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. 2010 Sep;131(1):107–117. doi: 10.1111/j.1365-2567.2010.03280.x

Figure 5.

Figure 5

IFN-α suppresses Treg expansion by inhibiting IL-2 production. (a) PBMC from three separated donors were activated with anti-CD3 without (control) or with 1000 U/ml of IFN-α, and IL-2 was determined in the supernatants by ELISA at 24 and 48 hr post-activation. Values are shown as percentages in which 100% represents IL-2 production in control anti-CD3-stimulated PBMC. Quantification of IL-2 (pg/ml) by ELISA was as follows. Donor 1 at 24 hr minus IFN-α, 202; plus IFN-α, 101; 48 hr minus IFN-α, 34; plus IFN-α, 24. Donor 2 at 24 hr minus IFN-α, 1546; plus IFN-α, 1023; 48 hr minus IFN-α, 1416; plus IFN-α, 452. Donor 3 at 24 hr minus IFN-α, 1020; plus IFN-α, 641; 48 hr minus IFN-α, 597; plus IFN-α, 208. (b) Exogenous IL-2 can restore Treg expansion in the presence of IFN-I. PBMC from three separate donors were activated with anti-CD3 in the absence (control) or presence of 1000 U/ml of IFN-α, or 1000 U/ml of IFN-α plus 100 U/ml of IL-2. After 3 days, the cells were stained and analysed by FACS for FoxP3 and IFN-γ expression in CD4+ cells. The number and mean values of CD4+ FoxP3HIIFN-γNeg Tregs are shown. The error bars represent the standard deviation. ELISA, enzyme linked immunosorbent assay; FACS, fluorescence-activated cell sorting; IFN-α, interferon-alpha; IL-2, interleukin-2; PBMC, peripheral blood mononuclear cells; Treg, regulatory T cell.