"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," Dr. Little said. "We wanted to see what would happen if we brought these regulatory T-cells back to the gums."
To do so, the researchers developed a system of polymer microspheres to slowly release a chemokine, or signaling protein, called CCL22 that attracts regulatory T-cells, and placed tiny amounts of the paste-like agent between the gums and teeth of animals with periodontal disease. The team found that even though the amount of bacteria was unchanged, the treatment led to improvements of standard measures of periodontal disease, including decreased pocket depth and gum bleeding, reflecting a reduction in inflammation as a result of increased numbers of regulatory T-cells. MicroCT-scanning showed lower rates of bone loss.
"Mummified remains from ancient Egypt show evidence of teeth scraping to remove plaque," Dr. Little noted. "The tools are better and people are better trained now, but we've been doing much the same thing for hundreds of years. Now, this homing beacon for Treg cells, combined with professional cleaning, could give us a new way of preventing the serious consequences of periodontal disease by correcting the immune imbalance that underlies the condition."
Next steps include developing the immune modulation strategy for human trials. In addition to Drs. Sfeir and Little, the research team included Ph.D. candidate Andrew J. Glowacki,, Sayuri Yoshizawa, D.D.S., Ph.D., Siddharth Jhunjhunwala, Ph.D., all of the University of Pittsburgh; and Andreia E Vieira, Ph.D., and Gustavo P. Garlet, D.D.S., Ph.D., of Sao Paulo University, Brazil.
|Contact: Anita Srikameswaran|
University of Pittsburgh Schools of the Health Sciences