Evaluation of Oxidative Metabolism in Leukocytes during Phagocytosis of Escherichia coli Carrying Genetic Constructs soxS::lux or katG::lux

We studied ROS generation by human peripheral blood monocytes and granulocytes during phagocytosis of Escherichia coli soxS::lux or katG::lux responding by luminescence (bioluminescence) to the development of oxidative stress. Initially high sensitivity of the bioluminescent reaction of E. coli katG::lux strain to the effects of model ROS (KO 2 and H 2 O 2 ) and pronounced induction of luminescence upon contact with granulocytes, whereas E. coli soxS::lux demonstrated less pronounced reaction to chemical oxidants and bioluminescence was observed primarily upon contact with monocytes. A correlation was found between quantitative characteristics of E. coli katG::lux bioluminescence and luminol-dependent chemiluminescence of leukocytes in some patients, but no dependence of this kind was noted for E. coli soxS::lux . The results can provide experimental substantiation of a new approach for evaluation of ROS production by leukocytes during phagocytosis and choosing the optimal object for these studies.