CD8 T cells can be transduced to express genes transferred by retroviral transduction. This protocol outlines the steps for generating retrovirus from PLAT-E packaging cells to transduce primary murine CD8 T cells isolated from donor mouse spleens.In brief: The ectropic retroviral packaging cell line, Platinum (Plat)-E cells (Cell Biolabs, Inc.), were plated (2.2x106 cells) in PLAT-E media on 10 mm culture plates. After 24 hours, Plat-E cells were transfected with DNA encoding the desired TCR and\/or construct using the Effectene transfection kit (Qiagen). At 48 hours, media was replaced with T cell media. On days 2 and 3 post-transfection (at 72 and 96 hours) virus-containing supernatant was collected. Splenic T cells isolated from P14 Thy1.1+ female mice were stimulated with a-CD3e (clone: 145-2C11) and a-CD28 (clone: 37.51 (both from BD Pharmingen) and IL-2 (50 IU\/ml Aldesleukin, UW Pharmacy), and transduced with retroviral supernatant by spinfection in polybrene (5mg\/mL, 90 minutes at 1000xg) at 24 and 48 hours after T cell activation.