A Two-Component DNA-Prime/Protein-Boost Vaccination Strategy for Eliciting Long-Term, Protective T Cell Immunity against Trypanosoma cruzi

Shivali Gupta, Nisha J. Garg

Research output: Contribution to journalArticle

27 Scopus citations

Abstract

In this study, we evaluated the long-term efficacy of a two-component subunit vaccine against Trypanosoma cruzi infection. C57BL/6 mice were immunized with TcG2/TcG4 vaccine delivered by a DNA-prime/Protein-boost (D/P) approach and challenged with T. cruzi at 120 or 180 days post-vaccination (dpv). We examined whether vaccine-primed T cell immunity was capable of rapid expansion and intercepting the infecting T. cruzi. Our data showed that D/P vaccine elicited CD4+ (30-38%) and CD8+ (22-42%) T cells maintained an effector phenotype up to 180 dpv, and were capable of responding to antigenic stimulus or challenge infection by a rapid expansion (CD8>CD4) with type 1 cytokine (IFNγ+ and TFNα+) production and cytolytic T lymphocyte (CTL) activity. Subsequently, challenge infection at 120 or 180 dpv, resulted in 2-3-fold lower parasite burden in vaccinated mice than was noted in unvaccinated/infected mice. Co-delivery of IL-12- and GMCSF-encoding expression plasmids provided no significant benefits in enhancing the anti-parasite efficacy of the vaccine-induced T cell immunity. Booster immunization (bi) with recombinant TcG2/TcG4 proteins 3-months after primary vaccine enhanced the protective efficacy, evidenced by an enhanced expansion (1.2-2.8-fold increase) of parasite-specific, type 1 CD4+ and CD8+ T cells and a potent CTL response capable of providing significantly improved (3-4.5-fold) control of infecting T. cruzi. Further, CD8+T cells in vaccinated/bi mice were predominantly of central memory phenotype, and capable of responding to challenge infection 4-6-months post bi by a rapid expansion to a poly-functional effector phenotype, and providing a 1.5-2.3-fold reduction in tissue parasite replication. We conclude that the TcG2/TcG4 D/P vaccine provided long-term anti-T. cruzi T cell immunity, and bi would be an effective strategy to maintain or enhance the vaccine-induced protective immunity against T. cruzi infection and Chagas disease.

Original languageEnglish (US)
Article numbere1004828
JournalPLoS pathogens
Volume11
Issue number5
DOIs
StatePublished - May 1 2015

ASJC Scopus subject areas

  • Parasitology
  • Microbiology
  • Immunology
  • Molecular Biology
  • Genetics
  • Virology

Fingerprint Dive into the research topics of 'A Two-Component DNA-Prime/Protein-Boost Vaccination Strategy for Eliciting Long-Term, Protective T Cell Immunity against Trypanosoma cruzi'. Together they form a unique fingerprint.

  • Cite this