title: Induction of feline immunodeficiency virus specific antibodies in cats with an attenuated Salmonella strain expressing the Gag protein.
abstract: Salmonella typhimurium aroA strains (SL3261), expressing high levels of the Gag protein of feline immunodeficiency virus (FIV) fused with maltose binding protein (SL3261-MFG), were constructed using an invertible promoter system that allows the stable expression of heterologous antigens at levels toxic for bacteria. A SL3261 strain expressing the B subunit of cholera toxin by a similar system (SL3261-CtxB) served as a control in FIV-immunization experiments. Cats immunized once orally or intraperitoneally with SL3261-MFG or SL3261-CtxB all developed serum antibodies to SL3261 lipopolysaccharide and against maltose binding protein or the B subunit of cholera toxin, respectively. Two intraperitoneal immunizations with SL3261-MFG also resulted in the development of Gag specific serum antibodies. Two oral immunizations with SL3261-MFG primed for a Gag specific response, which was demonstrated upon FIV challenge. All challenged cats became infected and no significant differences in viral loads were found between SL3261-MFG and SL3261-CtxB immunized cats.
authors.affiliation: School of Biological and Medical Sciences, University of St Andrews, Scotland.
authors.forename: E J
authors.initials: EJ
authors.lastname: Tijhaar
authors.forename: K H
authors.initials: KH
authors.lastname: Siebelink
authors.forename: J A
authors.initials: JA
authors.lastname: Karlas
authors.forename: M C
authors.initials: MC
authors.lastname: Burger
authors.forename: F R
authors.initials: FR
authors.lastname: Mooi
authors.forename: A D
authors.initials: AD
authors.lastname: Osterhaus
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis / Q000276:immunology*; D002415:Cats; D007446:Chromosome Inversion; D015870:Gene Expression; D015683:Gene Products, gag / Q000235:genetics / Q000276:immunology*; D005822:Genetic Vectors; D016089:Immunodeficiency Virus, Feline / Q000276:immunology*; D010957:Plasmids; D012486:Salmonella typhimurium; D014613:Vaccines, Attenuated / Q000276:immunology; D014614:Vaccines, Synthetic / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D015683:Gene Products, gag; D014613:Vaccines, Attenuated; D014614:Vaccines, Synthetic; D014765:Viral Vaccines