Reactive oxygen species promote raft formation in T lymphocytes.
Lipid rafts are involved in many cell biology events, yet the molecular mechanisms on how rafts are formed are poorly understood. In this study we probed the possible requirement of reactive oxygen species (ROS) for T-cell receptor (TCR)-induced lipid raft formation. Microscopy and biochemical analyses illustrated that blockage of ROS production, by superoxide dismutase-mimic MnTBAP, significantly reduced partitioning of LAT, phospho-LAT, and PLC-gamma in lipid rafts. Another antioxidant N-acetylcysteine (NAC) displayed a similar suppressive effect on the entry of phospho-LAT into raft microdomains. The involvement of ROS in TCR-mediated raft assembly was observed in T-cell hybridomas, T leukemia cells, and normal T cells. Removal of ROS was accompanied by an attenuated activation of LAT and PKCtheta, with reduced production of IL-2. Consistently, treating T cells with the ROS-producer tert-butyl hydrogen peroxide (TBHP) greatly enhanced membrane raft formation, distribution of phospho-LAT into lipid rafts, and increased IL-2 production. Our results indicate for the first time that ROS contribute to TCR-induced membrane raft formation.
Lu
Shu-Ping
SP
Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China.
Lin Feng
Ming-Hsien
MH
Huang
Huey-Lan
HL
Huang
Ya-Ching
YC
Tsou
Wen-I
WI
Lai
Ming-Zong
MZ
D006801:Humans; D008213:Lymphocyte Activation; D017382:Reactive Oxygen Species / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism*
D017382:Reactive Oxygen Species; D011948:Receptors, Antigen, T-Cell