Mary Ellen Davey, Ph.D., and Frank C. Gibson III, Ph.D., received a five-year, $2,885,264 grant from the National Institutes of Health National Institute of Dental and Craniofacial Research, or NIH NIDCR, for their project, “Microbial Sphingolipids and Suppression of Host Inflammation in Periodontal Disease.”
Gibson and Davey, in collaboration with Jorge Frias Lopez, Ph.D., are studying how a group of lipid molecules that are a common part of human cells, but are rarely produced by bacteria, participate in periodontal health and disease. All three are faculty in the UF Department of Oral Biology. They are interested in the fact that the periodontal pathogen Porphyromonas gingivalis, or P. gingivalis, makes the lipids, and their data shows that P. gingivalis can deploy the lipids to dampen the host immune response to this organism. They believe this could serve as a way that P. gingivalis manipulates inflammation in gingival tissues which ultimately impacts periodontal disease. By changing host inflammation in the subgingival tissues using these lipids, organisms such as P. gingivalis support their own need, and further may promote the ecological niche for other microbes living in the subgingival space during both health and disease.
The goal of their research is to more precisely understand how these rare bacterial lipids influence inflammation caused by P. gingivalis, and to define the downstream impacts these lipids have on key measures of periodontal disease using various pre-clinical testing platforms.
Davey also received a four-year $1,448,752 renewal award from the NIDCR for her project, “L-Arginine Impacts the Physiological State of Porphyromonas gingivalis.”
It is well known that bacteria can switch between surface-attached growth and a motile mode in response to environmental and host-related signals. Although P. gingivalis has long been described as a non-motile bacterium, during the first round of this grant, the Davey Laboratory discovered that P. gingivalis is capable of surface translocation, and that arginine metabolism and secretion of key virulence determinants are central to this change in physiological state.
The goals of this grant are to determine how P. gingivalis senses and regulates its gene expression in response to changes in arginine levels, and to determine the underlying mechanisms that allow P. gingivalis to migrate on a surface.
Davey has more than 25 years’ experience researching in bacterial physiology and biofilm-based infections, specializing in the study of anaerobic microbial communities. Davey is also interested in understanding connections between infections with P. gingivalis and other chronic systemic diseases, in particular rheumatoid arthritis and Alzheimer’s disease.
Gibson has more than 25 years’ experience researching the areas of disease pathogenesis and host-pathogen interaction, and for the past 20 years has focused his efforts to better understand the complex host immune response to bacteria closely associated with periodontal disease. In addition to his interests in the oral cavity, Gibson is also interested in understanding connections between periodontal disease and other chronic non-oral diseases such as cardiovascular disease and Alzheimer’s disease.