title: Control of simian immunodeficiency virus replication by vaccine-induced Gag- and Vif-specific CD8+ T cells.
abstract: For development of an effective T cell-based AIDS vaccine, it is critical to define the antigens that elicit the most potent responses. Recent studies have suggested that Gag-specific and possibly Vif/Nef-specific CD8(+) T cells can be important in control of the AIDS virus. Here, we tested whether induction of these CD8(+) T cells by prophylactic vaccination can result in control of simian immunodeficiency virus (SIV) replication in Burmese rhesus macaques sharing the major histocompatibility complex class I (MHC-I) haplotype 90-010-Ie associated with dominant Nef-specific CD8(+) T-cell responses. In the first group vaccinated with Gag-expressing vectors (n = 5 animals), three animals that showed efficient Gag-specific CD8(+) T-cell responses in the acute phase postchallenge controlled SIV replication. In the second group vaccinated with Vif- and Nef-expressing vectors (n = 6 animals), three animals that elicited Vif-specific CD8(+) T-cell responses in the acute phase showed SIV control, whereas the remaining three with Nef-specific but not Vif-specific CD8(+) T-cell responses failed to control SIV replication. Analysis of 18 animals, consisting of seven unvaccinated noncontrollers and the 11 vaccinees described above, revealed that the sum of Gag- and Vif-specific CD8(+) T-cell frequencies in the acute phase was inversely correlated with plasma viral loads in the chronic phase. Our results suggest that replication of the AIDS virus can be controlled by vaccine-induced subdominant Gag/Vif epitope-specific CD8(+) T cells, providing a rationale for the induction of Gag- and/or Vif-specific CD8(+) T-cell responses by prophylactic AIDS vaccines.
authors.affiliation: AIDS Research Center, National Institute of Infectious Diseases, Toyama, Shinjuku-ku, Tokyo, Japan.
authors.forename: Nami
authors.initials: N
authors.lastname: Iwamoto
authors.forename: Naofumi
authors.initials: N
authors.lastname: Takahashi
authors.forename: Sayuri
authors.initials: S
authors.lastname: Seki
authors.forename: Takushi
authors.initials: T
authors.lastname: Nomura
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Makoto
authors.initials: M
authors.lastname: Inoue
authors.forename: Tsugumine
authors.initials: T
authors.lastname: Shu
authors.forename: Taeko K
authors.initials: TK
authors.lastname: Naruse
authors.forename: Akinori
authors.initials: A
authors.lastname: Kimura
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Matano
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D015683:Gene Products, gag / Q000276:immunology*; D016346:Gene Products, vif / Q000276:immunology*; D008253:Macaca mulatta; D015302:Simian Immunodeficiency Virus / Q000502:physiology*; D019562:Viral Load; D014765:Viral Vaccines / Q000276:immunology*; D014779:Virus Replication / Q000276:immunology*
chemical_list: D015683:Gene Products, gag; D016346:Gene Products, vif; D014765:Viral Vaccines