title: Myxomavirus as a vector for the immunisation of sheep: protection study against challenge with bluetongue virus.
abstract: Recombinant poxviruses are well suited for the development of new vaccine vectors. Our previous data supported the idea that Myxomavirus (MYXV) is efficient at priming antibody responses in sheep. To provide definitive evidence on the potential of MYXV for vaccination against infectious diseases in ruminants, we investigated the immune protection provided by recombinant MYXV against bluetongue, a devastating disease in sheep. To test this concept, sheep were injected twice with an MYXV expressing the immunodominant VP2 protein (SG33-VP2). The SG33-VP2 vector promoted the production of neutralising antibodies and partially protected sheep against disease after challenge with a highly virulent strain of serotype-8 bluetongue virus (BTV-8). In contrast, an MYXV expressing both VP2 and VP5 proteins (SG33-VP2/5) elicited very little protection. The expression levels of the VP2 and VP5 proteins suggested that, greater than the co-expression of the VP5 protein which was previously thought to favour anti-VP2 antibody response, the high expression of VP2 may be critical in the MYXV context to stimulate a protective response in sheep. This highlights the requirement for a careful examination of antigen expression before any conclusion can be drawn on the respective role of the protective antigens. As a proof of principle, our study shows that an MYXV vaccine vector is possible in ruminants.
authors.affiliation: INRA, UMR1225, IHAP, F-31076 Toulouse, France.
authors.forename: Sokunthea
authors.initials: S
authors.lastname: Top
authors.forename: Gilles
authors.initials: G
authors.lastname: Foucras
authors.forename: Martine
authors.initials: M
authors.lastname: Deplanche
authors.forename: Germain
authors.initials: G
authors.lastname: Rives
authors.forename: Jérôme
authors.initials: J
authors.lastname: Calvalido
authors.forename: Loic
authors.initials: L
authors.lastname: Comtet
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bertagnoli
authors.forename: Gilles
authors.initials: G
authors.lastname: Meyer
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D000956:Antigens, Viral / Q000276:immunology; D001819:Bluetongue / Q000276:immunology / Q000517:prevention & control*; D001820:Bluetongue virus / Q000472:pathogenicity*; D036022:Capsid Proteins / Q000276:immunology; D008297:Male; D009233:Myxoma virus / Q000276:immunology*; D012756:Sheep / Q000276:immunology / Q000821:virology; D034561:Sheep, Domestic / Q000276:immunology* / Q000821:virology; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D000956:Antigens, Viral; D036022:Capsid Proteins; C442520:VP2 protein, Bluetongue virus; C488468:VP5 protein, Bluetongue virus; D014765:Viral Vaccines