Figure 7

Modulation of proliferation and cytokine production by ROS in activated T cells. (A) T cells from three healthy controls and three SSc patients were activated with CD3/CD28 magnetic beads, treated with DPI (20 μM, 1 hour) and pulsed with BrdU for 6 hours. Proliferation was measured with a colorimetric immunoassay in a plate reader fluorimeter. Data are means ± standard deviation (SD) of fold increase of SSc/N proliferation ratio. ^* P <0.05. (B) One representative flow cytometry analysis of IFNγ-producing T cells is shown. Normal T cells (upper panels) or SSc T cells (lower panels) were activated with CD3/CD28 magnetic beads and treated with DPI (20 μM, 1 hour). Plots represent live cells gated for CD4+ cells. Percentage of IFNγ-producing T cells in three healthy controls and three SSc patients are presented (right panel). Data are means ± SD. ^* P <0.05 compared to normal untreated T cells. ^** P <0.05 compared to SSc untreated T cells. (C) One representative flow cytometry analysis of IL-4-producing T cells is shown. Normal T cells (upper panel) or SSc T cells (lower panel) were activated with CD3/CD28 magnetic beads and treated with DPI (20 μM, 1 hour). Plots represent live cells gated for CD4+ cells. Percentage of IL-4-producing T cells in three healthy controls and three SSc patients are presented (right panel). Data are means ± SD. ^* P <0.05 compared to normal untreated T cells. ^** P <0.05 compared to SSc untreated T cells. BrdU, bromodeoxyuridine; DPI, diphenylene iodonium; IFN, interferon; PMA, phorbol myristate acetate; ROS, reactive oxygen species; SSc, systemic sclerosis.