Role of TNF receptor-associated factor 3 in the CD40 signaling by production of reactive oxygen species through association with p40phox, a cytosolic subunit of nicotinamide adenine dinucleotide phosphate oxidase.
To extend our previous report, which showed the production of the reactive oxygen species (ROS) after the CD40 ligation in the B cells, we further examined the possible mechanisms for ROS production and the involvement of CD40-induced ROS in p38 activation. Our research shows that the stimulation of WEHI 231 B lymphomas with anti-CD40 induced ROS production and p38 activation. An antioxidant N-acetyl-L-cysteine or an inhibitor for NADPH oxidase blocked both of these, but the inhibitors for 5-lipoxygenase did not. We also show that the treatment of cells with inhibitors for the phosphatidylinositol 3-kinase (PI3-K) interfered with the CD40-induced ROS production and p38 activation. In addition, when overexpressed with a dominant negative form of either Rac1 (N17Rac1) or the TNFR-associated factor (TRAF) 3, the WEHI 231 B cells did not show a full response to the CD40 stimulation to produce ROS. Molecular association studies further revealed that the TRAF3 association with p40(phox), a cytosolic subunit of NADPH oxidase and p85 (a subunit of PI3-K), may possibly be responsible for the production of ROS by CD40 stimulation in WEHI 231 B cells. Collectively, these data suggest that the CD40-induced ROS production by NADPH oxidase in WEHI 231 requires the role of TRAF3, as well as activities of PI3-K and Rac1.
Ha
Yun Jung
YJ
Division of Molecular Life Sciences and Center for Cell Signaling Research, College of Natural Sciences, Ewha Womans University, 11-1 Daehyun-Dong, Seodaemun-Gu, Seoul 120-750, Korea.
Lee
Jong Ran
JR
D000818:Animals; D001402:B-Lymphocytes / Q000201:enzymology / Q000276:immunology / Q000378:metabolism; D019013:CD40 Antigens / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D023201:CD40 Ligand / Q000378:metabolism; D045744:Cell Line, Tumor; D003600:Cytosol / Q000201:enzymology*; D004789:Enzyme Activation / Q000276:immunology; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D019255:NADPH Oxidases / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism*; D021122:Protein Subunits / Q000378:metabolism / Q000502:physiology; D011506:Proteins / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism*; D015398:Signal Transduction / Q000276:immunology; D048008:TNF Receptor-Associated Factor 3; D048051:p38 Mitogen-Activated Protein Kinases; D020744:rac GTP-Binding Proteins / Q000378:metabolism / Q000502:physiology
D019013:CD40 Antigens; D010750:Phosphoproteins; D021122:Protein Subunits; D011506:Proteins; D017382:Reactive Oxygen Species; D018124:Receptors, Tumor Necrosis Factor; D048008:TNF Receptor-Associated Factor 3; C085072:neutrophil cytosol factor 40K; D023201:CD40 Ligand; D019255:NADPH Oxidases; D019869:Phosphatidylinositol 3-Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D020744:rac GTP-Binding Proteins