Figure 2.

CD69 upregulation on preselection DP thymocytes and T cells stimulated with various ligands. Immature and mature T cells were stimulated, for 3 h at 37°C, with dilutions of plate-bound anti-CD3 mAb (A), OVAp + APC (B), anti-CD3 + APC (C), or OVA variant peptides + APC (D). For preselection (OT-I TAP^o) DP thymocytes (squares), OT-I CD8 SP thymocytes (circles), and OT-I CD8 SP splenocytes (triangles), the percentage of CD69-expressing cells on CD4/CD8-defined subpopulations was determined by flow cytometry. The data have been normalized such that the percentage of CD69⁺ cells in the presence of 5 μM OVAp = 100% for each cell subset. The graphs shown are representative of data from six to eight independent experiments.