IAI FigSearch
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
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
Services
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 arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Zusman, T.
Right arrow Articles by Segal, G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Zusman, T.
Right arrow Articles by Segal, G.
Infection and Immunity, July 2003, p. 3714-3723, Vol. 71, No. 7
0019-9567/03/$08.00+0     DOI: 10.1128/IAI.71.7.3714-3723.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

Functional Similarities between the icm/dot Pathogenesis Systems of Coxiella burnetii and Legionella pneumophila

Tal Zusman, Gal Yerushalmi, and Gil Segal*

Department of Molecular Microbiology & Biotechnology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Ramat-Aviv, Tel-Aviv 69978, Israel

Received 29 January 2003/ Returned for modification 17 March 2003/ Accepted 31 March 2003

Coxiella burnetii, the etiological agent of Q fever, is an obligate intracellular pathogen, whereas Legionella pneumophila, the causative agent of Legionnaires' disease, is a facultative intracellular pathogen. During infection of humans both of these pathogens multiply in alveolar macrophages inside a closed phagosome. L. pneumophila intracellular multiplication was shown to be dependent on the icm/dot system, which probably encodes a type IV-related translocation apparatus. Recently, genes homologous to all of the L. pneumophila icm/dot genes (besides icmR) were found in C. burnetii. To explore the similarities and differences between the icm/dot pathogenesis systems of these two pathogens, interspecies complementation analysis was performed. Nine C. burnetii icm homologous genes (icmT, icmS, icmQ, icmP, icmO, icmJ, icmB, icmW, and icmX) were cloned under regulation of the corresponding L. pneumophila icm genes and examined for the ability to complement L. pneumophila mutants with mutations in these genes. The C. burnetii icmS and icmW homologous genes were found to complement the corresponding L. pneumophila icm mutants to wild-type levels of intracellular growth in both HL-60-derived human macrophages and Acanthamoeba castellanii. In addition, the C. burnetii icmT homologous gene was found to completely complement an L. pneumophila insertion mutant for intracellular growth in HL-60-derived human macrophages, but it only partially complemented the same mutant for intracellular growth in A. castellanii. Moreover, as previously shown for L. pneumophila, the proteins encoded by the C. burnetii icmS and icmW homologous genes were found to interact with one another, and interspecies protein interaction was observed as well. Our results strongly indicate that the Icm/Dot pathogenesis systems of C. burnetii and L. pneumophila have common features.


* Corresponding author. Mailing address: Department of Molecular Microbiology & Biotechnology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Ramat-Aviv, Tel-Aviv 69978, Israel. Phone: 972-3-6405287. Fax: 972-3-6409407. E-mail: GilS{at}tauex.tau.ac.il.

Editor: J. T. Barbieri


Infection and Immunity, July 2003, p. 3714-3723, Vol. 71, No. 7
0019-9567/03/$08.00+0     DOI: 10.1128/IAI.71.7.3714-3723.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.




This article has been cited by other articles:




Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 2003 by the American Society for Microbiology. All rights reserved.