Periodontitis has been linked to the progression of COPD but understanding how the connection works in the immune system remains unclear.
Researchers at Sichuan University in China reported that bacteria associated with gum disease promote COPD by activating 2 types of cells, gamma delta T cells and M2 macrophages, which are important for the immune system.
Focusing on this process may offer new, practical strategies for preventing or controlling COPD, they said in a paper published in the journal MSystem.
“Periodontal Therapy Enhances and Targets the Inhibition of Gamma Delta T Cells and M2 Macrophages.” [we] may help control the progression of COPD,” said microbiologist Boyu Tang, a doctoral student in dentistry at West China Hospital of Sichuan University.
According to the World Health Organization, COPD is the sixth leading cause of death worldwide. It is not curable. In high-income countries, tobacco smoking is the leading cause of COPD; In low- and middle-income countries, both tobacco smoking and household air pollution are important risk factors.
Periodontitis is a disease of the gums that is primarily caused by the buildup of a sticky film of plaque made up of bacteria. Over time, the plaque can harden into tartar and cause irritation and inflammation of the gum tissue, and then create deep gaps between the teeth and gums where bacteria thrive and bone loss can occur.
For the study, the team used mouse models to show how that bacteria can accelerate the progression of COPD. In one experiment, they showed that mice infected with both periodontitis and COPD improved COPD worse than mice infected with COPD alone.
In another experiment, they found that P. In mice orally infected with gingivalis, the bacteria migrated to and infected the lung tissue, leading to a significant, observable change in the lung microbiota.
Further observations using flow cytometry and immunofluorescence revealed that periodontitis promotes the proliferation of immune cells in lung tissue. Finally, in experiments using mouse lung tissue, the group connected the dots and showed that P. gingivalis can activate immune cells, increasing their ability to produce cytokines that are associated with worsening of COPD.
In future studies, the team plans to investigate how exposure to smoke may affect increased immunity.