title: Expansion and diversification of virus-specific T cells following immunization of human immunodeficiency virus type 1 (HIV-1)-infected individuals with a recombinant modified vaccinia virus Ankara/HIV-1 Gag vaccine.
abstract: Affordable therapeutic strategies that induce sustained control of human immunodeficiency virus type 1 (HIV-1) replication and are tailored to the developing world are urgently needed. Since CD8(+) and CD4(+) T cells are crucial to HIV-1 control, stimulation of potent cellular responses by therapeutic vaccination might be exploited to reduce antiretroviral drug exposure. However, therapeutic vaccines tested to date have shown modest immunogenicity. In this study, we performed a comprehensive analysis of the changes in virus-specific CD8(+) and CD4(+) T-cell responses occurring after vaccination of 16 HIV-1-infected individuals with a recombinant modified vaccinia virus Ankara-vectored vaccine expressing the consensus HIV-1 clade A Gag p24/p17 sequences and multiple CD8(+) T-cell epitopes during highly active antiretroviral therapy. We observed significant amplification and broadening of CD8(+) and CD4(+) gamma interferon responses to vaccine-derived epitopes in the vaccinees, without rebound viremia, but not in two unvaccinated controls followed simultaneously. Vaccine-driven CD8(+) T-cell expansions were also detected by tetramer reactivity, predominantly in the CD45RA(-) CCR7(+) or CD45RA(-) CCR7(-) compartments, and persisted for at least 1 year. Expansion was associated with a marked but transient up-regulation of CD38 and perforin within days of vaccination. Gag-specific CD8(+) and CD4(+) T-cell proliferation also increased postvaccination. These data suggest that immunization with MVA.HIVA is a feasible strategy to enhance potentially protective T-cell responses in individuals with chronic HIV-1 infection.
authors.affiliation: MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford OX3 9DS, United Kingdom. ldorrell@gwmail.jr2.ox.ac.uk
authors.forename: Lucy
authors.initials: L
authors.lastname: Dorrell
authors.forename: Hongbing
authors.initials: H
authors.lastname: Yang
authors.forename: Beatrice
authors.initials: B
authors.lastname: Ondondo
authors.forename: Tao
authors.initials: T
authors.lastname: Dong
authors.forename: Kati
authors.initials: K
authors.lastname: di Gleria
authors.forename: Annie
authors.initials: A
authors.lastname: Suttill
authors.forename: Christopher
authors.initials: C
authors.lastname: Conlon
authors.forename: Denise
authors.initials: D
authors.lastname: Brown
authors.forename: Patricia
authors.initials: P
authors.lastname: Williams
authors.forename: Paul
authors.initials: P
authors.lastname: Bowness
authors.forename: Nilu
authors.initials: N
authors.lastname: Goonetilleke
authors.forename: Tim
authors.initials: T
authors.lastname: Rostron
authors.forename: Sarah
authors.initials: S
authors.lastname: Rowland-Jones
authors.forename: Tomás
authors.initials: T
authors.lastname: Hanke
authors.forename: Andrew
authors.initials: A
authors.lastname: McMichael
mesh_terms: D016915:AIDS Vaccines / Q000235:genetics / Q000276:immunology*; D023241:Antiretroviral Therapy, Highly Active; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000378:metabolism; D049109:Cell Proliferation; D015683:Gene Products, gag / Q000008:administration & dosage / Q000276:immunology*; D015658:HIV Infections / Q000517:prevention & control*; D015497:HIV-1 / Q000276:immunology; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000821:virology*; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D014616:Vaccinia virus / Q000276:immunology*
chemical_list: D016915:AIDS Vaccines; D015683:Gene Products, gag; D014614:Vaccines, Synthetic; D007371:Interferon-gamma