A recombinant non-pathogenic Leishmania vaccine expressing human immunodeficiency virus 1 (HIV-1) Gag elicits cell-mediated immunity in mice and decreases HIV-1 replication in human tonsillar tissue following exposure to HIV-1 infection

J Gen Virol. 2007 Jan;88(Pt 1):217-225. doi: 10.1099/vir.0.81995-0.


Live-vector human immunodeficiency virus (HIV) vaccines are an integral part of a number of HIV vaccine regimens currently under evaluation that have yielded promising results in pre-clinical testing. In this report, a non-pathogenic protozoan parasitic vector, Leishmania tarentolae, which shares common target cells with HIV-1, was used to express full-length HIV-1 Gag protein. Immunization of BALB/c mice with recombinant L. tarentolae led to the expansion of HIV-1 Gag-specific T cells and stimulated CD8(+) T cells to produce gamma interferon in response to specific viral Gag epitopes. A booster immunization with recombinant L. tarentolae elicited effector memory HIV-1 Gag-specific CD4(+) T lymphocytes and increased antibody titres against HIV-1 Gag. Most importantly, immunization of human tonsillar tissue cultured ex vivo with Gag-expressing L. tarentolae vaccine vector elicited a 75% decrease in virus replication following exposure of the immunized tonsils to HIV-1 infection. These results demonstrated that recombinant L. tarentolae is capable of eliciting effective immune responses in mice and human systems, respectively, and suggest that this novel non-pathogenic recombinant vaccine vector shows excellent promise as a vaccination strategy against HIV-1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • AIDS Vaccines / administration & dosage
  • AIDS Vaccines / immunology*
  • Animals
  • Antibody Specificity
  • Gene Products, gag / administration & dosage
  • Gene Products, gag / biosynthesis
  • Gene Products, gag / genetics
  • Gene Products, gag / immunology*
  • Genetic Vectors
  • HIV Infections / prevention & control*
  • HIV-1 / genetics*
  • HIV-1 / immunology
  • Humans
  • Immunity, Cellular
  • Leishmania / genetics*
  • Mice
  • Mice, Inbred BALB C
  • Vaccines, Synthetic
  • Virus Replication


  • AIDS Vaccines
  • Gene Products, gag
  • Vaccines, Synthetic