title: Mucosal immunization of sheep with a Maedi-Visna virus (MVV) env DNA vaccine protects against early MVV productive infection.
abstract: Gene gun mucosal DNA immunization of sheep with a plasmid expressing the env gene of Maedi-Visna virus (MVV) was used to examine the protection against MVV infection in sheep from a naturally infected flock. For immunization, sheep were primed with a pcDNA plasmid (pcDNA-env) encoding the Env glycoproteins of MVV and boosted with combined pcDNA-env and pCR3.1-IFN-gamma plasmid inoculations. The pcDNA plasmid used in the control group contained the lacZ coding sequences instead of the env gene. Within a month post-challenge, the viral load in the vaccinated group was lower (p < or = 0.05) and virus was only detected transiently compared with the control group. Furthermore, 2 months later, neutralizing antibodies (NtAb) were detected in all the control animals and none of the vaccinated animals (p < or = 0.01). These results demonstrated a significant early protective effect of this immunization strategy against MVV infection that restricts the virus replication following challenge in the absence of NtAb production. This vaccine protective effect against MVV infection disappeared after two years post-challenge, when active replication of MVV challenge strain was observed. Protection conferred by the vaccine could not be explained by OLA DRB1 allele or genotype differences. Most of the individuals were DRB1 heterozygous and none was totally resistant to infection.
authors: SIA (DGA), Zaragoza, Spain.
authors: Belén
authors: B
authors: González
authors: Ramsés
authors: R
authors: Reina
authors: Iker
authors: I
authors: García
authors: Sara
authors: S
authors: Andrés
authors: Idoia
authors: I
authors: Glaria
authors: María
authors: M
authors: Alzueta
authors: María Isabel
authors: MI
authors: Mora
authors: Begoña M
authors: BM
authors: Jugo
authors: Inés
authors: I
authors: Arrieta-Aguirre
authors: José M Pérez
authors: JM
authors: de la Lastra
authors: Dolores
authors: D
authors: Rodríguez
authors: Juan Ramón
authors: JR
authors: Rodríguez
authors: Mariano
authors: M
authors: Esteban
authors: María Jesús
authors: MJ
authors: Grilló
authors: Barbara A
authors: BA
authors: Blacklaws
authors: Gordon D
authors: GD
authors: Harkiss
authors: Yahia
authors: Y
authors: Chebloune
authors: Lluís
authors: L
authors: Luján
authors: Damián
authors: D
authors: de Andrés
authors: Beatriz
authors: B
authors: Amorena
mesh_terms: D000818:Animals; D019470:Biolistics; D005260:Female; D015686:Gene Products, env / Q000235:genetics* / Q000276:immunology; D005802:Genes, MHC Class II; D006684:HLA-DR Antigens / Q000235:genetics; D018928:Immunity, Mucosal; D007114:Immunization; D007371:Interferon-gamma / Q000235:genetics; D011021:Pneumonia, Progressive Interstitial, of Sheep / Q000517:prevention & control*; D012756:Sheep; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology*; D019562:Viral Load; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology*; D016182:Visna / Q000517:prevention & control*; D014790:Visna-maedi virus / Q000276:immunology*
chemical_list: D015686:Gene Products, env; D006684:HLA-DR Antigens; D019444:Vaccines, DNA; D014765:Viral Vaccines; D007371:Interferon-gamma