Immunization with recombinant canarypox vectors expressing membrane-anchored glycoprotein 120 followed by glycoprotein 160 boosting fails to generate antibodies that neutralize R5 primary isolates of human immunodeficiency virus type 1.

Journal Article (Clinical Trial;Journal Article)

Antibodies generated by candidate HIV-1 vaccines in a phase I clinical trial were assessed for neutralizing activity with a panel of eight well-characterized, genetically diverse clade B primary isolates having an R5 phenotype. The vaccines consisted of one of three different recombinant canarypox vectors expressing membrane-anchored HIV-1(MN)gp120 (ALVAC vCP205, vCP1433, and vCP1452) followed by boosting with a soluble gp160 hybrid consisting of MNgp120 and the majority of gp41 from strain IIIB. Serum samples from a subset of volunteers in each arm of the trial, containing moderate to high titers of neutralizing antibodies to HIV-1 MN, were analyzed. Competition assays with peptides revealed that the majority of neutralizing activity was specific for the MN-V3 loop. Despite MN-specific neutralization titers that sometimes exceeded 1:500, no neutralization of primary isolates was detected and, in some cases, mild infection enhancement was observed. In addition, little or no neutralization of the HIV-1 IIIB heterologous T cell line-adapted strain of virus was detected. These results reinforce the notion that monovalent HIV-1 ENV is a poor immunogen for generating cross-reactive neutralizing antibodies.

Full Text

Duke Authors

Cited Authors

  • Bures, R; Gaitan, A; Zhu, T; Graziosi, C; McGrath, KM; Tartaglia, J; Caudrelier, P; El Habib, R; Klein, M; Lazzarin, A; Stablein, DM; Deers, M; Corey, L; Greenberg, ML; Schwartz, DH; Montefiori, DC

Published Date

  • December 10, 2000

Published In

Volume / Issue

  • 16 / 18

Start / End Page

  • 2019 - 2035

PubMed ID

  • 11153085

International Standard Serial Number (ISSN)

  • 0889-2229

Digital Object Identifier (DOI)

  • 10.1089/088922200750054756


  • eng

Conference Location

  • United States