Premium
Fasciola hepatica cathepsin L cysteine proteinase suppresses Bordetella pertussis ‐specific interferon‐γ production in vivo
Author(s) -
O'Neill Sandra M.,
Mills Kingston H.G.,
Dalton John P.
Publication year - 2001
Publication title -
parasite immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.795
H-Index - 75
eISSN - 1365-3024
pISSN - 0141-9838
DOI - 10.1046/j.1365-3024.2001.00411.x
Subject(s) - fasciola hepatica , biology , bordetella pertussis , in vivo , immunology , cathepsin l , virology , cathepsin , microbiology and biotechnology , helminths , enzyme , biochemistry , genetics , bacteria
We have previously demonstrated that Fasciola hepatica infection significantly reduced Bordetella pertussis‐ specific interferon (IFN)‐γ production in mice coinfected with B. pertussis or immunized with a pertussis whole cell vaccine (Pw). In the present study, we have identified parasite molecules capable of mimicking this suppressive effect of F. hepatica . Parenteral injection of mice with culture medium in which adult F. hepatica were maintained (excretory/secretory, ES, products) suppressed B. pertussis ‐specific IFN‐γ production in mice immunized with Pw. The suppressive effect of ES was abrogated by coinjecting ES with the cysteine proteinase inhibitor, Z‐Phe‐Ala‐diazomethylketone. Furthermore, purified cathepsin L proteinase (FheCL), a major component of ES products, was capable of suppressing IFN‐γ production. The suppressive effect of FheCL was attenuated in interleukin (IL)‐4 defective (IL‐4 −/– ) mice. Therefore, FheCL released by F. hepatica is involved in the suppression of Th1 immune responses and this suppression may be dependent upon IL‐4.