe diseases, collectively termed porcine circovirus associated diseases (PCVAD). Involvement of porcine parvovirus (PPV, a common cause of reproductive failure in naïve dams) in PCVAD caused by PCV2, has been reported. As this co-infection can be difficult to eliminate, there is a critical need to develop an effective vaccine to protect against PPV or synergistic effects of PCV2 and PPV under field conditions. In this study, we designed chimeric PCV2 virus-like particles (cVLPs) displaying a B-cell epitope derived from PPV1 structural protein around the surface of the 2-fold axes of PCV2 VLPs, based on 3D-structure analysis of the PCV2 capsid. The cVLPs were successfully prepared, verified by transmission electron microscopy and chromatography, with robust antibody titers against PCV2 and PPV1 produced in mice and guinea pigs. In addition, in guinea pigs challenged with 106 TCID50 PCV2, cVLPs conferred more effective immune protection (based on viral load) than a commercial PCV2 vaccine. Finally, antibody responses and immune protection against PPV were also evaluated. In guinea pigs vaccinated with cVLPs, although PPV antibodies detected by a hemagglutination inhibition (HI) assay appeared later after vaccination in the PCV2 cVLPs group than in the commercial PPV vaccine group, there were fewer PPV genomic DNA copies in the PCV2 cVLPs group than in a PBS group. In conclusion, guinea pigs vaccinated with cVLPs developed effective protective immunity against PCV2 challenge, with some protective immunity against PPV. This study provided valuable research data to pursue molecular design of chimeric epitopes PCV2 VLPs.


Assuntos
Infecções por Circoviridae/veterinária , Coinfecção/veterinária , Epitopos de Linfócito B/imunologia , Imunidade Humoral , Infecções por Parvoviridae/veterinária , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Linfócitos B/imunologia , Infecções por Circoviridae/imunologia , Infecções por Circoviridae/prevenção & controle , Circovirus/imunologia , Coinfecção/virologia , Feminino , Cobaias , Camundongos , Infecções por Parvoviridae/imunologia , Infecções por Parvoviridae/prevenção & controle , Parvovirus Suíno/imunologia , Suínos , Doenças dos Suínos/prevenção & controle , Doenças dos Suínos/virologia , Vacinas Atenuadas/imunologia , Vacinas de Partículas Semelhantes a Vírus/imunologia
4.
J Appl Microbiol ; 127(3): 658-669, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31183947

RESUMO

AIMS: Purification of porcine circovirus type 2 (PCV2) using Gram-positive enhancer matrix (GEM) surface display technology and immunogenicity evaluation of the purified antigen. METHODS AND RESULTS: A recombinant bifunctional protein containing a protein anchor domain and a 'virus anchor' domain was designed as a protein linker (PL) between PCV2 and GEM particles. By incubating with PL and GEM particles sequentially, PCV2 could be purified and enriched through a simple centrifugation process with GEM surface display technology. Our data showed that one unit (2·5 × 109 particles) of GEM particles with 80 µg PL could purify 100 ml of PCV2-containing culture supernatant (viral titre: 106·5 TCID50 per ml-1 ) with a recovery rate up to 99·6%. The impurity removal efficiency of this method, calculated according to decreased total protein content during purification, was approximately 98%. Furthermore, in vivo experimentation showed that piglets immunized with purified PCV2 could elicit strong immune responses to prevent against PCV2 infection. CONCLUSION: Porcine circovirus type 2 could be efficiently purified and enriched with GEM display technology via a crucial PL, and the purified PCV2 could elicit effective immune responses against PCV2 infection. SIGNIFICANCE AND IMPACT OF THE STUDY: The GEM-based purification method established here is cost-efficient and high-throughput, and may represent a promising large-scale purification method for PCV2 vaccine production.


Assuntos
Circovirus/imunologia , Vacinas Virais/imunologia , Vacinas Virais/isolamento & purificação , Animais , Técnicas de Visualização da Superfície Celular , Infecções por Circoviridae/prevenção & controle , Proteínas Recombinantes , Suínos , Doenças dos Suínos/prevenção & controle , Doenças dos Suínos/virologia
5.
Transbound Emerg Dis ; 66(4): 1454-1461, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31059197

RESUMO

PCV2 is globally spread pathogen involved in a number of diseases (PCVD). Commonly used vaccines against PCV2 are proved to be highly efficacious. The role of recently discovered PCV3 for pig health and interference with PCV2 remains unknown. The study performed on serum samples from seven farms vaccinated against PCV2 and four non-vaccinated showed very low prevalence of PCV2 viremia in the former (3 out of 106 positive serum pools) and high prevalence of PCV2 viremia in the latter (35 out of 60 positive pools). Mean log10 PCV2 genome equivalents were lower in vaccinated farms (4.8 ± 0.6 log10  copies/ml) than in non-vaccinated farms (6.3 ± 1.3 log10  copies/ml). PCV3 was detected in 31 out of 106 and 12 out of 60 serum pools from vaccinated and non-vaccinated farms, respectively. Mean log10 PCV3 genome equivalents were significantly (p < 0.05) lower in vaccinated farms (3.9 ± 0.8 log10  copies/ml) than in non-vaccinated farms (4.4 ± 0.6 log10  copies/ml). Concurrent PCV2 and PCV3 infection was rare and found only in 1 out of 529 and 4 out of 292 individual serum samples from vaccinated and non-vaccinated farms, respectively. Our results showed lack of impact of PCV3 circulation on PCV2 vaccine efficacy. On the other hand, intensive PCV2 circulation and high viremia detected in non-vaccinated farms did not seem to increase the level of PCV3 infection.


Assuntos
Infecções por Circoviridae/veterinária , Circovirus/imunologia , Doenças dos Suínos/prevenção & controle , Vacinas Virais/imunologia , Viremia/veterinária , Animais , Infecções por Circoviridae/prevenção & controle , Infecções por Circoviridae/virologia , Feminino , Reação em Cadeia da Polimerase/veterinária , Suínos , Doenças dos Suínos/virologia , Viremia/prevenção & controle , Viremia/virologia
6.
Virol J ; 16(1): 57, 2019 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-31046793

RESUMO

BACKGROUND: Porcine circovirus type 2 (PCV2) is an economically important viral pathogen for swine industry worldwide. However, current PCV2 vaccines provide incomplete protection against the PCV2d, which has recently emerged as the predominant pathogenic form of PCV2. METHODS: To develop a novel DNA vaccine with high efficacy against PCV2d virus, we fused the ORF2 of PCV2d to three copies of the minimum-binding domain of the complement C3 cascade terminal component, C3d-P28. Expression of ORF2 alone (pVO) or fused C3d-P28 (pVOC3) were verified by immunofluorescent assay. Vaccine efficacy was tested by measured the DNA copy and T and B cell immune response. RESULTS: Vaccination with pVOC3 reduced the levels of PCV2 genomic DNA after pigs were infected with either PCV2b or PCV2d genotypes, produced potent antibodies against PCV2, and stimulated PCV2-specific interferon-γ secreting cells. CONCLUSION: Results suggested pVOC3 would be a safe and effective DNA vaccine to confer cross-protection against both PCV2b and PCV2d genotypes in pigs.


Assuntos
Proteínas do Capsídeo/imunologia , Infecções por Circoviridae/veterinária , Circovirus/genética , Complemento C3d/imunologia , Doenças dos Suínos/prevenção & controle , Vacinas de DNA/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Proteínas do Capsídeo/genética , Infecções por Circoviridae/prevenção & controle , Circovirus/imunologia , Complemento C3d/genética , Proteção Cruzada , DNA Viral/genética , Genoma Viral , Genótipo , Masculino , Suínos , Doenças dos Suínos/virologia , Vacinação , Vacinas de DNA/genética , Proteínas Virais de Fusão/genética , Proteínas Virais de Fusão/imunologia , Vacinas Virais/genética
7.
Vet Microbiol ; 231: 87-92, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30955830

RESUMO

The objective of this study was to compare the efficacy of a commercial porcine circovirus type 2a (PCV2a) subunit vaccine against experimental PCV2a, PCV2b, and PCV2d challenge. A total of 105 pigs were randomly divided into 7 groups (15 pigs per group). At 21 days old the pigs were intramuscularly administered the PCV2a vaccine as a 1.0 mL dose. Four weeks following vaccination, pigs were challenged with either Korean PCV2a, PCV2b, or PCV2d. All vaccinated pigs showed a significant (P < 0.05) reduction of clinical signs, PCV2 viremia, lymphoid lesions, and lymphoid PCV2 antigen levels compared to unvaccinated control pigs. Vaccination resulted also in significantly higher (P < 0.05) titers of neutralizing antibody against PCV2, and an increase in the frequency of PCV2-specific interferon-γ secreting cells (IFN-γ-SC). The vaccine showed similar protection among the vaccinated groups regardless of the genotype of the challenge. Interestingly, vaccinated pigs had higher levels of neutralizing antibody titers against PCV2a compared to PCV2b or PCV2d while the number of PCV2a-, PCV2b-, and PCV2d-specific IFN-γ-SC were similar. Taken together, the results presented here demonstrate that a PCV2a vaccine can be effective against experimental PCV2a, PCV2b, and PCV2d challenge.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Circoviridae/veterinária , Doenças dos Suínos/prevenção & controle , Vacinas Virais/uso terapêutico , Animais , Anticorpos Neutralizantes/sangue , Infecções por Circoviridae/imunologia , Infecções por Circoviridae/prevenção & controle , Circovirus/genética , Circovirus/imunologia , DNA Viral/sangue , Fazendas , Genótipo , Injeções Intramusculares , Interferon gama/imunologia , Gado , Distribuição Aleatória , Suínos , Doenças dos Suínos/imunologia , Vacinação , Vacinas de Subunidades/imunologia , Vacinas de Subunidades/uso terapêutico , Vacinas Virais/imunologia
9.
J Microbiol Biotechnol ; 29(3): 482-488, 2019 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-30609882

RESUMO

Porcine circovirus type 2 (PCV2) is the causative agent of postweaning multisystemic wasting syndrome (PMWS) in pigs. Replicase (Rep) proteins are considered essential for viral replication. Capsid (Cap) protein is the primary immunogenic protein that induces protective immunity. Little is known about comparison on the immunogenicity of PCV2 Rep and Cap fusion protein and Cap protein. In the present study, recombinant baculoviruses expressing the Rep-Cap fusion protein (Bac-Rep-Cap) and the Cap protein (Bac-Cap) of PCV2 were constructed and confirmed with western blot and indirect fluorescence assay. Immunogenicities of the two recombinant proteins were tested in mice. The titers of antibodies were determined with a PCV2-specific enzyme-linked immunosorbent assay (ELISA) and a serum neutralization assay. The IFN-γ response of immunized mice was measured by ELISA. The mice immunized with the Bac-Rep-Cap and Bac-Cap successfully produced Cap-specific immunoreaction. The mice immunized with the Bac-Cap developed higher PCV2-specific neutralizing antibody titers than mice injected with the Bac-Rep-Cap. IFN-γ in the Bac-Rep-Cap group was increased compared to those in the Bac-Cap group. Vaccination of mice with the Bac-Rep-Cap showed significantly decreased protective efficacy compared to the Bac-Cap. Our findings will indubitably not only lead to a better understanding of the immunogenicity of PCV2, but also improved vaccines.


Assuntos
Proteínas do Capsídeo/imunologia , Infecções por Circoviridae/imunologia , Infecções por Circoviridae/prevenção & controle , Imunogenicidade da Vacina/imunologia , Proteínas Recombinantes de Fusão/imunologia , Vacinas de Partículas Semelhantes a Vírus/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes , Anticorpos Antivirais/sangue , Formação de Anticorpos , Baculoviridae/genética , Western Blotting , Proteínas do Capsídeo/biossíntese , Proteínas do Capsídeo/genética , Circovirus/patogenicidade , Citocinas/sangue , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Feminino , Vetores Genéticos , Injeções Intramusculares , Interferon gama/sangue , Camundongos , Camundongos Endogâmicos BALB C , Testes de Neutralização , Proteínas Recombinantes de Fusão/genética , Vacinação , Vacinas de Partículas Semelhantes a Vírus/biossíntese , Vacinas de Partículas Semelhantes a Vírus/genética , Vacinas Virais/genética , Vacinas Virais/farmacologia
10.
Res Vet Sci ; 123: 192-194, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30682582

RESUMO

Porcine circovirus type 2 (PCV2) causes porcine circovirus-associated disease, which is characterized by systemic wasting syndrome, including respiratory problems worldwide. Most commercial PCV2 vaccines are derived from recombinant capsid protein or inactivated whole-virus. We compared average daily weight gain, interferon-γ, and neutralizing antibody levels of a recombinant protein vaccine and an inactivated whole-virus vaccine in a pilot study. Both PCV2 vaccines showed similar effect on immunity against PCV2 and a better average daily weight gain was found in both vaccinated groups compared to non-vaccinated animals.


Assuntos
Infecções por Circoviridae/veterinária , Circovirus/classificação , Doenças dos Suínos/prevenção & controle , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes , Anticorpos Antivirais/sangue , Infecções por Circoviridae/prevenção & controle , Infecções por Circoviridae/virologia , Interferon gama/metabolismo , Projetos Piloto , Suínos , Doenças dos Suínos/virologia , Vacinação , Vacinas de Produtos Inativados/imunologia , Vacinas Sintéticas
11.
Appl Microbiol Biotechnol ; 103(2): 833-842, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30421111

RESUMO

Porcine circovirus type 2 (PCV2) is a ubiquitous virus with high pathogenicity closely associated with the postweaning multisystemic wasting syndrome (PMWS) and porcine circovirus diseases (PCVDs), which caused significant economic losses in the swine industry worldwide every year. The PCV2 virus-like particles (VLPs) are a powerful subunit vaccine that can elicit high immune response due to its native PCV2 virus morphology. The baculovirus expression system is the widely used platform for producing commercial PCV2 VLP vaccines, but its yield and cost limited the development of low-cost vaccines for veterinary applications. Here, we applied a nonconventional yeast Kluyveromyces marxianus to enhance the production of PCV2 VLPs. After codon optimization, the PCV2 Cap protein was expressed in K. marxianus and assemble spontaneously into VLPs. Using a chemically defined medium, we achieved approximately 1.91 g/L of PCV2 VLP antigen in a 5-L bioreactor after high cell density fermentation for 72 h. That yield greatly exceeded to recently reported PCV2 VLPs obtained by baculovirus-insect cell, Escherichia coli and Pichia pastoris. By the means of two-step chromatography, 652.8 mg of PCV2 VLP antigen was obtained from 1 L of the recombinant K. marxianus cell culture. The PCV2 VLPs induced high level of anti-PCV2 IgG antibody in mice serums and decreased the virus titers in both livers and spleens of the challenged mice. These results illustrated that K. marxianus is a powerful yeast for cost-effective production of PCV2 VLP vaccines.


Assuntos
Infecções por Circoviridae/prevenção & controle , Circovirus/metabolismo , Kluyveromyces/metabolismo , Vacinas de Partículas Semelhantes a Vírus/imunologia , Proteínas Virais/metabolismo , Virossomos/metabolismo , Animais , Anticorpos Antivirais/sangue , Reatores Biológicos , Cromatografia , Infecções por Circoviridae/patologia , Infecções por Circoviridae/virologia , Circovirus/genética , Códon , Meios de Cultura/química , Modelos Animais de Doenças , Kluyveromyces/genética , Fígado/virologia , Camundongos , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Baço/virologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/isolamento & purificação , Vacinas de Partículas Semelhantes a Vírus/administração & dosagem , Vacinas de Partículas Semelhantes a Vírus/isolamento & purificação , Proteínas Virais/genética , Proteínas Virais/isolamento & purificação , Virossomos/genética
12.
Vet Microbiol ; 228: 69-76, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30593382

RESUMO

The porcine circovirus (PCV) is one of the most economically important infection diseases of pigs. Granulocyte-macrophage colony-stimulating factor (GM-CSF) or Flic as an immune adjuvant has been shown to enhance the immunogenicity of vaccines in previous study. However, the composite biological adjuvants stimulate more effective immunological response. In this study, the porcine GM-CSF (pGM-CSF) and FliC protein were expressed by pSUMO in E.coli Rosetta (DE3) and purified by Ni-NTA Sepharose, respectively. The immunogenicity of PCV vaccine with pGM-CSF and FliC was firstly evaluated to identify the immunoenhancement in mice. The results indicated that mice immunized with vaccine + pGM-CSF + FliC enhanced immune responses ability significantly and quickly. Then, the immune response level of PCV vaccine with pGM-CSF and FliC was assessed in piglets. The results indicated that pigs immunized with vaccine + pGM-CSF + FliC showed significantly higher PCV antibody level than those immunized with vaccine and single adjuvant or vaccine alone. Furthermore, pigs in the vaccine + pGM-CSF + FliC group elicited stronger CD4+ and CD8 + T cells proliferative responses than those in all other groups and showed the effectively up-regulated transcriptional level of IL-1, IL-8 and IL-17 stimulating the immune system. We demonstrated that GM-CSF and FliC as composite biological adjuvants of the vaccine showed a stronger immune response and it is promising application for vaccines to against PCV.


Assuntos
Adjuvantes Imunológicos , Infecções por Circoviridae/veterinária , Circovirus/imunologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/imunologia , Doenças dos Suínos/prevenção & controle , Vacinas Virais/imunologia , Animais , Infecções por Circoviridae/prevenção & controle , Infecções por Circoviridae/virologia , Feminino , Imunidade Humoral , Imunização/veterinária , Camundongos , Camundongos Endogâmicos BALB C , Suínos , Doenças dos Suínos/virologia
13.
Vet Ital ; 54(3): 219-224, 2018 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-30574999

RESUMO

The objective of this study was to determine the effect of the porcine circovirus type 2 (PCV2) vaccination on the levels of viremia, the number of viremic-positive pigs, and production performance [i.e. nursery mortality, post-weaning mortality, and average daily weight gain (ADWG)] under field conditions. There were 140 farrow-to-finish pig herds involved in this study. The vaccination of piglets was implemented in 82 of the 140 herds. In each herd blood samples were collected from sows and pigs in different age category. In addition, a questionnaire regarding the production performance was provided for each herd. Results demonstrate that the vaccination of piglets prevented the development of viremia in 23.2% of herds. Significant decreases in the levels of PCV2 DNA in serum and in the number of viremic pigs were also noted. These results indicate that the vaccination of piglets against PCV2 is a useful tool in controlling the PCV2 infection in herds with a high risk of a wide range of viral and bacterial agents, poor management strategies, and a low level of biosecurity practices.


Assuntos
Infecções por Circoviridae/prevenção & controle , Circovirus , Doenças dos Suínos/prevenção & controle , Doenças dos Suínos/virologia , Vacinação , Vacinas Virais , Animais , Suínos , Resultado do Tratamento , Vacinas Virais/imunologia
14.
Appl Microbiol Biotechnol ; 102(24): 10541-10550, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30338355

RESUMO

Mixed infection of porcine circovirus type 2 (PCV2) and foot-and-mouth disease virus (FMDV) is devastating to swine populations. To develop an effective vaccine that can protect the pigs from the infection of PCV2 and FMDV, we used the neutralizing B cell epitope region (aa 135-160) of FMDV to replace the regions aa 123-151 and aa 169-194 of the PCV2b Cap protein to generate a recombinant protein designated as Capfb. The Capfb protein was expressed in Escherichia coli system and the purified Capfb protein assembled into virus-like particles (VLPs) through dialysis. The ability of the Capfb protein to induce effective immune response against FMDV and PCV2b was tested in mice and guinea pigs. The results showed that the Capfb-VLPs could elicit anti-PCV2b and anti-FMDV antibody response in mice and guinea pigs without inducing antibodies against decoy epitope. Moreover, the Capfb-VLPs could enhance the percentage and activation of B cells in lymph nodes when the mice were stimulated with inactivated FMDV or PCV2b. These data suggested that the Capfb-VLPs could be an efficacious candidate antigen for developing a novel PCV2b-FMDV bivalent vaccine.


Assuntos
Circovirus/imunologia , Vírus da Febre Aftosa/imunologia , Proteínas Recombinantes/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/imunologia , Infecções por Circoviridae/prevenção & controle , Infecções por Circoviridae/veterinária , Circovirus/patogenicidade , Epitopos de Linfócito B/imunologia , Escherichia coli/genética , Febre Aftosa/prevenção & controle , Vírus da Febre Aftosa/patogenicidade , Cobaias , Camundongos Endogâmicos ICR , Microscopia Eletrônica de Transmissão , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Vacinas Virais/genética , Vírion/imunologia
15.
Vet Microbiol ; 225: 40-47, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30322531

RESUMO

Duck circovirus (DuCV) is an immunosuppressive pathogen that causes a huge economic loss in the avian industry. Efficient vaccination has become a necessary strategy for preventing DuCV infection in the breeding industry. Three DNA vaccines encoding the Capsid (Cap) protein of DuCV were developed in this study, which were based on the eukaryotic vector pcDNA3.1 containing (i) the full length of Cap gene, pcDNA3.1-Cap, (ii) the Cap gene with a deletion of its nuclear localization signal (NLS) peptide encoding sequence, pcDNA3.1-CapΔNLS, and (iii) the Cap gene without NLS but harboring a fragment encoding the secretory signal peptide of tissue plasminogen activator (tPA), pcDNA3.1-tPA-CapΔNLS. Production of Cap protein-derived antigens from these three DNA vaccines was confirmed in vitro. The deletion of the NLS coding sequence of the Cap gene changed the subcellular location of the Capsid protein from the nucleus to the cytoplasm. Secretion of the Cap protein was observed in pcDNA3.1-tPA-CapΔNLS-transfected cells. The immunogenicity of these three DNA vaccines was assessed in vivo by measuring Cap-specific antibody and related cytokine levels. The results demonstrated that all these vaccines could induce a significant, specific immune response to protect ducks from DuCV challenge. Notably, higher titers of Cap-specific antibody were produced in ducks vaccinated with pcDNA3.1-tPA-CapΔNLS, which provided the highest protective efficacy at a rate of 90% in the challenge experiment. Taken together, DNA vaccines expressing the DuCV Cap protein show promising immunogenicity, which can be enhanced by replacing the NLS of the Cap protein with a secretory signal peptide of tPA.


Assuntos
Proteínas do Capsídeo/imunologia , Infecções por Circoviridae/veterinária , Circovirus/genética , Patos/imunologia , Doenças das Aves Domésticas/prevenção & controle , Vacinas de DNA/imunologia , Animais , Proteínas do Capsídeo/administração & dosagem , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/metabolismo , Infecções por Circoviridae/imunologia , Infecções por Circoviridae/prevenção & controle , Infecções por Circoviridae/virologia , Circovirus/química , Ensaio de Imunoadsorção Enzimática , Vetores Genéticos/administração & dosagem , Vetores Genéticos/imunologia , Imunogenicidade da Vacina , Sinais de Localização Nuclear/deficiência , Sinais de Localização Nuclear/genética , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/virologia , Ativador de Plasminogênio Tecidual/genética , Ativador de Plasminogênio Tecidual/imunologia , Vacinas de DNA/administração & dosagem
16.
Virus Genes ; 54(5): 684-693, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30173363

RESUMO

Porcine bocavirus (PBoV) has a high prevalence in both healthy and diseased swine around the world. It was recently reported that PBoV and porcine circovirus type 2 (PCV2)-which contribute to porcine diarrheal disease-have a high rate of co-infection. To clarify the pathogenesis of PBoV, we examined the co-infection rate and effects of these two pathogens in IPEC-J2 porcine intestinal enterocytes. Both single and co-infection had cytopathic effects in IPEC-J2 cells. The apoptosis and proliferation rates of cells infected with both viruses did not differ significantly from those of cells infected with either one alone. PBoV and PCV2 induced the upregulation of inflammatory cytokines and the downregulation of the tight junction proteins occludin and claudin 1 in the early stage of infection, leading to destruction of epithelial barrier integrity and enhanced cytotoxicity. These findings provide insight into the pathogenic mechanisms of PBoV and PCV2 and a basis for developing effective strategies to prevent the spread of gastrointestinal diseases in pigs and other livestock.


Assuntos
Bocavirus/patogenicidade , Circovirus/patogenicidade , Doenças dos Suínos/virologia , Junções Íntimas/virologia , Animais , Apoptose , Linhagem Celular , Infecções por Circoviridae/prevenção & controle , Infecções por Circoviridae/virologia , Coinfecção , Citocinas/biossíntese , Efeito Citopatogênico Viral , Infecções por Parvoviridae/virologia , Suínos , Doenças dos Suínos/patologia , Doenças dos Suínos/prevenção & controle , Replicação Viral
17.
Benef Microbes ; 9(6): 951-961, 2018 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-30232907

RESUMO

In our previous study we confirmed an antiviral activity of probiotic Lactobacillus reuteri L26 which was mediated by stimulation of local intestinal immunity. The aim of this paper was to evaluate the influence of L. reuteri L26 on the systemic immune response in gnotobiotic mice infected with porcine circovirus type 2 (PCV2). A total of 30 germ-free mice were divided into 3 groups and animals in noninfected and infected control groups (NC and IC; n=10) received sterile de Man-Rogosa-Sharpe broth for 7 days and animals in experimental group L+PCV (n=10) were inoculated with L. reuteri L26. Subsequently, mice in L+PCV and IC groups were infected with PCV2; however, mice in the control group received virus cultivation medium (mock). The results showed an increase of percentage of cytotoxic cells (CD8+ and CD49b+CD8-) and oxidative burst of phagocytes, up-regulation of the gene expression of RANTES, granulocyte-macrophage colony-stimulating factor, interferon-γ and immunoglobulin A in blood above all in the later phase of infection (14 dpi) in L+PCV group accompanied by higher load of PCV2 in the serum. These findings indicate that L. reuteri L26 has a potential to induce systemic immune reaction, but in gnotobiotic mice immune stimulation can increase virus replication.


Assuntos
Infecções por Circoviridae/prevenção & controle , Circovirus/imunologia , Fatores Imunológicos/administração & dosagem , Lactobacillus reuteri/imunologia , Probióticos/administração & dosagem , Animais , Infecções por Circoviridae/imunologia , Citocinas/análise , Vida Livre de Germes , Imunoglobulina A/sangue , Lactobacillus reuteri/crescimento & desenvolvimento , Camundongos , Fagócitos/imunologia , Linfócitos T Citotóxicos/imunologia
18.
Xenotransplantation ; 25(4): e12428, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-30264879

RESUMO

BACKGROUND: We established a Source Animal (barrier) Facility (SAF) for generating designated pathogen-free (DPF) pigs to serve as donors of viable organs, tissues, or cells for xenotransplantation into clinical patients. This facility was populated with caesarian derived, colostrum deprived (CDCD) piglets, from sows of conventional-specific (or specified) pathogen-free (SPF) health status in six cohorts over a 10-month period. In all cases, CDCD piglets fulfilled DPF status including negativity for porcine circovirus (PCV), a particularly environmentally robust and difficult to inactivate virus which at the time of SAF population was epidemic in the US commercial swine production industry. Two outbreaks of PCV infection were subsequently detected during sentinel testing. The first occurred several weeks after PCV-negative animals were moved under quarantine from the nursery into an animal holding room. The apparent origin of PCV was newly installed stainless steel penning, which was not sufficiently degreased thereby protecting viral particles from disinfection. The second outbreak was apparently transmitted via employee activities in the Caesarian-section suite adjacent to the barrier facility. In both cases, PCV was contained in the animal holding room where it was diagnosed making a complete facility depopulation-repopulation unnecessary. METHOD: Infectious PCV was eliminated during both outbreaks by the following: euthanizing infected animals, disposing of all removable items from the affected animal holding room, extensive cleaning with detergents and degreasing agents, sterilization of equipment and rooms with chlorine dioxide, vaporized hydrogen peroxide, and potassium peroxymonosulfate, and for the second outbreak also glutaraldehyde/quaternary ammonium. Impact on other barrier animals throughout the process was monitored by frequent PCV diagnostic testing. RESULT: After close monitoring for 6 months indicating PCV absence from all rooms and animals, herd animals were removed from quarantine status. CONCLUSION: Ten years after PCV clearance following the second outbreak, due to strict adherence to biosecurity protocols and based on ongoing sentinel diagnostic monitoring (currently monthly), the herd remains DPF including PCV negative.


Assuntos
Infecções por Circoviridae/prevenção & controle , Circovirus/patogenicidade , Organismos Livres de Patógenos Específicos , Doenças dos Suínos/prevenção & controle , Transplante Heterólogo , Animais , Xenoenxertos/virologia , Suínos , Doenças dos Suínos/virologia , Transplante Heterólogo/instrumentação , Transplante Heterólogo/métodos
19.
Vet Res ; 49(1): 80, 2018 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-30081944

RESUMO

Newcastle disease virus (NDV)-attenuated vaccine has been widely used since the 1950s and made great progress in preventing and controlling Newcastle disease. However, many reports mention exogenous virus contamination in attenuated vaccines, while co-contamination with fowl adenovirus (FAdV) and chicken infectious anaemia virus (CIAV) in the NDV-attenuated vaccine also emerged in China recently, which proved to be an important reason for the outbreaks of inclusion body hepatitis-hydropericardium syndrome in some flocks. It is amazing that exogenous virus contamination at extremely low doses still infected chickens and induced severe disease; thus, we speculated that there must be some interaction between the NDV-attenuated vaccine and the contaminated exogenous viruses within. Accordingly, simulation experiments were launched using FAdV and CIAV isolated from the abovementioned vaccine. The results showed that the pathogenicity of FAdV and CIAV co-infection through the contaminated vaccine was significantly higher than that of direct oral infection, while the synergistic reaction of these viruses and LaSota prompted their multiplication in vivo and disturbed the production of antibodies against each other. This study showed the interactions of FAdV, CIAV and LaSota after using contaminated NDV-attenuated vaccine, helping us to understand how the contaminated exogenous viruses cause infection and induce severe disease at a relatively low dose through the oral route.


Assuntos
Infecções por Adenoviridae/veterinária , Infecções por Circoviridae/veterinária , Doença de Newcastle/prevenção & controle , Vírus da Doença de Newcastle/imunologia , Doenças das Aves Domésticas/imunologia , Vacinas Virais/imunologia , Infecções por Adenoviridae/imunologia , Infecções por Adenoviridae/prevenção & controle , Animais , Aviadenovirus/imunologia , Aviadenovirus/patogenicidade , Vírus da Anemia da Galinha/imunologia , Vírus da Anemia da Galinha/patogenicidade , Infecções por Circoviridae/imunologia , Infecções por Circoviridae/prevenção & controle , Doença de Newcastle/imunologia , Vírus da Doença de Newcastle/patogenicidade , Doenças das Aves Domésticas/prevenção & controle , Distribuição Aleatória , Organismos Livres de Patógenos Específicos , Vacinas Virais/administração & dosagem , Virulência
20.
Can J Vet Res ; 82(2): 146-153, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29755195

RESUMO

A novel porcine circovirus type 2 (PCV2) peptide vaccine comprised of a consensus capsid (Cap) protein domain encoded by open reading frame 2 was developed to control PCV2 infection. The efficacy of the vaccine was evaluated against a commercial baculovirus-expressed recombinant PCV2 subunit vaccine based on the Cap protein. The amino acid sequence of this Cap protein was designed based on the alignment of amino acid sequences from different isolates from Europe, North America, and Asia. The vaccine was evaluated in either phosphate-buffered saline or adjuvanted with aluminum hydroxide, cobalt oxide, or liposome. Overall the PCV2 peptide vaccine was less efficacious against PCV2 challenge compared with the commercial PCV2 vaccine. The peptide vaccine was the most efficacious when liposome was used as an adjuvant, significantly (P < 0.05) reducing viremia while increasing the levels of neutralizing antibodies and interferon-γ secreting cells. This suggests, in the presence of liposome, the peptide vaccine was able to elicit both humoral and cellular immune responses.


Assuntos
Infecções por Circoviridae/veterinária , Circovirus/classificação , Doenças dos Suínos/prevenção & controle , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/sangue , Infecções por Circoviridae/prevenção & controle , Infecções por Circoviridae/virologia , Circovirus/imunologia , DNA Viral/sangue , Interferon gama/metabolismo , Suínos , Doenças dos Suínos/virologia , Vacinas de Subunidades/imunologia , Vacinas Sintéticas/imunologia
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