Figure 2.

Expression of CXCR3 on CD4⁺ Tregs. Freshly isolated mononuclear cells were stained with antibodies to CD4, CD25, CXCR3 and FOXP3. (A) After gating on lymphocytes, the expression of CXCR3 was evaluated on CD25^hi (I), CD25^int/lo (II), and CD25^neg (III) CD4⁺ T cells, and FOXP3 expression (histograms) was evaluated in each subset. The box plots on the right illustrate the median, 25th and 75th percentile and range of FOXP3 expression among the CXCR3-expressing CD4⁺ T-cell subsets in n = 20 subjects. (B) FACS-sorted populations of CD25^hiCXCR3^neg or CD25^hiCXCR3^pos CD4⁺ T cells (as illustrated) were stimulated with immobilized anti-CD3 and soluble anti-CD28 in the presence of IL-2 (100 IU/mL) for 5 days. The expression of CXCR3 and FOXP3 was evaluated by flow cytometry on day 0 and on day 5 following activation. The histograms on the left illustrate representative expression of CXCR3 and FOXP3 on sorted CXCR3^neg cells before and after activation, as indicated. The histograms on the right illustrate expression of CXCR3 and FOXP3 on sorted CXCR3^pos cells. Representative of n = 3 experiments.