Immune Cells and Periodontal Disease

Researchers at The Forsyth Institute have confirmed in human gingival tissue that immune cells play a destructive role in periodontal disease. Although researchers had suspected the correlation between immune cells and bone loss in periodontal disease, this is the first time that this has been confirmed in human tissue samples. With this work, Forsyth scientists and colleagues hope to determine methods for intervening and halting bone loss and thus improving the health outcomes of the estimated 80 million Americans suffering from periodontal disease. The study, led by Toshihisa Kawai, DDS, PhD, examined whether immune response to periodontal bacteria is protective or pathogenic in the context of gum disease. Dr. Kawai and his colleagues had found that B cells (B and T lymphocytes are immune cells) can contribute to increased periodontal bone loss coordinating with activated T cells. Both cell types had previously been found to manifest a host immune response to the bacteria, causing bone loss in animal models. 

“This research validates our hypothesis that immune cells are harmful in gum disease,” said Dr. Kawai. The researchers found that RANKL, a protein that is a major factor in the regulation of osteoclasts (cells that destroy bone), expressed on the T and B cells in the patient’s gingival tissues, was sufficiently potent to induce osteoclasts in a laboratory culture system. RANKL expression by T cells and B cells proves to be one of the major stimuli of osteoclast precursor cells, and hence, bone loss through periodontal disease.