Fig. 1

mTOR inhibition enhances the immunosuppressive functions of MSCs. a–d Mesenchymal stem cells (MSCs) were pretreated without or with rapamycin (RAPA) for 4 h, and cocultured with carboxyfluorescein diacetate succinimidyl ester (CFSE)-labeled human peripheral blood mononuclear cells (PBMCs) (a, representative data; b, pooled data) or mouse splenocytes (c, representative data; d, pooled data) for 5 days at the indicated ratio. PBMC and splenocyte proliferation were analyzed by flow cytometry. e,f MSCs were pretreated with 100 nM rapamycin for 4 h or 72 h, followed by coculturing with PBMCs for 5 days at the indicated ratio. PBMC proliferation was analyzed by flow cytometry (e, representative data; f, pooled data). g MSCs were infected with lentivirus carrying scrambled shRNA (shNC) or tuberous sclerosis complex (TSC)2-specific shRNAs (shTSC2_1, shTSC2_2). TSC2 knockdown efficiency was assessed by quantitative RT-PCR. h MSCs with or without TSC2 knockdown were cocultured with PBMCs at the indicated ratio. Flow cytometry showed the PBMC proliferation after 5 days. Data represent mean ± SD of at least three independent experiments. *p < 0.05, **p < 0.01. N.S. not significant