Tonsil-derived mesenchymal stem cells exert immunosuppressive effects on T cells

Aim To assess the immunomodulatory effect of tonsilderived mesenchymal stem cells (MSCs) on T-lymphocyte proliferation and cytokine production. Methods Tonsils were obtained from children aged 3 to 12 years (n = 15) who underwent tonsillectomy for obstructive sleep apnea from April 2012-October 2014 at the Merkur University Hospital, Zagreb. Tonsil-derived MSCs were co-cultured with peripheral blood mononuclear cells (PBMCs) and phytohemagglutinin as a mitogen. PBMCs were induced to differentiate into T helper 1 or T helper 2 cells in the presence or absence of tonsil-derived MSCs, after which the production of interferon-gamma in T helper 1 and interleukin-4 in T helper 2 cells was assessed. Results Tonsil-derived MSC suppressed phytohemagglutinin- induced proliferation of PBMCs. Compared with controls, tonsil-derived MSC co-culture significantly decreased interferon-gamma production (P < 0.001) and increased interleukin- 4 production (P < 0.001). Conclusion Tonsil-derived MSCs exert immunomodulatory effects on T lymphocyte proliferation and T helper 1- and T helper 2-specific cytokine production.