Mesenchymal stem cells derived from inflamed periodontal ligaments exhibit impaired immunomodulation

Abstract

Aim: The purpose of this study was to investigate the immunomodulatory properties of periodontal ligament stem cells derived from inflamed periodontal ligament tissues.

Material and methods: Periodontal ligament stem cells were identified and isolated from healthy or inflamed periodontal ligament tissues. Peripheral blood mononuclear cells were cocultured with inflamed or healthy periodontal ligament stem cells, and T-lymphocyte proliferation was determined by incubation with carboxyfluorescein succinimidyl ester. T-helper cells (Th1/Th2, Th17) and regulatory T cells were analysed by flow cytometry. Cytokine profiles in supernatants were tested with a cytometric bead array.

Results: Compared to healthy cells, inflamed periodontal ligament stem cells showed significantly diminished inhibition of T-cell proliferation. In cocultures, stimulated peripheral blood mononuclear cells showed significantly less induction of CD4+CD25+FOXP3+ regulatory T cells and IL-10 secretion in the presence of inflamed compared with healthy periodontal ligament stem cells. Furthermore, suppression of Th17 differentiation and IL-17 production by inflamed periodontal ligament stem cells was significantly lesser than by healthy cells.

Conclusion: This study demonstrated that inflamed periodontal ligament stem cells had markedly dysfunctional immunomodulatory properties; this may contribute to an imbalanced immune response, acceleration of osteoclastogenesis and inflammatory alveolar bone loss in periodontitis.