Attempts to relate saliva levels of lysozyme (Lz), lactoferrin (Lf), salivary peroxidase (Spx), and secretory IgA (sIgA) to oral health and ecology have yielded inconsistent results. It has been difficult to define measures of the action of these antimicrobial proteins in vivo, and it also has been difficult to devise controls for factors which may influence those actions. Proposed research will address those questions in clinical studies of Lz, Lf, Spx, and sIgA binding to Streptococcus sanguis monolayers placed in the mouth. Studies will be designed with controls for variation due to oral clearance of antimicrobial proteins, interaction between antimicrobial proteins, bacterial affinity for antimicrobial proteins, and localization of antimicrobial proteins in different oral sites. Research will proceed in stages defined by these specific aims: (1) Combine electronic recording of swallowing activity with sensitive enzyme-linked immunoassay (ELISA) to develop a protocol for quantitation of Lz, Lf, Spx, and sIgA secreted during single swallowing cycles. (2) Combine that protocol with multivariate statistical methods to screen a population of 200 or 40 subjects with high or low levels of Lz, Lf, Spx, and sIgA to be recalled for in vivo studies. (3) Provide an outcome variable for in vivo studies by developing ELISAs to measure Lz, Lf, Spx, and sIgA bound to S. sanguis monolayers formed on bovine enamel chips. (4) Use chip ELISAs to screen a panel of S. sanguis isolates for two strains which differ greatly in binding of Lz, Lf, Spx, and sIgA. (5) Carry out in vivo studies by placing chips with S. sanguis monolayers on anterior and posterior teeth in upper and lower jaws. The binding of Lz, Lf, Spx, and sIgA to high and low affinity strains will be compared between subjects previously found to secrete high or low levels of those proteins in a swallowing cycle. The hypothesis is to be tested is that saliva levels of Lz, Lf, Spx, and sIgA determine binding of those proteins to oral bacteria in vivo when variation attributable to oral sites, bacterial strains, saliva clearance, and interaction between antimicrobial proteins is controlled. Results may clarify the interpretation of previous clinical studies. Approaches developed also will have broad applications for future studies of antimicrobial protein action in vivo.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE007233-10
Application #
2129704
Study Section
Oral Biology and Medicine Subcommittee 1 (OBM)
Project Start
1985-08-01
Project End
1996-08-31
Budget Start
1994-12-01
Budget End
1996-08-31
Support Year
10
Fiscal Year
1995
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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