Optimization of early transduction of EBVSTs with a retroviral vector encoding GFP. PBMCs were stimulated with autologous EBV-LCLs with or without IL-4 and IL-7. Two days later, the cells were transduced with a high titer retroviral vector encoding GFP. The transgene (GFP) expression by EBVSTs transduced (A) on day 2 (ET) or (B) on day 19 (LT) was determined by FACS analysis after the number of stimulations indicated. (C) Show the total cell numbers of Day 2 (ET) transduced cells in the presence or absence of IL-4 and IL-7 over time. Data represent the mean +/− sd of 2 donors.