FIG. 1.

T_R cells suppress superantigen-induced cytokine production. IFN-γ expression in T cells in PBMC was compared with that of T cells in PBMC depleted of CD25⁺ cells (a). The cultures were stimulated for 18 h with SEB. Brefeldin A was added for the last 5 h to promote cytokine accumulation. Means ± standard errors of the mean are shown (n = 3). (b) CD25⁺ T cells were added back into PBMC depleted of CD25⁺ cells at increasing ratios. The CD25⁺ T cells were stained with CFSE before being added back and were gated out of the analysis. (c) CD25⁺ T cells and sorted CD25⁺ CD4⁺ T cells (>99% pure) were added back into PBMC depleted of CD25⁺ cells. Means ± standard errors of the mean are shown (n = 2).