Immunophenotyping of transfected T cells. PBLs from 2 donors were nucleofected with pT2/DsRed or with pT2/DsRed plus pUbSB10, or without DNA (mock, data not shown), and then the cells were stained with anti-CD4, CD8, CD19, and isotype mouse IgG1 mAbs on days 1, 15 (not shown), and 29 for analysis by flow cytometry. Representative data from one donor is shown. Similar data from at least 3 other donors were obtained 3 to 4 weeks after transfection (not shown).