Biochemical and Biophysical Research Communications, Vol.338, No.2, 1110-1117, 2005
Biophotonic hydrogen peroxide production by antibodies, T cells, and T-cell membranes
Rapidly accumulating evidence indicates that inflammatory T cells sensitively respond to their redox environment by activating signal transduction pathways. The hypothesis that T-cell receptors have the potential to catalytically transform singlet oxygen into H2O2 attracted our attention since the biophysical regulation of this process would provide a new tool for therapeutically directing T cells down a preferred signaling pathway. Light-dependent production of H2O2 was first described in antibodies, and we reproduced these findings. Using a real-time H2O2 sensor we extended them by showing that the reaction proceeds in a biphasic way with a short-lived phase that is fast compared to the slow second phase of the reaction. We then showed that Jurkat T cells biophotonically produce about 30 nM H2O2/min/mg protein when pretreated with NaN3. This activity was concentrated 4 to 5 times in T-cell membrane preparations. The implications of these observations for the development of new therapeutic tools for inflammatory diseases are discussed. (c) 2005 Elsevier Inc. All rights reserved.
Keywords:reactive oxygen species;ROS;H2O2;O-1(2);T lymphocytes;real-time sensor;ultraviolet light;photosensitizer