J Med Microbiol International Journal of Systematic and Evolutionary Microbiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Héchard, C.
Right arrow Articles by Rodolakis, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Héchard, C.
Right arrow Articles by Rodolakis, A.
Agricola
Right arrow Articles by Héchard, C.
Right arrow Articles by Rodolakis, A.
J Med Microbiol 53 (2004), 861-868; DOI: 10.1099/jmm.0.05442-0
© 2004 Society for General Microbiology
ISSN 0022-2615

Molecular cloning of the Chlamydophila abortus groEL gene and evaluation of its protective efficacy in a murine model by genetic vaccination

Céline Héchard, Olivier Grépinet and Annie Rodolakis

Unité de Pathologie Infectieuse et Immunologie, INRA-Centre de Tours, 37380 Nouzilly, France

Correspondence Olivier Grépinet grepinet{at}tours.inra.fr

Received August 21, 2003
Accepted May 17, 2004

The immunogenicity and protective effect of a DNA vaccine encoding the heat-shock protein (Hsp) GroEL of Chlamydophila abortus AB7, an obligate intracellular bacterium that causes abortion in sheep, was evaluated in pregnant and non-pregnant mouse models. The C. abortus groEL gene was cloned by screening a genomic library constructed in {lambda}FIX II arms with a nucleic acid probe corresponding to the central portion of the groEL gene from C. abortus. Sequence analysis of a positive clone revealed an open reading frame of 1632 bp encoding a 544 amino acid polypeptide with a predicted molecular mass of 58 256 Da and highly similar to GroEL of Chlamydia trachomatis (93 %) and Chlamydophila pneumoniae (94 %). As observed in other sequenced chlamydial genomes, the groEL gene belongs to an operon comprising another gene encoding the Hsp GroES. OF1 outbred mice were immunized intramuscularly with plasmid DNA carrying the groEL gene three times at 3 week intervals and challenged 2 weeks after the last DNA injection. In pregnant mice, no reduction in abortion was observed and the DNA vaccination failed to reduce the bacterial infection in the placenta and spleen of mice. Nevertheless, partial protection of fetuses was obtained. Immunization of non-pregnant mice with the groEL gene resulted in a specific humoral response with the predominant IgG2a isotype, suggesting a Th1-type immune response. The anti-GroEL antibodies showed no neutralizing effect in vitro on C. abortus infectivity. Although the DNA vaccine induced a delayed-type hypersensitivity response, it failed to elicit an efficient cellular immune response since the mice were not protected against bacterial challenge.

Abbreviations: DTH, delayed-type hypersensitivity; Hsp, heat-shock protein; MOMP, major outer-membrane protein.

The GenBank accession number for the groES–groEL operon of Chlamydophila abortus is AY052785.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
INT J SYST EVOL MICROBIOL J MED MICROBIOL MICROBIOLOGY J GEN VIROL ALL SGM JOURNALS
Copyright © 2004 Society for General Microbiology.