Enhanced simian immunodeficiency virus-specific immune responses in macaques induced by priming with recombinant Semliki Forest virus and boosting with modified vaccinia virus Ankara.
The immunogenicity of two vector-based vaccines, either given alone or in a prime-boost regimen, was investigated. Cynomolgus macaques were immunised with modified vaccinia virus Ankara (MVA) expressing simian immunodeficiency virus (SIV)macJ5 env, gag-pol, nef, rev, and tat genes (MVA-SIVmac) or primed with a Semliki forest virus (SFV) vaccine expressing the same genes (SFV-SIVmac) and boosted with MVA-SIVmac. Generally, antibody responses, T-cell proliferative responses and cytotoxic T-cell responses remained low or undetectable in vaccinees receiving MVA-SIVmac or SFV-SIVmac alone. In contrast, monkeys who first received SFV-SIVmac twice and then were boosted with MVA-SIVmac showed increased antibody responses as well as high T-cell proliferative responses. Three of these vaccinees had cytotoxic T-lymphocytes directed against three or four of the gene products. No evidence of protection was seen against an intrarectal heterologous SIVsm challenge given 3 months after the last immunisation. The study demonstrates a prime-boost strategy that efficiently induces both humoral and cellular immune responses.
Nilsson
C
C
Swedish Institute for Infectious Disease Control, SE-171 82, Solna, Sweden. charlotta.nilsson@smi.ki.se
Mäkitalo
B
B
Berglund
P
P
Bex
F
F
Liljeström
P
P
Sutter
G
G
Erfle
V
V
ten Haaft
P
P
Heeney
J
J
Biberfeld
G
G
Thorstensson
R
R
D016915:AIDS Vaccines / Q000008:administration & dosage / Q000302:isolation & purification; D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis; D000918:Antibody Specificity; D005822:Genetic Vectors; D007111:Immunity, Cellular; D007117:Immunization, Secondary; D008213:Lymphocyte Activation; D018655:Lymphocyte Count; D008252:Macaca fascicularis; D012367:RNA, Viral / Q000097:blood; D018449:SAIDS Vaccines / Q000008:administration & dosage* / Q000235:genetics; D012672:Semliki forest virus / Q000235:genetics / Q000276:immunology*; D015302:Simian Immunodeficiency Virus / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics; D014616:Vaccinia virus / Q000235:genetics / Q000276:immunology*
D016915:AIDS Vaccines; D000914:Antibodies, Viral; D012367:RNA, Viral; D018449:SAIDS Vaccines; D014614:Vaccines, Synthetic