Vaccination of cats with attenuated feline immunodeficiency virus proviral DNA vaccine expressing gamma interferon.
A feline immunodeficiency virus (FIV) provirus with a vif gene deletion (FIVDelta vifATGgamma) that coexpresses feline gamma interferon (IFN-gamma) was tested as a proviral DNA vaccine to extend previous studies showing efficacy with an FIV-pPPRDelta vif DNA vaccine. Cats were vaccinated with either FIVDelta vifATGgamma or FIV-pPPRDelta vif proviral plasmid DNA or with both FIV-pPPRDelta vif DNA and a feline IFN-gamma expression plasmid (pCDNA-IFNgamma). A higher frequency of FIV-specific T-cell proliferation responses was observed in cats immunized with either FIVDelta vifATGgamma or FIV-pPPRDelta vif plus pCDNA-IFNgamma, while virus-specific cytotoxic-T-lymphocyte responses were comparable between vaccine groups. Antiviral antibodies were not observed postvaccination. Virus-specific cellular and humoral responses were similar between vaccine groups after challenge with a biological FIV isolate (FIV-PPR) at 13 weeks postimmunization. All vaccinated and unvaccinated cats were infected after FIV-PPR challenge and exhibited similar plasma virus loads. Accordingly, inclusion of plasmids containing IFN-gamma did not enhance the efficacy of FIV-pPPRDelta vif DNA immunization. Interestingly, the lack of protection associated with FIV-pPPRDelta vif DNA immunization contrasted with findings from a previous study and suggested that multiple factors, including timing of FIV-pPPRDelta vif inoculations and challenge, as well as route of challenge virus delivery, may significantly impact vaccine efficacy.
Gupta
Soumi
S
Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
Leutenegger
Christian M
CM
Dean
Gregg A
GA
Steckbeck
Jonathan D
JD
Cole
Kelly Stefano
KS
Sparger
Ellen E
EE
D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002415:Cats; D016181:Feline Acquired Immunodeficiency Syndrome / Q000517:prevention & control*; D016089:Immunodeficiency Virus, Feline / Q000235:genetics / Q000276:immunology*; D007371:Interferon-gamma / Q000008:administration & dosage* / Q000276:immunology / Q000378:metabolism; D011533:Proviruses / Q000235:genetics / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D014611:Vaccination / Q000662:veterinary; D014613:Vaccines, Attenuated / Q000008:administration & dosage* / Q000276:immunology; D019444:Vaccines, DNA / Q000008:administration & dosage* / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology
D000276:Adjuvants, Immunologic; D000914:Antibodies, Viral; D014613:Vaccines, Attenuated; D019444:Vaccines, DNA; D014765:Viral Vaccines; D007371:Interferon-gamma