Title: Ontogeny of Soluble Toll-Like Receptor 2 in Saliva
Sable Staller (Presenter)
Indiana University School of Dentistry
Mythily Srinivasan, Indiana University School of Dentistry
Elizabeth Ramos, Indiana University School of Dentistry
Priya Thomas, Indiana University School of Dentistry
Alison Lindsay, Indiana University School of Dentistry
Objectives: Toll like receptors (TLR) are a class of proteins that recognize the conserved molecular patterns shared by groups of microorganisms and mediate host responses. In addition to cell surface expression, soluble forms of TLRs have been recognized. Previously we reported that sTLR-2 is present in healthy saliva of children and adults. Further while sTLR-2 was elevated in children with dental caries, it was lower in periodontitis saliva. Functionally sTLR-2 is thought to quench microbes and microbial products in saliva. Since oral flora is known to change with age, we postulated that the sTLR-2 concentration in saliva is likely to be modulated by the changing composition of oral flora. By extension, assessment of sTLR-2 in saliva could suggest an indirect measure of changes in oral flora and susceptibility of oral diseases. The objective of this study is to investigate whether the sTLR-2 concentration in saliva exhibits an age associated change.
Methods: Groups of individuals at specific age (4-6 years, 6-12 years, and 13-20 years, 21-30 years, and 31-50, and >51 yrs) reporting to the clinics of the Indiana University School of Dentistry were recruited after obtaining informed consent. Unstimulated whole saliva was collected by the drooling method. Clarified saliva was assessed for sTLR-2 concentration by enzyme linked immunosorbent assay.
Results: Preliminary data suggest that sTLR-2 is lower in the adult samples then the pediatric samples. Samples are currently being collected from individuals in all other age ranges.
Conclusions: Soluble TLR-2 in saliva exhibits a decreasing trend with aging. Since TLR-2 has been shown to recognize the peptidoglycan of Gram+ bacteria as well as the lipopolysaccharide of Porphyromonas gingivalis, the most critical periodontal pathogen, it is tempting to speculate that the proportion of Gram positive oral bacteria decrease with aging.