title: Induction of positive cellular and humoral immune responses by a prime-boost vaccine encoded with simian immunodeficiency virus gag/pol.
abstract: It is believed likely that immune responses are responsible for controlling viral load and infection. In this study, when macaques were primed with plasmid DNA encoding SIV gag and pol genes (SIVgag/pol DNA) and then boosted with replication-deficient vaccinia virus DIs recombinant expressing the same genes (rDIsSIVgag/pol), this prime-boost regimen generated higher levels of Gag-specific CD4+ and CD8+ T cell responses than did either SIVgag/pol DNA or rDIsSIVgag/pol alone. When the macaques were i.v. challenged with pathogenic simian/HIV, the prime-boost group maintained high CD4+ T cell counts and reduced plasma viral loads up to 30 wk after viral challenge, whereas the rDIsSIVgag/pol group showed only a partial attenuation of the viral infection, and the group immunized with SIVgag/pol DNA alone showed none at all. The protection levels were better correlated with the levels of virus-specific T cell responses than the levels of neutralization Ab responses. These results demonstrate that a vaccine regimen that primes with DNA and then boosts with a replication-defective vaccinia virus DIs generates anti-SIV immunity, suggesting that it will be a promising vaccine regimen for HIV-1 vaccine development.
authors.affiliation: AIDS Research Center, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Someya
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ami
authors.forename: Tadashi
authors.initials: T
authors.lastname: Nakasone
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Izumi
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Matsuo
authors.forename: Shigeo
authors.initials: S
authors.lastname: Horibata
authors.forename: Ke-Qin
authors.initials: KQ
authors.lastname: Xin
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Kenji
authors.initials: K
authors.lastname: Okuda
authors.forename: Naoki
authors.initials: N
authors.lastname: Yamamoto
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Honda
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis* / Q000097:blood; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002478:Cells, Cultured; D005260:Female; D005434:Flow Cytometry; D015683:Gene Products, gag / Q000235:genetics* / Q000276:immunology*; D015684:Gene Products, pol / Q000235:genetics* / Q000276:immunology*; D005822:Genetic Vectors; D007111:Immunity, Cellular; D007117:Immunization, Secondary; D007371:Interferon-gamma / Q000378:metabolism; D007700:Kinetics; D008252:Macaca fascicularis; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology / Q000517:prevention & control; D015302:Simian Immunodeficiency Virus / Q000235:genetics / Q000276:immunology*; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology*; D014616:Vaccinia virus
chemical_list: D000914:Antibodies, Viral; D015683:Gene Products, gag; D015684:Gene Products, pol; D019444:Vaccines, DNA; D007371:Interferon-gamma