FIG. 3.

U24 impairs antibody-mediated internalization of CD3ɛ and inhibits recycling. (A) Jurkat cells were transfected with U24/EGFP or EGFP alone. After 24 h, cells were stained at 4°C with PE-conjugated anti-CD3ɛ antibodies, and unbound antibodies were washed away. Cells were then placed at 37°C and allowed to internalize for various times. Surface antibodies were removed with an acid wash, and mean fluorescence was determined by flow cytometry. (B) Jurkat cells were transfected with U24/EGFP or EGFP alone. After 24 h, cells were incubated with PE-conjugated anti-CD3ɛ antibodies at 37°C to allow for internalization. Surface-bound antibodies were stripped with an acid solution, and the cells were again incubated at 37°C. Samples were taken at various time points over a period of 1 h. Cells were again stripped, and the mean fluorescence was determined by flow cytometry.