Salivary proteins may influence dental plaque through mechanisms such as cell killing, bacterial aggregation, and adherence to pellicle. In vitro studies have identified saliva proteins involved in each process. However, it has been difficult to show how particular proteins affect plaque composition in vivo. Persons with different saliva protein levels typically are compared. One issue in such comparisons is that saliva proteins form complexes which may function differently than their components. Many proteins also show redundant functions. Those problems make it difficult to isolate the role of salivary proteins in human subjects. This project will employ a novel approach to that problem. Persons who differ greatly for saliva functions will be identified, to test the hypothesis that they differ for saliva and plaque composition. That goal will be addressed through the following specific aims: 1.) Develop microplate methods for quantifying cell- killing, aggregation, and adherence. 2.) Apply those methods to screen unstimulated whole saliva from 170 dental students. Multivariate analysis will be used to group subjects opposite for cell-killing, aggregation, and adherence. 3.) Compare groups by image analysis of native and reducing gels to test the hypothesis that redundancy and complexing will allow salivas with different compositions to exert similar effects. Biotinylated protein overlays will be used to compare proteins and complexes involved in aggregation and adherence. Results from 1-D gels will direct further comparisons using 2-D gels or specific protein assays. 4.) Test hypotheses that saliva proteins exert selective effects in vivo. Plaque will be accumulated on enamel chips placed at sites adjacent to salivary ducts. An arbitrarily- primed PCR method for streptococcal identification will be used to test the hypothesis that indigenous floras differ between groups whose salivas function differently. Saliva coated chips will be treated with anti-idiotype antibodies recognizing an amylase-sIgA complex, to test the hypothesis that redundancy will present inhibition of colonization by cells with a corresponding receptor. Bacteria-coated chips will be treated with the original antibody to the receptor, to test the hypothesis that amylase binding to cells lacking amylase receptors is mediated by amylase-sIgA complexes. Proposed work directly addresses the hypothesis that saliva is an ecological determinant of plaque, and has the potential to validate in vitro studies which suggest that such a relationship exists. By focusing on redundancy and complexing, this project also addresses the question of whether individual proteins exert unique and specific effects in the mouth.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE007233-13
Application #
2896966
Study Section
Special Emphasis Panel (ZRG4-OBM-1 (03))
Project Start
1985-08-01
Project End
2002-03-31
Budget Start
1999-04-01
Budget End
2000-03-31
Support Year
13
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of Minnesota Twin Cities
Department
Dentistry
Type
Schools of Dentistry
DUNS #
168559177
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
Rudney, J D; Staikov, R K; Johnson, J D (2009) Potential biomarkers of human salivary function: a modified proteomic approach. Arch Oral Biol 54:91-100
Rudney, J D; Chen, R (2004) Human salivary function in relation to the prevalence of Tannerella forsythensis and other periodontal pathogens in early supragingival biofilm. Arch Oral Biol 49:523-7
Rudney, J D; Pan, Y; Chen, R (2003) Streptococcal diversity in oral biofilms with respect to salivary function. Arch Oral Biol 48:475-93
Rudney, J D; Staikov, R K (2002) Simultaneous measurement of the viability, aggregation, and live and dead adherence of Streptococcus crista, Streptococcus mutans and Actinobacillus actinomycetemcomitans in human saliva in relation to indices of caries, dental plaque and periodontal dise Arch Oral Biol 47:347-59
Rudney, J D; Chen, R; Sedgewick, G J (2001) Intracellular Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in buccal epithelial cells collected from human subjects. Infect Immun 69:2700-7
Tran, S D; Rudney, J D; Sparks, B S et al. (2001) Persistent presence of Bacteroides forsythus as a risk factor for attachment loss in a population with low prevalence and severity of adult periodontitis. J Periodontol 72:1-10
Rudney, J D; Strait, C A (2000) Effects of Streptococcus crista and human saliva on the viability of Fusobacterium nucleatum ATCC 10953. Arch Oral Biol 45:667-74
Rudney, J D; Larson, C J (1999) Identification of oral mitis group streptococci by arbitrarily primed polymerase chain reaction. Oral Microbiol Immunol 14:33-42
Tran, S D; Rudney, J D (1999) Improved multiplex PCR using conserved and species-specific 16S rRNA gene primers for simultaneous detection of Actinobacillus actinomycetemcomitans, Bacteroides forsythus, and Porphyromonas gingivalis. J Clin Microbiol 37:3504-8
Tran, S D; Rudney, J D (1996) Multiplex PCR using conserved and species-specific 16S rRNA gene primers for simultaneous detection of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. J Clin Microbiol 34:2674-8

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