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

Vaccine. 2009 Jul 30;27(35):4857-66. doi: 10.1016/j.vaccine.2009.05.064. Epub 2009 Jun 9.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • AIDS Vaccines / administration & dosage
  • AIDS Vaccines / genetics
  • AIDS Vaccines / immunology*
  • Animals
  • CD8-Positive T-Lymphocytes / immunology
  • Genetic Vectors*
  • HIV Antibodies / blood
  • HIV-1 / genetics
  • HIV-1 / immunology*
  • Immunization, Secondary
  • Interferon-gamma / metabolism
  • Mycobacterium bovis / genetics*
  • Mycobacterium bovis / immunology
  • Papio
  • Protein Precursors / administration & dosage
  • Protein Precursors / immunology*
  • South Africa
  • Vaccines, Synthetic / genetics
  • Vaccines, Synthetic / immunology
  • Vaccines, Virosome / administration & dosage
  • Vaccines, Virosome / immunology

Substances

  • AIDS Vaccines
  • HIV Antibodies
  • Protein Precursors
  • Vaccines, Synthetic
  • Vaccines, Virosome
  • p55 gag precursor protein, Human immunodeficiency virus 1
  • Interferon-gamma