Gum disease is a very common problem that affects millions of adults and often results in swollen, painful gums and bone loss. These symptoms are typically treated with brushing and flossing or professional deep cleanings such as scaling and root planing which are designed to remove tartar and reduce the amount of oral bacteria. However, researchers at the University of Pittsburgh have found in a recent study with animals that invoking the right immune system cells may stop or prevent inflammation from gum disease. Their findings are published in an online version of the Proceedings of the National Academy of Sciences.
Current Gum Disease Treatment
“Currently, we try to control the build-up of bacteria so it doesn’t trigger severe inflammation, which could eventually damage the bone and tissue that hold the teeth in place,” according to co-author Charles Sfeir, D.D.S., Ph.D, director of Center for Craniofacial Regeneration and associate professor for the Departments of Periodontics and Oral Biology, Pitt’s School of Dental Medicine. “But that strategy doesn’t address the real cause of the problem, which is an overreaction of the immune system that causes a needlessly aggressive response to the presence of oral bacteria.”
When a mouth is healthy, there is a balance of bacteria and immune system response that prevents infection without resorting to inflammation. Yet in some people, an overload of bacteria may trigger a response from the immune system to swell in an attempt to eliminate the bacteria.
Lack of Regulatory T-Cells
Senior author Steven Little, Ph.D., associate professor and chair of the Department of Chemical and Petroleum Engineering, Pitt’s Swanson School of Engineering, states, “There is a lot of evidence now that shows these diseased tissues are deficient in a subset of immune cells called regulatory T-cells, which tells attacking immune cells to stand down, stopping the inflammatory response.” He explains that in this experiment, “We wanted to see what would happen if we brought these regulatory T-cells back to the gums.”
To test this, the researchers developed polymer microspheres that release a signaling protein called chemokine, or CCL22, meant to attract T-cells. The microspheres were formed into a paste-like agent which was placed on the gums and teeth of animals with gum disease. The researchers discovered that while the amount of bacteria remained the same, the animals showed improvements in several symptoms of periodontal disease such as decreased pocket depth and bleeding as well as reduced inflammation and bone loss. They also found an increase of regulatory T-cells.
Periodontal gum disease has always been treated with scrapings and planings but the results of this study could lead to a new way of approaching treatment. The next step for the research team is to develop an immune modulation strategy that can be applied to humans to treat the symptoms of periodontal disease.