title: Classical Swine Fever Virus vs. Classical Swine Fever Virus: The Superinfection Exclusion Phenomenon in Experimentally Infected Wild Boar.
abstract: Two groups with three wild boars each were used: Group A (animals 1 to 3) served as the control, and Group B (animals 4 to 6) was postnatally persistently infected with the Cat01 strain of CSFV (primary virus). The animals, six weeks old and clinically healthy, were inoculated with the virulent strain Margarita (secondary virus). For exclusive detection of the Margarita strain, a specific qRT-PCR assay was designed, which proved not to have cross-reactivity with the Cat01 strain. The wild boars persistently infected with CSFV were protected from superinfection by the virulent CSFV Margarita strain, as evidenced by the absence of clinical signs and the absence of Margarita RNA detection in serum, swabs and tissue samples. Additionally, in PBMCs, a well-known target for CSFV viral replication, only the primary infecting virus RNA (Cat01 strain) could be detected, even after the isolation in ST cells, demonstrating SIE at the tissue level in vivo. Furthermore, the data analysis of the Margarita qRT-PCR, by means of calculated ΔCt values, supported that PBMCs from persistently infected animals were substantially protected from superinfection after in vitro inoculation with the Margarita virus strain, while this virus was able to infect naive PBMCs efficiently. In parallel, IFN-α values were undetectable in the sera from animals in Group B after inoculation with the CSFV Margarita strain. Furthermore, these animals were unable to elicit adaptive humoral (no E2-specific or neutralising antibodies) or cellular immune responses (in terms of IFN-γ-producing cells) after inoculation with the second virus. Finally, a sequence analysis could not detect CSFV Margarita RNA in the samples tested from Group B. Our results suggested that the SIE phenomenon might be involved in the evolution and phylogeny of the virus, as well as in CSFV control by vaccination. To the best of our knowledge, this study was one of the first showing efficient suppression of superinfection in animals, especially in the absence of IFN-α, which might be associated with the lack of innate immune mechanisms.
authors.affiliation: IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Muñoz-González
authors.affiliation: IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Pérez-Simó
authors.affiliation: IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.|Servei d'Ecopatologia de Fauna Salvatge, Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
authors.forename: Andreu
authors.initials: A
authors.lastname: Colom-Cadena
authors.affiliation: IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.|Servei d'Ecopatologia de Fauna Salvatge, Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
authors.forename: Oscar
authors.initials: O
authors.lastname: Cabezón
authors.affiliation: IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
authors.forename: José Alejandro
authors.initials: JA
authors.lastname: Bohórquez
authors.affiliation: IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.|Departament d'Agricultura, Ramaderia, Pesca, Alimentació i Medi natural, Generalitat de Catalunya, 08007 Barcelona, Spain.
authors.forename: Rosa
authors.initials: R
authors.lastname: Rosell
authors.affiliation: Centro Nacional de Sanidad Agropecuaria (CENSA), La Habana, Cuba.
authors.forename: Lester Josué
authors.initials: LJ
authors.lastname: Pérez
authors.affiliation: Servei d'Ecopatologia de Fauna Salvatge, Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
authors.forename: Ignasi
authors.initials: I
authors.lastname: Marco
authors.affiliation: Servei d'Ecopatologia de Fauna Salvatge, Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
authors.forename: Santiago
authors.initials: S
authors.lastname: Lavín
authors.affiliation: IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.|Departament de Sanitat i Anatomia Animals (DAAM), Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
authors.forename: Mariano
authors.initials: M
authors.lastname: Domingo
authors.affiliation: IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
authors.forename: Llilianne
authors.initials: L
authors.lastname: Ganges
mesh_terms: D000818:Animals; D006691:Classical Swine Fever / Q000821:virology*; D006692:Classical Swine Fever Virus / Q000276:immunology / Q000302:isolation & purification*; D007111:Immunity, Cellular; D016898:Interferon-alpha / Q000097:blood; D015163:Superinfection / Q000821:virology*; D034421:Sus scrofa / Q000821:virology*; D013552:Swine
chemical_list: D016898:Interferon-alpha