A reduced induction of CD69 expression cannot be overcome by exogenous IL-2.

PBMCs were stimulated with immobilized anti-CD3 in the absence (dashed line) or presence (solid line) of exogenous IL-2 (25 U/mL) and analyzed by flow cytometry. The density of expression of CD69 (A) and of CD25 (B) was estimated by the mpc in histogram plots in control (○) and patient (■) CD4⁺ T cells from 4 to 48 hours of culture. Patient cells were obtained from a 12-year-old girl with ALL (patient 18) 3 months after MUD-BMT.