APCs were isolated from WT or TRAMP prostates at the indicated time after transfer of TcR cells. A, Phenotype of isolated APCs day 20 after T cell transfer (similar results were observed on days 5 and 10 after transfer). B,C, APCs isolated from non-transferred or mice receiving single transfers of TcR-I or TcR-II cells were analyzed for the ability to stimulate naïve CD8+ T cell proliferation in vitro. Data is expressed as mean ± SEM (**P = 0.0017, B) and is representative of at least 3 separate experiments. D, Mice were treated with FTY720 prior to TcR cell transfer and APCs were isolated 7 days after transfer of TcR cells and analyzed for the ability to stimulate naïve CD8+ T cell proliferation in vitro. Data is expressed as average CPM ± SEM (**P < 0.01).