FIG. 2.

U24 does not activate Jurkat T cells. (A) Jurkat cells deficient in either lck or zap70 were transiently transfected with U24/EGFP or EGFP alone. Twenty-four hours posttransfection, levels of surface CD3ɛ in cells displaying GFP expression were analyzed by flow cytometry. (B) Jurkat cells were cotransfected with firefly luciferase driven by promoters essential to T-cell activation and either U24 or vector alone. Experiments were performed in triplicate, and data were normalized with Renilla luciferase. (C) Jurkat cells were transfected with U24/EGFP or EGFP alone and were stained for CD69. Activated EGFP-transfected Jurkat cells were stimulated with PMA and ionomycin for 12 h before staining for CD69.