Open AccessA GRA1 DNA Vaccine Primes Cytolytic CD8+T Cells To Control AcuteToxoplasma gondiiInfection
Author(s) -
Tatiana Scorza,
Sushila D’Souza,
Marleen Laloup,
J. Dewit,
Jos De Braekeleer,
Hendrik Verschueren,
Martine Vercammen,
Kris Huygen,
Erik Jongert
Publication year - 2003
Publication title -
infection and immunity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.508
H-Index - 220
eISSN - 1070-6313
pISSN - 0019-9567
DOI - 10.1128/iai.71.1.309-316.2003
Subject(s) - biology , toxoplasma gondii , cd8 , dna vaccination , virology , cytolysis , t cell , cytotoxic t cell , immune system , immunology , t lymphocyte , in vitro , antibody , immunization , biochemistry
Protective immunity against Toxoplasma gondii is known to be mediated mainly by T lymphocytes and gamma interferon (IFN-gamma). The contribution of CD4(+) and CD8(+) T-lymphocyte subsets to protective immune responses against T. gondii infection, triggered by a GRA1 (p24) DNA vaccine, was assessed in this study. In vitro T-cell depletion experiments indicated that both CD4(+) and CD8(+) T-cell subsets produced IFN-gamma upon restimulation with a T. gondii lysate. In addition, the GRA1 DNA vaccine elicited CD8(+) T cells that were shown to have cytolytic activity against parasite-infected target cells and a GRA1-transfected cell line. C3H mice immunized with the GRA1 DNA vaccine showed 75 to 100% protection, while 0 to 25% of the mice immunized with the empty control vector survived challenge with T. gondii cysts. In vivo T-cell depletion experiments indicated that CD8(+) T cells were essential for the survival of GRA1-vaccinated C3H mice during the acute phase of T. gondii infection, while depletion of CD4(+) T cells led to an increase in brain cyst burden during the chronic phase of infection.