title: Degranulation of human eosinophils induced by Paragonimus westermani-secreted protease.
abstract: Eosinophil degranulation is considered to be a key effector function for the killing of helminthic worms and tissue inflammation at worm-infected lesion sites. However, relatively little data are available with regard to eosinophil response after stimulation with worm-secreted products which contain a large quantity of cysteine proteases. In this study, we attempted to determine whether the degranulation of human eosinophils could be induced by the direct stimulation of the excretory-secretory products (ESP) of Paragonimus westermani, which causes pulmonary paragonimiasis in human beings. Incubation of eosinophils for 3 hr with Paragonimus-secreted products resulted in marked degranulation, as evidenced by the release of eosinophil-derived neurotoxin (EDN) in the culture supernatants. Moreover, superoxide anion was produced by eosinophils after stimulation of the ESP. The ESP-induced EDN release was found to be significantly inhibited when the ESP was pretreated with protease inhibitor cocktail or the cysteine protease inhibitor, E-64. These findings suggest that human eosinophils become degranulated in response to P. westermani-secreted proteases, which may contribute to in vivo tissue inflammation around the worms.
authors.affiliation: Department of Parasitology, Institute of Tropical Medicine, and Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, Korea. myeong@yumc.yonsei.ac.kr
authors.forename: Myeong Heon
authors.initials: MH
authors.lastname: Shin
authors.forename: Young-Bae
authors.initials: YB
authors.lastname: Chung
authors.forename: Hirohito
authors.initials: H
authors.lastname: Kita
mesh_terms: D000818:Animals; D015550:Cell Degranulation; D003546:Cysteine Endopeptidases / Q000378:metabolism / Q000502:physiology*; D047208:Eosinophil-Derived Neurotoxin / Q000378:metabolism; D004804:Eosinophils / Q000502:physiology*; D006801:Humans; D048492:Paragonimus westermani / Q000201:enzymology*; D013481:Superoxides / Q000378:metabolism; D013997:Time Factors
chemical_list: D013481:Superoxides; D047208:Eosinophil-Derived Neurotoxin; D003546:Cysteine Endopeptidases