Expression of eosinophil peroxidase in the immature basophil cell line KU812-F

Although peroxidase activity in basophils can be detected by optical and ul trastructural cytochemistry, its characteristics remain to be determined. W e have demonstrated the characteristics of peroxidase activity induced in t he immature basophil cell line, KU812-F. Ultrastructurally, peroxidase acti vity was detected in granules as well as in the perinuclear space and endop lasmic reticulum. Immunocytochemistry revealed that KU812-F cells were stai ned by anti-eosinophil peroxidase antibodies, and eosinophil peroxidase mRN A, not myeloperoxidase, was detected in the cells using Northern hybridizat ion and reverse transcription-polymerase chain reaction. Eosinophil peroxid ase can be one of the molecules shared with eosinophils and basophils. The biological function of eosinophil peroxidase detected in basophils remains uncertain. (C) 1999 Elsevier Science Ltd. All rights reserved.