Fig. 2.

Mph suppress T-cell activation in a ROS-dependent fashion. T cells (150,000) were activated with anti-CD3/28 Ab, and Mph or DC were added in increasing numbers (x axes). After 5 d of coculture, IFN-γ production (A) and proliferation (D) were determined by ELISA and ³H thymidine incorporation, respectively. Results shown are the average and SD of a representative experiment performed in triplicate. (B and E) We cocultured 150,000 T cells and 25,000 Mph in the absence or presence of different concentrations of apocynin (x axis) to study the effect of ROS on Mph-mediated T-cell suppression. After 5 d of coculture, IFN-γ production (B) and proliferation (E) were determined by ELISA and ³H thymidine incorporation, respectively. Representative experiments are shown. (C and F) Experiments were similar to those in A, B, D, and E, but the average and SD of three or four independent experiments are shown for an APC:T cell ratio of 1:6. Values shown are relative to the conditions without APC (100%, white bars). *P < 0.05