Korean J Parasitol.  2005 Mar;43(1):33-37. 10.3347/kjp.2005.43.1.33.

Degranulation of human eosinophils induced by Paragonimus westermani-secreted protease

• Shin MH
• Chung YB
• Kita H

• KMID: 1720497
• DOI: http://doi.org/10.3347/kjp.2005.43.1.33

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.

Keyword

Paragonimus westermani; excretory-secretory products (ESP); cysteine protease; eosinophils; degranulation

MeSH Terms

Animals
*Cell Degranulation
Cysteine Endopeptidases/metabolism/*physiology
Eosinophil-Derived Neurotoxin/metabolism
Eosinophils/*physiology
Humans
Paragonimus westermani/*enzymology
Research Support, Non-U.S. Gov't
Superoxides/metabolism
Time Factors