This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Howe, D. Articles by Heinzen, R. A. Search for Related Content PubMed PubMed Citation Articles by Howe, D. Articles by Heinzen, R. A.

 Previous Article  |  Next Article 

Infection and Immunity, September 2002, p. 5140-5147, Vol. 70, No. 9
0019-9567/02/$04.00+0     DOI: 10.1128/IAI.70.9.5140-5147.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.

Nitric Oxide Inhibits Coxiella burnetii Replication and Parasitophorous Vacuole Maturation

Department of Molecular Biology, University of Wyoming, Laramie, Wyoming 82071-3944

Received 23 January 2002/ Returned for modification 11 April 2002/ Accepted 25 May 2002

Nitric oxide is a recognized cytotoxic effector against facultative and obligate intracellular bacteria. This study examined the effect of nitric oxide produced by inducible nitric oxide synthase (iNOS) up-regulated in response to cytokine stimulation, or by a synthetic nitric oxide donor, on replication of obligately intracellular Coxiella burnetii in murine L-929 cells. Immunoblotting and nitrite assays revealed that C. burnetii infection of L-929 cells augments expression of iNOS up-regulated in response to gamma interferon (IFN-) and tumor necrosis factor alpha (TNF-). Infection in the absence of cytokine stimulation did not result in demonstrable up-regulation of iNOS expression or in increased nitrite production. Nitrite production by cytokine-treated cells was significantly inhibited by the iNOS inhibitor S-methylisothiourea (SMT). Treatment of infected cells with IFN- and TNF- or the synthetic nitric oxide donor 2,2'-(hydroxynitrosohydrazino)bis-ethanamine (DETA/NONOate) had a bacteriostatic effect on C. burnetii replication. Inhibition of replication was reversed upon addition of SMT to the culture medium of cytokine-treated cells. Microscopic analysis of infected cells revealed that nitric oxide (either cytokine induced or donor derived) inhibited formation of the mature (large) parasitophorous vacuole that is characteristic of C. burnetii infection of host cells. Instead, exposure of infected cells to nitric oxide resulted in the formation of multiple small, acidic vacuoles usually containing one C. burnetii cell. Removal of nitrosative stress resulted in the coalescence of small vacuoles to form a large vacuole harboring multiple C. burnetii cells. These experiments demonstrate that nitric oxide reversibly inhibits replication of C. burnetii and formation of the parasitophorous vacuole.

Editor: A. D. O'Brien

This article has been cited by other articles:

• Luhrmann, A., Roy, C. R. (2007). Coxiella burnetii Inhibits Activation of Host Cell Apoptosis through a Mechanism That Involves Preventing Cytochrome c Release from Mitochondria. Infect. Immun. 75: 5282-5289 [Abstract] [Full Text]  
• Andoh, M., Zhang, G., Russell-Lodrigue, K. E., Shive, H. R., Weeks, B. R., Samuel, J. E. (2007). T Cells Are Essential for Bacterial Clearance, and Gamma Interferon, Tumor Necrosis Factor Alpha, and B Cells Are Crucial for Disease Development in Coxiella burnetii Infection in Mice. Infect. Immun. 75: 3245-3255 [Abstract] [Full Text]  
• Shannon, J. G., Howe, D., Heinzen, R. A. (2005). Virulent Coxiella burnetii does not activate human dendritic cells: Role of lipopolysaccharide as a shielding molecule. Proc. Natl. Acad. Sci. USA 102: 8722-8727 [Abstract] [Full Text]  
• Brennan, R. E., Russell, K., Zhang, G., Samuel, J. E. (2004). Both Inducible Nitric Oxide Synthase and NADPH Oxidase Contribute to the Control of Virulent Phase I Coxiella burnetii Infections. Infect. Immun. 72: 6666-6675 [Abstract] [Full Text]  
• Zamboni, D. S., Rabinovitch, M. (2004). Phagocytosis of Apoptotic Cells Increases the Susceptibility of Macrophages to Infection with Coxiella burnetii Phase II through Down-Modulation of Nitric Oxide Production. Infect. Immun. 72: 2075-2080 [Abstract] [Full Text]  
• Zamboni, D. S., Rabinovitch, M. (2003). Nitric Oxide Partially Controls Coxiella burnetii Phase II Infection in Mouse Primary Macrophages. Infect. Immun. 71: 1225-1233 [Abstract] [Full Text]