Vaccination with fixed feline immunodeficiency virus (FIV) infected cells: protection, breakthrough and specificity of response

• Published in: Vaccine Vol. 14; no. 13; pp. 1243 - 1250
• Main Authors: Bishop, Sarah A., Stokes, Christopher R., Gruffydd-Jones, Timothy J., Whiting, Christine V., Humphries, James E., Osborne, Robert, Papanastasopoulou, Mary, Harbour, David A.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.09.1996; Elsevier
• Subjects: AIDS; AIDS/HIV; Animals; Antibodies, Viral - blood; Biological and medical sciences; Cats; Enzyme-Linked Immunosorbent Assay; Feline Acquired Immunodeficiency Syndrome - prevention & control; Feline immunodeficiency virus; feline leukemia virus; Flow Cytometry; Fundamental and applied biological sciences. Psychology; Immunoblotting; Immunodeficiency Virus, Feline - immunology; inactivated cell vaccine; Microbiology; Vaccination; vaccine breakthrough; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies; Viral Vaccines - immunology; Virology; virus neutralizing antibody; inactivated cell vaccine; AIDS; Feline immunodeficiency virus; virus neutralizing antibody; vaccine breakthrough; Immunoprotection; Fissipedia; Carnivora; Immunization; Immune response; Free form; Retroviridae; Vaccine; Virus; Vertebrata; Mammalia; Immunogenicity; Cat; Lentivirinae; Infected cell; Simian immunodeficiency virus; Humoral immunity; Neutralization
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/S0264-410X(96)00023-0

Infection of cats with feline immunodeficiency virus (FIV), a naturally occurring lentivirus infection of cats which causes an AIDS-like disease, has generated considerable interest as an animal model for HIV vaccination. This paper reports on experiments performed to examine the potential of a fixed infected cell vaccine to confer protection against intraperitoneal challenge with cell-free FIV. The cell vaccine was highly immunogenic and elicited antibody responses to virus core antigen, p24, high virus neutralizing (VN) antibody titres, and antibodies which recognized cellular components of the vaccine. Whilst protection, assessed by the inability to detect infectious virus by virus isolation or polymerase chain reaction, against homologous but not heterologous FIV isolates was apparent up to week 12 post-challenge, when cats were monitored longer up to week 50 post-challenge a breakthrough in vaccine protection against homologous virus was observed. Protection could not be correlated with levels of antibody to p24 or VN antibody titres. In contrast with simian immunodeficiency virus vaccine studies in macaques there was no clear evidence that antibodies recognizing cellular components of the vaccine, including MHC class I and II antigens, conferred any protective effect following challenge. These results indicate that long-term post-challenge monitoring for infection is essential in lentivirus vaccine trials.