title: A prime-boost immunisation regimen using recombinant BCG and Pr55(gag) virus-like particle vaccines based on HIV type 1 subtype C successfully elicits Gag-specific responses in baboons.
abstract: Mycobacterium bovis BCG is considered an attractive live bacterial vaccine vector. In this study, we investigated the immune response of baboons to a primary vaccination with recombinant BCG (rBCG) constructs expressing the gag gene from a South African HIV-1 subtype C isolate, and a boost with HIV-1 subtype C Pr55(gag) virus-like particles (Gag VLPs). Using an interferon enzyme-linked immunospot assay, we show that although these rBCG induced only a weak or an undetectable HIV-1 Gag-specific response on their own, they efficiently primed for a Gag VLP boost, which strengthened and broadened the immune responses. These responses were predominantly CD8+ T cell-mediated and recognised similar epitopes as those targeted by humans with early HIV-1 subtype C infection. In addition, a Gag-specific humoral response was elicited. These data support the development of HIV-1 vaccines based on rBCG and Pr55(gag) VLPs.
authors.affiliation: Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Anzio Road, Observatory, Cape Town, South Africa.
authors.forename: Gerald K
authors.initials: GK
authors.lastname: Chege
authors.forename: Robin
authors.initials: R
authors.lastname: Thomas
authors.forename: Enid G
authors.initials: EG
authors.lastname: Shephard
authors.forename: Ann
authors.initials: A
authors.lastname: Meyers
authors.forename: William
authors.initials: W
authors.lastname: Bourn
authors.forename: Carolyn
authors.initials: C
authors.lastname: Williamson
authors.forename: James
authors.initials: J
authors.lastname: Maclean
authors.forename: Clive M
authors.initials: CM
authors.lastname: Gray
authors.forename: Edward P
authors.initials: EP
authors.lastname: Rybicki
authors.forename: Anna-Lise
authors.initials: AL
authors.lastname: Williamson
mesh_terms: D016915:AIDS Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D005822:Genetic Vectors; D015483:HIV Antibodies / Q000097:blood; D015497:HIV-1 / Q000235:genetics / Q000276:immunology*; D007117:Immunization, Secondary; D007371:Interferon-gamma / Q000378:metabolism; D009163:Mycobacterium bovis / Q000235:genetics* / Q000276:immunology; D010215:Papio; D011498:Protein Precursors / Q000008:administration & dosage / Q000276:immunology*; D013019:South Africa; D014614:Vaccines, Synthetic / Q000235:genetics / Q000276:immunology; D022721:Vaccines, Virosome / Q000008:administration & dosage / Q000276:immunology
chemical_list: D016915:AIDS Vaccines; D015483:HIV Antibodies; D011498:Protein Precursors; D014614:Vaccines, Synthetic; D022721:Vaccines, Virosome; C059767:p55 gag precursor protein, Human immunodeficiency virus 1; D007371:Interferon-gamma