Figure 2.

Combined treatment of interleukin (IL)-10 and CTLA4-Ig inhibited the DC-MLR. Nylon wool T cells were used in the DC-MLR at a stimulator:responder (S:R) ratio of 1 : 100. (a) The percentage inhibition of IL-10 (5 ng/ml) and CTLA4 (20 ng/ml) alone or in combination in the immature or mature DC-MLR. (b) The percentage inhibition in a secondary MLR. T cells from the primary MLR were isolated and used for restimulation in a secondary MLR in the absence of both immunomodulatory agents. Proliferation in (a) and (b) was measured by [³H] thymidine incorporation, with results presented as the percentage inhibition compared with untreated controls. P-values were determined by unpaired Student's t-test. All samples were run in triplicate, and data shown for (a) and (b) are representative of 12 and three independent experiments, respectively. (c) Inhibition of CD4⁺ and CD8⁺ T-cell proliferation by IL-10 and CTLA4-Ig in a CFSE-MLR. Nylon wool T cells were stained with CFSE and added to DC stimulators. After 5 days in culture, cells were stained with anti-CD4-phycoerythrin (PE) or anti-CD8-PE and analysed by flow cytometric analysis to determine CFSE dilution in comparison to nonactivated nylon wool T cells. Histograms represent the percentage of proliferating CD4⁺ and CD8⁺ T cells based on CFSE dilution and are representative of four independent experiments.