There are mechanisms involved in diseases of bone loss, such as periodontitis that are still not well understood, but an unexpected behaviour of a type of T-cell may shed new light on the matter.
Looking at periodontal disease in mice, scientists found that regulatory T (Treg) cells start behaving unexpectedly. They lose their ability to regulate bone loss and begin to promote inflammation instead.
“That is important because, in many therapies analyzed in in-vivo models, researchers usually check if the number of regulatory T cells has increased. But they should check if these cells are indeed functioning,” said lead author Dr Carla Alvarez, a postdoctoral researcher at the Forsyth Institute.
In periodontal disease, bone loss occurs because the immune system responds disproportionately, destroying tissue through inflammation. The Treg cells normally suppress the immune system but lose the ability to do so during periodontal disease.
Understanding this falls into the field of osteoimmunology, which is about understanding the interaction of bone metabolism and the immune system. “This is an interesting mechanism highlighting how the bone loss is taking place in periodontal disease,” said Dr Alpdogan Kantarci, at Forsyth and co-author of the paper.
A potential treatment for periodontal disease would involve reactivating the Treg cell’s immunosuppression function, but this is a complex, nonlinear task complicated by the fact that periodontal disease is initiated by oral microbes.
“The relationship between immune response and bone is not so straightforward,” said Alvarez. “There are multiple components. You have to imagine a complex network of signaling and cells that participate.”
The researchers’ next step is to examine the process in humans.
Source:Medical Xpress
Journal information: Alvarez, C., Suliman, S., Almarhoumi, R. et al. Regulatory T cell phenotype and anti-osteoclastogenic function in experimental periodontitis. Sci Rep 10, 19018 (2020). doi.org/10.1038/s41598-020-76038-w
