Exploratory study on Th1 epitope-induced protective immunity against Coxiella burnetii infection.

ABSTRACT: Coxiella burnetii is a Gram-negative bacterium that causes Q fever in humans. In the present study, 131 candidate peptides were selected from the major immunodominant proteins (MIPs) of C. burnetii due to their high-affinity binding capacity for the MHC class II molecule H2 I-A(b) based on bioinformatic analyses. Twenty-two of the candidate peptides with distinct MIP epitopes were well recognized by the IFN-? recall responses of CD4(+) T cells from mice immunized with parental proteins in an ELISPOT assay. In addition, 7 of the 22 peptides could efficiently induce CD4(+) T cells from mice immunized with C. burnetii to rapidly proliferate and significantly increase IFN-? production. Significantly higher levels of IL-2, IL-12p70, IFN-?, and TNF-? were also detected in serum from mice immunized with a pool of the 7 peptides. Immunization with the pool of 7 peptides, but not the individual peptides, conferred a significant protection against C. burnetii infection in mice, suggesting that these Th1 peptides could work together to efficiently activate CD4(+) T cells to produce the Th1-type immune response against C. burnetii infection. These observations could contribute to the rational design of molecular vaccines for Q fever.

SUBMITTER: Xiong X 

PROVIDER: S-EPMC3907486 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature