Alloantigen stimulation induces NKG2D ligands expression on responder CD4⁺ and CD8⁺ T cells. Highly purified CFSE-labeled CD4⁺or CD8⁺ T lymphocytes were cultured with irradiated allogeneic PBMCs and harvested after 5 days. Cells were stained with mAbs specific for NKG2D ligands (MICA, ULBP1, 2, and 3) or for the activation markers CD69 and CD25. CD4⁺or CD8⁺ T lymphocytes showing a progressive loss of CFSE fluorescence intensity are gated in the R1 region. MFI values relative to each molecule and calculated on cells gated in R1, are reported. The percentage of cells in all the quadrants is also indicated. A representative donor of 5 is shown.