title: Expression of VP7, a Bluetongue virus group specific antigen by viral vectors: analysis of the induced immune responses and evaluation of protective potential in sheep.
abstract: Bluetongue virus (BTV) is an economically important Orbivirus transmitted by biting midges to domestic and wild ruminants. The need for new vaccines has been highlighted by the occurrence of repeated outbreaks caused by different BTV serotypes since 1998. The major group-reactive antigen of BTV, VP7, is conserved in the 26 serotypes described so far, and its role in the induction of protective immunity has been proposed. Viral-based vectors as antigen delivery systems display considerable promise as veterinary vaccine candidates. In this paper we have evaluated the capacity of the BTV-2 serotype VP7 core protein expressed by either a non-replicative canine adenovirus type 2 (Cav-VP7 R0) or a leporipoxvirus (SG33-VP7), to induce immune responses in sheep. Humoral responses were elicited against VP7 in almost all animals that received the recombinant vectors. Both Cav-VP7 R0 and SG33-VP7 stimulated an antigen-specific CD4+ response and Cav-VP7 R0 stimulated substantial proliferation of antigen-specific CD8+ lymphocytes. Encouraged by the results obtained with the Cav-VP7 R0 vaccine vector, immunized animals were challenged with either the homologous BTV-2 or the heterologous BTV-8 serotype and viral burden in plasma was followed by real-time RT-PCR. The immune responses triggered by Cav-VP7 R0 were insufficient to afford protective immunity against BTV infection, despite partial protection obtained against homologous challenge. This work underscores the need to further characterize the role of BTV proteins in cross-protective immunity.
authors.affiliation: UPE, ANSES, INRA, ENVA, UMR 1161 ANSES/INRA/ENVA, Maisons-Alfort, France.
authors.forename: Coraline
authors.initials: C
authors.lastname: Bouet-Cararo
authors.affiliation: Virologie et Immunologie Moléculaires, UR 892 INRA, Jouy-en-Josas, France.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Contreras
authors.affiliation: INRA, UMR1225, IHAP, Université de Toulouse, INP, ENVT, Toulouse, France.
authors.forename: Agathe
authors.initials: A
authors.lastname: Caruso
authors.affiliation: INRA, UMR1225, IHAP, Université de Toulouse, INP, ENVT, Toulouse, France.
authors.forename: Sokunthea
authors.initials: S
authors.lastname: Top
authors.affiliation: Centre de Physiopathologie de Toulouse Purpan, INSERM U1043, CNRS U5282, Université Paul-Sabatier, Toulouse, France.
authors.forename: Marion
authors.initials: M
authors.lastname: Szelechowski
authors.affiliation: UPE, ANSES, INRA, ENVA, UMR 1161 ANSES/INRA/ENVA, Maisons-Alfort, France.
authors.forename: Corinne
authors.initials: C
authors.lastname: Bergeron
authors.affiliation: UPE, ANSES, INRA, ENVA, UMR 1161 ANSES/INRA/ENVA, Maisons-Alfort, France.
authors.forename: Cyril
authors.initials: C
authors.lastname: Viarouge
authors.affiliation: UPE, ANSES, INRA, ENVA, UMR 1161 ANSES/INRA/ENVA, Maisons-Alfort, France.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Desprat
authors.affiliation: UPE, ANSES, INRA, ENVA, UMR 1161 ANSES/INRA/ENVA, Maisons-Alfort, France.
authors.forename: Anthony
authors.initials: A
authors.lastname: Relmy
authors.affiliation: Unité de pathologie des petits ruminants, ANSES, Sophia-Antipolis, France.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Guibert
authors.affiliation: Unité de pathologie des petits ruminants, ANSES, Sophia-Antipolis, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Dubois
authors.affiliation: Unité de pathologie des petits ruminants, ANSES, Sophia-Antipolis, France.
authors.forename: Richard
authors.initials: R
authors.lastname: Thiery
authors.affiliation: UPE, ANSES, INRA, ENVA, UMR 1161 ANSES/INRA/ENVA, Maisons-Alfort, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Bréard
authors.affiliation: INRA, UMR1225, IHAP, Université de Toulouse, INP, ENVT, Toulouse, France.
authors.forename: Stephane
authors.initials: S
authors.lastname: Bertagnoli
authors.affiliation: UPE, ANSES, INRA, ENVA, UMR 1161 ANSES/INRA/ENVA, Maisons-Alfort, France.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Richardson
authors.affiliation: INRA, UMR1225, IHAP, Université de Toulouse, INP, ENVT, Toulouse, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Foucras
authors.affiliation: INRA, UMR1225, IHAP, Université de Toulouse, INP, ENVT, Toulouse, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Meyer
authors.affiliation: Virologie et Immunologie Moléculaires, UR 892 INRA, Jouy-en-Josas, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Schwartz-Cornil
authors.affiliation: UPE, ANSES, INRA, ENVA, UMR 1161 ANSES/INRA/ENVA, Maisons-Alfort, France.
authors.forename: Stephan
authors.initials: S
authors.lastname: Zientara
authors.affiliation: UPE, ANSES, INRA, ENVA, UMR 1161 ANSES/INRA/ENVA, Maisons-Alfort, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Klonjkowski
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D000956:Antigens, Viral / Q000235:genetics* / Q000276:immunology; D001819:Bluetongue / Q000276:immunology* / Q000517:prevention & control / Q000821:virology; D001820:Bluetongue virus / Q000235:genetics* / Q000276:immunology; D002460:Cell Line; D006224:Cricetinae; D003429:Cross Reactions / Q000276:immunology; D004285:Dogs; D005260:Female; D015870:Gene Expression; D005822:Genetic Vectors / Q000235:genetics*; D007111:Immunity, Cellular; D007114:Immunization; D008297:Male; D011817:Rabbits; D012756:Sheep; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D014758:Viral Core Proteins / Q000235:genetics* / Q000276:immunology; D014765:Viral Vaccines / Q000235:genetics / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D014758:Viral Core Proteins; D014765:Viral Vaccines; C066862:VP7 protein, orbivirus