Protection against Mucosal SHIV Challenge by Peptide and Helper-Dependent Adenovirus Vaccines.


Journal Article

Groups of rhesus macaques that had previously been immunized with HIV-1 envelope (env) peptides and first generation adenovirus serotype 5 (FG-Ad5) vaccines expressing the same peptides were immunized intramuscularly three times with helper-dependent adenovirus (HD-Ad) vaccines expressing only the HIV-1 envelope from JRFL. No gag, pol, or other SHIV genes were used for vaccination. One group of the FG-Ad5-immune animals was immunized three times with HD-Ad5 expressing env. One group was immunized by serotype-switching with HD-Ad6, HD-Ad1, and HD-Ad2 expressing env. Previous work demonstrated that serum antibody levels against env were significantly higher in the serotype-switched group than in the HD-Ad5 group. In this study, neutralizing antibody and T cell responses were compared between the groups before and after rectal challenge with CCR5-tropic SHIV-SF162P3. When serum samples were assayed for neutralizing antibodies, only weak activity was observed. T cell responses against env epitopes were higher in the serotype-switched group. When these animals were challenged rectally with SHIV-SF162P3, both the Ad5 and serotype-switch groups significantly reduced peak viral loads 2 to 10-fold 2 weeks after infection. Peak viral loads were significantly lower for the serotype-switched group as compared to the HD-Ad5-immunized group. Viral loads declined over 18 weeks after infection with some animals viremia reducing nearly 4 logs from the peak. These data demonstrate significant mucosal vaccine effects after immunization with only env antigens. These data also demonstrate HD-Ad vectors are a robust platform for vaccination.

Full Text

Duke Authors

Cited Authors

  • Weaver, EA; Nehete, PN; Nehete, BP; Buchl, SJ; Palmer, D; Montefiori, DC; Ng, P; Sastry, KJ; Barry, MA

Published Date

  • December 1, 2009

Published In

Volume / Issue

  • 1 / 3

Start / End Page

  • 920 -

PubMed ID

  • 20107521

Pubmed Central ID

  • 20107521

Electronic International Standard Serial Number (EISSN)

  • 1999-4915

Digital Object Identifier (DOI)

  • 10.3390/v1030920


  • eng

Conference Location

  • Switzerland