title: Evaluation of cell-mediated immune responses against porcine circovirus type 2 (PCV2) Cap and Rep proteins after vaccination with a commercial PCV2 sub-unit vaccine.
abstract: This study investigated the development of cellular immunity to Porcine circovirus type 2 (PCV2) Cap and Rep proteins in pigs vaccinated with a commercial PCV2 genotype a (PCV2a) based sub-unit vaccine, before and after a heterologous challenge with a PCV2b isolate. At three weeks of age, 20 pigs were inoculated intramuscularly with either the vaccine product (V group, n=9) or phosphate buffered saline solution (PBS) (NV group, n=11). Three weeks after vaccination, pigs were challenged intranasally with PCV2b (V-C and NV-C groups) or PBS (V-NC and NV-NC groups). None of the pigs developed clinical signs during the whole experiment, but all NV-C and 3/5 V-C pigs developed viraemia. Vaccination induced the development IFN-γ-secreting cells in response to the Cap protein of PCV2, which appeared three weeks post-vaccination and increased after challenge. By that time, no significant differences were detected on PCV2 antibody titres between vaccinated and non-vaccinated pigs, although there were significant differences on day 7 post-challenge. PCV2-inoculation induced a cellular response against the Rep protein. Such response was significantly reduced or even absent in PCV2-inoculated pigs that were previously vaccinated (V-C group), presumably as a result of a lower PCV2 replication in vaccinated animals compared to non-vaccinated ones.
authors.affiliation: Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Fort
authors.forename: Marina
authors.initials: M
authors.lastname: Sibila
authors.forename: Miquel
authors.initials: M
authors.lastname: Nofrarías
authors.forename: Eva
authors.initials: E
authors.lastname: Pérez-Martín
authors.forename: Alex
authors.initials: A
authors.lastname: Olvera
authors.forename: Enric
authors.initials: E
authors.lastname: Mateu
authors.forename: Joaquim
authors.initials: J
authors.lastname: Segalés
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D016009:Chi-Square Distribution; D018173:Circoviridae Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary* / Q000821:virology; D017925:Circovirus / Q000276:immunology*; D007111:Immunity, Cellular / Q000276:immunology; D007371:Interferon-gamma / Q000097:blood; D013552:Swine; D013553:Swine Diseases / Q000276:immunology* / Q000517:prevention & control / Q000821:virology*; D022223:Vaccines, Subunit / Q000008:administration & dosage / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology*; D014766:Viremia / Q000276:immunology / Q000662:veterinary / Q000821:virology
chemical_list: D000914:Antibodies, Viral; D022223:Vaccines, Subunit; D014765:Viral Vaccines; D007371:Interferon-gamma