title: Generation in yeast of recombinant virus-like particles of porcine circovirus type 2 capsid protein and their use for a serologic assay and development of monoclonal antibodies.
abstract: BACKGROUND
  Porcine circovirus type 2 (PCV2) is considered to be an important emerging pathogen associated with a number of different syndromes and diseases in pigs known as PCV2-associated diseases. It has been responsible for significant mortality among pigs and remains a serious economic problem to the swine industry worldwide leading to significant negative impacts on profitability of pork production.
  
  
  RESULTS
  In this study we have demonstrated that PCV2 capsid (Cap) protein based virus-like particles (VLPs) were efficiently produced in yeast S. cerevisiae and induced production of monoclonal antibodies (MAbs) reactive with virus-infected cells. Moreover, PCV2 Cap VLPs served as a highly specific recombinant antigen for the development of an indirect IgG PCV2 Cap VLP-based ELISA for the detection of virus-specific IgG antibodies in swine sera. Four hundred-nine serum samples collected from pigs in Lithuania were tested for PCV2-specific IgG to determine the sensitivity and specificity of the newly developed ELISA in parallel using a commercial SERELISA test as a gold standard. From 409 tested serum samples, 297 samples were positive by both assays. Thirty-nine sera from 112 serum samples were determined as negative by SERELISA but were found to be positive both in the newly developed indirect IgG PCV2 Cap VLP-based ELISA and the PCR test.
  
  
  CONCLUSIONS
  We have demonstrated that S. cerevisiae expression system is an alternative to insect/baculovirus expression system for production of homogenous in size and shape PCV2 Cap protein-based VLPs similar to native virions. Yeast expression system tolerated native virus genes encoding PCV2 Cap protein variants as well as the codon-optimized gene. Moreover, yeast-derived PCV2 Cap VLPs were capable to induce the generation of PCV2-specific MAbs that did not show any cross-reactivity with PCV1-infected cells. The high sensitivity and specificity of the indirect IgG PCV2 Cap VLP-based ELISA clearly suggested that this assay is potentially useful diagnostic tool for screening PCV2-suspected samples.
authors.affiliation: Institute of Biotechnology, Vilnius University, Graiciuno 8, LT-02241, Vilnius, Lithuania. juozas.nainys@gmail.com.
authors.forename: Juozas
authors.initials: J
authors.lastname: Nainys
authors.affiliation: Institute of Biotechnology, Vilnius University, Graiciuno 8, LT-02241, Vilnius, Lithuania. rital@ibt.lt.
authors.forename: Rita
authors.initials: R
authors.lastname: Lasickiene
authors.affiliation: Institute of Biotechnology, Vilnius University, Graiciuno 8, LT-02241, Vilnius, Lithuania. rasa.burneikiene@bti.vu.lt.
authors.forename: Rasa
authors.initials: R
authors.lastname: Petraityte-Burneikiene
authors.affiliation: Institute of Biotechnology, Vilnius University, Graiciuno 8, LT-02241, Vilnius, Lithuania. jdabrisius@gmail.com.
authors.forename: Jonas
authors.initials: J
authors.lastname: Dabrisius
authors.affiliation: Institute of Microbiology and Virology, Veterinary Faculty of Veterinary Academy, Lithuanian University of Health Sciences, Tilzes 18, LT-47181, Kaunas, Lithuania. lelesius@lva.lt.
authors.forename: Raimundas
authors.initials: R
authors.lastname: Lelesius
authors.affiliation: Institute of Microbiology and Virology, Veterinary Faculty of Veterinary Academy, Lithuanian University of Health Sciences, Tilzes 18, LT-47181, Kaunas, Lithuania. sereika@lva.lt.
authors.forename: Vilimas
authors.initials: V
authors.lastname: Sereika
authors.affiliation: Institute of Biotechnology, Vilnius University, Graiciuno 8, LT-02241, Vilnius, Lithuania. aurelija.zvirbliene@bti.vu.lt.
authors.forename: Aurelija
authors.initials: A
authors.lastname: Zvirbliene
authors.affiliation: Institute of Biotechnology, Vilnius University, Graiciuno 8, LT-02241, Vilnius, Lithuania. kestutis.sasnauskas@bti.vu.lt.
authors.forename: Kestutis
authors.initials: K
authors.lastname: Sasnauskas
authors.affiliation: Institute of Biotechnology, Vilnius University, Graiciuno 8, LT-02241, Vilnius, Lithuania. agedv@ibt.lt.
authors.forename: Alma
authors.initials: A
authors.lastname: Gedvilaite
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000032:analysis* / Q000276:immunology; D000914:Antibodies, Viral / Q000032:analysis / Q000276:immunology; D036022:Capsid Proteins / Q000235:genetics / Q000276:immunology*; D018173:Circoviridae Infections / Q000662:veterinary* / Q000821:virology; D017925:Circovirus / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000295:instrumentation / Q000379:methods; D051379:Mice; D008807:Mice, Inbred BALB C; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D013552:Swine; D013553:Swine Diseases / Q000175:diagnosis / Q000821:virology*; D014771:Virion / Q000235:genetics / Q000276:immunology / Q000502:physiology*
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D036022:Capsid Proteins