ES-SCs suppress T cell proliferation.

<p>(A) MLR assay: C3H T cells vs. bone marrow-derived DCs. Where indicated, 129 ES-DCs or ES-SCs were added to MLR culture and inhibitory effects were measured by proliferation rate (CFSE cell division). (B) ES-SCs and MLR assay: C3H T cells were stimulated with irradiated bone marrow-derived DCs, and then graded numbers of ES-SCs were added to MLR culture. T cell proliferation was estimated by [³H] thymidine uptake. Results are expressed as mean cpm ± SD. (C) ES-SCs and MLR assay. Several immunosuppressive molecules were blocked by specific inhibitors: Anti-TGFβ mAb (10 µg/mL), anti-PD-L2 mAb (10 µg/mL), _L-NMMA (50 µM), or corresponding isotype-matched controls were added. T cell proliferation was estimated by [³H] thymidine uptake. Results are expressed as mean cpm ± SD. (D) Measurement of NO concentration in the supernatants of ES-DCs or ES-SCs. (E) Specificity of immune suppression by ES-SCs. Splenic T cells from ES-SCs- or PBS-administered C3H mice were stimulated with bone marrow-derived DCs from the indicated mice including C3H (Syn; Syngeneic), 129 (Allo; allogeneic but same background as ES-SCs), and BALB/c (3rd; allogeneic, third party). T cell proliferation was estimated by [³H] thymidine uptake. Data represent mean ± SD of three wells. Similar results were obtained from three independent experiments. *P<0.05, **P<0.01, ***P<0.001.