scholarly journals Characterisation of porcine circovirus type 2 in porcine circovirus disease cases in England and Wales

2017 ◽  
Vol 182 (1) ◽  
pp. 22-22 ◽  
Author(s):  
Sylvia S Grierson ◽  
Dirk Werling ◽  
Cornelia Bidewell ◽  
Susanna Williamson
Keyword(s):  
Great Britain ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus Type 2 ◽  
Porcine Circovirus ◽  
England And Wales ◽  
The World ◽  
Partial Fragment ◽  
Pcv2 Genome

Confirmed cases of porcine circovirus disease (PCVD) in Great Britain have shown a steady decline since the availability of porcine circovirus type 2 (PCV2) vaccines. However, PCVD is still occasionally diagnosed. The authors carried out a genotyping study to characterise PCV2 associated with confirmed PCVD cases in England and Wales from 2011 to January 2016 (n=65). A partial fragment of PCV2 genome encompassing ORF2 was amplified and sequenced from 45 cases of PCVD. The majority of sequences were genotype PCV2b but four sequences were PCV2d. The significance of the emergence of PCV2d in England and elsewhere in the world is not yet known, although it does appear to represent an ongoing global genotype shift.

scholarly journals Conformational Changes and Nuclear Entry of Porcine Circovirus without Disassembly

2019 ◽  
Vol 93 (20) ◽  
Author(s):  
Huijuan Wang ◽  
Kailun Zhang ◽  
Cui Lin ◽  
Jianwei Zhou ◽  
Yulan Jin ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Viral Genome ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus Type 2 ◽  
Porcine Circovirus ◽  
Nuclear Targeting ◽  
Early Endosomes ◽  
Pcv2 Genome ◽  
Infectious Cycle

ABSTRACT A relatively stable and flexible capsid is critical to the viral life cycle. However, the capsid dynamics and cytosol trafficking of porcine circovirus type 2 (PCV2) during its infectious cycle are poorly understood. Here, we report the structural stability and conformation flexibility of PCV2 virions by genome labeling and the use of three monoclonal antibodies (MAbs) against the native capsid of PCV2. Genome labeling showed that the infectivity of the PCV2 virion was not affected by conjugation with deoxy-5-ethynylcytidine (EdC). Heat stability experiments indicated that PCV2 capsids started to disassemble at 65°C, causing binding incompetence for all antibodies, and the viral genome was released without capsid disassembly upon heating at 60°C. Antibody binding experiments with PCV2 showed that residues 186 to 192 were concealed in the early endosomes of epithelial PK-15 and monocytic 3D4/31 cells with or without chloroquine treatment and then exposed in PK-15 cytosol and the 3D4/31 nucleus. Viral propagation and localization experiments showed that PCV2 replication and cytosol trafficking were not significantly affected by microtubule depolymerization in monocytic 3D4/31 cells treated with nocodazole. These findings demonstrated that nuclear targeting of viral capsids involved conformational changes, the PCV2 genome was released from the assembled capsid, and the transit of PCV2 particles was independent of microtubules in 3D4/31 cells. IMPORTANCE Circovirus is the smallest virus known to replicate autonomously. Knowledge of viral genome release may provide understanding of viral replication and a method to artificially inactivate viral particles. Currently, little is known about the release model of porcine circovirus type 2 (PCV2). Here, we report the release of the PCV2 genome from assembled capsid and the intracellular trafficking of infectious PCV2 by alterations in the capsid conformation. Knowledge of PCV2 capsid stability and dynamics is essential to understanding its infectious cycle and lays the foundation for discovering powerful targets for therapeutic and prophylactic intervention.

scholarly journals Identification and Functional Analysis of the Novel ORF4 Protein Encoded by Porcine Circovirus Type 2

2012 ◽  
Vol 87 (3) ◽  
pp. 1420-1429 ◽  
Author(s):  
Jialing He ◽  
Jingjing Cao ◽  
Niu Zhou ◽  
Yulan Jin ◽  
Jiusheng Wu ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Flow Cytometric Analysis ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus Type 2 ◽  
Site Directed Mutagenesis ◽  
Porcine Circovirus ◽  
Viral Gene ◽  
Orf4 Protein ◽  
Pcv2 Genome

ABSTRACTPorcine circovirus type 2 (PCV2) is the primary causative agent of porcine circovirus-associated diseases in pigs. To date, viral proteins Cap, Rep, Rep′, and ORF3, encoded by the PCV2 genome, have been described. Here, transcription and translation of a novel viral gene within the PCV2 genome (designated ORF4) was determined and functionally analyzedin vitroandin vivo. Northern blot analysis indicated that the RNA transcribed from the ORF4 gene is about 180 bp in length and overlaps ORF3 in the same direction. Site-directed mutagenesis confirmed that the viral ORF4 protein is not essential for virus replication in PK-15 cells and in mice infected with an ORF4-deficient PCV2 (PCV2Δ). PCV2Δ triggered higher activity levels of caspase-3 and -8 than wild-type PCV2 (wPCV2) in PK-15 cells. The antigenic epitopes of two mouse monoclonal antibodies (MAbs) raised against the viral ORF4 protein were mapped to the same 19KSSASPR25 peptide. Expression of ORF4 was confirmed using the specific MAbs in wPCV2-infected PK-15 cells and mice. Mice infected with PCV2Δ had a higher serum viral load (genomic copies) and more severe lymphoid tissue damage in the spleen than those infected with wPCV2. Meanwhile, flow-cytometric analysis indicated that the PCV2Δ infection caused a significant decrease of CD4+and CD8+T lymphocytes. Our results demonstrate that ORF4 is a newly discovered viral protein that is not essential for PCV2 replication but plays a role in suppressing caspase activity and regulating CD4+and CD8+T lymphocytes during PCV2 infection.

Immunoenhancement of Recombinant Neisseria meningitides PorB Protein on Porcine Circovirus Type 2 and Mycoplasma hyopneumoniae Genetically Engineered Vaccines

2019 ◽  
Vol 26 (10) ◽  
pp. 776-784
Author(s):  
Rui Yang ◽  
Yu Tao ◽  
Gaojian Li ◽  
Jian Chen ◽  
Jianhong Shu ◽  
...  
Keyword(s):  
Recombinant Protein ◽  
Mycoplasma Hyopneumoniae ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus Type 2 ◽  
Genetically Engineered ◽  
Porcine Circovirus ◽  
Practical Applications ◽  
Neisseria Meningitides ◽  
Short Period

Background:Porcine circovirus and Mycoplasma hyopneumoniae can cause respiratory diseases in pigs, which cause serious economic loss in the worldwide pig industry. Currently, these infections are mainly prevented and controlled by vaccination. The new vaccines on the market are mainly composed of subunits and inactivated vaccines but usually have lower antigenicity than traditional live vaccines. Thus, there is an increasing need to develop new adjuvants that can cause rapid and long-lasting immunity to enhance the antigenic efficacy for vaccines. Studies have shown that meningococcal porin PorB can act as a ligand to combine with Toll-like receptors to activate the production of immunological projections and act as a vaccine immunological adjuvant.Objective:In this article, we expressed and purified the recombinant PorB protein and verified its immunogenicity against porcine circovirus type 2 and Mycoplasma hyopneumoniae genetically engineered vaccine.Methods:In this article, we used prokaryotic expression to express and purify recombinant PorB protein, four different concentrations of PorB protein, Freund's adjuvant with two genetically engineered vaccines were combined with subcutaneous immunization of mice.Results:Our study shows that the appropriate dose of the recombinant protein PorB can enhance the levels of humoral and cellular responses induced by two genetically engineered vaccines in a short period of time in mice. The PorB adjuvant group may cause statistically higher antibody titers for both genetically engineered vaccines compared to Freund's commercial adjuvant (P<0.001).Conclusion:The recombinant protein PorB may be a good candidate adjuvant for improving the protective effect of vaccines against porcine circovirus type 2 and Mycoplasma hyopneumoniae, and the protein can be used for future practical applications.

scholarly journals A Comparison of Virulence of Three Porcine Circovirus Type 2 (PCV2) Genotypes (a, b, and d) in Pigs Singularly Inoculated with PCV2 and Dually Inoculated with PCV2 and Porcine Reproductive and Respiratory Syndrome Virus

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 891
Author(s):  
Jeongmin Suh ◽  
Taehwan Oh ◽  
Keehwan Park ◽  
Siyeon Yang ◽  
Hyejean Cho ◽  
...  
Keyword(s):  
Porcine Circovirus Type ◽  
Porcine Circovirus Type 2 ◽  
Daily Weight Gain ◽  
Porcine Circovirus ◽  
Respiratory Syndrome Virus ◽  
Average Daily Weight Gain ◽  
Significant Difference ◽  
Lesion Severity ◽  
Severe Lung

The aim of this study was to compare the virulence of porcine circovirus type 2 (PCV2) genotypes in dually inoculated pigs with both three genotypes (a, b, and d) of PCV2 and porcine reproductive and respiratory syndrome virus-2 (PRRSV-2) versus pigs singularly inoculated with the same three PCV2 genotypes (a, b, and d). Differences in this comparison were found in PCV2 viremia levels, lung and lymphoid lesion severity, and the amount of PCV2 antigen within the lymphoid lesions. Regardless of PCV2 genotypes, pigs that were dually inoculated with PCV2/PRRSV had significantly higher clinical scores, less average daily weight gain, higher levels of PCV2 viremia, and more severe lug and lymphoid lesions compared to pigs singularly inoculated with PCV2. Among the dually infected pig groups, pigs infected with PCV2d/PRRSV-2 had significantly higher levels of PCV2 viremia, more severe lung and lymphoid lesions, and more PCV2-positive cells within lymphoid lesions compared to pigs dually inoculated with PCV2a/PRRSV-2 and PCV2b/PRRSV-2. The results of this study demonstrated significant differences in the virulence among dual inoculation of PCV2a/PRRSV-2, PCV2b/PRRSV-2, and PCV2d/PRRSV-2. A significant difference in the virulence among PCV2a, PCV2b, and PCV2d single-inoculated pig groups was not found with respect to the levels of PCV2 viremia and production of PCV2-associated lymphoid lesions.

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