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 Google Scholar
Google Scholar
Right arrow Articles by Hansen, J. K.
Right arrow Articles by Forest, K. T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Hansen, J. K.
Right arrow Articles by Forest, K. T.

 Previous Article  |  Next Article 

Infection and Immunity, August 2007, p. 4138-4147, Vol. 75, No. 8
0019-9567/07/$08.00+0     doi:10.1128/IAI.02015-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Conserved Regions from Neisseria gonorrhoeae Pilin Are Immunosilent and Not Immunosuppressive{triangledown}

Johanna K. Hansen, Karen P. Demick, John M. Mansfield, and Katrina T. Forest*

Department of Bacteriology, University of Wisconsin—Madison, Madison, Wisconsin 53706

Received 22 December 2006/ Returned for modification 4 April 2007/ Accepted 29 May 2007

PilE is the primary subunit of type IV pili from Neisseria gonorrhoeae and contains a surface-exposed hypervariable region thought to be one feature of pili that has prevented development of a pilin-based vaccine. We have created a three-dimensional structure-based antigen by replacing the hypervariable region of PilE with an aspartate-glutamine linker chosen from the sequence of Pseudomonas aeruginosa PilA. We then characterized murine immune responses to this novel protein to determine if conserved PilE regions could serve as a vaccine candidate. The control PilE protein elicited strong T-cell-dependent B-cell responses that are specific to epitopes in both the hypervariable deletion and control proteins. In contrast, the hypervariable deletion protein was unable to elicit an immune response in mice, suggesting that in the absence of the hypervariable region, the conserved regions of PilE alone are not sufficient for antibody production. Further analysis of these PilE proteins with suppressor cell assays showed that neither suppresses T- or B-cell responses, and flow cytometry experiments suggested that they do not exert suppressor effects by activating T regulatory cells. Our results show that in the murine model, the hypervariable region of PilE is required to activate immune responses to pilin, whereas the conserved regions are unusually nonimmunogenic. In addition, we show that both hypervariable and conserved regions of pilin are not suppressive, suggesting that PilE does not cause the decrease in T-cell populations observed during gonococcal cervicitis.

* Corresponding author. Mailing address: Department of Bacteriology, University of Wisconsin—Madison, 420 Henry Mall, Madison, WI 53706. Phone: (608) 265-3566. Fax: (608) 262-9282. E-mail: forest{at}bact.wisc.edu

{triangledown} Published ahead of print on 11 June 2007.

Editor: V. J. DiRita

Infection and Immunity, August 2007, p. 4138-4147, Vol. 75, No. 8
0019-9567/07/$08.00+0     doi:10.1128/IAI.02015-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.





Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»