As one of the most common mycotoxins, deoxynivalenol (DON) can contaminate a wide range of crops and foods. Porcine circovirus 2 (PCV2) is a kind of immunosuppressive virus, which can cause porcine circovirus associated disease (PCVD) in pig farms infected with PCV2. Pigs are extremely sensitive to DON, and PCV2-infected pig farms are often contaminated with DON. Our previous studies indicated that Bacillus amyloliquefaciens B10 (B10) has the potential to alleviate the toxicity of mycotoxins. The research was aimed at investigating the effects of Bacillus amyloliquefaciens B10 on the immunosuppressive effects caused by both DON and PCV2 infection. The results indicated that the expression of the PCV2 capsid protein CAP was significantly decreased after pretreatment with Bacillus amyloliquefaciens B10. Then, the effects of the Bacillus amyloliquefaciens B10 pretreatment on the type I interferon, antiviral protein and the antiviral signal pathway cGAS-STING was further investigated. The findings displayed that the expression of the type I interferon and antiviral protein were increased, while the IL-10 were decreased after pretreatment with Bacillus amyloliquefaciens B10. The inhibition of DON on the cGAS-STING signal pathway was relieved. Furthermore, it was found that this intervention effect was produced by inhibiting autophagy. In summary, Bacillus amyloliquefaciens B10 can mitigate the immunosuppressive effects of PCV2 and DON by inhibiting the production of autophagy.
A host's immune system can be invaded by mycotoxin deoxynivalenol (DON) poisoning and porcine circovirus type 2 (PCV2) infections, which affect the host's natural immune function. Pro-inflammatory cytokines, IL-1β and IL-6, are important regulators in the process of natural immune response, which participate in inflammatory response and enhance immune-mediated tissue damage. Preliminary studies have shown that DON promotes PCV2 infection by activating the MAPK signaling pathway. Here, we explored whether the mRNA expression of IL-1β and IL-6, induced by the combination of DON and PCV2, would depend on the MAPK signaling pathway. Specific pharmacological antagonists U0126, SP600125 and SB203580, were used to inhibit the activities of ERK, JNK and p38 in the MAPK signaling pathway, respectively. Then, the mRNA expression of IL-1β and IL-6 in PK-15 cells was detected to explore the effect of the MAPK signaling pathway on IL-1β and IL-6 mRNA induced by DON and PCV2. The results showed that PK-15 cells treated with DON or PCV2 induced the mRNA expression of IL-1β and IL-6 in a time- and dose-dependent manner. The combination of DON and PCV2 has an additive effect on inducing the mRNA expression of IL-1β and IL-6. Additionally, both DON and PCV2 could induce the mRNA expression of IL-1β and IL-6 via the ERK and the p38 MAPK signal pathways, while PCV2 could induce it via the JNK signal pathway. Taken together, our results suggest that MAPKs play a contributory role in IL-1β and IL-6 mRNA expression when induced by both DON and PCV2.
- MeSH
- Cell Line MeSH
- Circovirus * MeSH
- Circoviridae Infections genetics metabolism MeSH
- Interleukin-1beta genetics MeSH
- Interleukin-6 genetics MeSH
- MAP Kinase Signaling System drug effects MeSH
- RNA, Messenger MeSH
- Swine MeSH
- Trichothecenes toxicity MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The aim of this study was to develop a suitable vaccine antigen against porcine circovirus 2 (PCV2), the causative agent of post-weaning multi-systemic wasting syndrome, which causes significant economic losses in swine breeding. Chimeric antigens containing PCV2b Cap protein sequences based on the mouse polyomavirus (MPyV) nanostructures were developed. First, universal vectors for baculovirus-directed production of chimeric MPyV VLPs or pentamers of the major capsid protein, VP1, were designed for their exploitation as vaccines against other pathogens. Various strategies were employed based on: A) exposure of selected immunogenic epitopes on the surface of MPyV VLPs by insertion into a surface loop of the VP1 protein, B) insertion of foreign protein molecules inside the VLPs, or C) fusion of a foreign protein or its part with the C-terminus of VP1 protein, to form giant pentamers of a chimeric protein. We evaluated these strategies by developing a recombinant vaccine against porcine circovirus 2. All candidate vaccines induced the production of antibodies against the capsid protein of porcine circovirus after immunization of mice. The candidate vaccine, Var C, based on fusion of mouse polyomavirus and porcine circovirus capsid proteins, could induce the production of antibodies with the highest PCV2 neutralizing capacity. Its ability to induce the production of neutralization antibodies was verified after immunization of pigs. The advantage of this vaccine, apart from its efficient production in insect cells and easy purification, is that it represents a DIVA (differentiating infected from vaccinated animals) vaccine, which also induces an immune response against the mouse polyoma VP1 protein and is thus able to distinguish between vaccinated and naturally infected animals.
- MeSH
- Circovirus * genetics immunology MeSH
- Mice MeSH
- Nanostructures * MeSH
- Polyomavirus * genetics immunology MeSH
- Swine MeSH
- Recombinant Fusion Proteins * genetics immunology MeSH
- Sf9 Cells MeSH
- Spodoptera MeSH
- Capsid Proteins * genetics immunology MeSH
- Viral Vaccines * genetics immunology pharmacology MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Psittacine beak and feather disease (PBFD) is one of the most significant viral diseases in psittacine birds. The aim of the presented study was to develop a highly specific and sensitive TaqMan real-time PCR assay for universal detection of beak and feather disease virus (BFDV). Primers and a hydrolysis probe were selected on the highly conserved regions belonging to the ORF1 of the BFDV genome which were identified by aligning 814 genomic sequences downloaded from the GenBank database. The evaluation of the reaction parameters suggested a reaction efficiency of 97.1%, with consistent detection of 101 virus copies/μl of nucleic acid extract. The low values of standard deviation and coefficient of variation indicate a high degree of reproducibility and repeatability. The diagnostic applicability of the assay was proven on 36 BFDV positive and 107 negative specimens of psittacine origin representing 28 species. The assay showed a 100% ability to detect distinct genetic variants of the virus. Our data suggest that the presented TaqMan real-time PCR represents a specific, sensitive and reliable assay facilitating the molecular detection of BFDV.
- MeSH
- Circovirus genetics isolation & purification MeSH
- Molecular Diagnostic Techniques methods MeSH
- DNA Primers genetics MeSH
- Circoviridae Infections diagnosis veterinary virology MeSH
- Real-Time Polymerase Chain Reaction methods MeSH
- Bird Diseases diagnosis virology MeSH
- Oligonucleotide Probes genetics MeSH
- Birds MeSH
- Reproducibility of Results MeSH
- Sensitivity and Specificity MeSH
- Veterinary Medicine methods MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Evaluation Study MeSH
A loop-mediated isothermal amplification (LAMP) method with a real-time monitoring system was developed for the detection of porcine circovirus type 1 (PCV1) in commercial swine vaccines. This method was highly specific for PCV1. No cross-reaction to porcine circovirus type 2, porcine parvovirus, pseudorabies virus, classical swine fever virus, and porcine reproductive and respiratory syndrome virus was observed. The analytical sensitivity of the LAMP for PCV1 DNA was 10 copies/μl in the case of positive recombinant plasmid comparable to that obtained from the nested polymerase chain reaction (nested PCR). Furthermore, 25 commercial swine vaccines were tested by both the LAMP and the nested PCR, and three of them were tested positive for PCV1 DNA. These results indicate that PCV1 DNA can be real-time detected by the LAMP; the method was highly specific, sensitive, and rapid for the detection of PCV1 DNA, particularly in commercial swine vaccines.
- MeSH
- Circovirus classification genetics isolation & purification MeSH
- DNA Primers genetics MeSH
- Circoviridae Infections prevention & control veterinary virology MeSH
- Swine Diseases prevention & control virology MeSH
- Swine MeSH
- Nucleic Acid Amplification Techniques methods MeSH
- Viral Vaccines genetics isolation & purification MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Evaluation Study MeSH
A capsid protein of porcine circovirus 2 (PCV 2) serves as a diagnostic antigen for the detection of PCV 2-associated disease known as a postweaning multisystemic wasting syndrome (PMWS). In this report, a bacterial expression system was developed for the expression and purification of the full-length PCV 2 capsid (Cap) protein from a codon-optimized cap gene. Replacement of rare arginine codons located at the 5' end of the cap reading frame with codons optimal for E. coli was found to overcome the poor expression of the viral protein in the prokaryotic system. The Cap protein was purified to greater than 95% homogeneity by using a single cation-exchange chromatography at a yield of 10 mg per litre of bacterial culture. Despite the failure of the E. coli-expressed Cap protein to self-assemble into virus-like particles (VLPs), the immunization of mice with recombinant Cap yielded antibodies with the same specificity as those raised against native PCV 2 virions. In addition, the antigenic properties of the purified Cap protein were employed in a subunit-based indirect ELISA to monitor the levels of PCV 2 specific antibodies in piglets originating from a herd which was experiencing PCV 2 infection. These results pave the way for a straightforward large-scale production of the recombinant PCV 2 capsid protein and its use as a diagnostic antigen or a PCV 2 subunit vaccine.
- MeSH
- Circovirus genetics immunology metabolism MeSH
- Escherichia coli genetics metabolism MeSH
- Immunization MeSH
- Molecular Sequence Data MeSH
- Swine Diseases diagnosis prevention & control virology MeSH
- Swine virology MeSH
- Antibodies, Viral blood MeSH
- Recombinant Proteins genetics immunology metabolism MeSH
- Amino Acid Sequence MeSH
- Porcine Postweaning Multisystemic Wasting Syndrome diagnosis prevention & control virology MeSH
- Virion metabolism MeSH
- Capsid Proteins diagnostic use genetics immunology metabolism MeSH
- Viral Vaccines administration & dosage immunology MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Evaluation Study MeSH
- Research Support, Non-U.S. Gov't MeSH
Expression and purification of whole and nuclear localization signal (NLS) deleted ORF2 capsid protein of porcine circovirus 2 (PCV2) is demonstrated in the present study. Gene coding for both protein forms were cloned into pDest17 vector and expressed in BL21 (DE3)AI cells and in BL21-CodonPlus (DE3)-RIPL E. coli cells. The later cells were used to overcome difficulties with the heterologous expression of viral proteins in prokaryotic systems. Whole 30 kDa recombinant ORF2 protein was successfully expressed in BL21-CodonPlus (DE3)-RIPL cells only, 3 mg of pure protein was consistently obtained per liter of bacterial culture. NLS deleted ORF2 protein was expressed in both cell types. Resulting proteins reacted with PCV2 positive swine serum in immunofluorescent test and immunoblot.
- MeSH
- Circovirus genetics isolation & purification MeSH
- Swine Diseases diagnosis virology MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- MeSH
- Circovirus pathogenicity MeSH
- DNA, Viral MeSH
- Adult MeSH
- Circoviridae Infections diagnosis MeSH
- Liver Cirrhosis surgery microbiology MeSH
- Middle Aged MeSH
- Humans MeSH
- Polymerase Chain Reaction MeSH
- Liver Transplantation MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Review MeSH
- Comparative Study MeSH
