Proliferation of OT-I T cells in irradiated syngeneic hosts. OT-I CD8+ T cells were purified from Thy1.1 donor mice (OT-I.PL), CFSE labeled and transferred into B6 (A), irradiated B6 (B and D), or irradiated TAP0/0 (C) hosts. (D) The mice also were immunized with OVAp. Five days after transfer, lymph nodes were recovered, and the CFSE expression on donor CD8+ cells was determined. Data are shown for one of the two animals in each group.