The Gram-negative bacterium, Neisseria gonorrhoeae, is the only causative agent of the sexually transmitted disease gonorrhea. One important facet of gonococcal pathogenesis is the process of pilin antigenic variation (Av), which allows for immune evasion by the bacterium and continual retransmission through the high risk/core group of infected people. In addition, the pilus functions in the initiating events of colonization and the functional properties of the pilus can be altered by pilin antigenic variation. Understanding the mechanisms used to effect and control pilin Av is essential to understanding this aspect of the pathogenesis of gonococcal disease. This proposal will continue our genetic studies into the molecular mechanisms used to enable pilin Av. There are two specific aims:
Aim 1 will continue our identification and characterization of genes and protein products, revealed by a genetic screen, that are involved in mediating and regulating pilin antigenic variation.
Aim 2 will explore the mechanisms of pilin antigenic variation by defining the role of conserved DNA sequences in pilin antigenic variation, by testing novel models that explain pilin antigenic variation, by defining how variability of pilin variation is maintained, and by re-examining a controversial hypothesis that DNA transformation has a role in mediating pilin Av. The results from these studies will help maintain pilin antigenic variation as one of the main prokaryotic paradigms for systems based on genomic translocations, and further our understanding of how DNA recombination can be central to an important mechanism of microbial pathogenesis. ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
2R37AI033493-10
Application #
6575941
Study Section
Bacteriology and Mycology Subcommittee 2 (BM)
Program Officer
Quackenbush, Robert L
Project Start
1994-05-01
Project End
2008-01-31
Budget Start
2003-02-01
Budget End
2004-01-31
Support Year
10
Fiscal Year
2003
Total Cost
$334,782
Indirect Cost
Name
Northwestern University at Chicago
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
005436803
City
Chicago
State
IL
Country
United States
Zip Code
60611
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Quillin, Sarah J; Hockenberry, Adam J; Jewett, Michael C et al. (2018) Neisseria gonorrhoeae Exposed to Sublethal Levels of Hydrogen Peroxide Mounts a Complex Transcriptional Response. mSystems 3:
Quillin, Sarah Jane; Seifert, H Steven (2018) Neisseria gonorrhoeae host adaptation and pathogenesis. Nat Rev Microbiol 16:226-240
Xu, Jing; Seifert, H Steven (2018) Analysis of Pilin Antigenic Variation in Neisseria meningitidis by Next-Generation Sequencing. J Bacteriol 200:
Seifert, H Steven (2017) Haemophilus spills its guts to make a biofilm. Proc Natl Acad Sci U S A 114:8444-8446
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Anderson, Mark T; Byerly, Luke; Apicella, Michael A et al. (2016) Seminal Plasma Promotes Neisseria gonorrhoeae Aggregation and Biofilm Formation. J Bacteriol 198:2228-35
Palmer, Guy H; Bankhead, Troy; Seifert, H Steven (2016) Antigenic Variation in Bacterial Pathogens. Microbiol Spectr 4:

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