title: Memory T cell proliferative responses and IFN-γ productivity sustain long-lasting efficacy of a Cap-based PCV2 vaccine upon PCV2 natural infection and associated disease.
abstract: Porcine circovirus type 2 (PCV2) vaccination represents an important measure to cope with PCV2 infection; however, data regarding the modulation of the immune cell compartment are still limited, especially under field conditions. This study is aimed at investigating the features of the cellular immune response in conventional piglets induced by vaccination using a capsid (Cap) protein-based PCV2 vaccine compared to unvaccinated animals when exposed to PCV2 natural infection. Immune reactivity was evaluated by quantifying peripheral cell subsets involved in the anti-viral response and characterizing the interferon-gamma (IFN-γ) secreting cell (SC) responsiveness both in vivo and upon in vitro whole PCV2 recall. The vaccination triggered an early and intense IFN-γ secreting cell response and induced the activation of peripheral lymphocytes. The early increase of IFN-γ SC frequencies resulted in a remarkable and transient tendency to increased IFN-γ productivity in vaccinated pigs. In vaccinated animals, soon before the onset of infection occurred 15-16 weeks post-vaccination, the recalled PCV2-specific immune response was characterized by moderate PCV2-specific IFN-γ secreting cell frequencies and augmented productivity together with reactive CD4+CD8+ memory T cells. Conversely, upon infection, unvaccinated animals showed very high frequencies of IFN-γ secreting cells and a tendency to lower productivity, which paralleled with effector CD4-CD8+ cytotoxic cell responsiveness. The study shows that PCV2 vaccination induces a long-lasting immunity sustained by memory T cells and IFN-γ secreting cells that potentially played a role in preventing the onset of infection; the extent and duration of this reactivity can be an important feature for evaluating the protective immunity induced by vaccination.
authors.affiliation: Department of Veterinary Science, University of Parma, Via del Taglio, 10, 43126 Parma, Italy. luca.ferrari@unipr.it.
authors.forename: Luca
authors.initials: L
authors.lastname: Ferrari
authors.forename: Paolo
authors.initials: P
authors.lastname: Borghetti
authors.forename: Elena
authors.initials: E
authors.lastname: De Angelis
authors.forename: Paolo
authors.initials: P
authors.lastname: Martelli
mesh_terms: D000818:Animals; D018173:Circoviridae Infections / Q000276:immunology / Q000662:veterinary* / Q000821:virology; D017925:Circovirus / Q000276:immunology*; D058501:Enzyme-Linked Immunospot Assay / Q000662:veterinary; D005434:Flow Cytometry / Q000662:veterinary; D007111:Immunity, Cellular; D007371:Interferon-gamma / Q000096:biosynthesis; D008934:Mitogens / Q000276:immunology; D016133:Polymerase Chain Reaction / Q000662:veterinary; D013552:Swine; D013553:Swine Diseases / Q000276:immunology* / Q000821:virology; D013601:T-Lymphocytes / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage
chemical_list: D008934:Mitogens; D014765:Viral Vaccines; D007371:Interferon-gamma
references.citation: BMC Vet Res. 2009 Dec 22;5:45
references.pmid: 20028550
references.citation: J Vet Sci. 2010 Sep;11(3):177-83
references.pmid: 20706023
references.citation: Dev Comp Immunol. 2009 Mar;33(3):394-409
references.pmid: 18771683
references.citation: J Gen Virol. 2003 Aug;84(Pt 8):2117-2125
references.pmid: 12867643
references.citation: J Vet Diagn Invest. 2000 Jan;12(1):3-14
references.pmid: 10690769
references.citation: Vaccine. 2009 Jun 8;27(28):3788-99
references.pmid: 19442420
references.citation: Dev Comp Immunol. 2009 Mar;33(3):310-20
references.pmid: 18601948
references.citation: Virus Res. 2013 Jun;174(1-2):60-8
references.pmid: 23499996
references.citation: Vet Immunol Immunopathol. 2013 Feb 15;151(3-4):193-206
references.pmid: 23228653
references.citation: Vet Microbiol. 2011 May 5;149(3-4):339-51
references.pmid: 21216540
references.citation: Vaccine. 2009 Feb 11;27(7):1002-7
references.pmid: 19100807
references.citation: Vet Microbiol. 2008 Jun 22;129(3-4):367-77
references.pmid: 18164875
references.citation: Cell Immunol. 2009;258(2):131-7
references.pmid: 19427634
references.citation: BMC Vet Res. 2012 Oct 19;8:194
references.pmid: 23078878
references.citation: J Gen Virol. 2003 Dec;84(Pt 12):3453-3457
references.pmid: 14645926
references.citation: J Vet Diagn Invest. 2004 May;16(3):175-85
references.pmid: 15152830
references.citation: Vet Microbiol. 2013 Apr 12;163(1-2):42-53
references.pmid: 23290117
references.citation: Vet Immunol Immunopathol. 2001 Aug 30;81(1-2):37-44
references.pmid: 11498245
references.citation: Clin Diagn Lab Immunol. 2002 Mar;9(2):236-42
references.pmid: 11874858
references.citation: Vet Immunol Immunopathol. 2003 May 12;92(3-4):97-111
references.pmid: 12730011
references.citation: Can Vet J. 2007 Jul;48(7):716-24
references.pmid: 17824156
references.citation: Vet Microbiol. 2012 Jul 6;158(1-2):69-81
references.pmid: 22406346
references.citation: Vet Immunol Immunopathol. 2010 Oct 15;137(3-4):226-34
references.pmid: 20566220
references.citation: Vet Immunol Immunopathol. 2006 Mar 15;110(1-2):17-25
references.pmid: 16213031
references.citation: Vet J. 2012 Nov;194(2):151-7
references.pmid: 22841450
references.citation: J Gen Virol. 2008 Mar;89(Pt 3):760-765
references.pmid: 18272768
references.citation: Vaccine. 2007 Apr 30;25(17):3400-8
references.pmid: 17276558
references.citation: Vet Microbiol. 2005 Dec 20;111(3-4):223-9
references.pmid: 16289542
references.citation: Vet Microbiol. 2008 Nov 25;132(1-2):74-86
references.pmid: 18556150
references.citation: Vet Immunol Immunopathol. 2009 May 15;129(1-2):101-7
references.pmid: 19167096
references.citation: Vet Res Commun. 2010 Jun;34 Suppl 1:S63-7
references.pmid: 20512626
references.citation: Vet Immunol Immunopathol. 2007 Feb 15;115(3-4):261-72
references.pmid: 17175030
references.citation: Virus Res. 2012 Mar;164(1-2):10-9
references.pmid: 22056845
references.citation: Vet Immunol Immunopathol. 2008 Aug 15;124(3-4):355-66
references.pmid: 18554727
references.citation: Vet J. 2012 Jul;193(1):199-205
references.pmid: 22104506
references.citation: Vet Microbiol. 2003 Aug 29;95(1-2):15-25
references.pmid: 12860073
references.citation: Vet Microbiol. 2013 Mar 23;162(2-4):558-571
references.pmid: 23206413
references.citation: Vet Immunol Immunopathol. 2012 Nov 15;150(1-2):128-32
references.pmid: 23010221
references.citation: Vaccine. 2010 Mar 8;28(11):2340-9
references.pmid: 20056179
references.citation: Vaccine. 2008 Feb 20;26(8):1063-71
references.pmid: 18237827
references.citation: Vet Immunol Immunopathol. 2010 Aug 15;136(3-4):185-93
references.pmid: 20451259
references.citation: J Virol Methods. 2004 Apr;117(1):75-80
references.pmid: 15019262
references.citation: Vaccine. 2009 Jun 19;27(30):4031-7
references.pmid: 19379787
references.citation: Vet Microbiol. 2011 Dec 29;154(1-2):185-90
references.pmid: 21784586
references.citation: J Interferon Cytokine Res. 2005 Nov;25(11):684-93
references.pmid: 16318582
references.citation: Vet Immunol Immunopathol. 2008 Jul 15;124(1-2):41-9
references.pmid: 18304652
references.citation: Methods Mol Biol. 2012;792:125-43
references.pmid: 21956507
references.citation: Res Vet Sci. 2011 Apr;90(2):321-3
references.pmid: 20542307