T-cell inhibition by HSCs. (a) B6, BALB/c, IFN-γR1 KO, or B7-H1 KO HSCs cultured in uncoated plastics for 7 days were γ-irradiated (50 Gy) and added at the beginning of an MLR culture in which splenic T cells (2 × 105) from BALB/c mice, and irradiated (20 Gy) B6 DCs were cultured at a final T-cell/DC/HSC ratio of 20 : 2 : 1 for 3 days. In some groups, irradiated HSCs pre-incubated with 100 μM U0126 or anti-B7-H1. Controls were without HSCs. The data are representative of three separate experiments. (b) Cells following cultures for 2 or 3 days were double stained with FITC-anti-CD3 and PE-anti-Annexin V for flow analysis. The data demonstrated Annexin V expression in CD3+ populations. In some groups, irradiated HSCs pre-incubated with 100 μM U0126 or anti-B7-H1. Controls were without HSCs. The data are representative of three separate experiments.
