Comparative efficacy of subtype AE simian-human immunodeficiency virus priming and boosting vaccines in pigtail macaques.
Vaccination against AIDS is hampered by great diversity between human immunodeficiency virus (HIV) strains. Heterologous B-subtype-based simian-human immunodeficiency virus (SHIV) DNA prime and poxvirus boost vaccine regimens can induce partial, T-cell-mediated, protective immunity in macaques. We analyzed a set of DNA, recombinant fowlpox viruses (FPV), and vaccinia viruses (VV) expressing subtype AE HIV type 1 (HIV-1) Tat, Rev, and Env proteins and SIV Gag/Pol in 30 pigtail macaques. SIV Gag-specific CD4 and CD8 T-cell responses were induced by sequential DNA/FPV vaccination, although lower FPV doses, VV/FPV vaccination, and DNA vaccines alone were not as consistently immunogenic. The SHIV AE DNA prime, FPV boost regimens were significantly less immunogenic than comparable B-subtype SHIV vaccination. Peak viral load was modestly (0.4 log10 copies/ml) lower among the AE subtype SHIV-immunized animals compared to controls following the virulent B subtype SHIV challenge. Protection from persistent high levels of viremia and CD4 T-cell depletion was less in AE subtype compared to B subtype SHIV-vaccinated macaques. Gag was highly immunodominant over the other AE subtype SHIV vaccine proteins after vaccination, and this immunodominance was exacerbated after challenge. Interestingly, the lower level of priming of immune responses did not blunt postchallenge Gag-specific recall responses, despite more modest protection. These studies suggest priming of T-cell immunity to prevent AIDS in humans is possible, but differences in the immunogenicity of various subtype vaccines and broad cross-subtype protection are substantial hurdles.
De Rose
Robert
R
Department of Microbiology and Immunology, University of Melbourne, Victoria 3010, Australia.
Batten
C Jane
CJ
Smith
Miranda Z
MZ
Fernandez
Caroline S
CS
Peut
Viv
V
Thomson
Scott
S
Ramshaw
Ian A
IA
Coupar
Barbara E H
BE
Boyle
David B
DB
Venturi
Vanessa
V
Davenport
Miles P
MP
Kent
Stephen J
SJ
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D005587:Fowlpox virus / Q000235:genetics; D015685:Fusion Proteins, gag-pol / Q000235:genetics; D015686:Gene Products, env / Q000235:genetics; D015683:Gene Products, gag / Q000276:immunology; D015694:Gene Products, rev / Q000235:genetics; D015696:Gene Products, tat / Q000235:genetics; D015497:HIV-1 / Q000235:genetics; D007117:Immunization, Secondary; D008254:Macaca nemestrina; D018449:SAIDS Vaccines / Q000276:immunology*; D015302:Simian Immunodeficiency Virus / Q000145:classification / Q000235:genetics / Q000276:immunology*; D014611:Vaccination / Q000379:methods; D014615:Vaccinia / Q000235:genetics; D019562:Viral Load; D054321:rev Gene Products, Human Immunodeficiency Virus; D054322:tat Gene Products, Human Immunodeficiency Virus
D015685:Fusion Proteins, gag-pol; D015686:Gene Products, env; D015683:Gene Products, gag; D015694:Gene Products, rev; D015696:Gene Products, tat; D018449:SAIDS Vaccines; D054321:rev Gene Products, Human Immunodeficiency Virus; C514860:rev protein, Human Immunodeficiency Virus-1; D054322:tat Gene Products, Human Immunodeficiency Virus