Marked T-cell proliferation evident in allogeneic mixed lymphocyte reaction. (A) Kinetics of CFSE fluorescence in allogeneic MLR and unmanipulated T cells (n = 5). FACS analysis of a representative example of the kinetics of CFSE fluorescence in allo-MLR of CFSE-labeled T cells cultured with/without HLA-mismatched DCs. Proliferation of alloreactive T cells results in reduction in CFSE fluorescence intensity. Gating on the CFSE^dim region, which selectively identifies the proliferating T-cell population, is shown on the day 7 FACS plots. (B) Time course of proliferation in allogeneic MLR (n = 5). FACS analysis demonstrating the percentage of CFSE^dim proliferating alloreactive T cells in the MLR, assessed serially over a week. Results are the means ± SD. The percentage of CFSE^dim populations in the unstimulated control has been subtracted from the results obtained in the MLR.