Figure 5: Suppression of autologous CD4+CD25- conventional T cell proliferation by HA+ and HA- Treg cells. CFSE-labeled CD4+CD25- T cells were co-cultured at different ratios with HA+ and HA- fractions of CD4+CD25+ Tregs isolated from 5 healthy donors. After 72 h incubation with PHA, proliferation of CFSElabeled T cells was measured by flow cytometry. Percentage of proliferating T cells is shown.