Fig. 2

ROS in activation-induced T-cell death. TCR triggering leads to the activation of DUOX-1, which produces H₂O₂ that enhances the activation of ZAP-70 and the formation of the SHP-2-GAB-2-GRB-2-PLCγ-1 complex. MEK-ERK pathway increases O₂ ^•- production by mitochondrial Complex I (CI), which leads to the expression of FasL. Superoxide dismutase (SOD), vitamin E (VitE), and glutathione (GSH) interfere with FasL expression. FasL triggers Fas that initiates apoptosis execution, further enhances O₂ ^•- production by CI, and activates NOX-2. NOX-2 produces H₂O₂ that enters the cell and activates AKT but inhibits MEK. H₂O₂ is neutralized by peroxiredoxin (PRX) and GSH. Black solid arrows indicate production, black dashed arrow indicates import, green solid arrows indicate activation, red bar-headed lines indicate inhibition. Skull and bones indicate apoptosis