title: Neutralization of primary HIV-1 SF13 can be detected in extended incubation phase assays with sera from monkeys immunized with recombinant HIV-1 SF2 gp120.
abstract: Phase III efficacy trials of recombinant human immunodeficiency virus type 1 (HIV-1) envelope glycoproteins were postponed. In Phase I and II trials these candidate vaccines had failed to induce neutralizing antibodies against virus which had been isolated by co-culture with human peripheral blood mononuclear cells (PBMC). The aim of the present study was to determine assay conditions for detecting neutralization of primary HIV-1 isolates with sera from immunized individuals. We show that in two immunogenicity trials in rhesus macaques, recombinant HIV-1 SF2 gp120 induced antibodies which neutralized the primary HIV-1 SF13 isolate. Statistically significant in vitro neutralization required assays in which the incubation phase was extended. Sterile immunity was only seen with the highest level of neutralization, induced by a recombinant prime, peptide boost strategy. We recommend that neutralization assays with extended incubation phases should be used to monitor Phase III efficacy trials.
authors.affiliation: Laboratory of Virology, Department of Microbiology, Institute of Tropical Medicine, Antwerp, Belgium. davis@bprc.nl
authors.forename: David
authors.initials: D
authors.lastname: Davis
authors.forename: Helen
authors.initials: H
authors.lastname: Donners
authors.forename: Betty
authors.initials: B
authors.lastname: Willems
authors.forename: Karin
authors.initials: K
authors.lastname: Lövgren-Bengtsson
authors.forename: Lennart
authors.initials: L
authors.lastname: Akerblom
authors.forename: Guido
authors.initials: G
authors.lastname: Vanham
authors.forename: Susan
authors.initials: S
authors.lastname: Barnett
authors.forename: Bror
authors.initials: B
authors.lastname: Morein
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Heeney
authors.forename: Guido
authors.initials: G
authors.lastname: van der Groen
mesh_terms: D016915:AIDS Vaccines / Q000276:immunology*; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018920:Coculture Techniques; D003713:Dendritic Cells / Q000276:immunology; D015483:HIV Antibodies / Q000032:analysis / Q000096:biosynthesis; D015488:HIV Antigens / Q000032:analysis / Q000276:immunology; D015699:HIV Envelope Protein gp120 / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D008253:Macaca mulatta; D009000:Monocytes / Q000276:immunology; D009500:Neutralization Tests; D014614:Vaccines, Synthetic / Q000276:immunology
chemical_list: D016915:AIDS Vaccines; D015483:HIV Antibodies; D015488:HIV Antigens; D015699:HIV Envelope Protein gp120; D014614:Vaccines, Synthetic