Figure 6

LAP mediates Treg-induced inhibition of Th17 cells. Freshly purified pleural CD39⁺Tregs (A) and cultured CD39⁺Tregs (B) were analyzed by flow cytometry for determining the surface expression of LAP, data for one representative donor of 5 tested are shown. Naïve CD4⁺ T cells isolated from malignant pleural effusion (open bars) and blood (closed bars) were cultured CD39⁺Tregs (ratio, 1 : 1), an anti-LAP mAb or isotype control IgG was added into the coculture, Th17 cell numbers were determined by flow cytometry (C) and IL-17 concentrations in the cultured supernatants were determined by ELISA (D). The results are reported as mean ± SEM from 5 independent experiments. * p < 0.01 compared with isotype control.