CD25 and CD71 are highly expressed on alloreactive T cells. (A) Kinetics of surface marker and cytokine expression in proliferating alloreactive T cells (n = 5). Normal donor PBMCs were cocultured with HLA-mismatched DCs, and the expression of surface markers and intracellular cytokines in the proliferating alloreactive T-cell population was determined by gating on the CFSE^dim population using FACS analysis. Data shown are means ± SD. (B) CD71 is highly expressed in proliferating CD25⁻ alloreactive T cells (n = 5). CFSE labeled T cells were cocultured with HLA-mismatched DCs, and the kinetics of expression of surface markers and intracellular cytokines in the proliferating alloreactive CD25⁻ population were determined flow cytometrically by gating on the CFSE^dimCD25⁻ cells. Results are means ± SD.