Effects of CP690,550 on the apoptosis induction in CD3 Ab activated CD4+ T cells. CD4+ T cells were stimulated with CD3 monoclonal antibodies in the presence or absence of CP690,550. After 24-hr, the cells were stained with FITC-conjugated Annexin V and PI and were then analyzed by flow cytometry. Ten thousand cells were measured and plotted. The proportion of cells residing in each quadrant is expressed as a percentage. Results are representative of 3 independent results.