Dental plaque (biofilm) has been implicated as a primary causative agent of adult periodontal disease. The key event leading to initiation of the disease is the transition from commensal Dental biofilm to pathogenic biofilm. It is well known that the process of the transition is involved in the colonization of several specific periodontal pathogens such as Porphyromonas gingivalis. The long-range goal is to understand events and factors leading to the transformation of healthy plaque to pathogenic plaque and to change the course of development of periodontopathogenic biofilm by preventing attachment of P. gingivalis. In our ongoing studies, we have identified several environmental factors that can influence expression of fimA gene, a virulence gene encoding a major protein unit (fimbrillin) of fimbriae. One of the striking findings is that the presence of Streptococcus cristatus molecule(s) could significantly repress fimA expression in P. gingivalis at the transcriptional level. As a result, S. cristatus could inhibit the formation of P. gingivalis biofilm in vitro. In this grant application, we will put our focus on characterization of S. cristatus signaling molecule, biochemically and genetically. The hypothesis for this application is that S. cristatus plays an important role in impeding P. gingivalis' colonization on Dental biofilm through intergeneric signaling systems. To test this hypothesis, we will start with identification and purification the signaling molecule(s) of S. cristatus. The signaling molecule will be characterized in the terms of functional and genetic structures. We will also attempt to understand regulation of the signaling gene expression in oral biofilm. Therefore, the signaling gene of S. cristatus will be cloned. The promoter region of the gene will be fused with the reporter gene such as chloramphenicol acetyltransferase gene, and level of the gene expression will be determined by measuring enzymatic activity. Finally the role of this molecule in the formation of pathogenic oral biofilm will be investigated. Studies will be initiated to determine the distribution of the signaling molecule in the Dental plaques from healthy subjects and periodontitis patients. Our ultimate goal is to convert the knowledge gained from these laboratory studies to practical technology that may be used to reprogram development of the Dental biofilm and to reduce the incidence of adult periodontitis. ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE014699-03
Application #
6984107
Study Section
Oral Biology and Medicine Subcommittee 1 (OBM)
Program Officer
Lunsford, Dwayne
Project Start
2004-01-01
Project End
2008-11-30
Budget Start
2005-12-01
Budget End
2006-11-30
Support Year
3
Fiscal Year
2006
Total Cost
$172,273
Indirect Cost
Name
Meharry Medical College
Department
Dentistry
Type
Schools of Dentistry
DUNS #
041438185
City
Nashville
State
TN
Country
United States
Zip Code
37208
Ho, Meng-Hsuan; Lamont, Richard J; Chazin, Walter J et al. (2018) Characterization and development of SAPP as a specific peptidic inhibitor that targets Porphyromonas gingivalis. Mol Oral Microbiol 33:430-439
Wu, Jie; Xie, Hua (2010) Role of arginine deiminase of Streptococcus cristatus in Porphyromonas gingivalis colonization. Antimicrob Agents Chemother 54:4694-8
Wang, Bing-yan; Wu, Jie; Lamont, Richard J et al. (2009) Negative correlation of distributions of Streptococcus cristatus and Porphyromonas gingivalis in subgingival plaque. J Clin Microbiol 47:3902-6
Wu, Jie; Lin, Xinghua; Xie, Hua (2009) Regulation of hemin binding proteins by a novel transcriptional activator in Porphyromonas gingivalis. J Bacteriol 191:115-22
Wu, Jie; Lin, Xinghua; Xie, Hua (2008) OxyR is involved in coordinate regulation of expression of fimA and sod genes in Porphyromonas gingivalis. FEMS Microbiol Lett 282:188-95
Lin, Xinghua; Lamont, Richard J; Wu, Jie et al. (2008) Role of differential expression of streptococcal arginine deiminase in inhibition of fimA expression in Porphyromonas gingivalis. J Bacteriol 190:4367-71
Xie, Hua; Lin, Xinghua; Wang, Bing-Yan et al. (2007) Identification of a signalling molecule involved in bacterial intergeneric communication. Microbiology 153:3228-34
Wu, Jie; Lin, Xinghua; Xie, Hua (2007) Porphyromonas gingivalis short fimbriae are regulated by a FimS/FimR two-component system. FEMS Microbiol Lett 271:214-21
Lin, Xinghua; Wu, Jie; Xie, Hua (2006) Porphyromonas gingivalis minor fimbriae are required for cell-cell interactions. Infect Immun 74:6011-5