Open AccessImmunization with dendritic cells loaded with α‐galactosylceramide at priming phase, but not at boosting phase, enhances cytotoxic T lymphocyte activity against infection by intracellular bacteria
Author(s) -
Enomoto Noriyuki,
Nagata Toshi,
Suda Takafumi,
Uchijima Masato,
Nakamura Yutaro,
Chida Kingo,
Nakamura Hirotoshi,
Koide Yukio
Publication year - 2007
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1111/j.1574-695x.2007.00316.x
Subject(s) - ctl* , cytotoxic t cell , priming (agriculture) , biology , immune system , cd8 , immunology , intracellular parasite , immunization , epitope , listeriolysin o , microbiology and biotechnology , listeria monocytogenes , antigen , listeria , in vitro , bacteria , biochemistry , botany , germination , genetics
We evaluated the effect of immunization with dendritic cells (DCs) pulsed with α‐galactosylceramide (αGalCer) and listeriolysin O (LLO) 91‐99 peptide, a dominant cytotoxic T lymphocyte (CTL) epitope of Listeria monocytogenes by observing the responses of specific CD8 + T cells and in vivo CTL activity. DCs were pulsed with various combinations of αGalCer and LLO91‐99 peptide and administered to BALB/c mice. Immunization with DCs pulsed with αGalCer and LLO91‐99 at priming phase and with DCs pulsed with LLO91‐99 alone at boosting phase induced stronger in vivo CTL activity, reduced the bacterial load in spleens of Listeria ‐challenged mice and augmented CD62L + CD8 + central memory T cells compared with other immunization protocols. The blockade of interferon‐γ (IFN‐γ) at boosting phase reversed the induction of CD8 + central memory T cells and reduced the bacterial load in spleens of Listeria ‐challenged mice immunized with DCs pulsed with αGalCer and LLO91‐99 at both phases, suggesting that αGalCer at boosting phase has deleterious effects through IFN‐γ production. These results indicate that immunization with DCs pulsed with CTL epitope peptide together with αGalCer at priming phase, but not at boosting phase, is feasible for eliciting a specific CTL activity and protective immunity against infection of intracellular bacteria.