This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Kuroda, A. Articles by Arizono, N. Search for Related Content PubMed PubMed Citation Articles by Kuroda, A. Articles by Arizono, N.

Up-Regulation of Fas (CD95) and Induction of Apoptosis in Intestinal Epithelial Cells by Nematode-Derived Molecules

Department of Medical Zoology, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kyoto 602-8566,¹ Department of Parasitology, Akita University School of Medicine, Hondo Akita 010-8543, Japan²

Received 7 January 2002/ Returned for modification 25 February 2002/ Accepted 26 April 2002

Infection by the intestinal nematode Nippostrongylus brasiliensis induces acceleration of apoptosis in the small intestinal villus epithelial cells in vivo. In the present study, we examined whether worm extract or excretory-secretory product induces apoptosis in the rat intestinal epithelial cell line IEC-6 in vitro. In the presence of worm extract or excretory-secretory product (6 µg/ml), IEC-6 cell growth was significantly suppressed, and there was a concomitant increase in the number of detached cells in culture dishes. Detached cells showed nuclear fragmentation, activation of caspase-3, and specific cleavage of poly(ADP-ribose) polymerase, suggesting that apoptosis was induced in these cells. Semiquantitative reverse transcription-PCR showed that expression of Fas (CD95) mRNA was up-regulated as early as 6 h after addition of excretory-secretory product, while Fas ligand expression and p53 expression were not up-regulated. Fluorescence-activated cell sorter analyses revealed a significant increase in Fas expression and a slight increase in FasL expression in IEC-6 cells cultured in the presence of excretory-secretory product, while control IEC-6 cells expressed neither Fas or FasL. These results indicated that N. brasiliensis worms produce and secrete biologically active molecules that trigger apoptosis in intestinal epithelial cells together with up-regulation of Fas expression, although the mechanism of induction of apoptosis remains to be elucidated.

Editor: W. A. Petri, Jr.