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

Objective: To assess the immunomodulatory effect of tonsil-derived 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).

Conclusions: Tonsil-derived MSCs exert immunomodulatory effects on T lymphocyte proliferation and T helper 1- and T helper 2-specific cytokine production.