Immunization trial of cats with a replication-defective adenovirus type 5 expressing the ENV gene of feline immunodeficiency virus.
Our aim was to develop a recombinant replication-defective adenovirus suitable for the vaccination of cats against feline immunodeficiency virus. We first demonstrated that this vector was able to transfer a marker gene (E. coli beta-galactosidase) in feline cells in vitro. We then constructed an adenovirus type 5 expressing the Feline Immunodeficiency Virus (FIV) envelope (ENV) gene of the Wo isolate in the absence of the rev gene (Ad-ENV-Wo). Ad-ENV-Wo was then tested in four cats in a 3 injections scheme (at day 0, day 30 and day 210). Four other control cats received Ad-gp50, a similar recombinant adenovirus expressing gp50 (Ad-gp50) of pseudorabies virus (PRV). Viruses were formulated in two different kind of oil adjuvants (water/oil and water/oil/water), a protocol previously shown to enhance the immune response against the virus-induced protein. The control cats developed neutralizing antibodies against PRV, demonstrating the potency of recombinant human adenovirus 5 (Ad5) as a vector in cats. Antibody responses appeared after the first injection and were higher with the water/oil/water formulation than with the water/oil controls. However, none of the four cats vaccinated with Ad-ENV-Wo developed antibodies against two peptides of the envelope protein. Animals were challenged with 20 infectious doses 50% of the strain Wo. All of them developed antibodies against FIV within 4 to 5 weeks, and FIV virus could be isolated from all.
D000256:Adenoviridae / Q000276:immunology* / Q000502:physiology; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D000917:Antibody Formation; D002415:Cats; D002460:Cell Line; D003673:Defective Viruses / Q000276:immunology* / Q000502:physiology; D004926:Escherichia coli / Q000235:genetics; D016181:Feline Acquired Immunodeficiency Syndrome / Q000097:blood / Q000276:immunology / Q000517:prevention & control*; D015686:Gene Products, env / Q000096:biosynthesis / Q000235:genetics; D015752:Genes, env; D006801:Humans; D007114:Immunization; D016089:Immunodeficiency Virus, Feline / Q000235:genetics / Q000276:immunology*; D011994:Recombinant Proteins / Q000096:biosynthesis; D014162:Transfection; D014765:Viral Vaccines; D014779:Virus Replication; D001616:beta-Galactosidase / Q000096:biosynthesis / Q000235:genetics
D000914:Antibodies, Viral; D015686:Gene Products, env; D011994:Recombinant Proteins; D014765:Viral Vaccines; D001616:beta-Galactosidase