Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 12 4 2013 12 15 331 344 EN Razieh Alipour Department of Immunology, Medical School, Isfahan University of Medical Sciences, Isfahan, Iran Minoo Adib Department of Immunology, Medical School, Isfahan University of Medical Sciences, Isfahan, Iran Masoumeh Masoumi Karimi Department of Immunology, Medical School, Isfahan University of Medical Sciences, Isfahan, Iran Batool Hashemi-Beni Department of Anatomical Sciences and Molecular Biology, Medical School, Isfahan University of Medical Sciences, Isfahan, Iran Nasrin Sereshki Department of Immunology, Medical School, Isfahan University of Medical Sciences, Isfahan, Iran 2015 10 16 Stem cells from human exfoliated deciduous teeth (SHED) have been introduced recently and  possess characteristics similar to  mesenchymal stem  cells (MSCs). Because of  their convenient accessibility and safety of harvest, SHED can be a preferable source for the ever- increasing MSCs’ applications. While they are new, their immunoproperties have not been adequately studied. In this study, we aimed to explore the effect of SHED on T lymphocytes and compare it to conventional MSCs (BMMSCs). At first the isolated T lymphocytes were activated specifically/nonspecifically in vitro and cocultured  with  SHED   or  BMMSCs under  the  same  conditions,  subsequently  their proliferation and cytokine secretion (IL-2 and IFN-γ) were measured. In   our   experiment,  BMMSCs  and  SHED   inhibit  the  proliferation  and  cytokine production  of both  PHA  and alloantigen stimulated T lymphocytes in a dose-dependent manner. In direct and indirect contact to T lymphocytes, the inhibition of BMMSCs (but not of SHED)  was significantly different The cytokine production  from activated T cells was affected differently by two types of MSCs. The inhibition decreased by the separation of lymphocytes and MSCs by a semipermeable membrane, but it was not abolished. This study showed that SHED suppress the activation of human T lymphocytes in vitro like other  MSCs. Compared  to  BMMSCs, this suppression  was alleviated. In  the  equal conditions,  the  pattern  of  immune-modulation  of  BMMSCs and  SHED  was different, suggesting that SHED do not exert the exact mechanisms of BMMSCs' immunosuppression. This finding should be verified by further studies focused on the detailed mechanisms of the immunomodulation of SHED and also BMMSCs. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/494 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/494/550