Env-specific CTL predominate in cats protected from feline immunodeficiency virus infection by vaccination.
Animal models of HIV-1 have a key role to play in elucidation of the cellular mechanisms responsible for protective immunity. Vaccination of domestic cats with whole inactivated feline immunodeficiency virus (FIV) elicits virus-neutralizing Abs and virus-specific CTL in the peripheral blood and lymphoid organs and affords protection from homologous virus challenge. In the present study we confirm the induction of virus-specific CTL following immunization with whole inactivated FIV vaccine and demonstrate that cats are protected for up to 1 yr following vaccination. Long term protection in vaccinated cats correlates with both higher levels of FIV Env-specific CTL in the peripheral blood following vaccination and the presence of FIV Env-specific memory CD8+ CTL in the lymph nodes, which persist for up to 1 yr following challenge in the absence of detectable virus. The CTL responses observed in vaccinated protected cats differ qualitatively from those in FIV-infected cats. The latter cats either do not generate a memory CTL response or exhibit a Gag-specific memory CTL response. These results show that the protective immunity observed in whole inactivated virus-vaccinated cats is associated with the induction of high levels of Env-specific CTL activity.
Flynn
J N
JN
Department of Veterinary Pathology, University of Glasgow, Bearsden, Scotland.
Keating
P
P
Hosie
M J
MJ
Mackett
M
M
Stephens
E B
EB
Beatty
J A
JA
Neil
J C
JC
Jarrett
O
O
D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002415:Cats; D016181:Feline Acquired Immunodeficiency Syndrome / Q000276:immunology* / Q000517:prevention & control*; D015686:Gene Products, env / Q000276:immunology*; D015683:Gene Products, gag / Q000276:immunology; D015497:HIV-1 / Q000276:immunology; D016089:Immunodeficiency Virus, Feline / Q000276:immunology*; D007156:Immunologic Memory; D008198:Lymph Nodes / Q000276:immunology; D013154:Spleen / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014611:Vaccination
D015686:Gene Products, env; D015683:Gene Products, gag