Immunoregulatory Effects of Dental Mesenchymal Stem Cells on T and B Lymphocyte Responses in Primary Sjögren's Syndrome

Background: In this article, the authors investigate the modulatory effects of dental mesenchymal stem cells (MSCs) on lymphocyte responses in primary Sjögren's syndrome (pSS), which is an autoimmune disease resulting from keratoconjunctivitis sicca and xerostomia. Methods: Mononuclear cells isolated from pSS patients cultured with or without dental MSCs and analyzed for lymphocyte responses via flow cytometry. Results: Dental-follicle (DF)- and dental-pulp (DP)-MSCs downregulated CD4+ T lymphocyte proliferation by increasing Fas-ligand expression on T lymphocytes and FoxP3 expressing Tregs, and decreasing intracellular IFN-γ and IL-17 secretion in pSS patients. DF-MSCs decreased the plasma B cell ratio in the favor of naive B cell population in pSS patients' mononuclear cells. Conclusion: DF- and DP-MSCs can be the new cellular therapeutic candidates for the regulation of immune responses in pSS.Plain language summary In this article, the authors investigate the modulatory effects of dental mesenchymal stem cells (dental MSCs) on lymphocyte responses in primary Sjögren's syndrome (pSS), which is characterized by the infiltration of lymphocytes in exocrine glands. Lymphocyte proliferation, apoptosis, Tregs and total Bregs, intracellular cytokine secretion, total memory, plasma and naive B cell subsets were analyzed in pSS patients and compared them with healthy individuals. Dental follicle- and dental pulp-MSCs modulated CD4+ T lymphocyte responses in pSS patients' mononuclear cells by increasing Fas-ligand expression, enhancing FoxP3-expressing Tregs, and decreasing pro-inflammatory cytokine secretion. Our findings provide evidence for the potential role of dental-MSCs as a cellular therapy option in the treatment of pSS.