Characterization of a single-cycle rabies virus-based vaccine vector

J Virol. 2010 Mar;84(6):2820-31. doi: 10.1128/JVI.01870-09. Epub 2010 Jan 6.

Abstract

Recombinant rabies virus (RV)-based vectors have demonstrated their efficacy in generating long-term, antigen-specific immune responses in murine and monkey models. However, replication-competent viral vectors pose significant safety concerns due to vector pathogenicity. RV pathogenicity is largely attributed to its glycoprotein (RV-G), which facilitates the attachment and entry of RV into host cells. We have developed a live, single-cycle RV by deletion of the G gene from an RV vaccine vector expressing HIV-1 Gag (SPBN-DeltaG-Gag). Passage of SPBN-DeltaG-Gag on cells stably expressing RV-G allowed efficient propagation of the G-deleted RV. The in vivo immunogenicity data comparing single-cycle RV to a replication-competent control (BNSP-Gag) showed lower RV-specific antibodies; however, the overall isotype profiles (IgG2a/IgG1) were similar for the two vaccine vectors. Despite this difference, mice immunized with SPBN-DeltaG-Gag and BNSP-Gag mounted similar levels of Gag-specific CD8(+) T-cell responses as measured by major histocompatibility complex class I Gag-tetramer staining, gamma interferon-enzyme-linked immunospot assay, and cytotoxic T-cell assay. Moreover, these cellular responses were maintained equally at immunization titers as low as 10(3) focus-forming units for both RV vaccine vectors. CD8(+) T-cell responses were significantly enhanced by a boost with a single-cycle RV complemented with a heterologous vesicular stomatitis virus glycoprotein. These findings demonstrate that single-cycle RV is an effective alternative to replication-competent RV vectors for future development of vaccines for HIV-1 and other infectious diseases.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Antibodies, Viral / genetics
  • Antibodies, Viral / immunology
  • CD8-Positive T-Lymphocytes / immunology
  • Female
  • Gene Products, gag / genetics
  • Gene Products, gag / metabolism
  • Genetic Vectors* / genetics
  • Genetic Vectors* / immunology
  • Humans
  • Interferon-gamma / immunology
  • Mice
  • Mice, Inbred BALB C
  • Rabies / immunology
  • Rabies / prevention & control*
  • Rabies Vaccines* / genetics
  • Rabies Vaccines* / immunology
  • Rabies virus / immunology*
  • Rabies virus / pathogenicity
  • T-Lymphocytes, Cytotoxic / immunology
  • Virus Internalization
  • Virus Replication / physiology

Substances

  • Antibodies, Viral
  • Gene Products, gag
  • Rabies Vaccines
  • Interferon-gamma