HUMAN EOSINOPHILS LACK HUMAN-LEUKOCYTE ELASTASE

Recently, human leukocyte elastase has been detected in human eosinoph ils. Reinvestigating these findings, 2.5 pg active human leukocyte ela stase (E.C. 3.4.21.37) were found per neutrophil isolated from periphe ral blood, whereas the elastase activity of eosinophil preparations wa s linearly correlated with the content of contaminating neutrophils. A lso spontaneous or stimulated release of active elastase was absent in eosinophils. By immunohistochemistry no elastase immunoreactivity cou ld be demonstrated in human eosinophils. Therefore, we conclude that h uman eosinophils do not contain considerable amounts of human leukocyt e elastase.