title: Immunogenic and replicative properties of classical swine fever virus replicon particles modified to induce IFN-α/β and carry foreign genes.
abstract: Virus replicon particles (VRP) are genetically engineered infectious virions incapable of generating progeny virus due to partial or complete deletion of at least one structural gene. VRP fulfil the criteria of a safe vaccine and gene delivery system. With VRP derived from classical swine fever virus (CSF-VRP), a single intradermal vaccination protects from disease. Spreading of the challenge virus in the host is however not completely abolished. Parameters that are critical for immunogenicity of CSF-VRP are not well characterized. Considering the importance of type I interferon (IFN-α/β) to immune defence development, we generated IFN-α/β-inducing VRP to determine how this would influence vaccine efficacy. We also evaluated the effect of co-expressing granulocyte macrophage colony-stimulating factor (GM-CSF) in the vaccine context. The VRP were capable of long-term replication in cell culture despite the presence of IFN-α/β. In vivo, RNA replication was essential for the induction of an immune response. IFN-α/β-inducing and GM-CSF-expressing CSF-VRP were similar to unmodified VRP in terms of antibody and peripheral T-cell responses, and in reducing the blood levels of challenge virus RNA. Importantly, the IFN-α/β-inducing VRP did show increased efficacy over the unmodified VRP in terms of B-cell and T-cell responses, when tested with secondary immune responses by in vitro restimulation assay.
authors.affiliation: Institute of Virology and Immunoprophylaxis (IVI), Sensemattstrasse 293, CH-3147 Mittelhäusern, Switzerland.
authors.forename: Rolf
authors.initials: R
authors.lastname: Suter
authors.forename: Artur
authors.initials: A
authors.lastname: Summerfield
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: Thomann-Harwood
authors.forename: Kenneth C
authors.initials: KC
authors.lastname: McCullough
authors.forename: Jon-Duri
authors.initials: JD
authors.lastname: Tratschin
authors.forename: Nicolas
authors.initials: N
authors.lastname: Ruggli
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D000917:Antibody Formation; D002460:Cell Line; D006691:Classical Swine Fever / Q000276:immunology / Q000517:prevention & control*; D006692:Classical Swine Fever Virus / Q000235:genetics / Q000276:immunology* / Q000502:physiology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000276:immunology*; D016898:Interferon-alpha / Q000235:genetics / Q000276:immunology*; D016899:Interferon-beta / Q000235:genetics / Q000276:immunology*; D012367:RNA, Viral / Q000096:biosynthesis / Q000097:blood; D012093:Replicon; D013552:Swine; D013601:T-Lymphocytes / Q000276:immunology; D014759:Viral Envelope Proteins / Q000276:immunology; D014765:Viral Vaccines / Q000235:genetics / Q000276:immunology*; D014779:Virus Replication
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D016898:Interferon-alpha; D012367:RNA, Viral; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C087086:glycoprotein E2, classical swine fever virus; D016899:Interferon-beta; D016178:Granulocyte-Macrophage Colony-Stimulating Factor