Eosinophils from schistosome-induced hepatic granulomas produce superoxide and hydroxyl radical.

摘要: Human peripheral blood eosinophils generate superoxide (O2.-) in response to PMA stimulation. These cells are also capable of forming the highly reactive hydroxyl radical (HO.) by a process that is dependent on presence active eosinophil peroxidase. To extend this work tissue-resident cells, we chose study murine model Schistosoma mansoni infection which parasite ova induce granulomas whose cellular content 50% eosinophils. In contrast peritoneal lavage eosinophils, dispersed granuloma were unable reduce ferricytochrome c (as an indicator O2.-) Furthermore, when human neutrophils pretreated with conditioned medium from they failed following stimulation, implying existence inhibitory factor. However, using 5,5-dimethyl-1-pyrroline-N-oxide spin-trapping system, able demonstrate significant generation O2.- not only but medium-treated neutrophils, demonstrating factor was affecting generation, rather interfering reduction. addition, alpha-(4-pyridyl-1-oxide)-N-tert-butyl-nitrone/ethanol detect HO. formation these same This inhibited dismutase, azide, and thiocyanide, NaSCN, consistent mechanism requiring enzymatic peroxidase activity. results tissue associated schistosome-induced have ability form both HO., point out potential problems measurement whole preparations.